February 2002 Forecast Outlook, Discussion & Report Page

Victoria

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March Forecast Outlook, Discussion & Report page

Future Developments: The high in the Bight will ridge slowly eastwards over the next few days before reaching the Tasman Sea early in the week. The baric ridge will shift slightly northwards to lie over Victoria. The front moving through NSW will move into the northeast corner during Thursday. The area of convective activity in the eastern Coral Sea is moving southeast with decreasing central pressure. Ridging along the coast will block the eastwards movement of the inland Queensland trough & it may then move westwards for the next day or so triggering showers & storms along the troughline as well as in the moister air to its east.

The monsoon low in Western Australia looks to finally make ocean-fall over the next day or so.  The high in the Bight will direct an SE-E surface flow onto the southern WA  & SA coasts. The large area of moisture which originated from this low in has moved east and southeast during Tuesday and Wednesday & should continue to progress across the southeast of the continent under the influence of the subtropical jet during Thursday, which should see the cloud reach as far south as the Victorian ranges. The interaction between the front moving through the Bight & this rather large band of tropical moisture may also trigger showers & storms.  A series of fronts will pass over Tasmania during the next couple of days.

Potential Risks: Possible light falls of snow on the Tasmanian highlands may be triggered as a series of fronts moves east. Keep an eye on the continuing development in the areas around Suva & also northeast of Papua-New Guinea.

Rainfall potential
Victoria: Possible light showers along the coast, becoming more frequent south of the ranges with the passage of a front later Thursday.
NSW: Showers & isolated storms in the northeast quarter with occasional showers & just the risk of a storm along the southern & central coasts in a moist onshore flow.
Queensland: Isolated seasonal storm activity over the tropics. Showers & storms associated with the trough through the west of the state.
NT:  Isolated showers with the possibility of a storm over the Top End and western districts.
WA:  Continuing showers & thunderstorms with some heavy falls in the Pilbara, Goldfields & central areas of WA.  Drizzle along the southern coast.
SA: Showers & isolated thunderstorms north of ~33S in the moist ex-monsoonal airmass
Tasmania: Isolated showers becoming more frequent with possible light snow in highland areas.

Future Developments:   The ridge of high pressure extending through the Bight will initially strengthen, then weaken slowly as it moves east through Bass Strait.   The trough through southern New South Wales will move northeast triggering occasional storms with its passage. Increasing levels of moisture from Western Australia are being drawn into the trough which lies from the west of Queensland to the southeast corner & triggering storms along its length This Queensland trough is expected to remain quasi-stationery for the next day or so.

The WA heat trough will reform off the coast during Wednesday while the monsoon low edges ever closer to the Indian Ocean.This system is injecting large amounts of moisture into the area between 20S & 30S which will be transported east over the next few days. A series of weak fronts will pass through Tasmania during the remainder of the week bringing wind shifts towards cooler SW with passing showers.

Potential Risks: The monsoon low affecting much of central Western Australia may trigger widespread rain with occasional heavy falls in the Pilbara which may extend towards the SE of the state during Wednesday & Thursday.  A large area of strong convection to the NE of Papua - New Guinea is worth keeping an eye on for further development over the next 24-36 hours.

Rainfall potential
Victoria & Tasmania:  Showers with passing fronts through Tasmania.   Victoria should see drizzle along the coasts with mainly fine weather north of the ranges.
NSW: Scattered showers in the north & northeast of the state, with isolated storms east of the trough becoming more frequent close to the trough, especially in the southeast & central areas.
Queensland:  Isolated storms in the southeast moving east.  Coastal showers along the east coast with storms extending from the NW to the SE along the trough.
NT:  Seasonal storm activity in the Top End with the possibility of isolated storms in the southwest.
WA:  Widespread heavy falls in the west between 20S & 30S primarily, possibly extending to the Goldfields district. Drizzle in the southwest along the coast clearing.
South Australia: isolated showers & storms in the NW may be expected as the moisture from WA is drawn E-SE.  Isolated light showers along the coast in the onshore S-SW flow.

Future Developments:  The trough through southern parts of eastern Australia will continue to move eastwards. The weak trough currently through Queensland from the central west to the southern interior will remain almost stationary through much of the week triggering isolated storms . The low over the Pilbara, which is moving very slowly west along the ITCZ,  is expected to weaken, but is currently showing signs of restrengthening(?) both at the surface & in the middle levels. The high ridging into the Bight will strengthen for the next day or two bringing a S-SE onshore flow to South Australia and southern parts of Western Australia. The front moving through Tasmania & the southern part of Victoria will swing the winds around to the SW during Tuesday moderating temperatures particularly south of the ranges. 

Potential Risks: The redevelopment of the low over the ocean to the west of Western Australia may again increase shower & storm activity.

Rainfall potential
Victoria & Tasmania:  Showers are likely extending throughout Tasmanian with the approach of a front.  Possible storms as the front moves east. Showers & possible thunderstorms in the east & possibly central parts of Victoria through Tuesday, moving east.
NSW:  Areas of rain & isolated showers particularly east of the trough & in southern & central parts of the state.
Queensland:  Isolated storms in a band from the central west to the southeast.  Possible heavy falls in the SE. Seasonal storm activity over northern tropical areas. Isolated showers along the east coast becoming less frequent.
NT:  Isolated showers and storms likely throughout the NT.
WA:  Seasonal storm activity primarily in the Pilbara, but isolated storms extending into the central & eastern parts of the state, mainly north of 25S. Drizzle along the southern coastline.
South Australia: Isolated showers along the coast.  Isolated storms continuing in the north.

Future Developments:  The trough through New South Wales will deepen and move westward as Tasmania splits the band of high pressure and the ridge along the east coast strengthens.  The trough extending south into Victoria will become absorbed into the major trough moving into the southeast of the continent during the next couple of days. The formation of an upper level low during in west / central Queensland may trigger some heavy falls. Moisture will continue to move east & south east from the area around the monsoon low in Western Australia for the next few days, increasing the risk of shower & storm activity over much of central & eastern Australia. Seasonal storm activity will increase across northern Australia with the weakening of the monsoon trough.

Conditions in Western Australia will remain hot on the eastern side of the trough with slightly milder temperatures following its passage. Fine & hot conditions in southern parts of South Australia will moderate as a milder onshore airstream develops west of the trough with the approach of the next high, while the northern part of the state is expected to remain cloudy & showery.

Potential Risks: The area southwest of Suva continues to show strong possibility for TC development.  There is a risk that an upper disturbance may develop over South Australia midweek.

Rainfall potential
Victoria & Tasmania:  Tasmania should be dry!! Victoria may see scattered storms in the east during Monday. Risk of storms in the NW late Monday & into Tuesday.
NSW:  Isolated afternoon showers & storms east of the trough, with occasional showers along the coast, mainly in the north.  Patchy rain in the northern inland will continue.
Queensland:  Seasonal storm activity in the tropics, with isolated showers along the east coast becoming less frequent early in the week.  Patchy rain through the south will continue early in the week with occasional heavy falls.
NT:  Showers with occasional storms, mainly in the east & the Top End.   Showers continuing in the Alice.
WA:  Seasonal storm activity through the Kimberley & Pilbara with showers extending south & southeast over the next 48 hours.  Drizzle along the south coast as the front passes to the east.
South Australia: Showers continuing in the north & extending to central areas.  Isolated storms possible in the northwest.

Future Developments:  The trough over NSW will move slowly west during Sunday as the high strengthens in the Tasman. The ridge along the Queensland coast is expected to strengthen & the trough will move west triggering scattered showers and storms in the west of the state through Sunday. Seasonal storm activity will continue across the tropics with the weakening of the monsoon trough. The band of tropical moisture extending from Western Australia will continue expanding east & southeast over the next day or so in response to the upper jet.  A weak front will pass to the south of WA during Sunday. Temperatures will moderate west of the heat trough early next week as it moves east.  Temperatures through South Australia, Victoria and Tasmania will increase as the winds swing around to the NE.

Potential Risks: The development of an upper level low during Sunday / Monday in west / central Queensland during the early part of the week may trigger some heavy falls.  An increase in available moisture over much of northern Western Australia & into the southern part of the Northern Territory & northern part of South Australia should be monitored as it expands southeast & east over the next couple of days.  The strongly convective area northwest of Suva is continuing to show signs of improved organisation & should be watched.

Rainfall potential
Victoria & Tasmania:  The possibility of isolated storms on the far NE ranges Sunday, but more likely Monday. Patchy drizzle in Tasmania clearing.
NSW:  Isolated showers along the coast, particularly in the north.   Isolated storms inland east of the trough particularly in the north.
Queensland:   Possible heavy falls in far west, central & southern inland Queensland.  Isolated showers along the coast in the SE flow.  Isolated storms in the far northern tropics.
NT:  Scattered showers & storms across the Top End.  Areas of patchy rain continuing in the south.
WA:  Areas of heavy rain in the Kimberley & Pilbara extending SE over the next day or so.
South Australia: Rain areas in the north for the next couple of days with isolated storms developing further south during Sunday & Monday.

Future Developments:  The baric ridge will strengthen during the next couple of days and then shift south over the weekend to lie through Bass Strait.  The high in the Bight will position itself over the SE of Australia during the weekend.  A trough developing southwards through inland NSW late Saturday, early Sunday will extend into NE Victoria with possible storms.  Showers & storms are expected to become more widespread through inland South Australia (!!) under the influence of the monsoon low &its moist outflow.

Potential Risks The monsoon low over the Kimberley continues edging towards the Indian Ocean & is maintaining its 'TC' signature. Possible sleet on the higher parts of Tasmania Thursday night. Possible storms in South Australia!

Rainfall potential
Victoria & Tasmania:  Isolated drizzle along the coast in the morning for Victoria, fine elsewhere.  Tasmania will have showers in the SW stream with isolated sleet on the higher parts clearing as the coldest air moves through tonight & early tomorrow.
NSW:  Showers & isolated storms contracting NE with the trough.
Queensland:  Increasing showers along the northeastern tropical coast with rain areas south of the Gulf contracting to the northwest.  Showers & storms in the SE under the influence of the trough.
NT:   Scattered showers & storms mainly in the western part of the Territory north of Tennant Creek.
WA:  Rain areas in the Kimberley with locally heavy falls & isolated storms, extending into the Pilbara.
South Australia: Scattered showers along the coast clearing early Friday.  Showers & isolated storms remaining over the north of the state under the tropical outflow cloudband.

Future Developments:  The high in the Bight will maintain a SW flow over southeastern Australia during the next day or so. Showers will be more frequent across Tasmania & the coastal fringes of SA & Victoria, while north of the ranges in Victoria should remain mostly fine.  A series of deep lows will pass through the south of the Bight over the next few days while the high will ridge through Bass Strait.

Potential Risks The monsoon low currently moving westwards along the ITCZ is beginning to develop a 'tropical low' signature & should be monitored as it approaches the Indian Ocean.  There is a very small risk that a wave low may develop off the far south coast of NSW  or east of Tasmania early Thursday.

Rainfall potential
Victoria & Tasmania:  Stream showers over Tasmania & southern Victoria can be expected over the next day or so. 
NSW:  Showers & storms contracting NE.
Queensland:  Isolated coastal showers in a SE onshore flow with storms in the northern tropics as well as the SE corner, associated with the approaching trough. Some continuing heavy falls in the NW tropics.
NT:   Rain areas with scattered heavy falls, mainly over the Top End.
WA:  Widespread rain areas with thunderstorms throughout the Kimberley extending west under the influence of the monsoon low. 
South Australia:  There is a risk of isolated storms in the far north of SA under the influence of the cloudband extending from the NW tropics. Stream showers becoming less frequent in the SE corner.

Future Developments:  The trough continues to deepen as it approaches Victoria. Showers and scattered storms are likely to develop along its length as it progresses east. Temperatures will increase in inland NSW ahead of the trough.  Mainly fine conditions NE of the trough through northern NSW and SE Queensland under the influence of the ridge with isolated showers on the NE Queensland coast. Possible storms in the SW with the trough. Widespread rain & storms in the Atherton Tableland region and into the Northern Territory.  Warmer conditions return to WA as the heat trough reforms along the west coast during the next couple of days & the ridge building through the Bight strengthens the easterly flow. South Australia will see isolated showers in the southeast following the front & a general SW flow will become established except in the NE.

Potential Risks
There is a possibility that the high in the Bight may send a ridge to the SE of this low and keep it in our latitudes. Tasmania may see hail and possibly sleet at higher levels in the cold air following the front.

Rainfall potential
Victoria & Tasmania:  Early drizzle about the coast in Tasmania, with isolated storms midweek.  Victoria should see showers & storms developing with the passage of the front.  Scattered showers following the front.
NSW:  Isolated storms inland ahead of the trough moving from the SW possibly extending to the south & central coast. Patchy rain with the cloudband feeding down from NW WA.
Queensland:   Rain areas & scattered storms continuing in the tropics with some heavy falls in the northwest. 
NT:   Cloudy throughout with patchy rain and isolated heavy falls particularly in the north.  Thunderstorms more likely over the Top End.
WA:  Some seasonal storm activity to continue in the Kimberley & the Pilbara.
SA:  Showers & storms associated with the front are likely with coastal showers in the SW flow behind the front.  Patchy rain in the NE.

Future Developments: Clearing conditions in NSW as the trough moves slowly NE. An E-SE flow will continue to be directed onto the southern Queensland coast with only isolated showers while the tropical Queensland coast will see some heavier falls. The low over the NT will continue to move slowly west.  Temperatures in the SW of WA will moderate with an onshore  SW-S flow as the WA trough, & the front in the Bight move east.  Strengthening N - NW winds over South Australia on Tuesday & Victoria during Wednesday will see temperatures rise sharply from a mild start to the week before the passage of the front.  This trough looks to deepen as it approaches Victoria.

Potential Risks
Tasmania may see hail and possibly sleet at higher levels in the cold air following the front midweek.

The area to the north of Suva should be monitored for the possible development of a tropical cyclone over the next 24 hours.

Rainfall potential
Victoria & Tasmania:  Early drizzle about the coast in Tasmania,  with isolated storms midweek.  Victoria should see scattered showers & storms, developing midweek associated with this system. Storms on the far northeastern ranges in a humid NE flow are also possible Tuesday.
NSW:   heavy falls in thunderstorms persisting in a narrowing band through the north of the state are possible as the trough remains slow moving & also in the south as the next trough moves into NSW.
Queensland:   the monsoon low moving slowly west will trigger rain & scattered storms with some heavy falls during the next few days in the north.  Patchy rain can be expected from the cloudband extending SE from the monsoon low.
NT:   Cloudy throughout with patchy rain and isolated heavy falls particularly in the north.  Thunderstorms more likely over the Top End.
WA:  Showers in the SW behind the trough, with seasonal storm activity in the Kimberley & the Pilbara extending east.
SA:  Showers & storms associated with the front are likely. Scattered storms may persist in the far NE of the state.

500mb and 300mb temps aren't the best but I think there will be plenty of lift with the front, nice temp gradient.

Moisture is good at the surface with drier air up high. (major dry out ahead of the front)
Looks like there could be some cloud ahead of the front (i hope not). Quite moist up top ahead of the front.

Atm I think we will see an early morning cloud band, a clearance for a hour or so before the front and then a lovely squall line coming through (that's what I'm wishing for)

Main concern atm is cloud ahead of the front, either way a day to watch for.

Future Developments:  The trough moving NE through NSW will stall during Sunday over the central coast to mid-north coast. The strongly  convective area over the Gulf of Carpentaria is showing reasonable outflow, especially in the SW quadrant and should be monitored for futher changes. The West Australian heat trough will deepen and move eastwards into early next week & is likely to trigger showers & storms through the Goldfields, while a passing front will extend cooler conditions throughout the south. This ridge of high pressure is likely to weaken slightly during the weekend and into the early part of the week. The east Australian trough will stagnate over western Queensland over the next day or two, triggering isolated storms in that area as well as through the northeast of South Australia as the available moisture increases.  Showers are likely in the south & west of Tasmania early Sunday, contracting to the SW into Monday.  Temperatures should increase towards midweek.  Victoria should remain mainly fine and mild in a continuing southeasterly flow, with temperatures increasing towards midweek as winds become more NE-N'ly.

Potential risks: Storms are likely through the Hunter & north coast of NSW through Sunday - there is the potential for some of these to be severe with strong winds & hail. It looks likely that the tropical low over the Gulf of Carpentaria will deepen further during the next 24-48 hours if it remains over water.

Rainfall potential
Victoria & Tasmania:  isolated coastal showers or drizzle are possible on Sunday and Monday mornings, clearing through the day while remaining fine north of the ranges.   Showers along the west & south coasts of Tasmania will contract to the southwest, before becoming more frequent midweek
NSW:   NE NSW should experience some heavy falls in thunderstorms during Sunday.
Queensland:   the tropical areas of Queensland are expected to receive moderate to possibly substantial falls over the next few days.  The east coast will experience only scattered showers while the trough to the west may trigger some locally heavy falls.
NT:   Scattered showers and storms throughout the NT may produce occasional locally heavy falls.  Storm activity is likely to be more widespread through the Top End than the Alice, although storms are possible.
WA:   Isolated storms near the trough, mainly in the north & through the Kimberley.  Light showers in the far south into the early part of the week.
SA:  Possible storms through the NE of the state through most of the week, with the chance of falls to the west toward mid-week

The upper temperatures will be quite warm (from my understanding of storm situations down here), 500mb temps are only progged down to -11 to -12C. This concerns me a little, not so much the warm upper temps - but -6 LIs with -11C at 500mb and surface temps in the mid-high 30s (even pushing 40) is equating to a mixed DP of 15-16C, which will be at the upper end of the potential tomorrow. There is a slightly moister slab of air sitting over the far east of the state and in SE NSW (can see it on the satpic), and while I'm very encouraged by the direct Tasman-Sea NE flow over most of Victoria, I still think (as is nearly always the case), moisture is going to be a problem. Possibly a double whammy - upper level moisture will be high and a lot of cloud has built up over SA over the past 12hrs, so that will be a waiting game to see whether or not that breaks up or not and how much of an effect that plays. I certainly would like to wake up to a nice skies of broken ACCAS though!

In saying this, I don't believe moisture will be such a problem to the extent that there won't be storms - they'll just be high based. 850 temps are warm (in the low 20s I believe at a quick glance) but the bottom layer will probably end up being super adiabatic anyway so the cap shouldn't become too much of an issue.

Shear is rather nice, particularly around Melbourne and the far SW of the state. Again off the top of my head from flicking through a few charts, surface 15-20 knots NE, back to NNW 20-25 knots at 850mb, NW 30-40 knots at 700mb, 40-50 knots WNW at 500mb and WNW 55-60 kots at 300mb. So some backing with height and good speeds, but the bases will probably be so high that they won't feel much of the low level backing.

I think that things will develop rather latish, eventually becoming isolated to scattered TS and perhaps a squall-type line behind it on a cooler southerly change. Upper temps will be warm, so hail may not be such a big issue - but still large hail is certainly possible. Storms should probably move too fast to give flash flooding (although a 5mm shower can flood Melbourne! <g> but the dry air could certainly result in a few nice dry microbursts. The high bases should hopefully provide a nice CG show.

I think the general thinking is that we will see the advection southwards of some moisture from NSW and Queensland where there is some exceptionally moist air a long way south and west (precipitable water near 50mm). With the front acting as a trigger and frontal passage expected through central Victoria late in the day, Victoria looks "primed" for some decent storm action. This scenario is mapped out by the model progs which all suggest widespread rainfall tomorrow... possibly locally heavy.

Now moisture continues to be a worry. AVN seems to be downplaying the amount of moisture coming into this system now.

A tricky one to predict, but critical on moisture input, without it it will be just hot and windy. The moisture has made it about as far south as Bourke atm, so a lot of work still to be done.

Concern for today: Apart from the fact that I have to work tonight (meaning storms will be spectacularly photogenic), I'm a tiny bit worried about moisture levels. I won't be around to look at the soundings for YMML and YSWG this morning but I noted yesterday that in the NW of the state the sfc moisture mixed out rapidly once things warmed up sending DP's crashing below zero. This indicated some dry air not far above the sfc. There is a possibility that the PBL has moistened up overnight but we won't know until the heating kicks in over the next 3-5hrs. A quick look at last night's sounding for YMML shows a nice (relatively) moist PBL and with upper temps progged to drop a bit today and warmer sfc temps we should see some activity if the moisture can maintain itself.

Some indicators are pointing at more activity tomorrow as well as Friday. Of note for Friday is the developing cloud in central southern WA - is this going to play a part in reducing the chances of a storm for Friday? More to come tonight/tomorrow.

Future Developments: The high in the Australian Bight will gradually move along the baric ridge south of Tasmania to the south Tasman Sea, initially weakening, then restrengthening midweek east of Tasmania.  This will strengthen the ridge along the east coast although it will remain rather broad.  The ridge will also continue to affect SE Queensland.  The tropical disturbance will continue to develop in the Coral Sea bringing coastal showers & drizzle will persist along the NSW coast    By mid week the east Australian trough will be deepening from inland NSW through to Victoria.  Increasing moisture along this trough should lead to late afternoon showers or thunderstorms.  The ITCZ should remain active across north Queensland, the Top End and the Kimberley, bringing outbreaks of rain with some heavy falls, particularly in the Top End.  The trough extending southwards through WA will deepen Tuesday & Wednesday when the southern portion gradually extends into South Australia.  Victoria will come under the influence of a NE - E flow as the high moves into the Tasman Sea although a relatively weak trough during Wednesday & Thursday may generate showers and storms along the ranges.  This trough will become absorbed into a more substantial trough moving in from South Australia during Friday & Saturday.

Potential risks: The ITCZ continues to be active across  the tropical regions of Australia with continued potential for tropical disturbances in the Coral Sea, Gulf of Carpentaria & off the NW coast of WA.  At the moment, upper level support tends to favour the development of tropical storms west of Darwin, although this will be improving over the Coral Sea and the Gulf region later in the week.

Rainfall potential
Victoria & Tasmania:     while there is the possibility of afternoon showers and storms on the ranges Wednesday & Thursday, and the risk of convective activity more generally on Friday, most regions should remain mainly dry with increasing temperatures.  Better prospects for precipitation are likely later Friday & Saturday across Victoria & Tasmania.  
NSW:   showers & drizzle persisting through the week along the coast & ranges.  The risk of high based inland storms along in the east Australian trough, remaining dry at this stage in the west.
Queensland:   tropical Queensland will see tropical showers with more prolonged rain areas for much of the week with some heavy falls possible.  Continued development in the Coral Sea through the week may pose risks to coastal areas although the presence of a weak ridge may deflect the TC to the S rather than to the SW. 
NT:   general moderate to heavy falls across the Top End, mainly dry in the central & southern parts although some risk of increasing instability in the south during Thursday & Friday with the possibility of storms. 
WA:   moderate to heavy falls across the Kimberley as a tropical low drifts slowly westward.  Significant falls are possible.  Risk of developing cyclone NW  of the Kimberley later Tuesday through Thursday. If this occurs, the risk may extend southwards along the coast to the Pilbara.   Elsewhere, isolated storms through the Pilbara extending to the Goldfields. 
SA:   the passage of a trough through SA during Wednesday through to Friday may generate localised high based shower & storm activity

Areas to watch: the mid & upper level baroclinic region in WA which marks the position of an upper trough.  The low pressure area in the Coral Sea for improving organisation & divergence aloft.

Widespread shower & storm activity over the Top End & northern WA.  The WA heat trough will deepen just off the coast, and together with the high in the Bight, will direct  E-NE winds across much of the state maintaining fine conditions except possibly in the southern Pilbara & Gascoyne where moisture levels are on the increase. South Australia will continue to have unseasonably cool temperatures with drizzle along the southern coast through Sunday.   The mid-level 'cool pool' in the Bight south of the WA-SA border should be watched for signs of destabilisation as it approaches SA during Sunday.  Showers over Tasmania clearing through Sunday.  Unseasonably cool conditions in the SE of the country. Victoria should also see showers through Sunday, with possible hail & thunder in the south as the mid-levels cool behind the front.

The influence of this trough extends through to the southern part of the Top End. A drier S-SW flow will become established as the trough clears southern & central Queensland & moves northeast. Tropical storms continue through the weekend & the monsoon trough remains active over the Top End, while seasonal storms will redevelop in the northern parts of WA with the clearing of the area of the influence of ex-TC Chris.  The heat trough will deepen down the west coast while the high in the Bight will continue to direct a cooler, showery SE flow onto the southern coast & much of South Australia.  Weak front passing Tasmania through Saturday should trigger showers over the southern parts especially.

Areas to watch: .... the cloud patch in the Indian Ocean near to the WA coast for a developing upper disturbance as the area captures an infeed of moisture from TC Francesca.  The upper low SW of WA is also expected to capture some of this moisture during early Saturday.   The interaction between the cloudband  returning from the Tasman across the NSW coast & eastern Victoria due to the interaction between the upper level circulation & the surface trough may see some heavy falls.

No Otways site got over 100 (although the flood warning that's just been issued for the upper Barwon says rainfalls of up to 64 metres have occurred in the catchment!). The heavy rains at Aireys Inlet and surrounds seem to have been the result of local storm activity (Aireys got 73mm between 0400-0700 this morning) rather than more general onshore flow.

Also, I notice that the models are starting to get a little more bullish about the follow-up cold front on Sunday, with thickness values now being progged to drop to around 540-548 over southern Victoria late Sunday. At the colder end we could see some heavy rain and hail showers develop and possibly some cold air thunderies (given the "warmth" of bass strait and the bays), and even some snow flurries around the peaks of Lake Mt and Baw Baw...

Then AVN has a 70 kt jet nosing into the Mildura region at 500 by 06Z, putting us into the right forward quadrant supporting lift. A reasonably sharp surface wind change / trough has set up in extreme SW VIC, extending from Warrnambool through Casterton into SA. A meridionally oriented line of convection is approaching the longitude of Cape Otway to Colac, but the lightning tracker shows (almost) zilch? The inland BL airmass E of the wind change averages surface parcels around 24/11. Enhanced sea breeze/bay breeze convergence is setting up from W of MML down the coastline past Geelong, with convection located between Geelong and Anglesea.

The Cape Otway-Colac line and SW Geelong convection is the obvious "cat-in-the-bag" play for today. The best air would be nearer the coast, maybe right along the sea breeze front. I wonder whether the combination of stronger upper-level flow and higher surface T,Td is going to produce something bigger in NE VIC later?

Or, what about the good W Gippsland moisture later?

As for storms... these certainly look quite likely this afternoon, though I would expected a rapid change over to more general stratiform rain this evening.

The northern part of the country will be under the monsoonal influence which is steadily becoming more active, with widespread seasonal showers & storms, particularly in the east.  Outflow from 'Chris' covers the northern half of the continent. Widespread heavy rains are likely over the Pilbara & west Kimberley area, extending south & east through Thursday. Hot E - NE winds are directed across southern WA and into the heat trough located off the west coast.  The ridge through the Bight will maintain  cooler conditions on the southern WA coast. There is a risk that some mid & upper level moisture from 'Chris' may be drawn towards the SE of the continent as the 300hPa jet strengthens along its southern edge.  This could affect the northern parts of South Australia where there may be rain periods, while in the east there is a risk of isolated storms under the influence of the deepening trough.   Scattered showers for Tasmania.

I will certainly be watching the skies thursday. Interesting to note AVN now has CAPE values exceeding 1000 over Melbourne at 9Z Thurs...(not the most reliable) With the upper levels as cold as they are and with potential for high CAPE values, large hail could be a feature.

Will be interesting to see where the trough is positioned at prime time Thursday (5-7pm).

I'll be watching from the comfort of my computer room, keeping an eye on the TC (no pun intended) and also on today's convection in the W of the state.

Tomorrow is another matter. Tomorrow (Thurs) is looking *extremely* interesting IMO. A strong shortwave upper trough is progged to enter the W of the state during the afternoon. The sfc trough is progged to deepen further tomorrow and progress E'wards across Victoria, sitting close to Melbourne by about 8pm tomorrow night. NE to N'ly sfc flow into this trough should bring in some additional moisture. I'll be happy if I wake up to 13-15C DP's tomorrow across central districts. 850 temps are progged to be between 10 and 14C (depending on which model you believe) giving potential sfc temps of about 26-34C across the state. Given those temps, the cap should be moderate, supressing convection until mid afternoon. The upper level shortwave trough will see upper level temperatures cool to -17C at 500mb and -44C at 300mb (which is very nice for this time of year). Of note is the comparison b/w the YMML and YMTG soundings today. The YMML sounding is relatively moist all the way up whereas the YMTG sounding is quite dry above 800mb. If this dry air moves across western/central Victoria tomorrow (quite likely) we could see some very interesting storms develop. Shear is again marginal although IMO better than Friday just gone. The shear is strong enough IMO for organised storms to develop especially along the trough and other localised boundaries which may exist (ie the sea breeze). Given the progged shear, storms should move more ESE - E'ly tomorrow. There is also a chance of storms on the E and NE ranges tomorrow as well but these storms will be forming in a weakly sheared environment with somewhat less instability than the areas close to the trough. I think the best areas tomorrow will be along the trough given the upper level support pushing in. I'll be looking in the morning for places with additional moisture and as the day goes on also the sfc temps (the higher the better in both cases). Severe storms are possible in the eastern parts of the Western, Wimmera and Mallee districts and Central, North Central and Northern Country districts tomorrow for large hail (given the upper level temps and dry air I'd think hail to golf ball size is not out of the question), damaging winds (in the form of straight line winds and also a very slight chance of tornadoes) and also heavy rainfall is possible. There is also a *slight* chance of severe storms over the North East and Eastern districts for very heavy rainfall (given the weakly sheared environment but the moist sfc air).

TC Chris will cross the coast during Tuesday night / Wednesday morning & remain slow moving over land.   Widespread heavy rains are likely over the Pilbara & west Kimberley, while the trough along the west coast shifts southwards, maintaining a hot easterly flow & isolated storms in the SW of the state.  The high in the Bight ensures that   South Australia remains mainly fine under a SE-E flow, although there is the likelihood of  an increase in mid level moisture in the east of the state later Wednesday.  This moisture, together with cooling mid levels will lead to a destabilisation of conditions in the west of Victoria later Wednesday with isolated storms developing. There is a chance of storms along the eastern ranges during the afternoon.   Light rain over the east of the state remains likely under the influence of the upper low in southern NSW.  Isolated showers on the eastern coast of Tasmania, remaining unseasonably cool.

This TC is EXTREMELY DANGEROUS and hopefully will change course or move across uninhabited regions.  Another area showing persistent positive convection is just east of Cape Wessel off the NT coast although upper divergence is rather weak

TC Chris looks to cross the coast as per Clyve's prog & then may continue to move southwards before being captured by the subtropical jet.  Heat trough off the WA coast will remain unchanged for the next day or so with TC Chris dominating the area.  Scattered showers & thunderstorms likely for the western parts of the state. South Australia will see generally fine weather. Tasmania looks to experience warming conditions as the high moves into the Tasman Sea.  Although the heaviest falls are to be expected along the east coast of Australia, South Gippsland and Otway coasts see a risk of light to moderate rains during the next couple of days.  Watch for a risk of a wraparound cloudband across southern Victoria during the next day or two. 

Thursday has the makings of a very interesting day. Heaps of moisture will be funnelled into Victoria over the next couple of days from the east.

A surface trough is forecasted to deepen over Western and Central parts of Vic on Thursday. The upper levels are expected to be quite cold. Temperatures at 500mb are progged to be about -17 over Melbourne at 5pm, -44 @ 300, 850 temps are expected to be to be 10 to 12, so surface temps in the mid-high 20's can be expected. If significant heating occurs things could become very unstable. Li's are predicted to be down in the -3 to -4 range with CAPE near 1000. Shear is o.k, but has the potential to improve with a jetstream moving in from the NW. Moisture at the surface is great, RH of 90%.

Now moisture is my main concern, the upper levels look to be moist which may result in quite a bit of middle/upper level cloud.

EC and NGP all go for a significant trough system over Vic on Thursday.

Now for a bit of a dream outlook. The models are hinting at quite a strong upper trough, moving into from the SW. If this upper level system were to link up with the surface trough we could see very nice instability. This scenario may come into play later Thurs in the west and east on Friday. At this stage it looks like this system will play behind the surface trough, but worth a look.

Oh, and watch for possible storms on Wednesday, if the winds go more to the NE. All we need in Vic would be some clear air and the central and eastern parts could see storms. Clearance being the key.

Of interest is a low with an extra-tropical signature to the SW of Sumatra at ~15S!

Tomorrow is going to be an interesting day. The inland trough will deepen slightly and push SW wards into NE/North Country districts of Victoria. Currently a large NW cloud band runs from WA down across most of Victoria. I think this cloud band will be the feature which will determine whether or not there are storms in Victoria. The latest satellite loops show the cloud band slowly drifting across Victoria with the western edge now sitting just W of the border (the 22:30 image). Of more interest is the clear slot pushing into the NW of the state. I think the cloud band will drift far enough E overnight to leave at least half of the state clear tomorrow (W of 145E). I also think the "clear slot" could potentially move far enough E to sit close to, if not right over the sfc trough tomorrow. The clear slot most likely indicates drier air pushing into the W edge of the cloudband. If the area E of a line from Echuca - Bendigo clears to allow some heating into the area near the trough, some convection should kick off. Upper levels are slightly cooler than late last week and 850mb temps are quite a bit cooler too meaning that deep convection will require less heating to initiate. A guesstimate at a convective temperature tomorrow would be about 28C. Given that the sfc winds are progged to be E-ENE across the NE and Northern Country tomorrow not a lot of heat is going to be drawn from warm inland areas so the heating will depend almost solely on the cloud clearing. Dew points in the far NE of the state are sitting between 11 and 13C and with more moisture sitting in SE NSW waiting to be transported into Vic by the NE'lies tomorrow, these DP's should increase a little tomorrow making things more interesting. AVN is currently progging this entire cloud mass to virtually cease Sward movement as of about now (given its current position) and then shift due E meaning that the clear slot lies across the Central West areas of NSW. S of the clear slot has more moisture (and hence cloud). Due to this they are progging the best instability to be in the Central West of NSW. The idea is right in that where the clear slot interacts with the trough, storms will kick off but the question is still posed as to where the clear slot will be. I think the current sat pic indicates that this clear slot will be further S than AVN is progging and there is a chance that we could see it sitting over the northern parts of Victoria at prime time tomorrow.

Of course I'm working so I can't chase but wherever the clear slot lies it will be worth keeping an eye on the area. Shear is going to be quite good with sfc flow being NE'ly and the potential is there for mid to upper level flow to be quite strong from the NW. If deep convection can be initiated I wouldn't rule out organised storms with the chance of severe storms with the works (hail, winds and heavy rain).

I'll be interested to see where the cloud lies Tues and Wed as well as I think there is a chance we could see Victoria virtually cloud free with most of the cloud sitting JUST over the border in NSW (hehe) which will leave our skies clear and primed for storms...hehe. This may depend on what happens with the TC currently sitting just off the WA coast (and incidentally is now progged to be Cat 3 within 24hrs of it being named) and the direction it moves and the interaction it has with the jet.

The trough is progged to be in the W of the state at about 4pm running from about Lorne - Mortlake - Swan Hill. Storms should fire near the axis of the trough with some nice convergence. The trough will be clearly defined as it was yesterday and I wouldn't want to be on the wrong wide of it as it will be dry with S'ly winds. The ranges will also kick off storms today given the unsettled nature of the day. 850mb temps are progged to warm slightly throughout the day from 16C to about 18C which should aid in capping convection until later on. The ranges should start to fire around Mt Baw Baw, Mt Hotham, Mt Buller after 2pm, other ranges will go closer to 4pm with the plains (off the ranges) probably going even later - close to 5pm. Of course the cap will be slightly weaker in the S so the SW areas near trough could potentially go a little earlier if they get some decent heating.

Shear across the state is quite marginal but not as slack as yesterday (although I was surprised by the anvils of the storms getting dragged off to the SE on a jet which looked to be about 25knts which was a bit more than progged). Given the shear progged by AVN and the BoM's aviation forecast, storms should move generally NW to SE but again storms could move in weird directions due to propagation. Although the shear is marginal I think there will be just enough for storms to be somewhat organised. Given this and the fact that upper level temperatures are relatively cool I think we could see some severe storms today. Central, North Central, North Eastern, South/West Gippsland, Eastern and Alpine districts should all see severe storms. Note that these are all E of a line from about 144E - I think the upper level ridging will not allow for convection to reach severe levels (storms should still form along the trough but i don't think they'll be the best ones - they could, however, flatten to thundery rain later this evening giving us Melbournites a nice show tonight). Heavy rainfall leading to flash flooding (given that storms will be moving relatively slowly), damaging winds are possible and some large hail is also possible. I would speculate that hail could get as large as 3cm in the strongest storms today E of 144E especially in elevated areas where the FZL is lower.

While typing it looks like a cell popped up and down again to the WNW of Sale which is interesting. We could see things go a bit earlier than anticipated if heating gets in before the cap increases a bit. Given that its already 30/16 at my place and hitting high 20's/low 30's across much of central and north central Victoria, storms *may* take off early than initially thought. Some nice AcCas is sitting on the ranges at the moment and some Ac extends across to the western suburbs of Melbourne.

I'll be staying here for a while, watching and waiting. I don't think I'll be chasing west of 144E and given the current situation I think the area bounded by Melbourne - Seymour - Noojee - Mansfield would be a good start for today. I also think Seymour - Mansfield - Bright - Albury will be OK today. For those who like to sit and watch it happen from a distance a few places to watch from are the fire tower at Kangaroo Ground, Doncaster Shopping Town carpark and Mt Dandenong - all places have great views in almost all directions.

There is always uncertainty, but I wouldn't be surprised if the best action occurs very close to Melbourne. The instability indices in the models are tending to maximise through central Victoria, as is mid level moisture (700hPa RH approach 100% for tonight), while the local aspect and topography should yield healthy low to mid 30s temperature across the Melbourne metro area through the afternoon in the broad ENE to NNE surface flow. Melbourne is also going to be relatively close (this arvo) to the surface trough currently over western Victoria, which should provide some low level convergence.

Looking out the window, the scattered Ac and odd bit of castellated Ac points to (at least) reasonable mid level instability and moisture, while inthe low levels dewpoints have increased by 3-5C since this time yesterday (we even had a good dew this morning at Ferny Creek with a minimum if 15C which points to quite a depth of warm humid PBL air).

BTW gazing further into the future, it seems that yet again the northern end of the thickness trough associated with the front crossing the waters south of the Bight is expected to "cut-off" from the more southerly section near Ceduna and then stall. At the same time, the high approaching Victoria first ridges, then establishes its main centre south of the mainland. Such a scenario often precedes the development of easterly dips through NSW and Victoria and eventually cyclogenesis... certainly something to watch for..

January Forecast Outlook, Discussion & Report page

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