921 
fxus61 kpbz 030845 
afdpbz 


Area forecast discussion 
National Weather Service Pittsburgh PA 
345 am EST Wednesday Dec 3 2008 


Synopsis... 
high pressure over our area will provide dry and mild conditions 
today. Overnight rain showers will spread in from the west as a 
cold front approaches. We can expect a change over from rain to 
snow during the day on Thursday as colder air moves in after the 
front passes. Much colder air is in store for the weekend. 


&& 


Near term /until 6 PM this evening/... 
mostly sunny and mild today under high pressure. This will be the 
first day in over two weeks that the high temperature is above 
normal. 


&& 


Short term /6 PM this evening through Friday/... 
a cold front will approach from the west this evening spreading 
rain into our area. Rain will move into east central Ohio after 
8pm and into western PA around midnight. Cold front will move 
through during the morning on Thursday with falling temperatures Thursday 
afternoon. There will be a change over from rain to rain/snow mix 
to all snow as colder air advects in after frontal passage. This 
is a fast moving system so rainfall/liquid equivalent will be 
light...less than 0.20 inches. Chance of snow across northwest 
Pennsylvania...Lee of Lake Erie...on Friday. 


&& 


Long term /Friday night through Tuesday/... 
a low pressure system will push eastward across the Great Lakes 
Saturday and off the New England coast by late Sunday. This system 
will bring a chance of snow showers Saturday and Sunday. Upslope 
snow Sowers possible into the ridges east and southeast of 
Pittsburgh Saturday and on into Sunday. Temperatures will be much below 
normal over the weekend. 


Surface high pressure is expected to bring dry weather Monday with 
the next system bringing rain showers Monday night and Tuesday. 
Temperatures should recover to near normal Tuesday. 


&& 


Aviation /08z Wednesday through Sunday/... 
VFR conditions may be expected for today, but surface wind will 
again increase as pressure gradient between middle Atlantic high and 
James Bay low tightens. Initial forecast will be southerly at 10 to 12 
kts with gusts near 20kt. That low will pull a cold front across 
the upper Ohio Valley early on Thursday morning with restrictions 
likely in developing precipitation. 


Stratocumulus may be expected in the cold westerly flow in the 
wake of the front, but improvements are indicated with building 
high pressure late Friday and early Saturday. 


Restrictions are again possible by late Saturday and Sunday as 
another low pressure system is projected across the region. 


&& 


Pbz watches/warnings/advisories... 
Maryland...none. 
Ohio...none. 
PA...none. 
WV...none. 


&& 


$$