Area Forecast Discussion Issued by NWS Wilmington, OH
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000
FXUS61 KILN 131908
AFDILN
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
308 PM EDT Wed Mar 13 2024
.SYNOPSIS...
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More warm weather and gusty winds are likely on Thursday ahead
of a low pressure and cold front which will cross the area on
Friday. With the gusty winds will come higher moisture, and
shower and thunderstorm chances will increase with most areas
seeing rain at some point from Thursday into Friday. Behind the
front the airmass will cool considerably as high pressure builds
into the area. Secondary cold fronts will swing through the
Great Lakes during the weekend into early next week, reinforcing
the cooler air and continuing the mostly dry weather from the
upcoming weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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Primary concern tonight will be with shower and thunderstorm
chances/coverage.
Ample sunshine and warm breezes across the ILN CWA early this
afternoon, and dew points have held steady in the lower 40s
which is keeping humidities in the 30-40% range, so with the
more sporadic wind gusts vs yesterday`s more widespread and
stronger winds, did not feel a need to message any fire weather
concerns into this evening on a larger scale.
After midnight, increasing theta-e advection aloft will drive
the potential for an arc of showers and perhaps a few elevated
storms from southwest to northeast across mainly the northwest
half of the ILN forecast area. This is not a high confidence
signal across the suite of convective allowing and global
ensemble members, however, thus chances along I-71 are
maintained in the 20-40% range. A better /spatial and forcing/
signal exists for showers and thunderstorms to develop tonight
in Illinois and cross Indiana on an ENE trajectory toward the
northwestern third of the ILN forecast area, arriving in the
hours before or just after sunrise in west central Ohio. Likely
elevated in nature, these are unlikely to be strong / severe but
do warrant the maintenance of higher rain chances that were
ongoing in the forecast already across west central Ohio in the
10Z-12Z timeframe.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
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Expect the cluster of showers/storms mentioned above entering
west central Ohio around sunrise to continue on a east-northeast
trajectory toward central Ohio during the morning hours, but it
is at this point where the forecast begins to lose some degree
of certainty, and how long these hold together downstream over
central Ohio (or perhaps moving more into northern Ohio) remains
to be seen.
In general, as a potent mid level speed max ejects northeast
owing to height falls digging into the Rockies and with heights
rising downstream over the Ohio Valley, activity should have
the propensity to either weaken/diminish over central Ohio or
lift more north into northern Ohio as forcing diminishes
immediately over the ILN CWA, leaving somewhat of an open-warm-
sector lull across much of our forecast area from late morning
into early mid afternoon.
That being said, as this speed max and embedded shortwave
arrives into Indiana/Michigan during the afternoon, expect a
renewed storm cluster/MCS to develop across ILN/IN and move
rapidly toward MI/OH. There are some convective-allowing
solutions which develop a rather robust MCS that rides along the
synoptic warm front lying either just north of our area or
across our northern tier, taking on linear/bowing
characteristics. Some solutions ride this activity well north of
our area, but there is a general / overarching trend in most
guidance /backed up by machine learning probabilities based on
GEFS/HREF/ that our northern half of our forecast area is under
a threat for severe storms tomorrow that could - if things come
together - exceed current Level 1 /Marginal Risk/ categories
from the SPC. But the uncertainty tied to the coverage / track
of this cluster of storms, coupled with marginal thermodynamics
are likely playing a role here. What we do know is that low
level and deep level shear /hodograph curvature/ is rather
optimal for storm longevity and organization for any MCS or
discrete cells which may form, but there is some concern for the
level of moistening that can be maintained in an open warm
sector scenario. If dewpoints can`t ascend past the mid 50s -
which is being hinted by some of the CAMS which have handled low
level moisture more optimally this week - overall convection
may struggle to maintain intensity outside a more optimal setup
with regards to shear/warm front/synoptic forcing with the jet
streak. This situation will need to be watched closely, and if a
more robust storm cluster can get going in this kind of shear
environment across the northern half of the ILN forecast area,
all modes of severe weather including a tornado or two will be
in play.
After the potential afternoon-early evening storm threats, we
are not out of the woods as the passing jet streak will begin to
push low pressure and associated cold front southeast toward our
area later Thursday night into Friday morning, and another wave
of storms /likely focused more to the southwest of the ILN CWA/
may impact areas along the Ohio River and points south later in
the night. While severe threats with this activity would be
less, there would still be ample low level shear in play,as
despite the more reduced instability by coming through at such a
late time of night.-- End Changed Discussion --
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
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Showers and a chance of thunderstorms will continue into Friday
morning, but should be tapering off from the northwest through late
morning and into the afternoon as the cold front moves southeast of
our area. In the developing CAA behind the front, highs on Friday
will range from the mid 50 northwest to the mid 60s in the
southeast. Surface high pressure will build briefly into the lower
Ohio and Tennessee Valleys Friday night into Saturday. This will
provide for drier conditions with highs on Saturday in the mid 50s
to lower 60s.
Mid level short wave energy, embedded in a broader upper level
trough, will drop down across the Great Lakes on Sunday, leading to
the potential for a few rain showers across our area. Temperatures
will continue to cool with highs on Sunday in the mid 40s to mid 50s.
A somewhat stronger secondary short wave will rotate through the
base of the trough and across the lower Great Lakes and upper Ohio
Valley on Monday. This will bring a chance for mainly snow showers
to the region as high on Monday will only be in the upper 30s to
lower 40s.
The upper level trough will shift off to the east and surface high
pressure will build into the region through mid week. This will lead
to drier conditions and slowly moderating temperatures. Highs on
Tuesday will be mostly in the 40s with highs on Wednesday in the
upper 40s to mid 50s.-- End Changed Discussion --
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions expected for the most part across the terminals
through the TAF cycle, though shower and thunderstorm chances
later tonight and Thursday morning at DAY/CMH could threaten
some MVFR visibilities and/or ceilings depending on coverage.
For the rest of the daylight hours, plenty of sunshine and
southwest winds of 8-12kts. There have been some gusts here and
there above 15kts at ILN and LCK, but these are not expected to
be persistent or widespread. Winds will decrease and back to the
south or even southeast this evening.
Later in the night - after about 07Z - increasing
warmth/moisture aloft will drive the potential for a few showers
and storms from southwest to northeast across the area.
Uncertainty on the coverage of these is quite high, but maintained
these in the CVG/LUK/ILN TAFs as the signal remains in play
enough for mention on a few of the models. The better signal is
for a larger cluster of showers and a few storms to move out of
central Indiana toward DAY/CMH in the hours around sunrise, so
maintained the prevailing mention of SHRA with VCTS at these
locations as this arc of activity is expected to cross
western/central Ohio during the morning hours.
Should be some lull or scattering out of rain chances and clouds
a the warm front continues to shift north on Thursday, and there
is a growing concern/threat of a second complex of showers and
storms /which could be strong or even severe/ that moves out of
Indiana in the early-mid afternoon into and across many of the
terminals after 18Z, likely staying north of CVG/LUK during the
afternoon hours, but confidence is low on the track of these
storms, with some solutions just grazing the I-70 corridor and
DAY/CMH/LCK, and other solutions hitting these TAFs and also ILN
with an impacting round of storms in the mid/late afternoon
hours.
Gusty southwest winds will also be a concern outside of storms
on Thursday afternoon with some 30kt gusts not entirely out of
the question.
OUTLOOK...MVFR ceilings and visibilities likely Thursday night
into Friday night with IFR possible. Thunderstorms also possible
Thursday into Friday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Binau
NEAR TERM...Binau
SHORT TERM...Binau
LONG TERM...JGL
AVIATION...Binau