X-Sender: carls at ford.ace-net.com.au Date: Wed, 22 Nov 2000 23:19:52 +1000 To: Aussie Weather List From: Carl Smith Subject: aus-wx: Fwd: SUMMARY: Part 3 of August TC Summary Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY AUGUST, 2000 (For general comments about the nature of these summaries, as well as information on how to download the tabular cyclone track files, see the Author's Note at the end of this summary.) NOTE: The August summary is being disseminated in three parts. But instead of breaking the summary up by basins, I am going to attempt to cover storms in all the basins forming in 10-day periods. Part 3 will cover tropical cyclones forming in the period 21-31 August. The entire history of these systems will be covered in this installment. *********************************************************************** AUGUST HIGHLIGHTS --> Northeast and Northwest Pacific basins very active --> Destructive super typhoon strikes Taiwan and Chinese mainland --> Central North Pacific area remains active --> Long-lived Atlantic hurricane sets several records *********************************************************************** ***** Topic of the Month for August ***** MONTHLY STATISTICS FOR THE EASTERN NORTH PACIFIC The following table is based on information compiled by John Wallace of San Antonio, Texas. John prepared a monthly table for all cyclones reaching tropical storm intensity (NS), one for all storms reaching hurricane intensity (H), and one for intense hurricanes (IH), i.e., those hurricanes which reached Category 3 or higher on the Saffir/ Simpson Scale. I combined the NS and H tables into one in the interest of saving space, and just included the monthly totals and averages for the IHs. The only month in which four IHs formed was August, 1972, while several months produced three intense hurricanes. The first number in each column is the number of NS which initially reached tropical storm intensity (1-min avg MSW of 34 kts) during the month. The number in parentheses is the number of tropical cyclones which initially reached hurricane intensity (1-min avg MSW of 64 kts) during the month. John's counting procedure is apparently the same which I now personally prefer also (although I haven't always). Taking September and October, 1972, as an example: the only NS forming in October, Tropical Storm Kathleen, did not reach hurricane intensity. But Tropical Storm Joanne, which formed in September, reached hurricane intensity in October. Hence, Joanne is counted as a September NS but as a hurricane for October. Similarly, the only storm initially reaching tropical storm intensity in October, 1973, was Hurricane Lillian. But Tropical Storm Katherine, which formed in September, reached hurricane intensity in October; therefore, October is shown as having one NS but two hurricanes. TROPICAL STORMS and HURRICANES for the EASTERN NORTH PACIFIC (East of 140W) 1971 - 1999 -------------------------------------------- May Jun Jul Aug Sep Oct Nov Total 1971 1 (1) 1 (1) 6 (4) 5 (3) 2 (2) 2 (1) 1 18 (12) 1972 1 (1) 1 6 (6) 2 1 (1) 1 12 ( 8) 1973 3 (1) 4 (3) 1 3 (1) 1 (2) 12 ( 7) 1974 1 3 (2) 3 (2) 6 (4) 2 (2) 2 (1) 17 (11) 1975 2 (1) 4 (2) 5 (3) 3 (1) 1 (1) 1 16 ( 8) 1976 2 (2) 4 (1) 3 (2) 4 (2) 1 (1) 14 ( 8) 1977 1 1 1 (1) 1 (1) 3 (1) 1 (1) 8 ( 4) 1978 1 (1) 3 (2) 4 (3) 6 (4) 2 (2) 2 (1) 18 (13) 1979 2 (1) 2 (1) 2 (2) 1 (1) 2 (1) 1 10 ( 6) 1980 3 (2) 5 (1) 2 (3) 2 (1) 2 14 ( 7) 1981 1 1 (1) 3 (1) 4 (3) 2 (1) 4 (2) 15 ( 8) 1982 1 1 6 (4) 5 (3) 3 (3) 3 (1) 19 (11) 1983 1 (1) 1 (1) 6 (2) 3 (1) 4 (3) 4 (3) 1 21 (12)** 1984 2 (1) 3 (3) 3 (2) 4 (2) 4 (4) 1 1 18 (12) 1985 5 (2) 7 (2) 4 (2) 4 (4) 2 (2) 22 (12) 1986 1 (1) 2 (1) 3 (2) 5 (1) 5 (2) 1 (2) 17 ( 9) 1987 1 6 (2) 5 (3) 3 (3) 3 (1) 18 ( 9) 1988 2 6 (2) 3 (3) 1 (1) 1 13 ( 6) 1989 3 (2) 4 (2) 6 (2) 4 (3) 17 ( 9) 1990 1 (1) 4 (2) 4 (4) 3 (3) 5 (4) 3 (2) 20 (16) 1991 1 3 (2) 2 (2) 2 (1) 3 (2) 2 (2) 1 (1) 14 (10) 1992 3 (1) 6 (4) 5 (2) 5 (5) 5 (2) 24 (14) 1993 2 (1) 3 (3) 5 (4) 3 (2) 1 14 (10) 1994 3 (1) 4 (2) 4 (3) 5 (2) 1 (1) 17 ( 9) 1995 1 (1) 3 (2) 3 (1) 3 (3) 10 ( 7) 1996 1 2 (2) 2 (1) 4 (1) (1) 9 ( 5) 1997 3 4 (3) 3 (2) 5 (2) 1 (1) 1 (1) 17 ( 9) 1998 2 (1) 3 (2) 3 (2) 2 (1) 3 (3) 13 ( 9) 1999 1 (1) 2 (1) 3 (2) 2 (2) 1 9 ( 6) Total NS: 13 64 111 107 91 51 8 445 Avg NS: 0.45 2.21 3.83 3.69 3.14 1.76 0.28 15.35 ------------------------------------------------------------------------ Total H: 6 35 61 68 61 33 2 266 Avg H: 0.21 1.21 2.10 2.35 2.10 1.14 0.07 9.17 ------------------------------------------------------------------------ Total IH: 0 13 34 32 33 19 0 131 Avg IH: 0 0.45 1.17 1.10 1.14 0.66 0 4.51 ** - Hurricane Winnie, which formed in December, is counted in the seasonal total for NS and H. During the average Eastern North Pacific season, approximately 56% of all tropical storms reach hurricane intensity while 31% of all storms eventually become intense hurricanes. Also, about 56% of all hurricanes reach intense hurricane status. The year 1966 is most often quoted as the year in which Eastern North Pacific tropical cyclone records became reliable due to the availability of complete operational satellite coverage beginning that year. However, the Best Track file for the NEP basin does not show a single intense hurricane for the years 1966-1970, whereas in 1971 there were six. That season, as well as the following two, saw fairly extensive aerial reconnaissance of Eastern North Pacific cyclones, so, even though the initial Dvorak method had not been developed in the early 1970s, the reconnaissance data, in conjunction with some earlier methods of assessing storm intensity from satellite imagery, give the Best Track MSW values a reasonable degree of reliability beginning with 1971. The maximum number of intense hurricanes seen to develop in Eastern Pacific waters is eight, and that has occurred four times: 1983, 1985, 1992 and 1993. In 1997 seven hurricanes reached Category 3-plus status, including Hurricane Linda, which was the most intense tropical cyclone observed in the NEP basin since the advent of satellites. Several years have seen six intense hurricanes develop while the only year with no major storm was 1977, and only one was observed in 1981. *********************************************************************** ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for August: 1 tropical depression 1 possible tropical depression or storm ** 1 subtropical storm 2 tropical storms 2 hurricanes ** - no warnings were issued on this system by TPC/NHC NOTE: Much of the information presented below was obtained from the TPC/NHC discussion bulletins issued with every regular advisory. All references to sustained winds imply a 1-min averaging period unless otherwise noted. Atlantic Tropical Activity for August ------------------------------------- Following two tropical depressions in the month of June, the Atlantic basin was very quiet through the month of July as unfavorable upper-level westerlies spread over much of the basin at lower latitudes. However, the situation changed very quickly in August as the long-lived Hurricane Alberto formed early in the month and lasted almost three weeks. Alberto became the first hurricane and the first major hurricane (Category 3 on the Saffir/Simpson scale) of the season as winds climbed to 110 kts. Three more storms were named during the month, but only one--Debby--reached minimal hurricane intensity. In addition, advisories were issued on a tropical depression (TD-04) off the east coast of Florida. Another system attended by deep convection moved northeastward off the mid-Atlantic coast on 10-13 Aug. A reconnaissance aircraft had flown into the system on the afternoon of the 10th but found no closed low-level circulation. But as the LOW moved northeastward on 11 Aug it did appear to have a circulation. SAB assigned T-numbers of 2.0 during the morning of 12 Aug and a ship reported 35-kt winds around 1200 UTC. For these reasons I am including a report on this system, which I have dubbed "Lambda", in this summary. The first installment of the August summary, posted on 16 Oct, included reports on Hurricane Alberto, Tropical Depression #4, and the possible tropical cyclone "Lambda". The second installment, which was disseminated on 10 Nov, covered Tropical Storms Beryl and Chris and Hurricane Debby. Finally, a LOW with some distinctive subtropical characteristics developed in the western Atlantic just off the southeast U. S. coast in late August and moved inland along the North Carolina coast on the 30th. David Roth of HPC has supplied me with a track for this system, and it appears to have briefly reached subtropical storm intensity on 30 Aug when there were some ship reports of winds to 35 kts. The initial weak LOW formed on 28 Aug just east of West Palm Beach and drifted northward for about 24 hours, then moved somewhat to the northeast to a point about 200 nm south of Cape Hatteras by 30/0600 UTC. The system then turned back to the west- northwest toward the Carolina coast. At 1200 UTC it was centered approximately 125 nm southwest of Cape Hatteras, and it was at this time that David's track assigns a MSW of 35 kts. The LOW began to weaken slightly as it approached the coast, and the maximum winds were estimated at 30 kts as it made landfall near Carolina Beach (just north of Cape Fear) around 1800 UTC. The system continued moving toward the west across southeastern North Carolina and South Carolina, eventually reaching north-central Georgia by 1800 UTC on the 31st. David's notes indicate that the strongest winds were found in the northeastern quadrant except just prior to landfall when some higher winds were noted on the western side. The LOW was slowly acquiring tropical characteristics as temperatures at 500 mb rose from -12 C to -6 C in less than two days near the center, and the core was neutral to slightly warm when it made landfall. (A special thanks to David for the information he provided.) *********************************************************************** NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for August: 5 tropical storms ** 2 hurricanes ** - one of these was a "warningless" system which Mark Lander felt reached minimal tropical storm intensity NOTE: Much of the information presented below was obtained from the TPC/NHC discussion bulletins issued with every regular advisory (CPHC for locations west of 140W.) All references to sustained winds imply a 1-min averaging period unless otherwise noted. Northeast Pacific Tropical Activity for August ---------------------------------------------- In contrast to July when tropical cyclone activity was somewhat below average, the month of August was rather active in the eastern half of the North Pacific Ocean. As the month opened, former Hurricane Daniel was a weakening tropical storm north of Hawaii. (See the July summary for the full report on Hurricane Daniel.) Five tropical storms formed east of 140W and were assigned names by TPC/NHC. Of these, two--Gilma and Hector--became hurricanes. Another depression in mid-month formed in subtropical latitudes just west of the Dateline and moved northeastward into the Central North Pacific, strengthened, and was named Wene by CPHC. Additionally, another system late in the month southeast and south of Hawaii was not covered in any official warnings, but Dr. Mark Lander of the University of Guam sent me a track for this system which he feels briefly reached tropical storm intensity. I have designated this system with the Greek letter "Mu". Finally, a new tropical depression (TD-13E) formed on the last day of August and became Tropical Storm Kristy on 1 Sep. This brief cyclone will be covered in the September summary. The first installment of the August summary, disseminated on 16 Oct, covered Tropical Storm Fabio and Hurricanes Gilma and Hector. The second installment, posted on 10 Nov, included reports on Tropical Storms Ileana and Wene. This final installment covers Tropical Cyclone "Mu" and Tropical Storm John. Tropical Storm John (TC-12E) 28 August - 1 September ----------------------------- A tropical wave which was likely the precursor of Tropical Storm John left the African coast on 9 Aug. The wave continued moving west- ward across the tropical Atlantic over the succeeding days with an associated tropical LOW being mentioned for several days in the Tropical Weather Discussions issued by TPC/NHC. The system reached the eastern Caribbean Sea on 15 Aug and continued tracking to the west, reaching the Eastern Pacific by 19 Aug. This information was taken from John Wallace's tropical wave log, which indicates that a 1009-mb LOW had formed along the wave near 15N, 137W, by 1800 UTC on 27 Aug. As best I can determine, the first mention of the pre-John disturbance by TPC/NHC in a Tropical Weather Outlook was early on the 27th, indicating that a large area of disturbed weather was located about 1300 nm east-southeast of Hilo, Hawaii. However, convection along the ITCZ in the Central and Eastern Pacific became quite active during late August, and Mark Lander suggested that the spate of tropical cyclones during this time, including John, the system described below ("Mu"), and Tropical Storm Kristy were not of African wave origin but rather had their roots in the Pacific. This increase in tropical activity in the Northeast Pacific basin was possibly due to an active phase of the Madden-Julian Oscillation in the area. Mark Lander is of the opinion that the system in question was likely of or near tropical storm intensity by late on 27 Aug, but no advisories were issued until the first visible images on the 28th revealed that deep convection had become involved with the LLCC and the overall cloud pattern had become more impressive than during the previous evening. The first advisory on TD-12E was issued by NHC at 1700 UTC, locating the depression's center approximately 1650 nm west- southwest of Cabo San Lucas or about 1025 nm east-southeast of Hilo. There was some southwesterly shear over the area and strengthening was forecast to be slow. However, at 28/2100 UTC the depression was upgraded to a 45-kt tropical storm and named John. Visible satellite imagery showed a well-organized tropical cyclone with banding features over the eastern semicircle, and Dvorak T-numbers from TAFB had reached 3.0. Tropical Storm John was moving west-northwestward at 4 kts and was forecast to intensify to 60 kts within 36 hours. The MSW was increased to 55 kts six hours later based on estimates from TAFB and SAB. Upper-level outflow was good to the east and improving to the west, due in part to the influence of the disturbance about 500 nm to the west ("Mu") which was helping to deflect strong 200-mb shearing winds to the north of John. A small CDO feature with -80 C overshooting tops had developed near the center, indicating that the storm was strengthening. However, John's intensity leveled off and remained at 55 kts, likely due to some westerly flow approaching the storm and undercutting the outflow. Convection weakened some on the 29th but made a comeback late in the day. The storm's motion was being impeded by the southwesterly shear it was running into, but a low- and mid-level ridge to the north was strong enough to keep the cyclone moving on a slow west-northwesterly track. By 0000 UTC on 30 Aug John's center was located about 875 nm east-southeast of Hilo and was just west of 140W, so TPC/NHC issued its final advisory and warning responsibility was transferred to the CPHC in Honolulu. Tropical Storm John continued to move slowly westward after entering the Central Pacific. The North Pacific HIGH at 45N was centered far to the north of its mean position for the summer months, and this made for weak steering flow at 17N. The storm maintained its intensity in spite of the shear, and at 30/1800 UTC the center had become hidden under a cold overcast and Dvorak estimates from SAB and Honolulu edged up to T4.0--65 kts. The MSW was bumped up to 60 kts, which was the peak intensity for the storm's history. (The minimum estimated CP of 994 mb had occurred on the 29th.) However, by 31/0000 UTC the convection had dramatically declined due to increased shear and the center was difficult to locate, there being uncertainty as to which side of 140W the center was located on. The MSW was decreased back to 55 kts, and six hours later the intensity was further dropped to 45 kts. Almost all the deep convection was gone due to the persistent southwesterly shear. At this point John had been essentially stationary for the previous 24 hours just west of 140W. After 0600 UTC the weakening cyclone did drift slowly to the west for about 12 hours until it became stationary again at 1800 UTC. By this time John was a minimal tropical storm with winds down to 35 kts. The storm was downgraded to a tropical depression at 0000 UTC on 1 Sep. The center was still stationary near the 31/1800 UTC position, and the CPHC discussion indicated that John was undergoing a weak Fujiwhara- type rotation with TD-13E (later TS Kristy) which was located about 575 nm to the east-southeast. The dissipating depression, consisting of a low-level cloud swirl with no associated deep convection, remained quasi-stationary on 1 Sep with scatterometer data indicating winds of only about 25 kts, and the final advisory on John was issued at 2100 UTC with the center located approximately 775 nm east-southeast of Hilo. Tropical Cyclone "Mu" 26 August - 2 September ----------------------- As mentioned above in the discussion of Tropical Storm John, the ITCZ became active in the Central and Eastern North Pacific area in late August, possibly due to the active phase of a Madden-Julian Oscillation moving through the region. Also mentioned in the discussion of John was another disturbance to the west of the tropical storm which, at one point, likely helped to deflect some strong 200-mb westerlies to the north of the storm, thereby enabling it to become stronger than it otherwise might have. No advisories were issued on this disturbance by either NHC or CPHC, but the author received a track for this system from Dr. Mark Lander of the University of Guam who estimates that the disturbance was a minimal tropical storm for a 36-48 hour period on 26-28 Aug. A Tropical Weather Outlook (TWO) issued by NHC on 17 Aug mentioned that an area of cloudiness and showers had developed about 475 nm south of the southern tip of Baja California. This seems to be the parent disturbance from which the subject cyclone developed. The system moved steadily westward for the next few days with a weak low- level circulation occasionally referred to in the TWOs. Mark's track begins at 0000 UTC on 26 Aug with a 25-kt depression located roughly 825 nm east-southeast of Hilo, Hawaii. A TWO issued by CPHC at 1400 UTC on the 26th indicated that convection associated with the system had intensified. Mark's track indicates that the system had reached tropical storm intensity by 0000 UTC on 27 Aug when it was centered about 650 nm east-southeast of Hilo. A TWO issued at 27/1400 UTC noted that peripheral convection associated with the system had weakened since the previous evening but that new thunderstorms had recently fired near the center of circulation. The system continued to move rather slowly generally to the west. Mark Lander's track, which consists of only 12-hourly positions, main- tains the cyclone as a tropical storm through 28/0000 UTC, then down- grades it to a depression. The depression passed about 300 nm south of the Big Island around 31/0000 UTC, and the final position in the track places the system about 450 nm east-southeast of Johnston Atoll at 0000 UTC on 2 Sep. In a message received along with the track, Mark writes that the track may be a bit crude, but his primary objective was to point out that scatterometer data and a strict adherence to Dvorak analysis of satellite imagery indicate that the system was likely a 35-40 kt tropical storm from around 26/1800 through 28/1800 UTC. In another e-mail Mark cited a 27/2000 UTC ERS-2 pass with 30-kt wind vectors depicted near the center of the system. These represent 8-min avg wind speeds, averaged over a pixel, thus implying that the 1-min avg MSW was likely around 35 kts. *********************************************************************** NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for August: 2 tropical depressions ** 3 tropical storms ++ 3 typhoons 1 super typhoon ** - one of these was a short-lived system carried only by JMA ++ - one of these was treated as a tropical depression by JTWC and JMA but Mark Lander felt that it reached tropical storm intensity NOTE: Most of the information on each cyclone's history presented in the narrative will be based upon JTWC's advisories, and references to winds should be understood as a 1-min avg MSW unless otherwise noted. However, in the accompanying tracking document I have made comparisons of coordinates with JMA (Japan) and the Philippines (PAGASA) when their positions differed from JTWC's by usually 40-50 nm or more. A special thanks to Michael V. Padua, owner of the Typhoon 2000 website, for sending me the PAGASA and JMA tracks. In the title line for each storm I plan to reference all the cyclone names/numbers I have available: JTWC's depression number, the JMA-assigned name (if any), JMA's tropical storm numeric designator, and PAGASA's name for systems forming in or passing through their area of responsibility. Northwest Pacific Tropical Activity for August ---------------------------------------------- August turned out to be a very active month in the Northwest Pacific basin. Six tropical storms were named by JMA with four of these reaching typhoon intensity. Bilis became an intense super typhoon and Jelawat nearly did do (according to Mark Lander it did briefly reach super typhoon intensity). All of the named cyclones eventually made landfall on the Asian continent except for Typhoon Ewiniar. JTWC issued warnings on two additional depressions (14W and 17W), and JMA issued two bulletins on another tropical depression. However, Mark Lander sent me alternate tracks for some of the systems, and his track for TD-14W assigns a peak MSW of 50 kts. Another depression, TD-16W, formed just west of the Dateline and moved into the Northeast Pacific basin where it developed into Tropical Storm Wene. Finally, Mark Lander sent a satellite picture on 30 Aug of a very tiny vortex in the subtropics accompanied by some deep convection. It isn't exactly clear just what the nature of this "micro-midget" system was. The first installment of the August summary, mailed out on 16 Oct, covered Typhoon Jelawat, Tropical Cyclone 14W, and Typhoon Ewiniar. The second installment, disseminated on 10 Nov, covered Super Typhoon Bilis and Tropical Storm Kaemi, plus contained some information on the two tropical depressions. This final portion includes reports on Typhoon Prapiroon and Tropical Storm Maria. Regarding the "micro-midget" alluded to above--the first visible image Mark sent was taken at 30/0530 UTC and shows a very small vortex centered near 30.5N, 164.5E. The center appears to be located near the southern edge of a small convective mass no more than 60 nm in diameter. A second visible image taken at 31/0500 UTC depicts a tiny vortex near 30.9N, 165.4E, and Mark indicates he checked several infrared pictures to make sure it was the same vortex. The 31 Aug image reveals a somewhat more ragged-looking system with the convection having decreased in areal extent and the LLCC located near the western edge of the convection. Mark estimates that the maximum winds were likely in the 20-25 kt range. No track is given for this system in the cyclone tracks file. Typhoon Prapiroon (TC-20W / TY 0012 / Lusing) 25 August - 1 September ---------------------------------------------- Prapiroon: submitted by Thailand, is the Thai god of rain An area of convection was noted deep in the tropics southeast of Guam on 22 Aug. The area was within a region of weak vertical shear, and a partial QuikScat pass revealed a possible broad LLCC located in the monsoon trough. The disturbed area migrated westward and was assigned a Fair development potential on 23 Aug. By early on the 24th the disturbance was located approximately 70 nm southeast of Yap. Animated visible satellite imagery indicated a fully-exposed LLCC with deep convection to the northwest. Synoptic observations from Yap indicated a 24-hour pressure fall of 3 mb with east-southeasterly sustained winds of 10 kts. A Formation Alert was issued at 2230 UTC, upgrading the development potential to Good. On 25 Aug satellite imagery indicated improved organization with deep convection located primarily to the north of the center. PAGASA initiated advisories on the system at 25/0000 UTC, naming it Tropical Depression Lusing. Lusing's center was located about 600 nm east- southeast of Catanduanes Island, or roughly 450 nm west-northwest of Yap, with maximum winds (10-min avg) estimated at 30 kts. JMA also began referring to the system as a tropical depression at 0600 UTC. There was a fair amount of difference between PAGASA's and JMA's coordinates (as might be expected for a weak, diffuse system), but Lusing generally moved slowly northward. JTWC issued a second Formation Alert at 2230 UTC followed by the first warning on TD-20W at 26/0000 UTC. Lusing/20W was centered approximately 400 nm east of Catanduanes Island at that time, moving northward at around 9 kts, but shortly thereafter underwent a significant acceleration to the north-northeast. At 26/1200 UTC Lusing was moving north-northeastward at 23 kts from a location about 560 nm east-northeast of Port San Vicente in the Philippines. The JTWC warning indicated that the rapid motion might be due in part to convection reconsolidating over a new LLCC. By 1800 UTC Lusing/20W was located roughly 375 nm south-southeast of Okinawa, and the system's motion had turned to the north-northwest, but still at a fairly fast clip of 20 kts. Based on satellite intensity estimates and a ship report of 35 kts, the depression was upgraded to a tropical storm at 1800 UTC and named Prapiroon by JMA. Deep convection was sheared approximately 15 nm to the north and east of a partially- exposed LLCC. Over the next 24 hours Prapiroon's forward motion slowed considerably and the storm turned increasingly toward the west- northwest and west as a subtropical ridge to the north strengthened. Vertical shear was weak and outflow aloft favorable, but the storm remained rather disorganized with multiple LLCCs evident. Early on the 27th satellite imagery revealed a large band of convection extending approximately 650 nm to the southeast of the center, but by 1800 UTC this feature was weakening and Prapiroon's center had separated from the band. At 0000 UTC on 28 Aug the storm was centered roughly 175 nm south of Okinawa and moving westward at 8 kts. JTWC's MSW estimate was still 35 kts based upon satellite intensity estimates of 30 kts and synoptic reports of 35 kts, and the remarks indicated that animated visible and infrared imagery still showed a broad circulation with smaller multiple LLCCs orbiting the center of the broader circulation. Interestingly, JMA had increased their maximum 10-min avg wind estimate to 50 kts at 27/1800 UTC. By 28/1800 UTC Prapiroon was moving slowly westward from a position about 240 nm east-southeast of Taipei. The MSW (per JTWC) had increased to 45 kts and convection was consolidating over the LLCC. At 0000 UTC on the 29th JTWC increased the MSW further to 55 kts. A SSM/I pass at 28/2202 UTC depicted a partially-exposed LLCC at the northern edge of some deep convection. Water vapor imagery indicated an upper-level HIGH to the northwest of the storm, resulting in poor outflow, and CIMSS shear analysis charts indicated weak to moderate northeasterly shear over Prapiroon. The tropical cyclone began to turn more to the northwest on 29 Aug and slowly became better organized. A SSM/I pass at 29/0919 UTC showed a convective band wrapping in toward the LLCC from the south- west, and 200-mb analysis indicated that an upper-level HIGH had developed over the system. The JTWC warning at 29/1200 UTC noted that a ship located approximately 20 nm east of the center had reported south-southeast winds of 50 kts (10-min avg) with a pressure of 981 mb. JTWC upgraded Prapiroon to a 65-kt typhoon at 1800 UTC when the storm was centered about 140 nm east-northeast of Taipei, moving northwest- ward at 10 kts. The MSW was increased to 70 kts six hours later as a 29/2149 UTC SSM/I pass revealed a ragged eye 50 nm in diameter with convective banding in the eastern semicircle. By 0600 UTC on the 30th Typhoon Prapiroon was located 330 nm south- southwest of Cheju Do (off the coast of Korea) and moving northward at 17 kts. A mid-level ridge to the north was weakening and a major short wave trough was approaching from the west. JMA upgraded the storm to a typhoon at 0600 UTC while JTWC upped their MSW estimate to the peak value for the storm's history, 75 kts, which was maintained for 18 hrs. (JMA's peak 10-min avg wind estimate for Prapiroon was 70 kts at 0000 and 0600 UTC on 31 Aug.) SSM/I imagery at 30/0907 UTC indicated a 33-nm irregular eye with an impressive banding feature about 180 nm southeast of the LLCC. A ship transiting beneath the convective band reported 10-min sustained winds of 45 kts from the south-southeast and 7.3 m swells. At 1800 UTC Prapiroon was located about 100 nm east of Shanghai and still tracking northward. Around 31/0000 UTC the typhoon passed about 120 nm west of Cheju Do, and the forward speed had increased to 19 kts. Also, convection was beginning to weaken and the MSW was lowered to 70 kts. (JMA, however, increased their maximum 10-min avg wind estimate from 65 to 70 kts at this point.) Based on a synoptic report of 54-kt winds from Kosan-Ni (WMO 47185), located on Cheju Do, the 50-kt wind radius was increased to 85 nm in the eastern semicircle. Gales at this time covered an area approximately 275 nm in diameter. By 1200 UTC on the 31st Prapiroon was located about 90 nm west of Seoul, South Korea, and was tracking north-northeastward at 22 kts. The storm had weakened to a minimal typhoon with 65-kt winds (JMA had downgraded it to a 60-kt tropical storm), and the convection associated with the system was beginning to elongate to the north-northeast. CIMSS wind shear charts showed moderate vertical shear over the storm with increasing shear to the north. Typhoon Prapiroon made landfall in southwestern North Korea shortly after 1200 UTC, and by 1800 UTC was weakening inland in North Korea about 115 nm north of Seoul. Hamheung (WMO 47401), North Korea, reported 30-kt winds at 31/1800 UTC. The storm continued to track rapidly northeastward across the Korean peninsula, moving up the coastal region of northeastern North Korea, and by 0600 UTC on 1 Sep had entered the Sea of Japan just south of Vladivostok, Russia. Animated infrared satellite imagery showed little deep convection, and no low-level circulation was evident as the system continued to transition into an extratropical LOW. This was the final warning by JTWC, but JMA issued a couple more bulletins, finally deeming Prapiroon extratropical at 1800 UTC as it moved eastward across the Sea of Japan. Although the center of Typhoon Prapiroon remained offshore as it swept past eastern China, the storm brought heavy rains to some areas. The official Chinese news agency (Xinhua) reported that at least four persons were killed and 80 injured in the northern part of Jiangsu province. Heavy rainfall resulted in the flooding of 363,933 hectares of farmland, and over 7500 houses were destroyed. Xiangshui county reportedly received 821 mm of precipitation--a record in the history of Jiangsu province. Rainfall amounts in the Huangpu district and Chongming county were reported as 85 mm and 79 mm, respectively. While Prapiroon's center made landfall in North Korea, it was near enough to South Korea to cause winds of up to 58 kts in the coastal region of the country. At least four persons were reported dead with another 21 missing following the storm. Two boats were sunk and many power lines downed. In the southern part of the nation a dike ruptured, flooding residential areas and farmland with approximately 300 persons left homeless. In North Korea flooding in the north- eastern sections of the country seems to have been the major impact caused by the storm. The death toll stands at 42 with most of these occurring in the northeastern province of South Hamgyong when rivers burst their banks. There was also extensive damage to crops, and road and rail connections were disrupted along the east coast. The region's major city, Chongjin, was flooded with up to about a metre of water in some sections. Earlier, while Prapiroon was passing through the Ryukyu Islands, Ishigakishima recorded 112 mm of rain in the twelve hours ending at 0000 UTC on 30 Aug. The monthly average for the station is 236 mm. (Thanks to Patrick Hoareau for sending me this tidbit of information.) Tropical Storm Maria (TC-21W / TS 0013) 28 August - 1 September ---------------------------------------- Maria: submitted by the United States, is the Latin/Hispanic form of Mary and is popular as a Chamorro woman's name A STWO issued by JTWC at 2200 UTC on 26 Aug mentioned that an area of convection had developed approximately 45 nm east-southeast of Hong Kong. The convection was disorganized and was located in an area of moderate northerly vertical shear. Synoptic analysis indicated that a LLCC was located just inland and north of the convection. By 1200 UTC on the 27th animated satellite imagery revealed increasing organization of the cloud mass and decreasing vertical shear. The development potential of the system was upgraded to Fair. (More than likely a Formation Alert was issued by JTWC, but I could not locate one anywhere in my files.) The first warning on TD-21W was issued by JTWC at 0000 UTC on 28 Aug with the center located approximately 100 nm east-southeast of Hong Kong. A small area of deep convection was organizing around a LLCC, shear was weak to moderate, and a 200-mb analysis showed an upper-level ridge axis just northwest of the system. The depression commenced a slow, generally southward, drift and gradually increased in organization. By 28/1200 UTC the system was centered about 150 nm south-southeast of Hong Kong and was upgraded to Tropical Storm Maria by JMA; JTWC, however, was still estimating the MSW at 25 kts. JTWC did upgrade the system to a tropical storm six hours later, based primarily on synoptic data. Maria displayed a partially-exposed LLCC with the convection to the south. Over the next 24 hours Maria continued to drift somewhat erratically to the south and southeast. Convection gradually increased near the LLCC, and JTWC bumped the MSW up to 45 kts at 30/0000 UTC when the storm was centered approximately 300 nm south-southeast of Hong Kong. A subtropical ridge was north of the system, and northeasterly flow over the storm caused most of the convection to be sheared to the southwest quadrant of the circulation. Maria's track, when plotted, looks like a slightly distorted "figure 8". The low- and mid-level steering flow in the northern South China Sea was being influenced by Typhoon Prapiroon to the northeast. The position at 30/0000 UTC was the southernmost point in Maria's track. By 0600 UTC the storm had moved very slightly to the west-northwest, then abruptly changed course and began tracking slowly to the northeast and later north-northwest, completing the right side of the "figure 8". The MSW was decreased back to minimal tropical storm intensity of 35 kts at 0600 UTC when animated visible imagery depicted the LLCC tucked in underneath the northeastern portion of the convection but also revealed another weaker, fully-exposed circulation about 60 nm to the northeast. Convection was seen to weaken somewhat over the next few hours but had begun to increase again by 1800 UTC. A TRMM pass at 30/2312 UTC located the center of the cyclone under the deep convection and also showed that an area of deep convection had formed on the southeastern side of the LLCC. The MSW was increased to 50 kts at 31/0600 UTC based on satellite intensity estimates of 45 and 55 kts. A 31/0155 UTC microwave image placed the center under the deep convection and also indicated a tight band of strong convection wrapping into the center from the south. Maria was located about 120 nm southeast of Hong Kong and was moving northward toward the southern coast of China at around 7 kts. By 1200 UTC deep convection was evident in all quadrants, and the storm reached its peak intensity of 55 kts at this time. (JMA's maximum 10-min avg wind estimate remained at 35 kts until just before the cyclone made landfall in China when it was increased to 40 kts.) At 1800 UTC on the 31st Tropical Storm Maria was located just off the Chinese coast about 50 nm east of Hong Kong, moving north-northwestward at 9 kts. The storm had maintained its intensity, and a 31/1309 UTC SSM/I pass indicated deep convection in a band circling the LLCC in all quadrants except the eastern. Maria made landfall shortly after 1800 UTC on 31 Aug and continued to track to the northwest after moving inland. The final JTWC warning at 0600 UTC on 1 Sep placed the center of the dissipating storm about 200 km north-northwest of Hong Kong. The only report of fatalities available to the author indicated that more than 50 persons lost their lives from Tropical Storm Maria, presumably in southern China and due to flooding caused by storm-related rainfall. (This information was gleaned from the Australian Broadcasting Corporation's website by Matthew Saxby, who forwarded it to me. Thanks to Matthew for sending me this information.) *********************************************************************** NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for August: 1 tropical depression ** ** - system was briefly mentioned as a depression by IMD only North Indian Ocean Tropical Activity for August ----------------------------------------------- During the latter part of August several LOWs formed in the monsoon trough in the Bay of Bengal and were mentioned by the IMD. One of these was classified as a depression on 23 Aug. An upper-level cyclonic circulation was noted on 19 Aug over the Bay off the South Orissa coast. This feature persisted and by 21 Aug was considered a well-marked low-pressure area. Around 0600 UTC on 22 Aug the center was near 16.5N, 85.5E, or about 150 nm east-southeast of Visakhapatnam. By 23/0300 UTC the LOW had been classified as a depression and was located near 16.5N, 83.5E, or about 80 nm south-southeast of Visak- hapatnam, moving slowly in a west-northwesterly direction. Nine hours later (1200 UTC) the depression's center lay near 16.5N, 82.5E, or about 55 nm southeast of Kakinada. The system continued to move generally westward and moved inland along the North Andhra coast without reaching cyclonic storm intensity. (No warnings on this system were issued by JTWC; in fact, I could find no TWOs which I'd saved for the period in question, which strongly suggests that the disturbance was not considered significant enough to be mentioned in JTWC's daily TWOs for the North Indian Ocean.) I did not include a tabular track for this depression in the cyclone tracks file, although in hindsight I rather wish that I had; hence, the reason for including the coordinates in the narrative. In IMD terminology, a depression usually implies maximum winds of 25 kts, while a 30-kt system is referred to as a deep depression. *********************************************************************** SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for August: 1 tropical disturbance ** ** - this system was treated as a minimal tropical storm by JTWC NOTE!!! See Part 1 of the August summary for the report on Tropical Disturbance #1 (TC-01S) and for the list of Southwest Indian Ocean tropical cyclone names for the 2000-2001 season. *********************************************************************** NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for August: No tropical cyclones *********************************************************************** NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for August: No tropical cyclones *********************************************************************** SOUTH PACIFIC OCEAN (SPA) - South Pacific Ocean East of Longitude 160E Activity for August: No tropical cyclones *********************************************************************** EXTRA FEATURE In order to shorten the amount of typing in preparing the narrative material, I have been in the habit of freely using abbreviations and acronyms. I have tried to define most of these with the first usage in a given summary, but I may have missed one now and then. Most of these are probably understood by a majority of readers but perhaps a few aren't clear to some. To remedy this I developed a Glossary of Abbreviations and Acronyms which I first included in the July, 1998 summary. I don't normally include the Glossary in most months in order to help keep them from being too long. If anyone would like to receive a copy of the Glossary, please e-mail me and I'll be happy to send them a copy. *********************************************************************** AUTHOR'S NOTE: This summary should be considered a very preliminary overview of the tropical cyclones that occur in each month. The cyclone tracks (provided separately) will generally be based upon operational warnings issued by the various tropical cyclone warning centers. The information contained therein may differ somewhat from the tracking and intensity information obtained from a "best-track" file which is based on a detailed post-seasonal analysis of all available data. Information on where to find official "best-track" files from the various warning centers will be passed along from time to time. The track files are not being sent via e-mail. They can be retrieved in the following manner: (a) FTP to: hrd-type42.nhc.noaa.gov [140.90.176.206] (b) Login as: anonymous (c) For a password use your e-mail address (d) Go to "data" subdirectory (Type: cd data) (e) Set file type to ASCII (Type: ascii) (f) Transfer file (Type: get remote_file_name local_file_name ) (The files will be named with an obvious nomenclature--using August as an example: aug00.tracks) (g) To exit FTP, type: quit Both the summaries and the track files are standard text files created in DOS editor. Download to disk and use a viewer such as Notepad or DOS editor to view the files. The first summary in this series covered the month of October, 1997. If anyone wishes to retrieve any of the previous summaries, they may be downloaded from the aforementioned FTP site at HRD. The summary files are catalogued with the nomenclature: aug00.sum, for example. Back issues can also be obtained from the following websites (courtesy of Michael Bath, Michael V. Padua, Tom Berg, Michael Pitt, and Rich Henning): OR Another website where much information about tropical cyclones may be found is the website for the UK Meteorological Office. Their site contains a lot of statistical information about tropical cyclones globally on a monthly basis. The URL is: TROPICAL CYCLONE REPORTS AVAILABLE I have discovered that JTWC now has available on its website the complete Annual Tropical Cyclone Report (ATCR) for 1999 (1998-1999 season for the Southern Hemisphere). Also, ATCRs for earlier years are available also. The URL is: Also, TPC/NHC has available on its webpage nice "technicolor" tracking charts for the 1999 Atlantic and Eastern North Pacific tropical cyclones; also, preliminary storm reports for all the 1999 Atlantic and Eastern North Pacific cyclones are now available. The URL is: Prepared by: Gary Padgett E-mail: garyp at alaweb.com Phone: 334-222-5327 (nights & weekends) / 850-882-2594 (weekdays) *********************************************************************** *********************************************************************** +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ X-Originating-IP: [210.8.224.2] From: "James Harris" To: aussie-weather at world.std.com Subject: aus-wx: TDU2K More Road Info Date: Thu, 23 Nov 2000 09:40:44 +1100 X-OriginalArrivalTime: 22 Nov 2000 22:40:44.0281 (UTC) FILETIME=[3FE05E90:01C054D5] Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Just another email to see if anyone knows any info or has a web page with the latest road conditions and so on for QLD and NSW. Currently the chasers are up at Emerald after watching another day of storms although this time the bigger ones (Yes Supercellular again !!!!!!!) were to their North. Apparantly some of the highest topped storms seen in ages. And yes we will get to see it for ourselves when they return . Anyway once again without having acces to AVN or other models (restricted at work... grrrrrr) it seems the BOM are going for storms in SW QLD again so they might after checking the models themselves , head out there today and then tommorow head down the Mitchell Highway , bypassing the floods around New England Highway and so on into Dubbo and SE NSW ready for the next System. The only other option seems to be the Pacific Highway atm which isnt the greatest option !!!! So any info on roads and so on would be much appreciated, esp for the chasers (Although I think Macca has taken a liking to the female Cop in Emerald , so he might go in there and ask for some "assistance" :P ) Anyway will keep you all updated on there progress. James H _____________________________________________________________________________________ Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ X-Sender: mbath at pop.ozemail.com.au X-Mailer: QUALCOMM Windows Eudora Version 5.0 Date: Thu, 23 Nov 2000 09:56:37 +1100 To: aussie-weather at world.std.com From: Michael Bath Subject: Re: aus-wx: TDU2K More Road Info Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Just got an SMS from Jimmy at 08.50am QLD time. They have set out on an 800km journey S from Emerald to Goondiwindi which is on the NSW/QLD border. Jet max up to 100 knots at 250hPa is over the region this arvo. Other parameters for storms are less favourable today, but we'll see !! There should be little problem using the New England Highway if they are heading further south. Michael At 09:40 23/11/2000 +1100, you wrote: >Just another email to see if anyone knows any info or has a web page with >the latest road conditions and so on for QLD and NSW. Currently the >chasers are up at Emerald after watching another day of storms although >this time the bigger ones (Yes Supercellular again !!!!!!!) were to their >North. Apparantly some of the highest topped storms seen in ages. And yes >we will get to see it for ourselves when they return . >Anyway once again without having acces to AVN or other models (restricted >at work... grrrrrr) it seems the BOM are going for storms in SW QLD again >so they might after checking the models themselves , head out there today >and then tommorow head down the Mitchell Highway , bypassing the floods >around New England Highway and so on into Dubbo and SE NSW ready for the >next System. The only other option seems to be the Pacific Highway atm >which isnt the greatest option !!!! >So any info on roads and so on would be much appreciated, esp for the >chasers (Although I think Macca has taken a liking to the female Cop in >Emerald , so he might go in there and ask for some "assistance" :P ) >Anyway will keep you all updated on there progress. > >James H >_____________________________________________________________________________________ >Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com > >+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com >with "unsubscribe aussie-weather your_email_address" in the body of your >message. >-----------------------jacob at iinet.net.au------------------------------ ============================================================= Michael Bath mailto:mbath at ozemail.com.au McLeans Ridges http://australiasevereweather.com/ NE NSW Australia http://www.lightningphotography.com/ ASWA Secretary http://www.severeweather.asn.au/ ============================================================= +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "clyve herbert" To: Subject: Re: aus-wx: TDU2K More Road Info Date: Thu, 23 Nov 2000 10:22:55 +1100 X-Mailer: Microsoft Outlook Express 5.00.2615.200 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Michael. Have made arrangements to meet up with Michael Thompson on Saturday morning around the Mudgee -Gulgong area for a bit of a look see,then head north and meet up with the rest of the chase mice. regards Clyve H. PS A trough due over Vic later Sat or Sun seems as if it may stall over inland N.S.W. Sun/Mon. ----- Original Message ----- From: Michael Bath To: Sent: Thursday, November 23, 2000 9:56 AM Subject: Re: aus-wx: TDU2K More Road Info > Just got an SMS from Jimmy at 08.50am QLD time. They have set out on an > 800km journey S from Emerald to Goondiwindi which is on the NSW/QLD border. > > Jet max up to 100 knots at 250hPa is over the region this arvo. Other > parameters for storms are less favourable today, but we'll see !! > > There should be little problem using the New England Highway if they are > heading further south. > > Michael > > > At 09:40 23/11/2000 +1100, you wrote: > > >Just another email to see if anyone knows any info or has a web page with > >the latest road conditions and so on for QLD and NSW. Currently the > >chasers are up at Emerald after watching another day of storms although > >this time the bigger ones (Yes Supercellular again !!!!!!!) were to their > >North. Apparantly some of the highest topped storms seen in ages. And yes > >we will get to see it for ourselves when they return . > >Anyway once again without having acces to AVN or other models (restricted > >at work... grrrrrr) it seems the BOM are going for storms in SW QLD again > >so they might after checking the models themselves , head out there today > >and then tommorow head down the Mitchell Highway , bypassing the floods > >around New England Highway and so on into Dubbo and SE NSW ready for the > >next System. The only other option seems to be the Pacific Highway atm > >which isnt the greatest option !!!! > >So any info on roads and so on would be much appreciated, esp for the > >chasers (Although I think Macca has taken a liking to the female Cop in > >Emerald , so he might go in there and ask for some "assistance" :P ) > >Anyway will keep you all updated on there progress. > > > >James H > >___________________________________________________________________________ __________ > >Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com > > > >+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > >To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > >with "unsubscribe aussie-weather your_email_address" in the body of your > >message. > >-----------------------jacob at iinet.net.au------------------------------ > > ============================================================= > Michael Bath mailto:mbath at ozemail.com.au > McLeans Ridges http://australiasevereweather.com/ > NE NSW Australia http://www.lightningphotography.com/ > ASWA Secretary http://www.severeweather.asn.au/ > ============================================================= > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "clyve herbert" To: Subject: Re: aus-wx: Questions Date: Thu, 23 Nov 2000 10:41:32 +1100 X-Mailer: Microsoft Outlook Express 5.00.2615.200 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Shaun. I was amazed back in 1988 standing on a beach in west Wales during a trip to Europe, at this location the main jet corridor from London to the USA was overhead , these jets were leaving so much contrail ice tracks that by the end of the day the overhead sky was almost completely covered by the spreading ice residue,sometimes such contrails can be seen on satellite pictures extending over great distances.In respect to the amount of water vapour added at these levels 10 to 12klm, one could do a calculation on the percentage of water in jet fuel and the already available water vapour present in the environmental area, as some of the condensation is the result of water vapour ingested by the jet engine intake and then recondensing at the jet exhaust where there is also a lot of additional nuclei for condensation to occur. It also seems that at -40 c water vapour will freeze almost immediately,observation of the rear of a jet contrails will show that freezing occurs within one or two seconds of emission from the jet exhaust, in regards to an increase of water vapour at these levels it would be very small in comparison to the amount of water vapour expelled into the atmosphere by tropical cyclones, and other weather systems not counting volcanic eruptions. regards Clyve Herbert. ----- Original Message ----- From: Shaun Whelan To: Sent: Wednesday, November 22, 2000 9:30 PM Subject: aus-wx: Questions > Just a few quick questions > 1/ What, if any, do contrails have in relation to upper (30k+) > water vapour levels? > 2/Is there a Radar that just reads actual cloud ? > 3/ What are the scalings of Tornadoes?, [(i.e IRT Beaufort scale > type of measurements)? F0 through to F5] > 4/ Actual speed of lightning. I have several different speeds in > as many publications. A reference to something would be much appr. > > From an inquisitive Birdie > Shaun Nowra > ____________________________________________________________________________ _________ > Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: Blair Trewin Subject: Re: aus-wx: TDU2K More Road Info To: aussie-weather at world.std.com Date: Thu, 23 Nov 2000 10:43:58 +1100 (EST) X-Mailer: ELM [version 2.5 PL3] Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com > > Just got an SMS from Jimmy at 08.50am QLD time. They have set out on an > 800km journey S from Emerald to Goondiwindi which is on the NSW/QLD border. > > Jet max up to 100 knots at 250hPa is over the region this arvo. Other > parameters for storms are less favourable today, but we'll see !! > > There should be little problem using the New England Highway if they are > heading further south. The RACQ web site is good for this, but only covers Queensland and far northern NSW. The NRMA site is terrible - it wasn't updated for more than a week until yesterday afternoon, and even now is incomplete. As far as I can tell, the major highway closures are the Newell between Coonabarabran and Moree, the Warrego River crossing at Charleville and the Oxley between Tamworth and Gunnedah. In essence the region bounded by Coonabarabran, Tamworth and Moree seems to be a no-go zone. As Michael says, New England Highway looks OK, but there don't seem to be any north-south routes fully open any further west than that. Blair +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "Michael Thompson" To: Subject: Re: aus-wx: TDU2K More Road Info Date: Thu, 23 Nov 2000 10:58:05 +1100 X-Mailer: Microsoft Outlook Express 5.50.4133.2400 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com I think the New England Hwy is open dispite the reports. The Pacific has been upgraded considerably over the last few years, with the Taree bypass and the Bulahdelah Mountain by pass. Michael > > Just another email to see if anyone knows any info or has a web page with > the latest road conditions and so on for QLD and NSW. Currently the chasers > are up at Emerald after watching another day of storms although this time > the bigger ones (Yes Supercellular again !!!!!!!) were to their North. > Apparantly some of the highest topped storms seen in ages. And yes we will > get to see it for ourselves when they return . > Anyway once again without having acces to AVN or other models (restricted at > work... grrrrrr) it seems the BOM are going for storms in SW QLD again so > they might after checking the models themselves , head out there today and > then tommorow head down the Mitchell Highway , bypassing the floods around > New England Highway and so on into Dubbo and SE NSW ready for the next > System. The only other option seems to be the Pacific Highway atm which isnt > the greatest option !!!! > So any info on roads and so on would be much appreciated, esp for the > chasers (Although I think Macca has taken a liking to the female Cop in > Emerald , so he might go in there and ask for some "assistance" :P ) > Anyway will keep you all updated on there progress. > > James H > ____________________________________________________________________________ _________ > Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "Les" To: Subject: Re: aus-wx: Questions Date: Thu, 23 Nov 2000 00:16:48 -0000 X-Mailer: Microsoft Outlook Express 5.50.4522.1200 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com ----- Original Message ----- From: "clyve herbert" To: Sent: Wednesday, November 22, 2000 11:41 PM Subject: Re: aus-wx: Questions > > 3/ What are the scalings of Tornadoes?, [(i.e IRT Beaufort scale > > type of measurements)? F0 through to F5] The nearest to a Beaufort scale measurement is the Torro scale; T0 - T10, read the section on how the Torro scale is derived, it is directly related to the Beaufort Scale and has been used in place of the Saffir - Simpson scale for tropical (and extratropical) cyclone (hurricane, typhoon, TC, etc) wind speed. This is opposed to the Fujita scale where the Beaufort wind speed has to be derived from the F-number. www.torro.org.uk/tnintens.htm Les (UK) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "Les" To: Subject: Re: aus-wx: Questions Date: Thu, 23 Nov 2000 00:25:19 -0000 X-Mailer: Microsoft Outlook Express 5.50.4522.1200 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com ----- Original Message ----- From: "clyve herbert" To: Sent: Wednesday, November 22, 2000 11:41 PM Subject: Re: aus-wx: Questions > > 1/ What, if any, do contrails have in relation to upper (30k+) > > water vapour levels? I live under one of the paths (55N 0130W) for Europe ----> Western USA air traffic taking the great circle route avoiding the atlantic jet (N. Ireland, Greenland, Canada, Alaska, E. USA). There are times when contrails are fairly dense and spread out merging into cirrus (approaching warm front - the clear air is already saturated for ice) and persist for a very long time and other times (Pm air) when they become visible and evaporate (sublimate) immediately with a short trail. At the heights (FL390+) that they're flying at the temperature is less than -40C and the water vapour will freeze immediately. Les (UK) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "rhettaj at ozemail.com.au" To: X-IPAddress: 210.9.117.134 X-SessionId: 44d9g6ev.iei Date: Thu, 23 Nov 2000 00:38:42 "GMT" X-mailer: AspMail 2.62 (SMTP85107B) Subject: Re: aus-wx: TDU2K More Road Info Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Contacted my parents according to the local paper today, apparently the New England Highway is the only way to go North-South at the moment, any further west is a no go for some time - bridges washed away in numerous locations. See the link below for a picture of a former bridge floating in Chaffey Dam East of Tamworth. http://tamworth.yourguide.com.au/detail.asp?class=news&subclass=local&story_id=4840&category=floods Rhett Blanch >I think the New England Hwy is open dispite the >reports. The Pacific has >been upgraded considerably over the last few years, >with the Taree bypass >and the Bulahdelah Mountain by pass. Michael __________________________________________________________ Message sent by MyMail http://www.mymail.com.au/ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "clyve herbert" To: Subject: aus-wx: Central Australian cloud mass. Date: Thu, 23 Nov 2000 12:42:34 +1100 X-Mailer: Microsoft Outlook Express 5.00.2615.200 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com

Hi all.

The large cloud area over central Aus:(Baroclinic origin) is looking interesting and appears to be moving southeast, with the upper low near to the head of the Australian Bight,worth keeping a check on this system especially if it moves towards the flood area of northern N.S.W..regards Clyve H.

From: "Pearce" To: Subject: aus-wx: Potentially interesting afternoon for Sydney Date: Thu, 23 Nov 2000 13:33:05 +1100 X-Mailer: Microsoft Outlook Express 5.00.2919.6700 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com

Hi all

Some very nice congestus has developed on the ranges west of Sydney in the last few hours and there are now some very interesting cells starting to go up on the Southern Highlands. It may get interesting later in the afternoon in Sydney when the S moves through, however the big problem will be moisture. Currently, the DP here is less than 10C(eeeeeek), but the seabreeze has just come in. If that can push the DP up a bit, then the interaction with the S later in the afternoon may set off something if we are lucky. I would give it about a 40% chance at the moment.

Matt