Australian Weather News

December 1997

31 Dec 1997 -- "Gullyraker" sweeps through Lithgow, NSW

New 02 Jan 1998

In an unusual quirk of nature, flash flooding from a thunderstorm at Lithgow late in the afternoon was made considerably worse by last month's bushfires. The downpour fell on ridges to the north of the city that had been severely burnt out in the 2 December fires. Although only 13mm was registered at the Lithgow weather station, on the southern side of Lithgow's valley, tonnes of blackened bushfire debris and mud was swept down from the ridges, through Morts Estate and across the Laidley Street bridge, flooding two or three houses. Mud slides were reported in some parts of town, and some roads were closed by thick mud and debris though little property damage was caused. The topsoil stripped from the denuded ridges has been washed down into Farmers Creek and towards Lake Lyell, Lithgow's water supply.

26 - 29 Dec 1997 -- Cyclones and an active monsoon start The Wet across northern Australia

Updated 29 Dec 1997

With Tropical Cyclone Sid moving around the Top End of the Northern Territory into the Gulf of Carpentaria, Tropical Cyclone Selwyn well to the northwest of Western Australia, and an active monsoon trough stretching from the Kimberleys in WA, across the Gulf of Carpentaria coast to Cape York, there has been plenty of rain across northern Australia. In the week to 09.00 on the 27th, the Darwin suburb of Casuarina recorded 402.6mm, whilst Black Point on the Cobourg Peninsula in NW Arnhem Land recorded 409.4. Many locations near the coast around the Top End have had 200mm or more during this period, including Darwin Airport with 299.0mm. On Cape York Peninsula and along the Queensland far north coast, falls of 100 to 250mm were common for the same period, and included: Palmerville 221.8, Cooktown 285, Port Douglas 256 and Townsville 235.6.

TC Sid moved slowly along the north Arnhem Land coast from Boxing Day until late on the 27th, when it rounded the corner, increased speed to about 25km/h and headed southeast past Groote Eylandt with wind gusts estimated at around 100 to 120 km/h. Alyangula, on the sheltered side of the island reported gusts to 90km/h, enough to blow down a few power lines. During the morning of the 28th, Sid was upgraded from a category 1 to a category 2 cyclone, and slowed slightly to 18km/h, still heading southeast. During the afternoon, Sid weakened again to a category 1, tending to move more to the south, and crossed the Qld coast about 50km west of Mornington Island late in the evening. It was downgraded to a tropical low. While enhancing rainfall in the area, Sid did not produce winds or flood rains at any of the rather sparse reporting stations in the Gulf country.

25 - 27 Dec 1997 -- Heatwave sets further records in WA

New 28 Dec 1997

After a short-lived cool spell, Perth had its hottest Boxing day on record with a maximum of 40.5 at 15.35, easily surpassing the previous record of 38.3 set in 1930. This followed the hottest Christmas Day in 18 years with a top temperature of 34.7. And Geraldton had its hottest December day on record when it hit a reported 46.8 degrees on Boxing Day, just topping the previous record set of 46.7 set back in 1968, and a whopping 17 degrees above average.

Christmas Day was scorchingly hot in the north, with Gascoyne Junction reaching at top of 48 degrees. Current Bureau computerised records for Gascoyne Junction give the highest December temperatures as 45.8, though this does not include early records not yet computerised.

Northeasterlies on Boxing Day brought a return to heatwave conditions in the south and along the west coast. Jurien with 45 degrees easily broke its previous (computer record) December top temperature of 42.1, as did Kalbarri 44 (43.4), Lancelin 43.2 (42.7) and Dalwallinu 43.1 (41.7). Jurien's maximum was 17 above average, Lancelin's was 15 above. Gascoyne Junction recorded 47 degrees after an overnight minimum of 32, 11 above.

A trough moving east spread progressively cooler conditions through the south of the state on the 27th, but centres along the south coast, southern inland and the southeast still reported extreme temperatures. Ravensthorpe on the south coast scored 14 above average with a top of 42 degrees.

24 - 25 Dec 1997 -- Christmas Eve storm rips through Ireland, Wales and central England

New 28 Dec 1997

A remarkably intense and rapidly developing storm cut across the United Kingdom during the evening of Christmas Eve, killing three people, leaving at least 35,000 homes without power, causing great damage to homes, power lines and trees, and causing traffic chaos. Winds and damage was greatest in a swathe from Northern Ireland, across north Wales and the Wirral and Merseyside regions about Liverpool.

Winds were strongest over Ireland in the afternoon and over Wales and the Mersey early evening as a small secondary low pressure system, which developed in the Atlantic northwest of Ireland earlier in the day, passed across the northern Irish Sea. Sustained winds between 40 and 50 knots were commonplace. Cork on the Irish south coast had a mean speed of 56 kts at 14.00 UTC with gusts to 80 kts at 15.00, at the same time as Valentia Observatory, on Ireland's southwest coast, recorded gusts to 87 kts. At 1650 UTC, Valley on the Isle of Anglesey off the NW coast of Wales had a mean speed of 53 kts, with gusts to 79 kts. Aberdaron Automatic Weather Station, on the tip of the Lleyn Peninsula in NW Wales, recorded a peak gust of 97 kts at 18.00. On the east coast, the gales arrived early Christmas morning, with 70kt gusts reported from a road bridge near Goole, west of Hull.

Pressure falls ahead of the low were as great as 15 hPa over 3 hours, with pressure rises behind the low of up to 22 hPa over 3 hours.

22 - 23 Dec 1997 -- Heatwave conditions set records in southern WA

New 24 Dec 1997

Hot northeasterlies blowing from the centre of the continent have given the south of Western Australia two days of extreme heat. Temperatures above 40 degrees were widespread on the 22nd, but the 23rd produced top temperatures of between 43 and 45 degrees in a broad swathe through the Great Southern north to the Central West and Gascoyne districts. Almost every station in the southern half of WA reported maxima more than 10 degrees above average, Albany's 43 being 19 above normal and a record December temperature. Perth City had its hottest December day in 23 years. After a minimum of 22.8 at 04.35, the maximum of 41.4 was reached very early at 11.00, making it the fifth hottest day on record. Perth Airport reported 43, its hottest December day on record. The state's top temperature of 45 was shared by Nyang (Gascoyne), Morawa (Central West), Hopetoun (South Coast) and Northam, York, Cunderdin and Hyden (Great Southern).

A massive bushfire developed during the day at Casuarina, south of Perth, destroying a home, 2 sheds and more than 10 kilometres of fencing and injuring six firefighters. It was contained by early evening. Another fire at Wooroloo, east of Perth, closed roads during the afternoon before also being contained.

22 Dec 1997 -- Unusual hailstorm near Port Macquarie, NSW

New 23 Dec 1997

A brief hailstom at Port Macquarie at 17.45 brought unusual hailstones. They were small, flat disc shaped stones with a very small opaque core but mostly clear. Falling more to the SW,of the town, the hail was accompanied by little if any rain. However, a report from Logans Crossing - further to the SW, indicated that 37 mm fell in less than 20 minutes. Further north, Casino recorded 34mm in a storm around 18.00.

21 - 23 Dec 1997 -- Heavy rain in Townsville, Qld

New 23 Dec 1997

Townsville Airport recorded 229mm, or 9 inches, of rain in the 2 days ended 09.00 Tuesday 23 December. The heaviest falls came overnight, with 86mm falling between 21.00 and 09.00 on the 22nd, and 120mm between 21.00 and 06.00 on the 23rd. Elsewhere in the area there were some heavy falls, but most were less than half Townsville's total. The rain appears to have been the result of local strong uplift in a moist airmass made unstable by the passage of an upper trough.

21 - 23 Dec 1997 -- Gales cover Tasmania and coastal Victoria

New 23 December 1997

Strong to gale force winds occurred throughout Tasmania, around the coast and high country in Victoria and in parts of NSW from late on Sunday 21st to Tuesday 23rd. The cause was a series of small secondary lows moving around a deep low south of Tasmania, brushing the southeast of the continent. Gales (measured, average wind speeds of 34 knots or more) persisted through Monday and well into Tuesday in Tasmania, with hail and heavy rain in the southwest of the state. Mount Wellington summit reported average winds around 45 knots most of the day, with the temperature mostly just above zero. In Victoria, Wilsons Promintory reported average winds of 37 to 49 knots through the day, with gusts to 70 knots.

21 - 22 Dec 1997 -- Hot, windy conditions in NSW and Victoria

New 23 Dec 1997

Strengthening NW winds brought hot condition to much of the southeast on Sunday and Monday, 21 and 22 December. Temperatures above the old century covered most of NSW and Victoria on Sunday, with many areas recording maxima over 40 degrees. In the Sydney area, Homebush, Liverpool and Badgery's Creek recorded top temperatures of 42, and Bankstown's 41 was 13 above normal. Nowra recorded 41 degrees, 16 above average, and in Victoria, 39 at Point Hicks in the east Gippsland was 17 above. Amazingly, Wilson's Promintory's maximum the same day was only 20. The hot weather contracted northeast during Monday as a cool change moved through, but many centres in northeastern NSW experienced a second day of above century heat.

A major blaze flared up on Monday morning in the Yalwal area of the Moreton National Park southwest of Nowra, while at Yerong Creek, near Wagga, a fire caused damage and stock losses over 9,000 hectares. In Sydney's outer western suburbs, fires burning close to Riverstone and Marsden Park destroyed one building. Other fires occurred north-west of Boorowa in the State's central-west, in forest east of Yass, at Dungog in the Hunter Valley and at Taree on the mid north-coast. By Tuesday morning, eight fires were still burning in NSW, with that at Yass burning across 400 hectares.

16 Dec 1997 -- Possible world record measured wind speed on Guam

New 19 Dec 1997

The US Anderson Air Force Base on Guam Island in the North Pacific may have experienced the highest ever recorded wind speed as Tropical Cyclone Paka passed the island on 16 Dec. The instrumentation at the base reported a peak gust of 205 kts (236 mph or 380 km/h) at 06.31 UTC. The current authenticated world record wind speed is 231mph held by Mount Washington in the northeastern United States.

For weather enthusiasts, Stu Ostro of The Weather Channel has given this useful summary (on bit.listserv.wx-talk) of the questions currently (19 Dec) surrounding the validation of the 205kt speed:

Being skeptical about the validity of the 236 mph wind gust observation from Guam for a number of reasons, I called the Joint Typhoon Warning Center Tuesday evening EST. They indicated that they also believed the report was in error.

They referred me to Anderson AFB ... the person to whom I spoke there was hesitant to categorically confirm or refute pending a review of the data, but indicated that there were power surges at the time, as well as "error codes" being received from the instrumentation (by the way, not a "cup"-type anemometer ... it's an "FMQ13"... anyone familiar with that?).

She in turn referred me to someone at the command post. He also confirmed that they believed there were problems with the data. However, during our conversation, a call came in on the other line suggesting that it was after the gust to 236 that the equipment had problems. He also referred to a sustained wind of 175 kts (201 mph) at the time whereas on the ob sent out on the wire it was only 84 kts (97 mph). (In one sense, that would perhaps make it more believable - less of a gust factor. On the other hand, a sustained wind of 200 mph at that point seems highly implausible.)

This Wed eve I spoke again to one of the people at Anderson AFB closest to the issue (same one as Tue) to see whether they had any new thoughts. The answer was no. The official line is still that there were power surges at the time and it is suspected that there were problems with the data. What a different person referred to last night as a late sentiment of there having not been any equipment issues at the time was clarified. At the precise moment of the gust, the equipment appeared to be operating okay, so therefore the decision was made at the time to release the ob to the circuit. But overall it was in the midst of these power surges and error codes, hence while there has been no categorical refutation, there has also been absolutely NO official confirmation of its validity. (She also had no idea where the notion of sustained winds of 200 mph originated and did clearly debunk that.)

In fact, she said they were aware of the fact that some other stateside media had picked up on this gust and were stating that a new world record had been set or at least citing the 236 mph without qualification, and encouraged TWC to let people know what the real story is. (Outside of this post to Wx-Talk and Wx-Chase, while we were still airing the Guam video on the cable network this evening we added some wording in the associated script to address the issue, and some OCMs have been commenting in other segments.)

She said that observers and meteorologists will be convening, hopefully within the next week or so, to review the data and issue a subsequent report. (One suspects that if the ob survives that phase, there will be further tests of the equipment and some politicking before it goes down in the books...)

I've left names and phone numbers out to avoid having them be deluged with calls. I myself was hesitant to call, and would like to mention that everyone with whom I spoke was extremely accomodating given the situation there - I'm sure they had a few other things to worry about! Their assistance is much appreciated.

12 - 16 Dec 1997 -- Historic snowfalls and cold in Mexico

New 23 Dec 1997

Snow fell for the first time this century in parts of northern and central Mexico on 12 - 13 December and again on 15 - 16 December. Freezing rain was also reported from southern Texas as a cold wave swept much further south than normal. In Mexico, at Guadalajara, which is only 20 N of the Equator, press reports indicated 40 cms of snow fell where none had fallen for 120 years! Intense snow fell in the northern deserts, from Chihuahua east to Tamaulipas. At least 28 deaths are attributed to the cold weather and roof collapses.

Further south, temperature records were falling, and coffee producers were fearing crop losses due to frost damage. Zacatecas broke a 27 year record with an overnight low of minus 12.6C, whilst Durango in the north reported minus 25.

6 - 9 Dec 1997 -- Major trough system brings widely spread rain and storms, and exceptionally cold temperatures to southern WA

Updated 9 Dec 1997

A broad, slow-moving surface trough covered much of the eastern two-thirds of Australia during this period, bringing widely scattered but intense thunderstorms to an unusually large part of the continent. Only the southern two-thirds of WA, and Vic and Tas were spared.

During Friday the 5th, six enormous storm complexes developed due to daytime heating as far afield as the Kimberley, the Territory Top End, NW and SW SA, SW Qld and northern NSW/central and southern Qld. For the 24 hours to 09.00 on the 6th, Drensmaine in the Qld Central Highlands reported 77.8mm, Alyangula in the NT Top End 70.6, and Croppa Creek in the NSW NW Plains had 60.8. Most falls were of relatively short duration and occurred during the afternoon of the 5th.

During Saturday the 6th, an upper level trough developed a cut off cold pool over Western Australia, increasing the convergence of warm moist air to the east resulting in the development of some substantial storm complexes in southern NT, southwestern Qld, northern SA and southeastern WA overnight 6/7 Dec. Among the heaviest falls in the 24 hours to 09.00 on the 7th in an area of sparse raingauges were Jervois (NT) 57mm, Rawlinna (WA) 54.6, Kulgera (SA) 34.7 and Eromanga (Qld) 34. Kulgera reported 29mm in the 3 hours 03.00 to 06.00 on the 7th, whilst Jervois, 250km ENE of Alice Springs, reported more or less continuous storms during the afternoon and evening of the 6th, with 44mm falling in the 9 hours to 21.00 on the 6th.

Meanwhile, the upper cold pool was producing daytime temperatures as much as 12 below normal over parts of southern WA, a situation that persisted until the 8th, by which time the cold area had moved to the WA/SA border.At Rawlinna, on the Transcontinental Railway north of Eucla, the top temperatures on the 6th and 7th were only 18 and 16, 14 and 16 below average respectively.

During the afternoon of Sunday the 7th, thunderstorms again developed from daytime heating, this time in a broad band extending from the Kimberleys of WA to the northern NSW coast. Top falls in the 24 hours to 09.00 on the 8th were in the NT, with Victoria North (near Victoria River Downs) receiving 90mm and Ammaroo Station, 250km northeast of Alice Springs, 83. Meanwhile, heavy storm falls occurred in widely scattered parts of northeastern NSW and southern Qld during the afternoon and evening giving 24 hour totals to 09.00 on the 8th of 79 to Nimbin on the North Coast, 65.6 to Pilliga on the North West Plains, and 62.4 to Murrurrundi in the upper Hunter. While these are 24 hour totals, most or all of the rain fell over an hour or two: the Murrurrundi storm, for example lasted from 11.30 to 13.45, Charleville (Qld) recorded 33mm between 18.00 and 21.00, Nimbin recorded 52mm in the hour to 16.54, and Wittitrin in the Macleay basin recorded 53mm in the hour to 12.28.

The early morning of Monday the 8th ushered in some violent storms along the west coast of SA due to the trough to the north, colder upper air approaching from the west and abundant low level moisture. 31mm fell at Nullarbor in the 3 hours up to midnight, 25 of that falling in one 20 minute period. Ceduna reported 47mm between midnight and 06.00, whilst Woomera reported a dust storm whipped up by wind gusts to 52kts. This area of storm activity weakened as the cold pool washed out, but produced general falls of around 20mm in the 6 hours to 15.00 as it moved ESE across the Eyre and Yorke Peninsulas, Kangaroo Island and the Adelaide area.

By the afternoon of Monday the 8th, the inland trough was sharpening and retreating east into Qld and NSW ahead of a ridge pushing cooler, drier southeasterlies into SA. In Qld, a band of storms developed during the afternoon in the trough extending diagonally across the state from the Gulf of Carpentaria to the NSW border. Burketown, on the Gulf, recorded 42mm between 09.00 and 15.00, Blackall 39 between 15.00 and 21.00, and Walgett in NSW 33 between 21.00 and 03.00 on Tuesday 9th.

The morning of Tuesday 9th now saw a well defined rain band with some embedded storms moving steadily across NSW and southern Qld, with the heaviest 24 hours falls to 09.00 around the border. Talwood in the Western Darling Downs top scored with 87.6mm, followed by Collarenebri (NSW Upper Western) 75, Whyenbah (Qld Warrego) 72.4, Tambar Springs (NSW Northwest Slopes) 72 and Mogil Mogil (Northwest Plains) 70.2. Falls of 10 to 50mm were widespread in a band running from the Gulf of Carpentaria to the southeast corner of NSW.

Between 09.00 and 15.00 on Tuesday 9th, the rainband crossed the NSW Central and Southern Tablelands and Coasts, giving falls of around 5 to 20mm with only isolated thunderstorms, peaking at 31mm at Oberon. However, there were still a few storms left about inland NSW, one giving Brewarrina 29mm during the 6 hours, and another at Mudgee dropping 8mm late in the afternoon.