WZ have written a news article and reckon potential for severe storms tonight.Pete Noticed them cranking up!
When l looked at the national loop and radar wind surface direction , the set up looked identical to last night.
A small partial surface low far south west corner near you and cloud pushing down south toward you. In fact the storms are pretty much in the same place as last night.
Had a look at ACCESS wind streams for the upper levels
http://www.bom.gov.au/australia/charts/ ... u&model=CG" onclick="window.open(this.href);return false;
and learnt tonight that the cloud pushing south down toward you is following the 200 , 500 and 700 hpascal wind stream which is united in traveling toward the south and coast .hence the cloud on national loop following upper and mid wind stream
Now at the surface there is a small surface low and cold moist southerlies streaming inland almost the opposite way . So the convergence is at about 850 hpascals lower mid level ( l assume)
So mild rotating surface air mass with fair uplift being sheared across at the mid levels.
Any way that's how l envisage the air streams and instability. As for how the thunderstorms start as a result of that l have no idea?? One day l read about it LOL
Anyway looks like plenty for stormchasers tonight. Hope they don't drink and drive!!
Noticed that last night some mountain to the east had 112mm. Couldn't help thinking that , that was all that was needed for some heav7y rain from those storms. They needed more uplift for rain..by the looks. You did mention the lifted index was pretty ordinary. Because the dew points around your area were excellent in the 18 deg c range
So l learnt a great deal from that weather watch. Thanks for the help and commentary pete. Appreciated
Happy new year to you and your family. Looks like you have your own fireworks show there tonight.
Wondering why the storms were more severe tonight . Was the LI and CAPE etc better tonight ?
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IDW28201
Australian Government Bureau of Meteorology
Western Australia
TOP PRIORITY FOR IMMEDIATE BROADCAST
SEVERE THUNDERSTORM WARNING
Large Hail, Damaging Winds and Heavy Rainfall
For people in southern inland parts of WA bounded by Northam to Katanning to
Bremer Bay to Israelite Bay to Salmon Gums to Northam including the town of
Esperance.
Issued at 6:25 pm on Saturday 31 December 2011
WEATHER SITUATION
People are advised that there is a risk of severe thunderstorms during Saturday
evening. Storms may be accompanied by VERY HEAVY RAINFALL conducive to FLASH
FLOODING and LARGE HAIL and DAMAGING WINDS that could result in DAMAGE TO HOMES
AND PROPERTY IN LOCALISED AREAS.
The overall weather pattern is not unusual for this time of year, but these
thunderstorms may
produce severe weather in localised areas.