Victoria - September 2000 Forecast Outlook, Discussion & Report Page



September 2000 Forecast Outlook, Discussion & Report Page Victoria
Date	Name	Information
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30	Dane Newman (Kilsyth)	Squall line just came through Kilsyth (6.35pm) with very heavy rain and small hail and very squally winds. We had 5mm of rain in 5 minutes but no thunder or lightning. Temperature has now (6.45pm) dropped back to 11c.
30	Jane ONeill (Bayswater)	As the front went through I recorded a rain rate over a period of 5 minutes equivalent to 130mm/hr. A burst of small hail at the end of it too. 10.5mm rain total.
30	Lindsay Smail (Grovedale)	Storm front reached Geelong around 4.45 pm and contributed westerly gusts of 114 kph at Lovely Banks, 111 kph at Point Wilson, 90 kph at Mt Duneed and 75 kph at St Albans Park. Much tree damage at Drysdale-St Leonards area of Bellarine Peninsula but no structural damage has been reported as yet although I'd be surprised if a few roofs didn't succumb. Short hail burst at Grovedale (5.15 pm) and lightning reported from St Leonards around 5.30 pm. But only 5-6 mm of rain generally.
30		Radar loops of the squall line that went through Melbourne
30	Clyve Herbert	Hello weather enthusiasts. A deep low west of Tasmania on Saturday will move to the south east of Tasmania by Sunday. The associated fast moving cold front will pass across the south east of South Australia, Victoria, Tasmania and southern New South Wales during Saturday and early Sunday. A colder southwest to westerly airflow will then affect the southeast of Australia including Tasmania. The baric ridge will strengthen in a line extending from just south of Perth to Adelaide on Sunday then extending a ridge across northern Victoria towards Sydney from Sunday to Monday. The coastal fringe of south east S.A and Victoria will probably remain in a westerly flow until at least Monday . Tasmania should remain affected by a moderate to strong Westerly flow throughout the forecast period. RAINFALL...The cold front on Saturday should bring general showers across southeast SA ,Victoria and Tasmania. Heavy falls are possible over western Tasmania, isolated thunderstorms are a risk over western and mountain areas of Tasmania and southwest Victoria on Saturday, there is also a slight risk of thunder over central Victoria and along the Victorian alps. With a strengthening ridge pushing towards south east Australia later Sunday, showers should then contract to southern coastal areas of south-eastern SA and Victoria and tend to drizzle patches. Tasmania should remain in a showery westerly flow until at least Tuesday. TEMPERATURES.... A colder air mass will reach the south east of Australia later Saturday, much cooler conditions will affect this region until at least Monday,Tasmania may see very cold conditions later Saturday and Sunday, night temperatures over sheltered inland areas of southeast Australia may become cold enough for light frosts. Snowfalls should affect higher ground of Tasmania later Saturday and Sunday, some snow may also develop over the higher Victorian mountains later Saturday and briefly Sunday possibly down to 1100m. The north of Australia will remain very warm with isolated storm activity throughout the forecast period. RISKS... Strong winds should affect southern and mountain areas of Victoria and Tasmania Saturday and early Sunday. Storm force winds may affect the southwest of Tasmania Saturday. Clyve Herbert and Geelong Weather Services.
29	Clyve Herbert	The prefrontal trough passed my home (Leopold,Geelong.) at around 0600 this morning with patchy rain, but was typically composed of very high based altocu / altost some embedded "altocumulonimbus", I estimated cloud base about 13.000 to 14.000ft all of this mid level stuff was occurring above the FZL which I guess was around 11.000ft. The actual cold front passed my location at 1110hrs local with only a narrow band of congesting cu and low top cbs but a wind gust of 85kph. There appears to have been marked dry air incursion below 10.000 with inflow ahead of the pre frontal trough rather common in this area.
29	Harald Richter (USA)	A band of thunderstorms has persisted for the better part of the night between Swan Hill (VIC) and Renmark (SA) in extreme NW VIC. Along the surface the storms occur in the NW corner of a surface moisture tongue extending N from MEL, and right along a baroclinic zone that locally extends E-W. According to the AVN initialised 12Z on 28 September, a strong mid-level/upper-level jet is nosing into the area (at 21Z) which might explain the longevity (and hence organisation) of the electric action. The AVN claims that the area of interest is (once again) CAPE-free, and the MEL radar composite probably overshoots most of the stuff as evident in the faint radar reflectivity. This goes to show that there is a possibility that radars do not clearly show existing storms, and that storms can exist in zero-CAPE AVN atmospheres (the same is probably true for other models).
27	Clyve Herbert	Hello weather enthusiasts. After some very useful rain across south eastern Australia over the past several days the synoptic set-up is again on the change. The large high east of Tasmania will edge further eastward today although will maintain a weakening ridge up the Queensland coast until later Thursday or Friday. For the rest of Australia a broad trough will persist across most of the continent and a series of cold fronts will effect the southern areas of Australia during this time. The baric ridge will remain very weak and ill defined over the Australian mainland. The centre of high pressure well west of Western Australia today (Wed 27.09.00) will push a weak ridge towards Port Headland, however the heating of the land areas of Australia will repel this advancing ridge, although a weak baric ridge may be detectable extending from near Exmouth towards central Queensland over the next two days. Frontal passages across south eastern Australia later Wednesday will bring general cloud and patchy rain, local storms are also possible, the persistent trough should see a continuation of showers through Thursday and another cold front later Friday will bring further showers, possibly tending to longer outbreaks of rain, mainly in southern and mountain areas of Victoria and Tasmania.Indications for the early part of the weekend show the possibility of a cold air mass invading much of the south east of the continent with the possibility of highland snow. Areas favoured for rainfall over the next three days are the southern and south-eastern areas of south Australia most of Victoria especially the highland areas and the Otway ranges, most of western and higher areas of Tasmania. Interesting Features. A large tropical disturbance about 1000klm east of Cairns is worth keeping a check on over the next two days, this system has a huge area of cloud associated with it, there is strong outflow on the south-western flank where the 300hpa 30.000ft level winds are interacting with the tropical moisture. Regards Clyve Herbert and Geelong Weather Services Victoria Australia (n.m.p.)
24	Andrew McDonald	Things have taken a turn for the better for early this week. Originally the trough and low currently developing in SA was forecast to blob across Victoria giving us E to SE'ly winds on Monday and Tuesday with moderate rainfall totals looking possible. The latest model runs have changed quite significantly with the trough of low pressure to slow significantly and move more SE (rather than ESE) before tracking E across Victoria on Tuesday. At the moment it looks at though an area of patchy rain and embedded isolated thunderstorms will develop in far NW Victoria on Sunday night and extend across Victoria on Monday and clearing to the E half of the state overnight Monday and into Tuesday. A detailed check of the models reveals a nice upper shortwave trough pushing through Tuesday which could make for some interesting weather. It looks to be a very similar situation to October 9th/10th 1999 where the rainband cleared overnight and allowed for enough heating for storms to develop behind the rainband in the moist air. At the moment AVN is going for a lifted index of -5 in central districts and CAPE up to about 1200j/kg in central districts of Victoria and forecast soundings have put a temperature of -20C at 500mb and -50C at 300mb. Shear looks to be OK and I wouldn't be surprised to see some severe storms pop up (with large hail and damaging winds a real possiblity given current figures). One thing to note is that on October 10th 1999 a dry line developed in western Victoria in very similar circumstances so keep an eye out for this feature to develop again.
23	Clyve Herbert	Hi all weather People. The persistence of a trough over Western Australia and South Australia over the past several days has been progressively forcing the high pressure belt towards the south, although a moderate strength high covers Victoria today (Saturday 23.09.2000) this high pressure area is being dissected by an upper trough and cloud band. The high over Victoria should move further south today with a new centre favouring the area west of Tasmania on Sunday. It appears then that a persistent trough should move from South Australia towards Victoria and will probably effect the south east of the Australian continent for the next few days. The baric ridge by Sunday should extend from west of Tasmania towards the central Tasman sea, this set up may also bring cloud and showers onto the east coast of NSW under the influence of a northeast to southeast flow. Elsewhere across south eastern Australia persistent mid and upper cloud generated by the trough may bring outbreaks of rain and isolated storms over the next several days. Temperatures across the interior of almost all of Australia should remain very warm through the next few days, isolated storms may effect the far top end of the Northern Territory during this period. Under the influence of the trough south eastern Australia should remain on the cool side although with increasing humidity. Favoured areas for rainfall over the next several days are the south east of Australia including Victoria the southern areas of South Australia and along the southeastern high country and along the central coastal areas of NSW. Isolated storms are also possible across the south east of the continent over this time period. Risks .... The possible development of a major cut off low pressure area near to the south east of Australia over the next three days may enhance the risk of heavier rainfall over this region of Australia. Clyve Herbert and Geelong Weather Services.
22	Paul Graham (NSW)	Whichever model you go by, it looks like we'll have some interesting thunderstorm weather ahead for the eastern states. The EC has the most dramatic situation, predicting a deep low to form south of Adelaide on Wednesday night with an upper cold pool and thicknesses down to the 530's. This would suggest excellent thunderstorm weather for Victoria and eastern Victoria (and may be a repeat of September 29, 1996) followed by snowfalls along the ranges in the south. Meanwhile, both GASP and NGP have a similar situation in terms of no significant upper cold pools, instead having a low forming through Victoria with a belt of high pressure to the south. NGP predicts an area of moderate to high rainfall through Victoria and southern NSW on both Tuesday and Wednesday as a couple of upper troughs move through and GASP agrees, showing a significant upper trough with the low on Tuesday and some quite hot and humid air moving into the east of NSW. EC also has an interesting situation for Monday, although not quite as dramatic as its prediction for Wednesday/Thursday. I think, whichever situation eventuates, we'll see some impressive thunderstorms over the next few days.
20	Clyve Herbert	Hi weather enthusiasts. This current phase of high pressure across the southern coastline of Australia appears set to continue until the weekend. The baric ridge will be maintained in a line extending from just south of Perth to near Sydney. However this ridge will be weaker over the Australian region with higher pressure favouring the Indian ocean west of Perth.Rather weak cold fronts should effect Tasmania and the southeast of Australia on Thursday and again later Friday or early Saturday with showers, mainly over the south of Victoria and Tasmania. An interesting feature on Wednesday is the development of a trough over south Australia with a rather large area of mid and upper cloud. This system may combine with the weakening front expected over Victoria on Thursday and may bring scattered showers and isolated thunderstorms across South Australia Wednesday and into North west Victoria Thursday. Temperatures should remain on the mild side over the south east of Australia over the next several days, although clear areas over inland areas may experience cold nights especially early Friday.Very warm conditions should prevail over the interior and northern Australia through the period, isolated showers and storms may also effect the far top end of the northern territory during the late afternoons . Weak troughs remaining after the passage of mid latitude frontal activity over the south of the continent may effect the inland areas of NSW and south QLD with the possibility of isolated showers and storms mainly in north east NSW and south east QLD. Favoured areas for rainfall appear only to be the west coast of Tasmania where moderate falls are again possible there over the next three days. Clyve Herbert and Geelong Weather Services.
17	Clyve Herbert	Hello Weather People. The trend for high pressure to persist across the southern half of Australia continues for the early part of the week. An interesting development is the positioning of a high pressure cell well south west of Western Australia on Sunday - this set up may accelerate a cold front towards the Australian Bight on Monday and to reach Tasmania and the south east of Australia later Tuesday and Wednesday. Conditions should remain on the mild side over the southern areas of southeast Australia. Much warmer conditions should persist over the interior of the continent. The baric ridge will continue to extend from west of Perth across southern South Australia and southern New South Wales.The marked heating of the interior of Australia will however weaken this ridge over Australian Longitudes. The approaching cold front looks interesting for the south east of Australia on Tuesday especially if the high over the south Indian Ocean maintains its higher latitude position as it moves east. The favoured area for rainfall is the west coast and mountains of Tasmania there is the possibility of heavy falls there over the next several days. showers should also effect Victoria later on Tuesday.A lingering trough over the north east of N.S.W Monday should be watched for possible development especially during the afternoons and evening, with possible thunderstorms in those areas. Clyve Herbert and Geelong Weather Services.
13	Clyve Herbert	Greetings weather people. The southeast of Australia has moved towards a high pressure phase following the passage of a fast moving cold front on Monday. Indications are for atmospheric pressure to remain relatively high across the southern half of Australia for the next few days. Occasional troughs and cold fronts should generally be rather weak. A marked warming trend appears to be the likely scenario across southeast Australia over the next several days with brief cooling after the passage of a cold front Thursday and later at the weekend. The present high pressure system over southern N.S.W. should move slowly eastward, and the larger high in the east Indian ocean should "amoeba" eastward with its eastern ridge combining with the retreating high over the Tasman on Friday. The baric ridge should run from near Perth across south Australia to near Sydney during the forecast period. At this stage no significant rain appears likely anywhere across Australia, the moderate falls seem to favour the west coast of Tasmania from Thursday. Temperatures may move into the mid to high 20c range over low lying southeast Australia during the weekend and very warm conditions may be experienced over northern N.S.W. and inland S.A at that time. Cold fronts should affect Victoria on Thursday and later Saturday or Sunday. Precipitation should be light and of a showery nature with these systems. RISKS. Isolated thunderstorms may accompany the frontal passage on Thursday over Victoria. The marked warming trend may see significant snow melt over the higher Australia Alps over the next five days which may exacerbate the current high river levels in areas affected by heavy rain over the past week. Clyve Herbert and Geelong Weather Services.
10	TORNADO Paul Graham (NSW)	There was very active lightning through NE Victoria last night. Lightning extended up into NSW also but there was at least one cell in NE Vic/SE NSW that may well have been severe.
10	TORNADO Jane ONeill	Images of Milawa tornado damage - 2 pages of 15 images: Milawa - 1 Milawa - 2
10	TORNADO Nick Sykes	There was a report of a possible tornado in NE Victoria last night on ABC radio news this morning. The tornado has reportedly destroyed a shed, damaged a number of homes and uprooted a number of large trees. A damage assessment team from the SES is on the way to assess the damage. The tornado occurred at 7pm last night. Eye Witness accounts describe a funnel with debris. An interviewee described how the funnel turned as it entered his backyard and hit his neighbours.
7	Blair Trewin	With the major caveat that some of these may well warm up considerably during the night or tomorrow morning, there have been some quite low maximum temperature to 1500 over Victoria and southern NSW. Many Victorian sites have not (yet) reached double figures, which takes some northern Victorian sites into unusual territory - Kerang's current maximum of 10 would, if it ends up being the maximum, be its second lowest on record for September. Canberra (9) is also currently looking at its coldest September day since 1985, although I'd be surprised if 9 ends up being the maximum.
7	Clyve Herbert	Greetings weather people. The high pressure belt will continue to be weak across the Australian region. The tendency for deep lows to move to relatively lower latitudes should persist with active weather systems continuing to affect southeastern Australia and Tasmania until at least Sunday, when a rather weak ridge should settle things down briefly, until the arrival of another trough and cold front Monday or early Tuesday. A deep low should advance towards Victoria on Thursday. The accompanying trough and cold front will be preceded by extensive cloud and rain which should mostly be light to moderate but a few heavy totals should affect mountain areas. Isolated heavy falls may also affect parts of southwest Victoria. This system should move eastward by Friday with a showery west to southwest airflow to follow with a few heavy showers in southern and mountain regions. Isolated thunderstorms may occur with this cold airstream especially near to the southwest coast. Showers should continue Saturday and may be reinforced by another cold front. The north of Victoria should become mainly dry by later Saturday. Sunday should see a weak ridge bring more settled conditions although cloud may persist in southern coastal areas. Monday should see the approach of another trough with strengthening north winds and further showers or patchy rain. RISKS. The deep low pressure trough approaching Victoria on Thursday may see a low pressure system passing close to the Victorian region. This occurrence may enhance rainfall across most of the state with the possibility of scattered thunderstorms. Snowfalls should redevelop along the higher (above 1400m) divide later Thursday with some moderate to heavy falls possible. Snow may descend to lower levels on Friday with areas as low as 900m receiving a few snow showers. Temperatures are expected to remain below average on Friday and Saturday with the possibility of light frost in sheltered northern areas. Further heavy falls of rain may affect the Otways and western Tasmania during the next few days. Other areas of potential heavy falls are the northeastern divide. Clyve Herbert and Geelong Weather Services.
5	Andrew McDonald	The models are forecasting a low pressure system to develop somewhere W of Victoria and the debate is on as to where it will form. Most models are putting it SW of Vic and W of Tassie but Anthony and I both feel that there is potential for it to develop further N than forecast due to the warm air being dragged down from the NT/WA heat trough. NGP put the low at 976hPa ON the west coast of Tassie on Thursday and GASP had it further S. AVN is just coming to the party and should have a full Thursday run up by tonight but yeah - Thursday could get very very interesting. BoM haven't done much with Thursday yet....going for showers (and windy I think)....but if NGP gets close we should see pressure get close to 992hPa here in Melbourne with gale-storm force winds across the state - particularly in S and mountain areas. 850mb winds on Thursday are currently expected to be in the 45-55knts range which will bring gusts up to 70knts (i think). AC is doubtful that it will get to 976hPa but it depends on how early the low forms and intensifies. A significant trough should develop into the "cut-off" low somewhere in the E half of the Bight by mid-late Wednesday and move rapidly ESE or SE. Whatever happens, things should get very very interesting by later Thursday down here. As it is so fast moving I don't think we can expect HUGE rainfalls from it but because of the nature of these systems it is likely that we will get 30-40mm in some areas. As for storms - not too sure yet - depends on too many things and its still a little too far out to say. On a bit of a different note we should all keep an eye on the potential of the flood situation in the NE of the state with rivers already hovering around the minor flood level and the ground is very sodden according to reports from Rutherglen and Corowa. Once the snow starts to melt, its not going to take much to set off a BIG flood up in the NE. I don't know who said this but someone said that the current snowfalls relates to about 7 inches of rain. They have been getting falls of 20-30mm fairly regularly which is keeping the rivers at or just below minor flood level already. The next 6-8 weeks will be interesting to watch to see what happens. A slow moving trough dumping 60-80mm in two days over the area would just about do it I think.
1	Clyve Herbert	Greetings weather people. The high pressure belt will continue to be rather weak across the Australian region for the next few days. The baric ridge will favour a line extending from near Carnarvon, WA across just north of Alice Springs and central QLD. Due to surface heating now starting to increase across the interior of Australia this will deter high pressure strengths with the main centre favouring the Indian Ocean west of Perth. This is good news for Victoria as this synoptic setup will allow a persistent and frequent procession of cold fronts and troughs throughout the coming week. A trough due on Friday night across Victoria will bring general patchy rain and local thunderstorms. Some moderate falls are possible mainly in western and mountain regions. This cloud band will move east of Victoria on Saturday, but will be followed by another trough Saturday night and Sunday morning with further showers and isolated thunderstorms. This system may bring heavier falls to the central district of Victoria. Sunday should see this trough move east and be replaced by a showery northwest to southwest flow ahead of another trough and low pressure system on Monday with further general rain local thunder and a few moderate to isolated heavier totals. A colder southwest to westerly airflow will follow on Tuesday with showers and isolated thunder. Showers should continue for most of the week with sporadic frontal activity. Temperatures. Friday should see a brief warmer trend before the arrival of the cold front overnight into Saturday. A progressively colder trend will follow through to next week with the coldest air arriving probably after Monday or Tuesday. Snowfalls will become more prevalent along the ranges from Saturday above 1400m and progressively lowering closer to 1000m by Tuesday. Some heavy falls are possible from Monday above 1400m. Rainfall over this period should be moderate over low lying southern areas of Victoria. Some heavier falls may occur over elevated mountain regions and the Otways. The Otways appear favoured for good falls over the next week with totals possibly approaching 100mm during this period. The west coast and mountain regions of Tasmania may also experience heavy to very heavy falls over the next week. Clyve Herbert and Geelong Weather Services.