Updated
2200AEDST - 17th November 1999 - J ONeill |
| November 1999 Forecast Outlook,
Discussion & Report Page ASWA Victoria |
| Date |
Name |
Information |
| 17 |
Clyve Herbert |
Thursday: high
pressure belt strengthening somewhat & extending across Tasmania and through the south
Tasman, then building a ridge progressively northwards along the NSW coast through
Thursday 18th and into Friday morning. A large low pressure area and associated
troughs across WA & SA encroaching towards Victoria on Friday. (look out for possible
generation of surface trough along western slopes of NSW divide into northern Victoria
with the possible generation of isolated convective showers on the north eastern, possibly
central divide, late Thursday, possibly Friday). Low pressure area developing over SA and
moving SE towards Victoria late Friday 19th or early Saturday 20th. Unfortunately
this system, although it may generate general patchy rain, extensive middle & upper
level cloud extending across SE Australia may spoil potential convective activity through
Saturday & Sunday, although any breaks may allow the generation of storms through
Saturday & Sunday especially near to the trough & low pressure system. This system
will probably move into NSW or the Tasman late Sunday 21st, & a high pressure system
will build in the Bight area. This may be good news for our NSW enthusiasts who may
see a lingering trough over the NE & E of the state Monday 22nd & Tuesday 23rdwith
the subsequent generation of shower & thunderstorm activity mostly contracting NE
through next Wednesday 24th & Thursday 25th. Meanwhile a new high in the Bight
from Monday / Tuesday will probably reach towards Tasmania on Tuesday will reach the
Tasman probably Wednesday / Thursday with a new trough approaching from SA Wednesday 24th
to Friday 26th next week destabilising conditions for Saturday 27th / Sunday 28th. Potential risks: moisture content will increase this weekend
(20/21st), although it appears that this system will be accompanied by large areas of
upper and middle level cloud, breaks in the cloudmass may, in some localities, allow the
generation of moderate to strong thunderstorm activity, and these localities extend from
eastern SA, through Victoria and into NSW. There is some potential for this system
to produce moderate to heavy rain across SE Australia, Saturday through to Monday with the
emphasis on Victoria at this stage. In respect to severe thunderstorm generation
during this time, upper level wind shear does not appear to show any major strength &
the upper level shear factor appears to be low. |
| 13 |
Jane ONeill |
ASWA meeting -
Pancake Parlour Doncaster - 9am start |
| 12 |
Clyve Herbert |
Cold
front expected in western Victoria tomorrow morning. The airmass, although not very
unstable is conditionally unstable. The timing of the cold front over central
Victoria will be critical with the combination with maximum diurnal heating. Risks:
isolated thunderstorms especially after 1300AEDST ahead of and along the frontal boundary.
Keep an eye on this front on Saturday. |
| 10 |
Jane ONeill |
Upper
cold pool to the west of Adelaide this morning should move ENE over the next 24 hours.
Keep an eye out for some middle level instability today and especially during the
period of maximum heating this afternoon. Area mostly affected along the ranges
& the north east of the state. |
| 10 |
Andrew McDonald |
8th
Nov - 13th Nov <---- dead - weak fronts and then a ridge of high pressure.
14th - ATM I'm forecasting a late thundery change - strength up to moderate - no upper
dynamics with it so it should be fairly run of the mill.
15th - Fairly boring with light winds from SW early then swinging around to E later in the
day (bringing moisture with it)
16th - Nice low pressure system over central Australia (centre near Ceduna). Here we
should see ENE'ly - NE'ly winds and increasing cloud as the low approaches. Weak-moderate
thunderstorms in the NW, N and W. Bit of upper level action starting to pick up in
SA with this too.
17th - Low still sitting to the W (over Adelaide in the morning) and sitting just W of Vic
by later in the day. Upper trough strengthening too. Moderate NE'ly winds across
whole state. 3 days of E'lys and NE'ly should see some decent amounts of moisture
too. Weak - Strong thunderstorms in the W and NW and weak-moderate thunderstorms in
N and C districts. Nice outbreak of severe storms in SA probable too.
18th - (Thurs) As the low doesn't seem to be moving very fast I'd say there isn't
much upper winds but they could be on the way. The low should move into the W
overnight and be sitting in perfect position. N - NE'ly winds and good chance of
storms in all districts. Upper system has been strengthening for the last two days
and will hopefully continue this trend. If it does that could possibly see some
interesting developments. Surface winds would be NE-N, 500 winds would be NW'ly (and
strengthening if the upper system is strengthening) and some sort of Jet should have moved
in (or be moving in) from the W. Should see weak-severe storms in Central, N, NE and
E as well as weak - strong thunderstorms in the W and NW.
19th-22st. - This low splits on Wednesday on the charts with half moving SE and the other
half retracting into the centre. If this happens the trough extending N form the SE low
will link up with the other low pressure system and move E over NSW and QLD if the jet is
in its normal position (across the centre). This could be perfect for us. We
really might be able to follow a system all the way there - starting with some warm-up
chasing in Vic and finishing up with severe storms in NSW and QLD. |
| 9 |
Clyve Herbert |
Interesting
development as cold front moved through western Victoria. It underwent frontolysis
and developed vorticity near Portland which moved NE. The flow pattern over Victoria
is being rearranged by the development of the deepening low in the Tasman Sea.
Vorticity north of Bendigo also probably reflects cold air at 500hPa which should then
move NE into NSW. Showers this evening over western Victoria may extend east to the
eastern ranges. 2 lightning discharges have been detected to the NW of Geelong, so there
is still a slight risk of storm activity. |
| 9 |
Clyve Herbert |
Trough
& cold front approaching central Victoria. Evidence of middle & upper level
cold pool. Surface heating this morning will destabilise conditions further.
Scattered showers in most southern and mountain areas. Risks: locally heavy showers, isolated thunder,
isolated hail. Snow showers probably down to 1140m on the dividing range.
Further afield, progressive injection of colder air above 600hPa may aid in cyclogenesis
over the Tasman, generally east of 151E & north of 34S. Potential risk to 33S /
152E. |
| 5 |
Greg Stewart |
Merbein:
Had up to 35mm (reported news) in Mildura today between 1 pm and 4pm. Only 13 mm at our
weather station in Merbein. About 50 - 65 mm of rain fell during the storms around
Mildura. |
| 4 |
Clyve Herbert |
Congesting Cu at
0921AEDST over the ranges to the NE of Melbourne. Good indication of continuing
destabilisation through Thursday with the prospect of isolated to scattered showers and
thunderstorms in the west & mountain areas with some activity sneaking onto the plains
& into Gippsland. Risk of very isolated more severe activity later this
afternoon in these districts. |
| 2 |
Clyve Herbert |
Large high pressure
system to the west of Tasmania will probably split with one centre east of Tasmania &
one to the west. Weak non-active trough may develop in the north of Victoria on
Wednesday afternoon with the risk of isolated congesting cumulus. Destabilisation
anticipated for the latter part of the week (Friday & Saturday) with increasing
likelihood of storms - but mostly middle level. |
| 2 |
Dane Newman |
We had 68mm of
rain here in Kilsyth for October Ave is 81mm. 2 thunderdays, 1 day of hail(small) and
fogs on 2 days. Ave max was 20.2c ave min was 9.1c. Currently (11.20am) temp is 17c
dew pt 6c Bar 1029S Wind light southerly Cloud 1 ockta Small Cu. Looks like
a low pressure trough will start to affect weather over Victoria on Thursday or
Friday. This trough should still be affecting Victoria on Saturday, instability with
this trough should should see the development of isolated showers and
thunderstorms over the state, slight chance tomorrow in western and northwestern
districts and more likely Thursday to Saturday in most districts |
