WTPS21 PGTW 20090316 13:00z
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 18.1S 163.5W TO 23.9S 160.9W
WITHIN THE NEXT 06 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT IM-
AGERY AT 161230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 18.9S 163.2W. THE SYSTEM IS MOVING SOUTHWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 18.1S
163.1W, IS NOW LOCATED NEAR 18.9S 163.2W, APPROXIMATELY 240 NM NORTH-
WEST OF RAROTONGA. ANIMATED INFRARED SATELLITE IMAGERY AND A 16/0803Z
METOP-A IMAGE INDICATE A RAPIDLY CONSOLIDATING LOW-LEVEL CIRCULATION
CENTER (LLCC) WITH MULTIPLE DEEP CONVECTIVE BANDS SPIRALING INTO THE
CENTER. THIS SYSTEM, LIKE TC 20P, IS DEVELOPING FROM THE MID-LEVELS
DOWN TO THE SURFACE. HOWEVER, UNLIKE 20P, THIS SYSTEM HAS BETTER
RADIAL OUTFLOW WITH MORE RAPIDLY IMPROVING CONVECTIVE BANDING EVID-
ENT AT THIS EARLY STAGE OF DEVELOPMENT. DESPITE SURFACE DEVELOPMENT
LAGGING SLIGHTLY BEHIND CONVECTIVE ORGANIZATION, SCATTEROMETER DATA
HAS INCREASINGLY SUPPORTED A STRENGTHENING LLCC. A PARTIAL 160805Z
ASCAT IMAGE SHOWS 25-30 KNOT NORTHERLY FLOW OVER THE EASTERN SEMI-
CIRCLE. THESE WINDS WERE VERIFIED BY A 16/00Z SHIP OBSERVATION FROM
MYMX5 OF 340/22 KNOTS. THE OVERALL ENVIRONMENT IS VERY FAVORABLE
FOR FURTHER DEVELOPMENT. UPPER-LEVEL ANALYSIS AND ANIMATED WATER
VAPOR IMAGERY INDICATE AN ANTICYCLONE OVER THE LLCC WITH VERY GOOD
POLEWARD OUTFLOW ENHANCED BY TWO UPPER-LEVEL LOWS (SOUTHWEST AND
SOUTHEAST OF THE SYSTEM), AS WELL AS EXCELLENT EQUATORWARD OUTFLOW
ENHANCED BY STRONG CROSS-EQUATORIAL FLOW. THE SST OF 29C, OCEAN
HEAT CONTENT AND A DEEP MOISTURE ENVELOPE (> 60MM) SUPPORT CONTIN-
UED CONSOLIDATION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1000 MB. BASED ON THE FAVORABLE ENVIRONMENT CHARACTERIZED BY
EXCELLENT OUTFLOW AND A RAPIDLY ORGANIZING LLCC, THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT
24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 171300Z.//
=========================================================================
WTPS31 PGTW 20090317 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR/JTWC//
SUBJ:  TROPICAL CYCLONE 21P (KEN) WARNING NR 001
REF/A/NAVMARFCSTCEN/161251Z MAR 09//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
1. TROPICAL CYCLONE 21P (KEN) WARNING NR 001
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   171200Z --- NEAR 22.2S 162.6W
     MOVEMENT PAST SIX HOURS - 165 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   REPEAT POSIT: 22.2S 162.6W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   180000Z --- 23.4S 162.2W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 160 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   181200Z --- 24.6S 161.7W
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            025 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 145 DEG/ 11 KTS
    ---
   36 HRS, VALID AT:
   190000Z --- 26.4S 160.2W
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 140 DEG/ 16 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   191200Z --- 28.8S 157.9W
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
    ---
REMARKS:
171500Z POSITION NEAR 22.5S 162.5W.
TROPICAL CYCLONE (TC) 21P (KEN), LOCATED APPROXIMATELY 170 NM WEST-
SOUTHWEST OF RAROTONGA, HAS TRACKED SOUTH-SOUTHEASTWARD AT 07 KNOTS
OVER THE PAST 06 HOURS. RECENT ANIMATED INFRARED SATELLITE IMAGERY
AND A 170452Z QUIKSCAT PASS REFLECT A RAPIDLY CONSOLIDATING LLCC OVER
THE PAST 12 HOURS. THE QUIKSCAT IMAGE INDICATE UNFLAGGED WINDS OF 30
TO 35 KNOTS NEAR THE CENTER OF THE LOW LEVEL CIRCULATION CENTER
(LLCC). ADDITIONALLY, A 170528Z SSMI PASS REFLECT INCREASED BANDING
CONVECTION DEVELOPING OVER THE LLCC. CURRENTLY THE LLCC IS LOCATED
OVER FAVORABLE SEA SURFACE TEMPERATURES AND IS TRACKING ALONG THE
EASTERN PERIPHERY OF A MID-LEVEL SUBTROPICAL RIDGE TO THE SOUTH-
SOUTHEAST. UPPER LEVEL ANALYSIS INDICATES THAT TC 21P IS LOCATED IN
A REGION OF LOW VERTICAL WIND SHEAR, WITH EXCELLENT EQUATORWARD
OUTFLOW, AND AN UPPER LEVEL LOW LOCATED EAST OF TC 21P PROVIDING
ADDITIONAL OUTFLOW ALONG THE EASTERN QUADRANT. INTENSITY IS EXPECTED
TO INCREASE SLOWLY OVER THE NEXT 48 HOURS AS KEN REMAINS IN A
FAVORABLE ENVIRONMENT THROUGH THE FORECAST PERIOD. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 161251Z MAR 09 TROPICAL
CYCLONE FORMATION ALERT (WTPS21 PGTW 161300). MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 171200Z IS 10 FEET. NEXT WARNINGS AT 180300Z
AND 181500Z.//
=========================================================================
WTPS31 PGTW 20090318 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21P (KEN) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 21P (KEN) WARNING NR 003
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   181200Z --- NEAR 23.9S 161.7W
     MOVEMENT PAST SIX HOURS - 145 DEGREES AT 08 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   REPEAT POSIT: 23.9S 161.7W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   190000Z --- 25.7S 160.4W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 24 HR POSIT: 145 DEG/ 16 KTS
    ---
   24 HRS, VALID AT:
   191200Z --- 28.3S 158.2W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
181500Z POSITION NEAR 24.4S 161.4W.
TROPICAL CYCLONE (TC) 21P (KEN), LOCATED APPROXIMATELY 190 NM SOUTH-
SOUTHWEST OF RAROTONGA, HAS TRACKED SOUTHEASTWARD OVER THE PAST
06 HOURS. RECENT ANIMATED INFRARED SATELLITE IMAGERY SHOWS LITTLE
CHANGE IN THE CONVECTIVE SIGNATURE OVER THE LOW LEVEL CIRCULATION
CENTER (LLCC). AN 180420Z QUIKSCAT PASS REFLECT AN ELONGATION IN THE
LLCC WITH 30 KT UNFLAGGED WINDS. THE LLCC IS CURRENTLY LOCATED IN
FAVORABLE SEA SURFACE TEMPERATURES, BUT SST VALUES WILL CONTINUE TO
DECREASE OVER THE NEXT 24 HOURS, BECOMING UNFAVORABLE BEYOND TAU 24.
AN APPROACHING MID-LATITUDE TROUGH HAS BEGUN TO ACCELERATE TC 21P
TO THE SOUTHEAST AND EXTRA-TROPICAL (ET) TRANSISTION HAS STARTED.
TC 21P WILL REMAIN AN INTENSE ET STORM WITH WINDS REMAINING NEAR
35 KNOTS AFTER TRANSITION. THE SYSTEM WILL COMPLETE ET BY TAU 24.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 181200Z IS 10 FEET. NEXT
WARNINGS AT 190300Z.//
=========================================================================
WTPS31 PGTW 20090319 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21P (KEN) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 21P (KEN) WARNING NR 004
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   190000Z --- NEAR 25.6S 160.1W
     MOVEMENT PAST SIX HOURS - 145 DEGREES AT 12 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   REPEAT POSIT: 25.6S 160.1W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   191200Z --- 28.5S 158.0W
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 24 HR POSIT: 150 DEG/ 25 KTS
    ---
   24 HRS, VALID AT:
   200000Z --- 32.8S 154.9W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
190300Z POSITION NEAR 26.3S 159.6W.
TROPICAL CYCLONE (TC) 21P (KEN), LOCATED APPROXIMATELY 265 NM SOUTH
OF RAROTONGA, HAS MOVED SOUTHEASTWARD AT 12 KNOTS OVER THE PAST SIX
HOURS. THE SYSTEM HAS MAINTAINED CONVECTION AROUND ITS LOW LEVEL
CIRCULATION CENTER AND HAS SLIGHTLY INCREASED INTENSITY. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS THAT A FRONT-LIKE CONVERGENT
LINE HAS FORMED ON THE NORTH TO NORTHEAST QUADRANT OF THE SYSTEM.
ENVIRONMENTAL ANALYSIS INDICATES TC 21P IS RAPIDLY APPROACHING THE
BAROCLINIC ZONE, CHARACTERIZED BY INCREASING VERTICAL WIND SHEAR AND
COLD AIR ADVECTION. THE CYCLONE IS EXPECTED TO FULLY TRANSITION INTO
AN EXTRA-TROPICAL SYSTEM WITHIN THE NEXT 24 HOURS. THIS IS THE FINAL
WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER
(NAVMARFCSTCEN).  THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF
REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 190000Z WAS 12 FEET.

Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.

Document: tropical_cyclone_ken_jtwc_advisories.htm Updated: 17 June 2020 [Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] [Privacy Policy]