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fxus61 Kiln 212023 
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Area forecast discussion 
National Weather Service Wilmington Ohio 
323 PM EST Sat Nov 21 2009 


Synopsis... 
high pressure will dominate the weather pattern through Sunday 
night. Low pressure will move up the Appalachians on 
Monday...and a stronger area of low pressure and cold front will 
move in from the west by Tuesday. 


&& 


Near term /until 6 am Sunday morning/... 
a surface high will keep control of things for the overnight 
period...with good radiational cooling setting up again. With a 
warmer starting point went a couple degrees above observed lows 
last night...but below guidance numbers. Clouds are not expected 
to stick around too long tonight so went kept things mostly clear. 


&& 


Short term /Sunday through Monday night/... 
looks like more of the same on Sunday...with mostly sunny 
conditions and temperatures a degree or two higher than 
today...matching guidance closely. Will see winds start to come in 
from the east...on the north side of a trough lifting up through 
the Appalachians. This may lead to temperatures sticking a few degrees 
higher Sunday night. 


Model consensus seemed to favor a drier solution going into Monday 
and Monday night. Overnight GFS runs showed precipitation over the 
area...but the 12z has also shifted more toward a drier solution. 
Looks like there will indeed be some moisture pushing north. 
Probably enough for some higher sky grids...but was not sold on 
the chances of precipitation. The moisture is shallow (generally 
between 850-700mb) and found very little to support any forcing. 
Weak short wave at 500mb indicated by the GFS should help the 
clouds...but ultimately have chosen to go with a dry forecast. 


Temperatures in the rest of the short term are close to guidance. 


&& 


Long term /Tuesday through Saturday/... 
have basically taken a blend of the 12z GFS and the 12z European model (ecmwf) for 
the long term forecast. Models were in fairly decent agreement with 
only some slight timing differences with each having their typical 
thermal profile biases. 


An upper level closed low will move from the Central Plains to the 
western/lower Great Lakes by Wednesday morning. Attendant cold front 
will swing through the region Tuesday night into early Wednesday 
morning. Showers will accompany the front followed by some small 
chances for wrap around showers on Wednesday. Another upper level 
closed low will be quick on the heels of aforementioned first low as 
it dives southeast from S central Canada to the Ohio River valley during the 
Wednesday/Thursday time frame. This will eject the first upper level 
closed low NE away from the region. The second low will also bring a 
cold front across the region on Thursday...with this low having more 
colder air filtering in behind the front. Again...will continue with 
a chance of showers on Thursday. With lowering critical thicknesses 
and freezing levels Thursday night...any wrap around shower activity 
will mix with and change to snow showers overnight. With a warm 
ground and precipitation not expected to be widespread/heavy in nature...am 
not looking for any accumulations at this point. GFS/European model (ecmwf) have 
trended a little slower in exiting upper level closed low from the Great 
Lakes/Ohio Valley for Friday/Friday night. Have not trended this way 
yet. Would like to see a couple more model runs before slowing down 
the system. High pressure at the surface and aloft is forecast to build 
back into the region for Saturday. 


As for temperatures...the warmest readings will occur on Tuesday 
with highs in the middle 50s to near 60. Readings will cool to below 
normal readings...at least for highs for the latter part of the 
week. Near normal readings will return by next weekend. 


&& 


Aviation /20z Saturday through Thursday/... 
very light east winds will be found over the region today as high 
pressure settles in Ohio. A few fair weather cumulus will pop from 
2500'-3500' today and quickly die later this afternoon. Another 
round of MVFR visibilities is expected overnight...although it will 
neither be as widespread nor as long in duration as it was earlier 
this morning. Atmosphere is drying under the easterly winds. Cirrus 
may spill into SW County Warning Area tomorrow...but even this is in question. It 
may hang on the horizon and never make it to the Airport as upper 
flow is still pulling in drier air on northwest winds. 


Outlook...MVFR ceilings possible Tuesday night into Wednesday. 


&& 


Iln watches/warnings/advisories... 
Ohio...none. 
Kentucky...none. 
In...none. 


&& 


$$ 
Synopsis...hatzos 
near term...hatzos 
short term...hatzos 
long term...Hickman 
aviation...franks