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fxus63 kiwx 030900 
afdiwx 


Area forecast discussion 
National Weather Service northern Indiana 
400 am EST Wednesday Dec 3 2008 


Short term... 
today through Thursday night...south to southwest winds will 
become west by early tonight as much colder air spreads into the 
area behind a cold front. Limited moisture will be able to reach 
the area before the front passes...and given the best upper level 
support behind the front...expect most precipitation to fall in 
the colder air. Rain will mix with and change to snow from 
northwest to southeast...with Lima Ohio changing over late this 
evening. Concern for traveling tonight as temperatures fall well 
below freezing causing icy conditions on roads. Some lake effect 
snowfall is possible...although winds are expected to back more to 
the west on Thursday...limiting the fetch over the lake and thus 
limiting lake effect snow. Also...very dry air will be spreading 
over the lake from Wisconsin without being modified by upstream 
lakes. Expect snowfall amounts through Thursday night to be 
between 1 and 3 inches...except 3 to 4 inches over far SW lower 
and far south central lower Michigan. Temperatures will remain 
below freezing Thursday as cold air advection continues. 


&& 


Long term... 
little change in model forecasts for long term period and therefore 
little reason to change much with current grids. Very cold long term 
with active northwest flow still expected. Numerous short waves to 
impact the region. Lake effect snow showers still expected with good 
instability but models not bullish on moisture or fetch with rather 
dry polar airmass so generally light accumulations expected at this 
time. 


Still expecting a fast moving clipper system with light 
accumulations Saturday followed by cold airmass. Another clipper by 
Monday or Tuesday. European model (ecmwf) still rather warm in lower levels so will 
keep rain or snow mention given uncertainty. Expect temperatures over the 
weekend to remain in the 20s for highs and teens to possibly single 
digits for lows. 


&& 


Previous discussion... /issued 123 am EST Wednesday Dec 3 2008/ 


Aviation... 
a low level jet of 50 kts was starting to mix down momentum with 
south to south-southwest winds increasing at the surface. Some concern for shear 
reaching 10 kts per 100 feet...but it looks like values will stay 
in the 10 kts per 300 to 400 feet per latest profiler and tamdar 
observation...so will leave out the mention of shear for now in tafs. 
Otherwise...expect conditions to deteriorate after 18z...with 
lower ceilings and visibilities along with a mix of precipitation changing to all 
snow this evening as the colder air behind the front spreads into 
the region. 


&& 


Iwx watches/warnings/advisories... 
in...none. 
Michigan...none. 
Ohio...none. 
Lm...Small Craft Advisory until 10 am EST this morning for lmz043-046. 


&& 


$$ 


Short term...skipper 
long term...Lashley 
aviation...skipper