Updated 2145AEST - 29th June 2000

June 2000 Forecast Outlook, Discussion & Report Page

ASWA Victoria

Information

Lindsay Smail & Geelong Weather Services

PAIR WATCHED STORM BREW.
Julie Tree called to her husband Tim late on Thursday afternoon because she couldn't believe what she was seeing. The couple live on the north-eastern edge of Rochester and from their backyard Julie could see a "hole" in the clouds - a hole that became a dome, growing larger and larger and rapidly sucking clouds up into itself. "The clouds were flat along the bottom edge and then it looked as if someone was pushing the sky up in one place and all these little clouds were being sucked into the hole - but you could see blue behind it. It was weird, eerie," Julie said.

The couple watched goggle-eyed as a cone shape appeared from the centre of the dome, which they estimated was only half a kilometre away. "It started with just a little point at the top of the arch and then the point grew a tail, then grew and grew until it was one massive tube," Tim explained. "The light was eerie, sort of green - and this thing never stopped moving. It travelled across the ground and the tube danced, sort of snaked - like a hula hoop - and all around it was really quite, no birds or anything."

Tim said they watched the tornado develop for close to 25 minutes. "At one point it looked like it was coming towards us, but it moved across to (Fairy Dell) and then it looked like there were birds whizzing around in it - but now we know it was probably someone's house and the 'birds' were probably pieces of tin. "It went from nothing to huge during the time we watched it. As it moved, further away, it looked as if it took up the whole sky over that way. We still can hardly believe what it was we were watching and we wished we'd had film in the camera so we could show people what we saw. It was incredible."

A large area of middle and high cloud should extend across most of SE Australia ahead of this system, bringing general patchy rain late Monday and Tuesday. Strong winds are also likely at this time. Some moderate rainfalls are possible in western and mountain areas.

The remainder of the week should see a cold trend with showers as further cold fronts move up from the Southern Ocean over Victoria. Snow showers can be expected to develop over the high ranges by Wednesday, and continue until at least Friday. Some of these showers could be locally heavy.

A new high pressure system should then push eastwards towards Victoria on Friday and Saturday, bringing more settled conditions.

Frosts are likely in northern Victoria from about Wednesday-Thursday.

RISKS: Possibility of low pressure development west-northwest of Tasmania on Tuesday - Wednesday. If this occurs rainfall will be enhanced across Victoria on Wednesday and Thursday.

Clyve Herbert and Geelong Weather Services

Anyone with information, photos, video or reports regarding this event, please send full details to me at cadence@rubix.net.au  The information will be passed onto the Bureau of Meteorology.  Please include contact names, phone numbers & locations.

More frequent showers should become evident through this afternoon and evening, with possible small hail, moving progressively eastward and clearing from the west.

It looks like there is the possibility of a repeat performance as another strong front enters Victoria. It is currently moving through SA, and looks very nice and radar and the sat pic.

My friend and I went surfing on the Monday morning and we were surprised to see so many rocks sticking out of the water. It was only the second time we had surfed at that reef so we just thought it was normal. Anyway....turns out that the low tide was 35cm below the forecast level. Any idea why? Well - I'll tell you anyway. It was the opposite of a storm surge. The high pressure system was SO strong that it forced the tide lower than forecast. It was 1038hPa later that day I think....Considering the tide varies only 1.2m (average) between high and low tide, a 35cm difference is fairly significant. Had the moon been in the right place as well it could've made things very interesting. It was by far not an exceptionally low forecast low tide anyway but had it been things may've been very very interesting.

A middle-level disturbance is generating cloudy conditions through much of Eastern Victoria and NSW. This system is generating mainly high-level cloud but some patchy rain can be expected with it.

SE Australia Satellite Images

However a more active frontal system should reach western Victoria on Tuesday, with showers developing mainly in western mountain and southern areas. A series of cold fronts should then continue to affect Victoria for the remainder of the week with increasingly cold conditions.

Snowfalls should start to develop on the higher ranges on Wednesday. Some showers from Wednesday to Saturday may be locally heavy.

Wind strengths may become gusty at times when accompanying the passage of the cold fronts during the week.

RISKS: The combination of the upper disturbance over western NSW and the approaching cold front may result in the potential for cyclogenesis southwest of Adelaide.

Clyve Herbert and Geelong Weather Services

For snow buffs it looks like this system will initially bring rain to most of the slopes, due to the warmer air ahead of the front. Snow should fall with the follow up fronts and the general showery conditions in their wake. Of interest is GASP's which has a low forming in the Eastern Tasman, this would see strong winds driven into the Snowy's, and could see some potentially good falls for the NSW Resorts. At this stage I'll tip between 20-30cm at the higher resorts.

SE Australia Satellite Images

SE Australia Satellite Images

In regard to barometer tapping, I fingernailed my trusty WILSN forecasting aneroid this morning which was showing 1025hpa when it suddenly jumped to 1040hpa!!. The indicating pointer had become stuck a bit like the present super high with its centre over Melbourne at around 1000 this morning. To look on a more positive side today we should see this anticyclone reach peak intensity (1042) as the system moves very slowly towards the Tasman Sea. This large high should maintain its influence for most of the week. A major long wave trough is evident west of Perth; this together with the cycling surface cold fronts and short wave troughs are expected to progressively invade and erode the present high pressure towards the end of the week.

The outlook for Victoria should see a continuation of fine sunny weather to at least Thursday or Friday but with increasing wind strengths from a northerly direction. The first wave of frontal activity should reach Victoria late Thursday or Friday, with increasing instability over Saturday and Sunday with showers merging to longer spells of mostly light rain especially over the Dividing Range. Colder southwest winds with further showers should persist from Monday through Tuesday; some snow may occur on high ground at this time. Temperatures will continue to be below average at night on Wednesday with widespread frost and some further fog. A warming trend Thursday to Friday should see day and night temperatures rising. A colder trend appears probable from Sunday to Tuesday.

Clyve Herbert and Geelong Weather Services

SE Australia Satellite Images

As the strengthening high pushes east on Sunday and Monday conditions across Victoria will stabilise with fog and inland frost developing. Some frost may extend to southern districts Sunday or Monday. From Monday the high pressure area should move east of Victoria and weaken allowing a trough to invade from the west. At this stage this system appears to be favourable for more general rain after Tuesday or Wednesday.

RISKS: The present cloud band over Queensland should be watched for the next 24 hrs in case it moves south to affect N.S.W. This may occur if the present trough approaching Victoria deepens.

Clyve Herbert and Geelong Weather Services

For all those ski enthusiasts heading up for the BIG opening weekend, enjoy the fresh snow on Saturday as Sunday and Monday could be a bit icy in the mornings. This will be caused by the ridge of high pressure taking hold and moving very slowly over the southern-eastern portion of the continent. In Victoria we should see widespread frosts developing by Sunday away from the coast. I wouldn't be surprised to see some minimum temperatures down below -3 on Sunday and Monday mornings (although Monday could be a little warmer if the high pushes to the E and we get a light Northwesterly surface flow, especially in the W of the state - low temps are still fairly likely in the E half of the state). Early next week should see the NW-WNW'ly surface flow increase gradually as the high drifts slowly into the Tasman so we may be lucky to see some slightly warmer temperatures (might even get about 15C) by mid week before the next frontal system comes through.

Clyve Herbert and Geelong Weather Services

These 6 hourly false colour infrared satpics are trimmed from JMA GMS-5 images downloaded from the BoM with a colour table applied to enhance visibility of the features. The colours show infrared temperature in 32 steps from white to blue for 'hot' areas (there are no white land or sea surfaces in this sequence - it's too cold), with freezing point being a bluish-green, green is below freezing, and yellow to red to brown to black for very 'cold' cloud tops (there is no brown or black either - more often seen in severe cyclone cloud tops, and not often evident in the BoM version of the GMS-5 images for some reason).

Some of the features you may notice are: - the very cold cloud tops in yellow - red which indicate areas where heavy rain/hail/sleet/snow is more likely to be occurring, some heavy snow dumps in the highlands are associated with some of these as the sequence progresses, and you can see the heavy hailstorm that hit Melbourne. - the green frontal bands which are where periods of rain/hail/sleet/snow may be occurring. - the mottled green clouds in the pools of very cold air behind some of the fronts which may be showers of rain/hail/sleet/snow.

- the daily solar heating/cooling cycle effecting the land surfaces seen as the alternating blue to blue green colour, with the extreme cooling of the land surfaces at night being very evident towards the end of the sequence by the extensive areas of more greenish colour (below freezing) covering much of the visible land area.

- those with an eye for detail may notice Lake Eyre which is currently full of water as a blue smudge in SA in some of the night-time frames.

 Hi Resolution Satpic: There is a false colour high resolution NOAA12 thermal satpic of 29 May 2000 at 1838 UTC (30th 2:38 am AEST) downloaded from the CSIRO where you can see the effects of the current cold snap on SE Australia. The URL is: http://www.ace-net.com.au/~carls/Images/SE291838UTCc.gif

The colours show infrared temperature in 256 steps from white to blue for 'hot' areas (there are no white land or sea surfaces in this image - it is too cold!), with freezing point being a bluish-green, green is below freezing, and yellow to red to brown to black for very 'cold' cloud tops. The relatively warm ocean is blue, with a warmer lighter-blue current visible flowing down the E coast. In contrast, the now cold land surface is bluish-green around freezing point, with the more greenish parts being sub-zero.

The banded green cloud areas across much of NSW are showing areas of snow falls on the higher ground and sleet/rain in lower areas as the cold frontal bands move through. The mottled green areas along the S coast indicate snow showers to lower levels, which are quite heavy in the yellow patches over the ranges N of Melbourne, and had recently been a heavy hail storm in Melbourne, and the yellow-red areas in Port Phillip Bay showing more hail storms that were about to hit Melbourne as this satpic was taken.

The yellow-red-brown-black area extending over the NE Highlands of Vic and the Southern Highlands of NSW indicates the likelihood of blizzard conditions in the high country, with heavy rain on the coast and out over the Tasman Sea.