Area Forecast Discussion
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FXUS61 KILN 221051
Area Forecast Discussion
National Weather Service Wilmington OH
651 AM EDT FRI JUL 22 2016
An upper level ridge positioned over the nations mid section will
continue to dominate the weather over the weekend before finally
breaking down at the beginning of next week. this ridge will offer
hot and humid weather conditions. The combination of heat and
humidity will create heat index values above 100 degrees. This
will result in period of storms to form through the weekend due to
the high levels of moisture. The chance for precipitation increases
early next week with the expected passage of a cold front.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Upper level ridge centered over the nations mid section will
continue to dominate our weather. Latest MCS which originated over
northern Illinois pushing south through Illinois and western
Indiana. Numerical models have been doing a poor job with
placement and timing of these systems. Expect this MCS to continuemore
southward into the most unstable air. Have trimmed back early
pops with only a chance/slight chance in the far sw counties and
this too may have to be cutback with the next update.
Much uncertainty regarding additional convective development
today. Expect boundary layer capes between 3000-3500 j/kg with
the most unstbl air over the north. With weak impulse expected to
ridge over the ridge...additional convection will likely occur
this aftn. Have limited pops to chance category due to
uncertainty of placement/timing. Combination of heat and humidity
will result in heat indices around 100 degrees. Therefore, have
continued current heat headlines.
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Possible ongoing MCS to start the evening expected to drop south-
southeast across ILN/s FA and weaken this evening. Remainder of
the night should be mainly dry but can not rule out stray pcpn.
Warm and humid conditions to continue with lows in the lower and
Difficult to pin point timing and placement of convection Saturday
and sunday. Have a mention of 40 percent both aftns with the best
threat across the north closer to warm front. Heat continues with
highs in the lower 90s on both Saturday and Sunday. Given high
dewpoints...heat indices above 100 likely Saturday afternoon and
possibly again Sunday. For now...have continue heat headlines for
Saturday but these headlines may have to be extended into Sunday.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
On Monday an upper level low will swing east across the Hudson
Bay bringing a weak front across the area. Surface convergence is
weak along the front and timing between the GFS and ECMWF is
slightly out of phase. The ECMWF is slightly faster than the GFS
with the GFS bringing the front through Tuesday morning. The ECMWF
bring the front through Monday evening. Have leaned towards the
Behind the front much drier air will filter in with PWATs less than
1.00". This will help to bring a temporary end in the precip until
Thursday. At the end of extended Thursday another shortwave will
approach the area bringing the chance of rain back to the area.
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Expect VFR to continue except at LUK where BR may reduce
visibility early Saturday. Otherwise, sky cover consists mainly
of cirrus to start. Models are not handling current convection
very well so forecast is more difficult than average.
Thunderstorms to the west and northeast may not directly affect
TAF sites. Additional convection may develop by afternoon peak
heating so have included VCTS at all sites. Timing is hard to
predict due to model uncertainty. Expect mainly clear skies after
sunset as thunderstorms diminish with loss of daytime heating. Winds
will generally be out of the west to southwest, with speeds 12
knots or less.
OUTLOOK...Thunderstorms possible Saturday through Monday.
OH...Heat Advisory from 10 AM this morning to 8 PM EDT Saturday for
Excessive Heat Warning from 10 AM this morning to 8 PM EDT
Saturday for OHZ061-077.
KY...Heat Advisory from 10 AM this morning to 8 PM EDT Saturday for
IN...Heat Advisory from 10 AM this morning to 8 PM EDT Saturday for