Australian Severe Weather Forum

Rainfall plot and 12 month drought map for Victoria to end of July 2009

The July rainfall plot generated from the Bureau of Meteorology "Water and the Land" is provided below and shows that south west Victoria and North East Victoria has received better rainfalls. Only East Gippsland and far NW Victoria has missed out on something during the month.

Additionally, the 12 month drought plot from 1 August 2008 to 31 July 2009 also generated from the same site shows the updated drought situation with the worst affected area concentrated around and close to Melbourne.

Harley Pearman

Possible rainfall for Victoria - August to October 2009

While the latest POAMA (Predictive Ocean Atmosphere Model for Australia) models and ensembles continue to show drier than normal conditions expected across Eastern Australia for the remainder of 2009 and into 2010 with a possible peak El Nino in January and February 2010, it is noted that some useful rainfall should still be occurring across some areas of Victoria during the August to October period. In particular:-

a) The 100 mm rainfall plot generated from the "Water and the Land site - Bureau of Meteorology" shows most of Victoria having an 85% chance of receiving at least this amount of rain during the period. The North West region is expected to remain reasonably dry.

b) The 150 mm rainfall plot generated from the "Water and The Land site - Bureau of Meteorology" shows the North East ranges and parts of Gippsland and the South West coast having an 85% chance of receiving at least this amount of rain. The remainder of the state has a lower chance of receiving significant rainfalls with the North West and Northern regions expected to remain reasonably dry.

The 200 mm rainfall plot show much smaller areas that may receive this amount which is largely limited to portions of the North East Highlands.

The latest Bureau of Meteorology rainfall updates show that Southern New South Wales and approximately 70% of the state of Victoria having only a 40% chance of reaching average rainfall during the next three months. However the area around Gippsland has a 50% chance of receiving average rainfall for the next three months.

In addition, the latest POAMA plots continue to show an El Nino development for 2009 and into 2010 with sea surface temperatures expected to be above average for the December to February period. Additionally the NINO 34 Plumes continue to show a peak during the January to February period.

The possible rainfall plots for Victoria and Southern New South Wales for the period August to October 2009 for 100 mm and 150 mm are provided below.

Harley Pearman

So, Harley, based on your statements re: the drought in VIC, do you think we might be pulling out of this severe drought soon? or are we still going to be covered in dust?

Big Pete

Likely POAMA Daily rainfall plots September to November 2009

I have been playing around with the likely POAMA daily rainfall ensembles for September to November 2009. The best way to answer Big Pete's question is to upload the ensembles produced. It is advised that POAMA (Prepared by the CSIRO) is only experimental at this stage but should give some indication how conditions are likely to prevail. Unfortunately it does not appear that major rainfall events are on the horizon for much of Victoria. While some rain is envisaged it is unlikely to be enough to overcome current conditions.

September - The ensemble suggest average daily rainfalls of minus 0.2 to minus 0.5 mm per day range for most of Victoria and much of Eastern New South Wales.

October - The ensemble suggest average or near average daily rainfalls for Melbourne within the range of 0.2 to negative 0.2 mm range. North East Victoria and Northern Victoria is in the minus 0.2 to minus 0.5 mm range per day which suggests below average falls. The ensemble suggest that eastern New South Wales will experience below average falls as well.

November - The ensemble suggests average or near average daily rainfalls for much of Victoria within the range of 0.2 to Negative 0.2 mm per day. It appears that no big events are suggested but enough rainfall to approach at least "average". Eastern Victoria is shown as being in the minus 0.2 to minus 0.5 mm range for daily rainfalls.

The Ensembles are provided below for the three months.

Harley Pearman

August rainfall Deficits continue but conditions ease in some South West regions

Rainfall deficits across much of Victoria continue however the dry conditions have eased across some parts of the state notably the South West.

Specifically the rainfall for the towns and cities in the case study to the end of August 2009 are outlined below:-

Location             Rainfall to end of August       Normal rainfall                 Deficits

Albury Wodonga   314.8 mm on 83 days           381.7 mm on 70 days      -66.9 mm
Ararat                310.2 mm on 98 days           385.9 mm on 97.9 days    -75.7 mm
Bairnsdale           189 mm on 82 days              396.5 mm on 90.7 days   -207.5 mm
Ballarat              286.8 mm on 110 days          445.9 mm on 109.8 days  -159.1 mm
Bendigo              251.6 mm on 85 days           300.7 mm                      -49.1 mm
Casterton           450.9 mm on 146 days          432.6 mm on 112 days     Plus 18.3 mm
Echuca              149.4 mm on 72 days            283 mm on 59.3 days      -133.6 mm
Geelong              203.2 mm on 106 days          335.4 mm on 94 days      -132.2 mm
Hamilton             366.4 mm on 131 days          386.9 mm on 116 days    -20.5 mm
Horsham             262.4 mm on 83 days            227.5 mm on 79.2 days   Plus 34.9 mm
Kerang               137.7 mm on 56 days            242.7 mm on 50.1 days   -105 mm
Melbourne           208 mm on 79 days              406.1 mm on 95 days      -198 mm
Mt Hotham          835 mm on 107 days            882.2 mm on 105.9 days  - 47.2 mm
Mildura               112.6 mm on 45 days           178.2 mm on 47.1 days    -65.6 mm
Portland              528.2 mm on 124 days         474.4 mm on 119.3 days   Plus 53.8 mm
Shepparton         183.2 mm on 81 days           262.2 mm on 64.1 days     -79 mm
Wangaratta         265.6 mm on 84 days           414 mm on 75.5 days       -148.4 mm
Warrnambool       499.6 mm on 131 days          470.4 mm on 129.9 days   Plus 29.2 mm

New South Wales

Griffith               165.6 mm on 47 days            259.8 mm on 48.7 days     -94.2 mm
Hay                   184.2 mm on 50 days            245.3 mm on 46.5 days     -61.1 mm
Wagga Wagga     208.2 mm on 66 days            369.8 mm on 69.9 days     -161.6 mm

A trend is emerging in which South West Victoria is now receiving rainfalls which are close to or slightly above the average and some centres in that region appear to be satisfactory. However Melbourne and Gippsland plus the Northern agriculture country as well as Southern New South Wales continue to show deficits. In particular:-

- Bairnsdale is showing a rainfall deficit that exceeds the amount of rain that has fallen so far.
- The rainfall deficit for Melbourne is still significant.
- The number of rainy days is satisfactory but the amounts that are falling are below average in most centres.

Some places received a wet August which has helped such as 106.2 mm at Casterton, 136 mm at Portland and 138 mm at Warrnambool. This has helped to reduce the deficits in the centres stated. Additionally, near average rainfalls occurred at Albury Wodonga.

When comparing the dams in the case study, it is becoming evident that the dams are unlikely to fill before summer.

Dam levels at 3 September 2009.

Dam name     Storage levels     Same time as 2008   Rainfall for 2009    Rainfall for same period 2008

Cairn Curren   2.63%               5.80%                    213 mm               219 mm
Dartmouth     24.6%               19.71%                   481.2 mm            493.4 mm
Eildon           21.78%              21.84%                  378.6 mm             411.9 mm
Eppalock       5.80%                6.95%                   228.6 mm             228.1 mm
Hume            24.05%             28.12%                  320.6 mm             343.4 mm
Tullaroop       4.54%               6.38%                    225.1 mm             179.8 mm

Dam levels are still low for September and some storages are worse off although Dartmouth is better off when compared to the same time last year (As at 3 September 2009). There has been inflows into Dartmouth and Hume from rainfall and melting snow since the beginning of August 2009.

According to Goulburn Murray Water, enough water has been stored in the upper catchment reservoirs to ensure essential services are maintained throughout summer but the system is heavily stressed.

The Melbourne system is still stressed in which storage capacity is at 28.8% as at 4 September 2009 with Melbourne's largest Reservoir only at 17.3% or holding 184,873 megalitres.

Overall parts of Victoria has seen some improvement during August but Gippsland and much of the Northern Country are still heavily stressed.

Information on this post is derived from:-

1 - Weatherzone (Rainfall data and rainfall averages).
2 - Bureau of Meteorology (Rainfall data and averages).
2 - Goulburn Murray Water (Rainfall and dam levels as 3/9/2009).
3 - Melbourne Water (Storage levels).

The plots describing the drought and drought statement, actual rainfall and rainfall anomalies are to be provided as a separate post.

Harley Pearman

Rainfall anomalies Victoria and Southern NSW August 2009

As per the previous post the actual rainfall and anomalies and drought statement for August 2009 is provided below.

Rainfall for August 2009

The rainfall for August is as follows:-

North West Victoria 10-25 mm.
Northern Country 25-50 mm.
Central and North East Hills 50-100 mm.
South West and North East Highlands 100-200 mm.
Gippsland 25-50 mm.
Southern New South Wales close to the Murray River received between 10-25 mm but it was drier further north.

The South West portion of Victoria received some good falls. The plot showing this is provided below which is generated from the Bureau of Meteorology "Land and Water" site.

Rainfall anomalies for August

The rainfall anomalies for August are as follows:-

South West Victoria has received above average rainfall in the order of 10 to 50 mm above average.
North West Victoria has received 10 to 25 mm below average rainfalls.
North East Victoria has received 10 to 50 mm below average rainfall however a small portion close to the New South Wales border received from average to 50 mm above average rainfall for the month.
Gippsland received 25 to 50 mm below average rainfall but it was drier at the far eastern portion of the state.
Southern New South Wales received from 10 mm to 50 mm below average rainfall but it was drier further north from the Murray River.

South West Victoria has seen some recovery. The plot showing this generated from the Bureau of Meteorology "Land and Water" site is provided below.

Drought Statement

The drought statement for August is as follows:-

3 Monthly anomalies - The worst of the short term deficits have been removed.
6 Monthly anomalies - Serious rainfall deficiencies exist around Melbourne and severe rainfall deficiencies exist for Eastern Victoria.
9 Monthly anomalies - Serious to severe rainfall deficiencies exist across southern and Eastern Victoria.
12 Monthly statement - Southern Victoria around Melbourne is hit hard including severe rainfall deficiencies and the Dandenongs experiencing "Lowest rainfall on record" from 1 September 2008 to 31 August 2009. The plot showing this generated from the Bureau of Meteorology "Land and Water" site is provided below.
 
Harley Pearman

Latest Seasonal rainfalls - Southern New South Wales and Victoria - Spring 2009

Latest El Nino Phase

The latest graphs and plots show the ENSO at Negative 5 as at 9/9/2009 but has not yet reached El Nino thresholds of Negative 7 (BOM 9/9/2009). Looking at the POAMA plots and Ensembles, it is noted that a large volume of warmer than normal surface water still lies across the Equatorial Pacific Ocean which is 1C above the normal but it appears that it will not reach Australian waters. Instead the POAMA is showing some warming of waters around Northern Australia during the summer months especially in February of 0.5C to 1.5C. The POAMA still suggest a peak in January however it seems that a weak El Nino phase is likely to eventuate but still enough to impact on rainfall.

Rainfall

I have been looking at the latest POAMA (Experimental Program produced by the CSIRO for research purposes) for rainfall predictions for spring and have noted a change particularly for South West Victoria. In particular I have noticed some recent recovery occurring in South West Victoria in which rainfalls seem to be returning to normal or approaching slightly above average. The latest POAMA plot / Ensemble seem to suggest that it may continue at least in this portion of the state. However this is limited in extent and the latest Seasonal POAMA Plot / Ensemble does not suggest good news elsewhere. The monthly Ensembles remain largely the same for the rest of the state. In particular:-

- South West Victoria "Showing Average" - Minus 0.2 to Plus 0.2 Range. It may suggest that conditions will not be as dry as first suggested in that region.
- Most of Victoria - Minus 0.2 to Minus 0.5 range.
- Far Eastern Victoria and far North East Victoria - Minus 0.5 to Minus 1 Range.

The Seasonal Rainfall Ensemble also show that much of inland New South Wales lies within the Minus 0.2 to Minus 0.5 banding while Eastern New South Wales lies within the Minus 0.5 to Minus 1 banding.

The Seasonal Plot for 3 months - Mean 24 Hour Rainfall Anomaly - September to November in which the variables were set to "Day 1" - Lead Time "Set to 3 Months" is provided below.

Harley Pearman 

September rainfall eases short term dry conditions

Useful September rainfall across large areas of Victoria has helped to ease the rainfall deficits although deficits still remain.  In particular, most regions, towns and cities received average to above average rainfall for the month with a few exceptions. The rainfall for the selected regional centres is provided below.

Town / City         Rainfall to end of September 09  Average rainfall to end of month  Deficit

Albury/Wodonga   376.2 mm on 93 days               440 mm on 81 days                    Minus 63.8 mm
Ararat                395 mm on 118 days                447 mm on 113.4 days                Minus 52 mm
Bairnsdale           240.2 mm on 98 days               451.3 mm on 104.6 days             Minus 211.1 mm
Ballarat              375.8 mm on 128 days              517.4 mm on 125.5 days             Minus 141.6 mm
Bendigo              304.6 mm on 100 days              348.9 mm on 80.7 days              Minus 44.3 mm
Casterton           539.1 mm on 174 days              506.2 mm on 130.2 days             Plus 32.9 mm
Echuca               179.4 mm on 80 days               322.2 mm on 68.8 days              Minus143.2 mm
Geelong              257.2 mm on 122 days              384.1 mm on 109.8 days            Minus 126.9 mm
Hamilton             440.2 mm on 151 days              457.5 mm on 134 days               Minus 17.3 mm
Horsham             345.4 mm on 98 days                262.4 mm on 92.5 days              Plus 83 mm
Kerang               185.3 mm on 65 days                278.2 mm on 58.1 days              Minus 86.9 mm
Melbourne           275.2 mm on 94 days               464 mm on 109.8 days               Minus 188.8 mm
Mt Hotham          1012.6 mm on 126 days            1,015.3 mm on 119.3 days          Minus 2.7 mm
Mildura               141.6 mm on 55 days                205.2 mm on 54.5 days              Minus 63.6 mm
Portland              625.2 mm on 140 days              551.1 mm on 137.8 days            Plus 74 mm
Shepparton         227.6 mm on 92 days                300 mm on 74 days                   Minus 72.4 mm
Wangaratta         319.2 mm on 96 days                470.7 mm on 87.7 days              Minus 151.5 mm
Warrnambool        583.2 mm on 152 days              538.8 mm on 149.8 days            Plus 44.4 mm

New South Wales

Griffith                185 mm on 55 days                 293.4 mm on 56.3 days               Minus 108.4 mm
Hay                    202.6 mm on 57 days              276.8 mm on 53.2 days               Minus 74.2 mm
Wagga Wagga      241 mm on 75 days                 419.6 mm on 80.7 days               Minus 178.6 mm

Comments:

The above shows that some places are relatively satisfactory. In particular, South West Victoria is also in a satisfactory position with respect to rainfall. Further, rainfall deficits across the North East highlands of Victoria have closed and rainfalls are near average. However, places like Bairnsdale, Echuca, Melbourne, Wagga Wagga and Wangaratta still continue to experience significant rainfall deficits.

Rainfall in September has helped to ease some of the short term deficits and places like Casterton, Horsham, Portland and Warrnambool experienced average to above average rainfall for the month.

However many areas are still stressed.

Storage levels:

September was a good month and some good inflows were recorded into upper catchment storages. The storages in the case study are shown below:-

Dam              Storage level at 7 October 09     Storage level at same time 2008

Cairn Curren    5.61%                                    6.17%
Dartmouth      27.68%                                   21.7%   
Eildon            29.14%                                   23.55% 
Eppalock        7.87%                                    6.9%
Hume            34.45%                                   35%
Tullaroop        5.75%                                    6.85%   

There has been an improvement at Hume, Dartmouth and Eildon Reservoirs mainly from better inflows from rainfall and snow melt and generally the big dams are in a better condition than at the same time for 2008.

However smaller dams away from the highlands do not fare as well.

There is enough water to meet some allocations now but the system is still stressed and it is doubtful that the dams will fill before the onset of summer.

Melbourne Water storages also show an improvement with its water capacity now at 32% which is an improvement on the 28.8% at 4 September 2009. Melbourne's largest Reservoir being Thompson Reservoir which can hold 1,068,000 megalitres is only holding 204,982 megalitres or 19.2% (7/10/2009).

However while improvements have occurred, the system is still stressed reflecting the rainfall deficits that have occurred.

The plots showing the September rainfall, rainfall anomalies and the drought statement is provided as a separate post.

So overall, an improvement has occurred in many areas and South West Victoria is satisfactory. However much of the state as well as South West New South Wales still show rainfall deficits.

The data from this post is derived from

Bureau of Meteorology (Rainfall for the various weather stations).
Weatherzone (Monthly climatic data for the locations).
Goulburn Murray Water (Dam levels).
Melbourne Water.

Harley Pearman     

Drought statement for September 2009

Rainfall amounts:

The plot generated from the Bureau of Meteorology - Land and Water site shows that good rains fell across much of Victoria during the month of September. The plot is provided below. In particular:-

- The majority of the east and south received more than 50 mm of rain during the month.
- Large areas received between 50 mm and 100 mm of rain for the month.
- Melbourne Water catchments and the North East received between 100 mm and 200 mm of rain.
- At least 50 mm of rain fell across large areas of North West Victoria.
- Isolated totals of up to 200 mm fell.

Lighter falls fell along the Murray River region but further north into New South Wales, rainfall tapered away and only light falls occurred for the month.

Rainfall anomalies:

During September, large areas of Victoria received at least average to above average rainfall for the month including Melbourne. In particular, Melbourne's water catchment, North East Victoria highlands and even North West Victoria (But mainly south of the Murray River) benefitted from September rainfalls. Hence the rainfall Anomaly plot provided below generated from the Bureau of Meteorology - Land and Water site shows that beneficial rains occurred across most areas of the state. There were a few pockets that received less than normal rainfall but generally September was a good month for rainfall across the state.

However, further north into New South Wales, September rainfalls tapered away increasing towards a deficit for the month.

Drought statement:

The 3 month plot shows no rainfall deficiencies across Victoria or Southern New South Wales. Rainfall in September has eliminated all the short term rainfall deficiencies that were previously occurring.

The 6 month plot shows only a small area in Eastern Victoria suffering from "Serious Rainfall deficiency". Following good September rainfall, much of the short term deficiencies have been removed.
 
The 9 monthly plot shows Melbourne and Southern Victoria suffering long term rainfall deficiencies including "Severe deficiencies". In Eastern Victoria, Gippsland continues to show "Severe deficiencies" to "Lowest on record". The area indicated as "Lowest on record" is inland from the coast but it crosses into South East New South Wales.

The 12 monthly drought statement still shows Melbourne suffering "Serious rainfall deficiency" which increases to "Severe Rainfall deficiency" for the Dandenongs east of Melbourne. There is also an area of "Serious rainfall deficiency" in far Eastern Victoria mainly along the state border of New South Wales. The rest of Victoria is generally satisfactory.

The 12 monthly drought statement plot generated from the Bureau of Meteorology - Land and Water site is provided below.

Harley Pearman

Likely October to December Rainfall 2009

I have been looking at some of the latest El Nino plots from POAMA (CSIRO) and sea surface temperature plots. The sea surface temperatures do in fact show "El Nino" Conditions and the oceans have warmed but the atmosphere conditions do not show it. The Southern Oscillation Index is currently Plus 3 or Neutral and the SOI now does not show an "El Nino" trend. Signals appear to be mixed. It is also noted that waters in the Eastern Indian Ocean are warmer than waters in the Western Indian Ocean which has helped over recent weeks in a positive way for Victoria.

The POAMA models continue to show El Nino conditions for sea surface temperatures with a peak during January and February of 1.64C and 1.63C above average but waning thereafter. The level of warming is not as strong as shown in previous months. It still appears to be a weak El Nino but signals seem to be mixed. It still appears that rainfall will be affected for Southern Australia.

Chance of exceeding median rainfall:

The Bureau of Meteorology rainfall prognoses for Victoria looks poor for the state. The plot shows that Northern Victoria has a 40% chance of exceeding median rainfall, dropping to 35% to 40% for Central areas, 30% to 35% for the South West and as low as 20% to 25% for some South West areas.

This is in contrast to the current rainfall regime which has been average to above average in this region. It may be a case that enough has fallen in this region to offset the likely dry for a period without significant stress assuming the model is accurate. Indications are, the good falls that have been occurring of recent weeks to close or reduce some of the deficits will not continue.

Chance of 100 mm Rainfall:

For the state of Victoria, the North West has a low chance of receiving 100 mm of rain being as low as 15% and as high as 35%. Generally large areas of the state should see at least 100 mm of rain varying between 25% and 85%. The regions with the greatest chance include the South West, Melbourne, North East and the East. However there is evidence of a drying trend taking hold at least across the West, North West and Northern Country and crossing into New South Wales.

While September saw some good rainfalls as per the models there is evidence to suggest that this will not continue and rainfalls will drop as summer approaches.

Chance of 200 mm Rainfall

Very few areas have much chance of receiving up to 200 mm of rainfall. The North West of the state, South West and Northern regions are considered to have a low chance of between 15% and 35% of receiving this amount of rain. Only Eastern Victoria has any meaningful chance of receiving this amount of rain ranging from a low 15% to a high of 75%. The highest chances lie within the ranges east of Melbourne and the North East ranges.

Western Victoria and Northern Victoria appear to show a drying trend for the October to December period.

The model plots referred to above have been generated from the Bureau of Meteorology "Water and the Land" for the "Chance of 100 mm Rainfall" and "Chance of 200 mm Rainfall.

Harley Pearman

October a dry month across much of Victoria - Some rainfall deficits worsen

The month of October saw good rainfall in East Gippsland and the North East Highlands but most other areas started to dry out as suggested by the long term weather models. In particular, October was a dry month across large areas of the state as well as inland South West New South Wales.

The table below shows the latest rainfall situation across the regional towns and cities and it shows that some centres are experiencing significant rainfall deficits. The South West portion of Victoria remains satisfactory. The details are obtained via:-

- Weatherzone (Specific to climatology data).
- Bureau of Meteorology (Specific to rainfall data for the month of October).
- Goulburn Murray Water (Dam levels as at 1 November 2009).
- Melbourne Water.

Place name          Rainfall to 31 Oct         Normal Rainfall                  Oct Rainfall    Deficit

Albury Wodonga     402.2 mm on 101 days   489.5 mm on 88.8 days     26 mm        Minus 87.5 mm
Ararat                  421.8 mm on 129 days   506 mm on 126.3 days      26.8 mm      Minus 84.2 mm
Bairnsdale             325 mm on 111 days     509.6 mm on 118.3 days    84.8 mm      Minus 184.6 mm
Ballarat                408 mm on 140 days      584.9 mm on 142 days      31.6 mm      Minus 176.9 mm 
Bendigo                338.2 mm on 109 days   390.5 mm on 90.1 days     33.6 mm      Minus 52.3 mm
Casterton             585.7 mm on 188 days   564.3 mm on 145.8 days   46 mm         Plus 21 mm
Echuca                200 mm on 88 days       364.7 mm on 77.2 days     20.6 mm       Minus 164.7 mm     
Geelong               283.4 mm on 134 days   437 mm on 123.4 days      26.2 mm       Minus 153.6 mm   
Hamilton              474.6 mm on 167 days   514.6 mm on 150.8 days    36.2 mm      Minus 38.2 mm
Horsham              366.6 mm on 104 days   296 mm on 101.5 days      21 mm          Plus 70.6 mm
Kerang                202.7 mm on 73 days     315.8 mm on 65 days        17.4 mm       Minus 113.1 mm   
Mt Hotham           1,135 mm on 144 days   1,117.5 mm on 130.3 days 122.4 mm      Plus 17.5 mm   
Melbourne            300.8 mm on 105 days   530.2 mm on 123.9 days   21.8 mm        Minus 229.4 mm
Mildura                153.8 mm on 61 days     235 mm on 61.5 days       10.4 mm        Minus 81.2 mm
Portland               666.2 mm on 155 days  598.9 mm on 154.1 days   41 mm           Plus 67.3 mm
Shepparton          248.2 mm on 101 days   332.9 mm on 82.8 days    20.6 mm         Minus 84.7 mm
Swan Hill             205.8 mm on 79 days     219.7 mm on 64.6 days    13.6 mm         Minus 13.9 mm
Wangaratta         351.2 mm on 106 days   522.7 mm on 96.9 days     32 mm           Minus 171.5 mm
Warrnambool        634.8 mm on 169 days   601.8 mm on 168.2 days   51.6 mm        Plus 33 mm

South West New South Wales

Place Name         Rainfall to 31 Oct          Normal Rainfall                Oct Rainfall     Deficit
 
Griffith               204 mm on 65 days        333.1 mm on 62.6 days   19 mm            Minus 129.1 mm
Hay                   207.8 mm on 62 days     311.9 mm on 59.4 days    5.8 mm          Minus 104 mm   
Wagga Wagga     269 mm on 83 days        477.8 mm on 90.4 days   27 mm            Minus 208.8 mm

In reference to the table above:-

- Bairnsdale received short term relief in which almost 85 mm of rain fell for the month being well above the average. However the rainfall deficit here is still 184.6 mm.

- The rainfall deficit for Melbourne worsened and now stands at 229.4 mm.

- The rainfall deficit within areas of the North East Highlands finally closed.

- At Wagga Wagga, the rainfall deficit reached 200 mm. It has been a very dry year in this region.

- Much of Northern and North Western Victoria started to dry out following a dry month.

Dam Name             Capacity as at 1/11/2009                 Capacity as at 1/11/2008

Cairn Curren            6.55%                                           5.8%
Dartmouth              30.27%                                          22.24%
Eildon                    33.25%                                          22.78%
Eppalock                8.21%                                            6.67%
Hume                    40.28%                                          33.11%
Tullaroop                6.06%                                           6.51%

(Source - Goulburn Murray Water 1/11/2009)

Lake Mokoan now holds 3.57% capacity which is a slight improvement. Generally the reservoirs hold more water than at the same time last year but it is clear that the reservoirs will not fill before the onset of summer.

As per the models, October saw a drier month across much of Victoria except for the Eastern areas being Gippsland and the North East Highlands. Away from the ranges, rainfall was mostly below average tending to well below average. Rainfall deficits are now very significant for places like Melbourne, Wagga Wagga and Wangaratta in the case study and rainfall deficits have started to widen elsewhere. This was caused by below average rainfall across large areas of the state.
 
Melbourne's water supply currently stand at 37.9% and there has been some good recent inflows mainly due to good runoff and rainfall in the upper catchments. This is an improvement on the same time last year where storage levels were at 33.9% capacity. Additionally, Melbourne's small dams look quite healthy in terms of storage capacity but the main water supply being Thompson Reservoir is only at 20.7% capacity (Melbourne Water 1/11/2009).

The dams are generally holding more water supply than at the same time last year mainly due to higher rainfall in the upper catchments however this rainfall did not penetrate into the Northern Plains for the month. Many areas are experiencing wide rainfall deficits which is not good approaching summer. Rainfall stress is evident in Northern areas and North Western areas of the state and well into New South Wales, especially across the inland regions. The plots showing these and the drought statement for the month of October will be completed as a separate statement.

Harley Pearman

Drought statement for October - Victoria and South West New South Wales

The drought statement is provided below.

3 month drought plot

A new region but within Western / Central Inland / South Western New South Wales is suffering serious to severe water stress. This appears to be a new region to watch due to low rainfall occurring. This region lies well within the Murray Darling Basin. The state of Victoria is effectively satisfactory due to good September rainfall having an impact.

6 month drought plot

The state of Victoria is mostly satisfactory except for small areas North East and South East of Melbourne.

9 month drought plot

Serious rainfall deficiencies exist around Melbourne and South East of Melbourne as well as parts of Gippsland. The rest of Victoria despite the rainfall deficiencies is satisfactory.

12 monthly drought plot:

The 12 month drought plot shows Melbourne continuing to suffer serious rainfall rainfall deficiency. The rest of Victoria despite some large rainfall deficits is satisfactory.

3 Month drought plot for the Murray Darling Basin

A different plot is used for October which is specific to the Murray Darling Basin. This is used because a new region suffering serious water deficiency and concern is becoming evident in South West and Western New South Wales specifically within the basin itself. The three month plot has been generated from the Bureau of Meteorology "Water and the Land" site.

Harley Pearman