Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
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FXUS61 KILN 181731
Area Forecast Discussion
National Weather Service Wilmington OH
131 PM EDT THU AUG 18 2016
Weak zonal flow aloft will settle over the eastern U.S. in the
wake of a weak shortwave exiting the Great Lakes region early
today. Surface patterns will be muddled until winds turn southerly
on Saturday ahead of a developing cold front. This front will
cross the region early Sunday morning and usher in a cooler,
drier, and overall more pleasant airmass for early next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Sratus and fog has expanded in the western fcst area the past
couple of hours. However appears that surface visbys for the most
part are higher than 1/4 mile. Thus will keep SPS in place for now
with no advisory. Fog and stratus should slowly lift through late
morning. Widely scattered showers already occuring just northwest
of CWA. Current pops look good with boundary across northern
areas. With increased cloud cover have tweeked highs down a bit
but did not want to go too much for now as any sun could cause
quick rise. No other changes past today period.
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
Any lingering showers or thunderstorms will be waning through the
evening and overnight. Cloud cover will clear in spots but a
generally partly to mostly cloudy overnight is expected with lows
only dropping to within a degree or two of 70. Friday will be
similar to Thursday with daytime heating driving a low chance -
scattered to isolated thunderstorms, peaking in the late day.
Sky cover overnight will again be pc/mc with lows dropping into
the upper 60s. Saturday will see another day of low chances of
storms primarily driven by daytime heating. However, this will be
the first day where the surface will see return flow set up ahead
of the next cold front. Storms immediately ahead of the front will
push in as early as late day, more likely in the evening. Storms
will continue overnight and a discernible back edge may occur in
the west and northwest with the frontal passage before daybreak
With weak forcing and little focus it is difficult to narrow down
an area with much higher probability than any other regarding the
afternoon and early evening convection during this period.
MOS blend seemed in the ballpark with highs...but continued to
shade a bit warmer than guidance for lows.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Upper trough will deepen across the upper Mississippi Valley early
in the period and then swing through the Great Lakes Sunday and
Monday. This will cause a cold front to push through the forecast
area Saturday night into Sunday. Showers and thunderstorms should
become more widespread later Saturday into Saturday night.
Precipitable water values will increase back over 2 inches which
could result in some storms producing heavy rainfall. High
pressure will build in for the first half of next week bringing a
drier airmass across the region.
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --Fog and stratus has lifted with CU clouds devloping across CWA.
Some MVFR cigs still around briefly for early afternoon becoming
mainly VFR. Boundary across the north already producing scattered
rain showers with thunder possible. Will keep vicinity shower in
northern TAF sites into the evening. Main fcst problem is extent
of fog and stratus again late tonight/Friday morning. Have opted
to not go as far as guidance but indicated the realm of
possibility with visbys and cigs indicated. Exception is LUK where
more confidence is given. Should see any fog and stratus lift
through the morning Friday. Light winds through fcst period.
OUTLOOK...Thunderstorms possible Saturday afternoon into Sunday
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