700 
fxus61 Kiln 231144 
afdiln 


Area forecast discussion 
National Weather Service Wilmington Ohio 
644 am EST Monday Nov 23 2009 


Synopsis... 
upper level disturbances will move northeast across the region 
today into this evening. A cold front will approach from the west 
Tuesday night and cross the area on Wednesday. An upper level low 
will bring unsettled weather for the latter part of the week. 


&& 


Near term /until 6 PM this evening/... 
satellite imagery shows a short wave over eastern Kentucky with 
another following close behind in southeast Missouri. Both of 
these systems will lift northeast through the day. Showers 
occurring out ahead of the Kentucky short wave have already spread 
into the southeast zones. Expect activity to increase in coverage 
as lift from second short wave reaches the area. Precipitation 
should be rather light. But there appears to be a fairly high 
probability of measurable precipitation for the eastern zones. 
Clouds and precipitation will keep temperatures from rising too 
much and guidance seems to have a reasonable handle on this. So 
stayed at or slightly below a MOS blend. 


&& 


Short term /6 PM this evening through Wednesday/... 
light rain may still be lingering in central Ohio in the evening 
before ending. Region will then be in between systems with light 
winds and abundant low level moisture. Appears that some 
visibility restrictions could develop late tonight into Tuesday 
morning. So inserted patchy fog. Next chance of precipitation 
should come during the latter half of Tuesday night into Wednesday 
when a weak cold front approaches and then crosses the area. NAM 
appears to be too slow with this system. But other available 
models were in relatively good agreement bringing the front 
through on Wednesday. After frontal passage there will be some 
gusty west southwest winds. Temperature forecast did not stray too 
far from guidance consensus. 


&& 


Long term /Wednesday night through Sunday/... 
models in general agreement bringing a potent system that will 
turn into a closed low across the region on Thursday and Friday. 
This should bring a good chance of rain on Thanksgiving with the 
chance of showers continuing through Friday before diminishing 
Friday night when the system departs off to the east. Cold air 
associated with this upper low will result in thermal profiles 
becoming favorable for some snow showers from Thursday night 
onwards until precipitation comes to an end. Ridging at the 
surface and aloft will build in over the weekend bringing dry 
conditions and allowing temperatures to rebound closer to normal 
for this time of year. 


&& 


Aviation /10z Monday through Friday/... 
upper level disturbance will impact the area by bringing some 
light showers to the taf sites today. Showers will be light enough 
not to impact visbys. Ceilings will gradually be on the decrease 
today. MVFR ceilings will begin to move into the taf sites by this 
afternoon. Lots of low level moisture will be around for tonight. 
Trended down on visbys and ceilings. For now went with MVFR ceilings 
across most taf sites however lower ceilings could be introduced once 
better timing is established. Visbys will also fall into the MVFR 
category overnight with lower visbys at kluk. Can not rule out a 
brief period of IFR visbys at other taf sites overnight. 
Conditions will begin to improve during the late morning hours on 
Tuesday. 


Outlook...MVFR ceilings/visbys possible Wednesday into Friday. 


&& 


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


&& 


$$ 
Synopsis... 
near term... 
short term... 
long term... 
aviation...Novak