NWS Watch, Warning, Advisory or Statement is in effect for Boone County, KY. View Alert

Information is from the NWS Wilmington, OH Office


ILN Area Forecast Discussion/SKEW-T

FXUS61 KILN 201752
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
152 PM EDT Sat Jul 20 2019

.SYNOPSIS...
Warm and humid conditions will continue through the weekend with
increased rain and storm chances from Sunday through Monday as
a cold front slowly pushes through the region. This will allow
for much cooler and drier air to filter into the Ohio Valley
Monday night through most of the upcoming workweek.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Little change to the forecast for today. It is looking like
today will be the hottest in this heat episode. While there
will be some clouds around today, don`t expect as many as
yesterday. This will allow highs to push into the mid 90s. With
dewpoints in the mid 70s, heat indices will be 105-110.

Kept the fa dry, as it looks like any convection that develops
over the Great Lakes will stay to the north.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
There remains the possibility of a weakening cluster of storms
to graze extreme northern/northeastern portions of the ILN FA
towards midnight tonight before the activity inevitably
dissipates altogether as it encounters a less favorable
environment locally. However, as is often the case with these
types of setups, CAMS often show a weakening/dissipation faster
than can sometimes be the case owing to the fact that any
convection is likely to pivot toward the higher axis of
instability pooling to the south/southwest. So while any
activity is expected to be in a weakening phase should it
meander into the local area late this evening, it will certainly
be watched to see if it can be maintained a bit further south
than is currently being depicted by some of the guidance.

Tonight is likely to be the most uncomfortable night of the
stretch with an increase in cloud cover helping keep
temperatures even a bit warmer. Lows tonight will bottom out in
the mid to upper 70s area-wide.

By Sunday, the center of the impressive and expansive mid/upper
level ridge will begin to retrograde, allowing for height
falls/suppression of the ridge across the Ohio Valley --
especially as troughing becomes more pronounced in the Upper
Midwest as it propagates/digs southeast late Sunday into Monday.
Recent model guidance has shown a slightly slower progression of
the frontal boundary through the local area, with rain and storm
chances likely to linger into the day on Monday before the
onset of cooler and drier conditions begins by Monday night.

One or more clusters of scattered storms is likely to develop by
Sunday afternoon (initially potentially in the CLE/IWX/IND CWAs)
amidst an environment with seasonably high instability and a
subtle increase/enhancement in low/mid level flow fields. This
being said, there is still not much overlap being depicted by
some of the models between the best instability and shear
fields, suggesting that while a few strong to severe storms may
be possible, organized convection may not be as favored.
Certainly gusty winds will still be possible in the strongest
cores, especially if the convection is able to become somewhat
cold-pool driven, but this may end up being more isolated in
nature -- especially as convection moves further away from the
focused forcing immediately along/ahead of the front draped from
near CLE west through north-central IN). Did maintain the
threat for a few strong to severe storms during this time period
in the HWO, especially as SPC Day 2 SWO has included nearly the
entire area in a MRGL risk for Sunday.

Warm and humid conditions may again lead to heat indices near
100 degrees for parts of the local area on Sunday afternoon --
particularly for areas which are able to remain
cloud/convection-free the longest. However, did not have
confidence enough at this time given inherent uncertainties in
clouds/precipitation to go with a heat advisory at this time.
Additionally, the setup for such heat indices to be met or
exceeded once again will be a bit more on the marginal side.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A cold front will push south into the area Sunday night. There will
likely be an area of showers and thunderstorms ongoing along and
ahead of the front early Sunday evening. These storms should then
push south across our area and likely weaken as we lose the daytime
heating/better instability. Nonetheless, will allow for likely pops
into Sunday night and then taper back to a chance late
Sunday night into early Monday.

The front will continue to sag slowly south on Monday, but a surface
wave/low is forecast to ride east along it. This will likely slow
the front up and keep fairly high pcpn chances going across our area
through much of the day on Monday. Strengthening mid level wind
fields and the possibility of a surface low moving east along the
front, will lead to a chance for at least a few severe storms on
Monday. Highs on Monday will range from the upper 70s in the
northwest to the lower 80s across the southeast.

High pressure and a drier airmass will settle into the Ohio Valley
through the remainder of the week. Highs on Tuesday will only be in
the mid to upper 70s. Temperatures will then slowly moderate through
the rest of the week with highs by Friday into the mid 80s.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Scattered cu will affect the tafs late this afternoon before
dissipating before sunset. Gusty winds at CMH/LCK are also
expected to diminish at the same time.

Overnight, some scattered mid or high clouds are forecast. At
CMH/LCK scattered clouds around 3500 ft could slip in from the
north. Southern tafs saw fog this morning and expect a repeat
tonight, so have mvfr fog at CVG/ILN and IFR at LUK.

Latest model runs suggest that convection might take a little
longer to get going, i.e. after 18Z. So will only mnetion VCTS
at CVG in the 30 hour taf.


OUTLOOK...Thunderstorms are expected Sunday afternoon into
Monday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Excessive Heat Warning until 8 PM EDT this evening for OHZ026-
     034-035-042>046-051>056-060>065-070>074-077>082-088.
KY...Excessive Heat Warning until 8 PM EDT this evening for
     KYZ089>100.
IN...Excessive Heat Warning until 8 PM EDT this evening for INZ050-
     058-059-066-073>075-080.

&&

$$
SYNOPSIS...KC
NEAR TERM...Sites
SHORT TERM...KC
LONG TERM...JGL
AVIATION...Sites


Skew-T

21,257 Page Views