Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
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FXUS61 KILN 241141
Area Forecast Discussion
National Weather Service Wilmington OH
641 AM EST Tue Jan 24 2017
Precipitation will continue to move east out of the area this
morning as surface low pressure also pulls east. Weak surface
high pressure will then build into the area this afternoon. Rain
chances return for Wednesday as another low pressure system
approaches the region.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Weak inverted trough axis is currently moving out of the area this
morning taking the weak band of light rain/ drizzle east with it.
During the afternoon today weak surface high pressure will move
overhead allowing for a dry afternoon. Low level moisture in NAM
and GFS forecast soundings remains though with some hints of
partial clearing shown. With 850 mb temperatures and 1000/850 mb
thicknesses slowly climbing expect high temperatures in the mid
to upper 40s.
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Tonight surface low pressure will move into Iowa with WAA
commencing in the low levels. It looks like that most of Wednesday
morning before sunrise will remain dry as the best isentropic
upglide will be in Michigan. Forecast soundings also indicate a
good amount of dry air remaining across the area. Wednesday
afternoon a warm front will wash north across the area allowing
dewpoints to rise into the middle 40s. At the same time a LLJ will
begin to move overhead. Looking at the GFS/ ECMWF/ NAM low level
convergence doesn`t look overtly impressive. Still though the GFS
and ECMWF have some light precip forming. For now have left a low
chance of precipitation in the forecast for Wednesday afternoon
as forecast soundings on the NAM and GFS don`t fully saturate
(dry air intrusion ~800 mb).
The surface low will then head east across central Michigan
dragging a cold front across the area Wednesday evening. Global
models are in fairly good agreement with having the front
approaching the IN/ OH border around 0z Thursday. The cold front
is then forecasted to push through the entire area by 6z Thursday.
Rain chances with the frontal passage itself look only slightly
better as western zones again have dry air present in forecast
soundings. Further east forecast soundings do saturate up to
around 600 mb or so so have kept higher chances of precipitation
Thursday morning behind the cold front, temperatures will begin
to fall with 850 mb temperatures collapsing to around 6 degrees
below zero (GFS has warm air lagging slightly further behind
compared to NAM/ ECMWF). The net result of this will be steepening
low level lapse rates. Also low level moisture will be on the
increase meaning the chance of snow showers will return to the
area. Thursday afternoon surface temperatures will likely be above
freezing but given 850 mb temperatures approaching 8 degrees below
zero have kept the p-type mostly snow (possible a rain/ snow mix
across the far southeast).
Thursday night into Friday morning the upper level low that
brought the surface cold front through the area will pull
northeast with heights rising out across the western United
States. This will allow a couple of pieces of energy to continue
to pull south while also keeping temperatures near normal Friday
morning. Snow showers should diminish in coverage Thursday night
into Friday morning but with lapse rates remaining steep have kept
the chance of precipitation in the forecast.
.LONG TERM /FRIDAY THROUGH MONDAY/...
A broad upper level trough will be in place across the eastern
United States through the weekend. Several weak embedded short waves
within the broader trough will drop down across the Great Lakes
region Friday into Saturday. The combination of these and continued
cold cyclonic low level flow will result in the threat of at least a
few snow showers Friday and Saturday so will allow for some slight
chance pops at times both days. A stronger short wave will help
sharpen up the trough heading into Sunday which will likely lead to
some better chances of snow showers through the end of the weekend.
Expect dry conditions for Monday as mid level short wave ridging
briefly builds across the area. With the upper level trough and a
cooler airmass in place, temperatures will remain a few degrees
below normal trough the end of the period with highs mainly in the
low to mid 30s.
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --Widespread IFR cigs are persisting across the region this morning
along with some areas of drizzle and fog occasionally
reducing visibilities into IFR category. The 0-2 km RH is
forecast to improve from west to east through the mid to late
morning hours. This should allow for the drizzle to gradually
taper off. Cigs will then slowly rise into MVFR category as we
head into this afternoon. Weak high pressure will build into the
region late this afternoon and then push quickly off to the east
overnight. As the low level flow begins to back around to the
southwest late in the day, the MVFR cigs should begin to scatter
out from the southwest with mainly VFR conditions then expected
through the remainder of the TAF period.
OUTLOOK...MVFR ceilings possible Wednesday night through
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