938 
fxus61 Kiln 091130 
afdiln 


Area forecast discussion 
National Weather Service Wilmington Ohio 
630 am EST Friday Jan 9 2009 


Synopsis... 
low pressure will develop in the lower Ohio Valley late this 
evening. As this system tracks across Kentucky and into West 
Virginia overnight and into Saturday...it will spread wintry 
precipitation across the region. High pressure will then build in 
Saturday night and Sunday. 


&& 


Near term /until 6 PM this evening/... 
lower clouds still slow to move east of the area. Meanwhile a middle 
deck is already approaching from the northwest and this will 
spread across the region this morning. Some snow has been 
occurring in the upper Mississippi Valley with a short wave that 
will be moving east southeast. Suspect that there will be a sharp 
cut off between measurable snow and flurries. Some accumulation is 
not out of the question along the far northern tier of zones but 
would think if anything it would be less than an inch. This round 
of snow should be short lived and end before the day is through. 
Forecast temperatures stayed close to MOS guidance. 


&& 


Short term /6 PM this evening through Sunday/... 
main focus remains on system that will develop tonight and pass 
south of the forecast area late tonight into Saturday. NCEP models 
are in pretty good agreement with the track of this low and even 
the European model (ecmwf) has trended this way although it is still on the 
northern edge of solutions. Surface temperatures and low level 
thickness are pretty similar between the NAM and GFS. But the NAM 
appears to be a bit warmer when comparing forecast soundings. The 
subtle difference between solutions could have a large impact on 
precipitation type. With the 850 mb low passing right across the 
forecast area expect to have a snow and freezing rain mix which 
will transition to primarily snow after the low passes and colder 
air gets drawn southward. The southern third of the area is 
forecast to rise above freezing which will allow for plain rain 
for a good part of the event. Temperatures will be non-diurnal 
with rising readings late tonight and falling readings on Saturday 
afternoon. Still appears that there could be substantial 
precipitation with this system. Thus opted to bring watch down to 
the I-70 corridor. 


Precipitation should wind down fairly quickly late in the day and 
only have chance probability of precipitation Saturday evening in the eastern zones. High 
pressure will ridge in for Sunday. With snow cover expected in the 
the northern half have undercut guidance both Saturday night and 
Sunday. 


&& 


Long term /Sunday night through Thursday/... 
dry weather is expected on Sunday as high pressure builds in from 
the southwest. Low pressure moving through the Great Lakes will 
produce snow showers on Monday and Tuesday. Another rapidly moving 
disturbance may bring more snow showers on Wednesday. High 
pressure and dry air will follow for next Thursday. 


Temperatures will be just below normal on Sunday and Monday with 
highs in the upper 20s to middle 30s. Deepening upper trough will allow 
Arctic air to spill southward Tuesday through Thursday. Look for 
highs in the teens and 20s...with lows in the single numbers to low 
teens. 


&& 


Aviation /11z Friday through Tuesday/... 
MVFR deck will move east of the Kiln...kcmh and klck terminals 
13z-14z. However...middle clouds will settle in west to east 13z-15z. 
Flurries are possible this morning and afternoon north of Kiln. 
West-southwest/SW winds generally less than 10 kts will turn S/southeast after 
16z..then east/east-southeast after 01z. 


Ceilings will lower below 6 kts after 04z in the west in advance of an 
approaching clipper system. West to east 06z to 09z...a high 
probability precipitation event will occur with MVFR cigs/vis. At kcvg and 
kluk...the precipitation will be mostly rain. Elsewhere...a wintry mix is likely. 


Outlook...MVFR/IFR ceilings/visibilities possible through Saturday night. 


&& 


Iln watches/warnings/advisories... 
Ohio...Winter Storm Watch from late tonight through Saturday evening 
for ohz026-034-035-042>046-051>056-060>065. 
Kentucky...none. 
In...Winter Storm Watch from late tonight through Saturday evening 
for inz050-058-059. 


&& 


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