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000 
FXUS61 KILN 250635
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
135 AM EST Sat Feb 25 2017

.SYNOPSIS...
A low pressure system will track into the Great Lakes tonight 
while its associated cold front sweeps east across the Ohio 
Valley. Widespread showers and thunderstorms are expected 
as the cold front moves through. High pressure will gradually 
build back into the region late Saturday night into Sunday. More
seasonable temperatures will spread into the area for the 
weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Severe Thunderstorm Watch #38 is in effect for entire CWA until
07Z or 2 am EST.  Previous discussion below is still valid.

For tonight, focus remains on the potential for severe weather
across the region as low pressure tracks toward Lake Huron 
while its attendant cold front sweeps east across the region. 
Convection to our west over Indiana still remains somewhat 
elevated. In addition, the airmass over our area is still 
slightly capped and somewhat mixed out in the low levels, which 
has lowered boundary layer moisture some from projected 
forecasts. With dynamic energy rounding the base of a large 
scale trough, and with large scale ascent taking place this 
evening, cap should erode, allowing thunderstorms to develop and
move into our western zones. High resolution models continue to
indicate that these storms may eventually merge amongst 
themselves while the cold front and any convection along its 
boundary catches up. Potential still exists for some rotating 
storms which will pose large hail and damaging winds. Tornado 
threat is still there but will depend largely how much the 
boundary layer remains linked to the atmosphere above into the 
evening hours. Severe threat will then tend toward more of a 
damaging wind threat as the convection tries to form a qlcs 
structure across our eastern zones. In any case, thunderstorms 
are expected to exit our far east between 1 am EST and 4 am EST.
A dry slot (i.e. sinking air and lack of deep moisture) is 
still expected late tonight in the wake of frontal passage. Lows
will be set by morning as CAA takes place and continues into 
Saturday. They should range from the mid 30s west to the upper 
40s east.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
Parent large scale mid level trough is expected to pass across
the Great Lakes and Ohio Valley on Saturday. CAA will result in
slowly falling temperatures through the day. A few instability 
rain/and or snow showers may occur, but should end by Saturday
evening. It will be brisk, but winds do not look as gusty as
previously forecast. Gusts should be more in the 30 to 35 mph
range. 

For Saturday night, mid level trough will exit to the east.
Surface high pressure will gradually build into the Ohio Valley
late. CAA stratocumulus will linger through at least early
morning, with clearing expected from southwest to northwest
late. Lows will fall into the lower to mid 20s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Period will begin with high pressure centered just to the south of 
the fa in se KY. Skies will be mostly sunny, but temperatures will 
be seasonal with highs in the lower to mid 40s.

Model continue with their differences for Sunday night into Monday 
with how quickly pcpn returns on the backside of the high. The 
GFS is slowed down it's pcpn from yesterday and is concentrating 
across southern sections. The CMC hemispheric and NAM are showing 
similar solutions, while the ECMWF remains dry. Trended the forecast 
towards the consensus solution. Temps and thicknesses are low enuf 
that the pcpn should fall as a rain snow mix.

This first shot of pcpn slips e on Monday, before a more substantial 
area of pcpn lifts up into the region during the later half of 
Monday night. A warm front lifting through the region will keep 
temperatures warm enough for all rain. The best rain chances on 
Tuesday will be in the morning. Well above normal temperatures will 
return as highs will range from the upper 50s to lower 60s. 

Pcpn chance taper down during Tuesday aftn, then a cold front will 
swing through the region on Wednesday. Showers and possibly a 
thunderstorms (around the Ohio River) will develop Tuesday night and 
will last into Wednesday until fropa. Highs on Wednesday will 
probably be early with falling temperatures in the afternoon.

Northwest flow develops for the end of the week, which should bring 
back more seasonable temperatures. In the fast flow, the models are 
having timing difference with embedded vort maxs. Ran a blend of the 
solutions to have chance PoPs during the time frame.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
The cold front is currently pushing through central Ohio and has
moved through both KCMH and KLCK. As a result, the TAF sites
will remain dry through the pre dawn hours. Cigs are mainly VFR,
but we are seeing some spotty MVFR cigs redeveloping across 
parts of eastern Indiana and western Ohio so these may affect
primarily KDAY over the next few hours. An upper level trough
axis will swing across the region through early afternoon. This
will be accompanied by some lower level moisture and a few light
rain and snow showers. This will also allow for more widespread
MVFR cigs to overspread the area later this morning and then
linger into early to mid afternoon. Cigs should then lift into
VFR later this afternoon and into this evening as the low level
begin to dry out.

OUTLOOK...MVFR ceilings and visibilities possible Monday, 
Tuesday night, and Wednesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...Hickman

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