-- Discussion containing changed information from previous version are highlighted. --
019
FXUS61 KILN 201739
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
139 PM EDT Fri Sep 20 2024

.SYNOPSIS...
Dry and unseasonably warm conditions will continue today. An
upper level disturbance will lead to a chance for a few
showers and thunderstorms tonight. Better chances for showers
and thunderstorms will develop early next week as a frontal
boundary approaches the region.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
No major changes with the morning update. Mostly sunny and warm
conditions are expected today with highs around 90. A weak front will
likely bring a decaying/scattered line of showers and a few
storms beginning near the end of the near term period west of
I-70 as our mid-level ridge begins to flatten.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Weakening mid level energy will push east into our area tonight
accompanied by a weak frontal boundary. As it does, scattered
showers and a few thunderstorms will continue to move southeast
into mainly our western areas this evening. However, expect to
see an overall weakening trend heading into tonight as the
instability will be decreasing. Will therefore allow for some
chance pops across our west early this evening and then taper
back to just 20 poops heading east into tonight. The boundary
will continue to push off to our east through the day on
Saturday. Suppose it will be tough to rule out a few showers
along the boundary across our southeast early Saturday morning,
but the better chance for any pcpn will be mainly off to our
southeast during the day. Lows tonight will be mostly in the
60s with highs on Saturday in the upper 80s to lower 90s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
H5 ridge in place to start the period will quickly propagate
eastward through the end of the weekend. How quickly this ridge
shifts eastward will be important to monitor because in its wake, a
robust, elongated trough will begin to carve its way through the
Midwest. Showers/storms will accompany this trough, which could
begin as early as Sunday afternoon based on latest guidance.
Instability is weaker on Sunday however, so thunderstorm coverage
expected to be more limited. Instability levels will increase Monday
into Tuesday, which will promote better thunderstorm potential. Long-
range machine learning guidance not overly excited about severe
potential, but will have to monitor trends in CAMs as we get closer.

Expecting periods of showers/storms Monday into Tuesday with the
development of a surface low and a slow moving cold front to our
west. QPF footprint continues to increase from ensemble guidance,
with anomalous PWAT values increasing to the 1.75" range. Thus, some
efficient rainfall may be observed as we finally receive a robust
forcing mechanism and sufficient instability for thunderstorm
development. This may help provide some short-term relief from the
drought conditions.

Cold front moves through the region late Tuesday/Tuesday night. Near
or just below seasonal normal temperatures will return by mid-week
as relatively cooler air funnels in.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Weak front will bring increasing VFR clouds and a slight chance
of showers overnight, perhaps making it as far as DAY before
the precipitation diminishes. Opted to keep the TAF dry due to
low coverage as well as uncertainty with how far east the
showers make it before drying out.

After the frontal passage, there could be just enough clearing
to produce some fog near DAY and points west. High resolution
models including HREF membership has been hitting this potential
with 50-70% probability of 1/2 mile or less visibility. The main
question is eastward extent... so for now have limited the
restriction to MVFR at DAY with IFR conditions remaining west
of the airfield. Elsewhere, skies will clear with VFR conditions
continuing through Saturday as high pressure briefly builds into
the Ohio Valley.

OUTLOOK...Hazardous weather is not expected.
-- End Changed Discussion --

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...JGL
NEAR TERM...
SHORT TERM...JGL
LONG TERM...Clark
AVIATION...