Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 241757
Area Forecast Discussion
National Weather Service Wilmington OH
157 PM EDT SUN JUL 24 2016
An upper level ridge will allow for continued hot and humid conditions
through the weekend. Widely scattered thunderstorms will be
possible in this hot an humid airmass. A cold front will move
through the region on Monday, bringing with it an enhanced chance
of thunderstorms. This front will stall out across Kentucky,
bringing a continued threat for storms across southern portions of
the region Tuesday and Wednesday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Ongoing shower and thunderstorm activity continues to move ESE
across northern Ohio. Activity may brush the extreme northern FA
through the late morning and early afternoon hours, so have
bumped PoPs a bit in these areas to account for this. Otherwise,
expect most precipitation to remain north and east of FA for the
remainder of the morning.
While overall forcing across FA will remain weak this afternoon,
decaying MCS across Michigan into northeast Ohio may lay out a
boundary across a portion of the FA later today, which may provide
a focus for convective development. Nevertheless, still expect
that coverage should be somewhat limited during the afternoon,
despite high instby.
With more extensive cloud cover across NE parts of the FA, have
trended temps down a degree for today. However, across the Tri-
State area of SW OH, nrthrn KY, and SE IN, ample sunshine and warm
air advection will allow temps to climb into the lower to mid 90s.
With dewpoints hovering in the low/mid 70s, heat indices will
near 105 for southern/southwestern parts of the area during peak
Upper level ridge will stretch east from the central plains across
the Ohio Valley with band of westerlies across the northern plains
and Great Lakes. Numerical models have been having a difficult
time pin pointing storms in weakly forced, unstable airmass
around the periphery of this ridge. Ongoing MCS tracking east
across Northern Indiana and weakening. This complex is expected to
push into west central Ohio and continue to weaken early this
morning. This MCS will lkly lay out a boundary which will be the
focus for additional convection later today with blyr cape values of
2500-3000 j/kg expected. Have limited pops to chance category far
north and then slight chance across the central counties.
Heat again will be a factor today with highs from 90 nw to the mid
90s se. These hot temperatures combined with dewpoints in the
lower and middle 70s will result in heat indices of 100 to 104
degrees. Therefore, will continue previous heat headlines.
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
Expect any ongoing diurnally driven storms to die off this evening
leaving a dry period. Approaching shortwave trough embedded in the
westerlies late tonight will bring an increased chance of storms
especially across the northwest. Will limit pops to chance
category. Warm and humid conditions to continue tonight with lows
in the lower and middle 70s.
Upper level s/w to pivot thru the Great Lakes with associated
surface cold front dropping southeast through the Ohio valley
Monday afternoon. This front combined with moderate instby is
expected to lead to thunderstorm development with the best
coverage across the south. Low level convergence is not real
impressive and the better forcing for ascent will be to our
north. Some uncertainty on coverage of storms and degree of instby
exists. Have opted to go likely across the south and will
continue to mention the potential for severe storms in HWO with
damaging winds being the primary threat. Highs on Monday to range
from the upper 80s nw to around 90 se.
Storms will end from the north but may linger across the far south
Monday night closer to weakening frontal boundary that stalls out
across Kentucky. Temperatures will be a little cooler with lows
from the mid 60s north to around 70 south.
Cold front which will stall out across Kentucky will be the focus
for diurnal storm development Tuesday. Will mention this potential
along and south of the Ohio river. Further north, drier air
should inhibit thunderstorm development. Highs on Tuesday will be
slightly cooler and generally in the mid and upper 80s.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Diurnal storms will be possible Wednesday across the south, close
to the stalled frontal boundary.
By Thursday, whatever is left of the stalled boundary will lift back
north as a warm front, allowing a moist air mass to return to the
entire CWA. Guidance suggests multiple shortwaves moving across the
Ohio Valley through the end of the week and perhaps even into
Saturday. This supports chance pops for thunderstorms during this
Temperatures are forecast to favor near average to slightly above
average values through the long term.
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --VFR Cu field has developed this afternoon as remnants of an MCS
continue to track through the Great Lakes region. A few -SHRA/TS have
popped across west-central and central Ohio this afternoon given
high instby environment. Expect this activity should stay north of
the terminals, so have kept sites dry through today.
For this evening, convection will likely develop across parts of
northern IL/IN and track SE. CAMs continue to indicate this
activity will weaken as it moves into central Indiana and
potentially extreme western Ohio. With instby waning after 02z
and convection moving away from primary forcing, it seems likely
that activity will dissipate before potentially affecting western
TAF sites of KCVG, KLUK, and KDAY. Therefore, have kept dry trend
through 06z despite uncertainty regarding exact convective
Main concern overnight will be potential for BR to form again,
especially for KLUK and KILN. Although conditions do not appear
to be ideal for widespread BR development across the region, MVFR
VSBYs are once again possible.
West-southwesterly winds of 5 to 10 kts are expected Monday as a
cold front drifts south through area. With high instby, plenty of
moisture, and a source for lift, expect that SHRA/TS will develop
across the Ohio Valley during the afternoon. There exists
uncertainty on exact timing and location of potential initiation,
so have handled this with a VCTS at all sites starting at 16z
(although initiation may be end up occurring after 18z Monday).
OUTLOOK...Thunderstorms possible Monday afternoon and again
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OH...Heat Advisory until 8 PM EDT this evening for OHZ026-034-035-
Excessive Heat Warning until 8 PM EDT this evening for OHZ061-
KY...Heat Advisory until 8 PM EDT this evening for KYZ089>100.
IN...Heat Advisory until 8 PM EDT this evening for INZ050-058-059-