SIGNIFICANT WEATHER - FEBRUARY 2000

Introduction Tropical Cyclones Thunderstorms Wind Bushfires Flooding Temperature
Rainfall

INTRODUCTION

Periods of heavy rainfall during February resulted in major flooding in many areas of Queensland and inland areas. At the end of February, tropical cyclone Steve affected Northern Queensland, resulting in extensive flooding and wind damage. In contrast, several major bushfires occurred in Tasmania during the month.

TROPICAL CYCLONES

Queensland/Northern Territory

Tropical cyclone Steve formed 210 km east of Port Douglas during the morning of the 27th, was upgraded to category 2 by 1pm and moved west across the coast at 7pm over the northern beaches of Cairns. Maximum wind gusts were 160 km/h at landfall. The cyclone then weakened to a rain depression causing flooding as it crossed the Cape. It reformed into a cyclone near Mornington Island on the morning of the 29th and continued in a westerly direction cross the Northern Territory coast near Port McArthur on the 1st of March and again weakening to a rain depression. Tropical cyclone Steve reformed in waters off the northwest coast of Western Australia during March.

Steve caused major flooding between Cairns and Mareeba as the cyclone tracked inland. A record flood level of 12.4 metres was reached at Mareeba on the 28th with 90 people requiring evacuation and the railway bridge was washed away.

Many building in Cairns suffered severe water damage including the Cairns hospital. Several buildings in Cairns and Kuranda lost their roofs, hundreds of trees were uprooted and powerlines were brought down throughout the district disrupting supplies to more than 40,000 residents. The two highways to the Atherton Tablelands were closed by fallen trees and landslides. Crop damage by floods and winds were severe, with sugar cane damage alone estimated at 20 million dollars. Preliminary costs were estimated to include 49 million dollars to restore local government assets and 20 million dollars for state roads and railways. Early estimates indicate that the total damage bill in north Queensland associated with cyclone Steve may exceed 100 million dollars.

Western Australia

A developing low was named tropical cyclone Leon on the 4th while located approximately 230 km south of Christmas Island. Following a general southwesterly track during the 5th and 6th the system developed into severe tropical cyclone Leon with an estimated central pressure of 960 hPa. By the 8th tropical cyclone Leon passed to the south of the Cocos (Keeling) Islands.

THUNDERSTORMS

New South Wales

On the 21st Broken Hill (Lower West) recorded 35mm of rain in 30 minutes causing very heavy rain and possible flash flooding.

Victoria

On the 8th at Club Terrace in east Gippsland large hail to 3cm was reported. Thunderstorms with heavy rain were reported in the Northern Country. At Tatura 32mm of rain was recorded in 30 minutes.

On the 21st at Yanac in the western Wimmera district, severe gusts to 93 km/h were recorded.

On the 23rd at Lauriston in the North Central district, 32mm of rain was recorded in 35 minutes.

On the 24th at Berringa in the Western district 94mm of rain was recorded in just over 2 hours.

On the 25th storms in and around Melbourne produced heavy rain leading to flash flooding. At Werribee 40mm was recorded in 30 minutes. A nursing home had to be evacuated due to flooding. Other suburbs which recorded high rainfall rates were Elwood, St Kilda, Elsternwick and Caulfield. A water spout was observed near Mt Martha.

South Australia

Many thunderstorms were reported on the 21st:

Heavy showers on the east of the Mount Lofty Ranges caused flooding. Strong winds associated with the thunderstorms brought down trees across the affected areas.

Lightning strikes caused power blackouts and heavy showers caused localised flooding at Eudunda, in the Lower Murray Valley.

Minor roads in the Adelaide Hills received substantial damage with a bridge collapsing and roads washed away.

Further rain and thunderstorms in the Riverland during the early morning added to the already flooded vineyards and is expected to reduce the grape harvest by up to 20 per cent.

On Kangaroo Island the thunderstorms forced a fishing boat onto the beach at Vivonne Bay, on the island's south side.

At Moonta Bay on Yorke Peninsula, a fishing boat moored next to the jetty sank after being struck by lightning.

During the afternoon of the 26th heavy showers at Booleroo Centre, northeast of Port Pirie in the Mid-North, caused localised flooding. At least 13 properties required sand-bagging.

Northern Territory

On the 2nd a downburst associated with an early morning squall line felled or damaged many large trees at Gunn Point Prison Farm (30 kilometres northeast of Darwin).

During the afternoon of the 3rd, wind gusts of 78 km/h were recorded at Jabiru and Humpty Doo during the passage of a long-lived thunderstorm squall line, but no significant damage was reported.

A gust of 83 km/h was recorded on the 6th at Charles Point, 30 km west of Darwin.

WIND

Tasmania

Gusts exceeding 90 km/h were reported at Cape Grim on the 21st and 22nd ; Derwent Estuary on the 5th, 10th, 12th and 26th; Flinders Island Airport on the 5th ; Hartz Mountain (Keoghs Pimple) on the 12th and 27th ; Maatsuyker Island Lighthouse on the 5th, 12th and 26th ; Mount Wellington on the 5th, 10th, 12th, 20th 22nd and 26th.

South Australia

A dust devil at Golden Grove, a northeast suburb of Adelaide, caused damage to three houses during the afternoon of the 16th.

BUSHFIRES

Tasmania

Many major bushfires were reported during the month which included: 2000 hectares of native forest near Glen Huon on the 5th and 6th ; 800 hectares of State forest near Lorinna on the 15th to the 17th ; 200 hectares of bush near Burnie on the 13th ; 1600 hectares of bush near Gowrie Park on the 20th ; 200 hectares of bush and houses were threatened at Ravenswood on the 20th.

FLOODING

Queensland

February 2000 represented one of the most significant months for several years with over 230 flood warnings being issued. Weather systems caused heavy rainfalls during three distinct wet periods. From early to middle of the month floods occurred in coastal catchments from Mackay to Ingham; From the middle of the month the monsoonal trough resulted in heavy rainfall over far western catchments and late in the month tropical cyclone Steve caused flooding in coastal rivers and streams from Ingham to Cooktown.

The most significant flooding occurred in the Haughton River on the 17th and continued intermittently until the end of the month. Major flooding resulted in the inundation of the township of Giru on two occasions with minor flooding continuing for long periods throughout the month.

Moderate to major flooding occurred in the lower Herbert River from the 6th to the 9th. As a result of tropical cyclone Steve, further heavy rainfall later in the month saw a prolonged period of moderate to major flooding, with two separate flood peaks commencing on the 25th and continued into March.

Similar to other river systems in the area the Tully River was subjected to two periods of flooding. Moderate flooding occurred from the 6th to the 11th while major flooding occurred from the 25th and continued into March.

A minor flood occurred in the Barron River on the 8-9th. Later in the month tropical cyclone Steve caused the Barron River at Mareeba to reach its highest flood since records began in 1921. Major flooding also occurred in the lower Barron River around the delta area at the same time.

Very heavy rainfall over a few days in the middle of the month resulted in major flooding in the Thomson River which continued downstream in Cooper Creek into March. The level of the Thomson River at Muttaburra was one of the highest flood peaks on record and this was reflected in the major flood levels reached at the downstream river height stations including Longreach.

The township of Winton was subjected to some of its most severe flooding on record during the middle of the month. The monsoonal trough which caused this rainfall resulted in widespread moderate to major flooding downstream along the Diamantina River which continued into March.

Flood warmings were issued for moderate to major flooding which commenced in the upper reaches of the Georgina River in mid February and continued in the lower reaches in March.

Western Australia

Heavy rainfall during the 28th that extended from the Northwest through to the Goldfileds and eastern parts of the Southwest Land Division were triggered by a tropical low over the Pilbara. Several sites reported more than 50mm of rain. Esperance recorded a notable 70mm of rain in the 9 hours to 9am on the 28th. The unseasonal rainfall produced localised flooding around the town and interrupted electricity supplies.

Northern Territory

Central Australia

The Todd River flowed through Alice Springs during February reaching a peak of 2.18 metres on the 14th.

The Hugh, Finke and Palmer Rivers all flooded and reached record heights at the Stuart Highway. During the period 12-13th, the Hugh River reached 6.7 metres (3.5 metres over the bridge); the Finke River reached 9.64 metres (6.3 metres over the bridge); and the Palmer reached 11 metres ( 1 metre over the bridge) following record rains in the West Macdonnells.

The Hugh river flooded the Owen Springs homestead to about 1 metre depth and at Orange Creek homestead it was about 2 metres deep in the homestead.

Top End

On the 16th, monsoonal rainfall in the Darwin region caused flash flooding in the suburbs and rural area from midday until mid afternoon. Arterial roads were cut and low visibility at Darwin Airport delayed many flights.

TEMPERATURE

Queensland

In Queensland 24 heat related deaths and hundreds of hospital admissions were initiated by hot westerly winds causing thermally stressful conditions in southeast Queensland. The temperatures were well above normal between the 20th and 23rd with Brisbane Aero having a record high January maximum of 39.1^oC on the 20th. In the city area a maximum of 40^oC was recorded on the 20th and 21st and at Amberley 39.8^oC was recorded on the 20th, 40.7^oC on the 21st, 39.6^oC on the 22nd and 35.4^oC on the 23rd.

RAINFALL

South Australia

Widespread rain over the northern interiors of the State between the 10th and 14th caused flooding over much of the area. All unsealed roads north of Port Augusta were closed, with the Stuart Highway cut, north of the South Australian/Northern Territory border, near Kulgera. The official rain gauges at Tieyon and Mount Dare were washed away during this flooding.

Heavy rain on the 20th caused flooding to parts of the eastern border districts, in particular the Riverland. More than 65 houses were flooded, towns isolated and roads cut across the Riverland, Mid North and also in Broken Hill.

The heavy rains caused major problems to grape growers in the Riverland, leaving vineyards inaccessible to grape harvesters and increasing the risk of outbreaks of downey mildew to the remaining fruit.

Further heavy rainfalls at Oodnadatta and William Creek in the Far North of the State on the 20th isolated those towns with all roads cut in the area.

Note: Some statistical records mentioned in this report are based on data that have yet to be fully validated.