Area Forecast Discussion Issued by NWS Wilmington, OH
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000
FXUS61 KILN 220813
AFDILN
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
413 AM EDT Fri Mar 22 2024
.SYNOPSIS...
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A low pressure system and associated frontal boundary will
track through the Ohio Valley bringing rain to the region
today into tonight. Dry conditions return for Saturday into
early next week, with a return of rain to the region Monday
night.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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A pair of systems to affect the weather across the Ohio Valley
and Great Lakes today.
A High amplitude southern stream short wave will be weakening
as it passes south of the region thru the Lower MS Valley into
the Gulf States. Meanwhile, a fast moving, lower amplitude
northern stream system will cross the Great Lakes. Airmass is
rather dry to start out with weak lift ahead of a warm front
resulting in the development of rain showers. Expect rain
showers to generally hold off until afternoon based on initial
dry airmass. These rain showers to affect areas along and south
of the Ohio River and then overspread the entire area by mid to
late afternoon with pops in the chance category ramping up to
likely late in the day. Rainfall through the daylight hours
will be less than a tenth of an inch.
Temperatures to warm to highs from the mid 50s north to the
lower 60s south.-- End Changed Discussion --
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.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
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Fast moving, low amplitude northern stream shortwave to cross
the Great Lakes. Moisture and lift increase this evening as
associated surface wave and front move thru the area. Have pops
increasing to categorical early across the eastern half of
ILN/s forecast area - with the highest pops east of I-71.
Surface cold front will move through tonight which will usher in
much cooler air along with breezy conditions. Rain showers may
briefly mix with and change to snow showers across the north
prior to ending late tonight. No accumulation is expected from
these snow showers.
Lows tonight to range from the upper 20s northwest to near 40
southeast.
Surface high pressure to build into the area Saturday with
morning clouds giving way to increasing sunshine. Temperatures
look to be 7 to 10 degrees below normal with highs ranging from
the lower 40s north to the lower 50s south.-- End Changed Discussion --
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.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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Focus during this time period will be on the deep storm system
moving through the Mississippi River Valley and the wet weather it
will bring on Tuesday. At this time, hazardous weather still does
not seem to be in cards for the WFO ILN forecast area.
In the details, Saturday night/Sunday will feature high pressure
initially over Michigan on Saturday night, and then drifting off
into southeast Canada on Sunday. Dry northeasterly and then
easterly flow will be feeding into the area around the high, so
plenty of clear skies are in the offing, with low humidities and
slightly below normal temperatures /lower 50s/ for Sunday after a
frosty Saturday night.
Warming begins Sunday night as winds turn southeasterly and then
eventually southerly on Monday under height rises and deep
southwesterly flow aloft as progressive longwave trough digs into
the Intermountain West and then east into the Plains, taking on
negative tilt as it does. Deep surface cyclone /sub-990mb surface
pressures/ to move out into the KS/IA area on Monday, ejecting
rapidly northeast into MN/WI by sunset on Monday. Given the
southeast/southerly trajectories of the lower level flow on Monday,
this should be a rather dry / lower theta-e airstream so am keeping
Monday dry as moistening / thickening clouds should be centered
rather high aloft. Temperatures though should respond nicely and
surge well above normal, with 60s areawide during the day on Monday
under thickening mid/high clouds.
Well-agreed-upon and consistent arc of strong forcing ahead of the
occluded front with the filling/weakening low on Monday night and
Tuesday should enter the forecast area during this time with shield
of rain/showers. Right now, most areas should remain under an inch
of rainfall with this system as this rain crosses the area, but
probabilities of > 1" have been creeping northward toward the ILN
CWA in recent ensemble trends, though still remaining south/west of
the area. If system slows /deeper surface low/ further could see
some potential of heavier rains into the Tri-State, but right now
vast majority of ensemble members are not in this camp. Dewpoints
peaking in the lower 50s should preclude the formation of deeper
instability during peak heating on Tuesday, so thunder threats seem
pretty low right now but those details admittedly low confidence
right now. There is still some measure of timing discrepancy -
enough when in combination with the mid level trough axis not
clearing the area until later Wednesday, that shower chances need to
remain in the forecast at least in some capacity during most of the
day on Wednesday despite the bulk of the rainfall falling Tuesday.
System clears the area by Thursday, with dry weather returning and
temperatures remaining seasonable.-- End Changed Discussion --
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
VFR conditions to prevail overnight into the first part of
Friday. Rain showers will develop Friday afternoon ahead of a
warm front lifting north into the Ohio Valley. These showers
will become more widespread affecting the TAF sites late in the
day into the evening hours as a wave of low pressure tracks
across the area. Can not rule out an embedded thunderstorm
along and south of the Ohio River but probability and coverage
is too low to mention in the TAF forecast at this time.
As the low and frontal boundary works east through the area
this evening, MVFR ceilings will develop across the TAF sites.
OUTLOOK...MVFR ceilings and gusty winds possible late tonight
into Saturday and again Monday night into Tuesday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...Binau
AVIATION...AR