Area Forecast Discussion Issued by NWS Wilmington, OH
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000
FXUS61 KILN 180549
AFDILN
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
149 AM EDT Mon Mar 18 2024
.SYNOPSIS...
An upper level low pressure system will bring scattered snow showers
and an unseasonable cold airmass to the Ohio Valley on Monday.
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.NEAR TERM /UNTIL 6 AM THIS MORNING/...
With colder air aloft widespread diurnal cumulus clouds
developed across areas north of the Ohio River. A few showers
developed across the far northern counties. With the loss of
daytime heating these clouds were decreasing in coverage. Latest
satellite imagery shows a good deal of clouds upstream. Have
adjusted the forecast going more pessimistic with cloud cover
but this may need to be adjusted for more clouds.
Gusty west to northwest winds this afternoon were beginning to
drop off to around 10 mph. These northwest winds will continue
at less than 10 mph overnight. Overnight lows will drop into
the mid to upper 20s.
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.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
An embedded mid level short wave will pivot down across the
Ohio Valley through the day on Monday. This will combine with a
fetch off of Lake Michigan, diurnal heating, and increasing low
level lapse rates, to result in fairly widespread snow shower
development from late morning on into the afternoon. This is
reflected in the snow squall parameter which lights up pretty
nicely across at least the northeast two thirds of our area.
For now will go with high chance pops/scattered wording across
most of the area but pops may need to be nudged up further with
later forecasts. Given the cold air aloft and the fact that
these will be convective showers, will keep ptype as all snow.
While ground temperatures will still be warm, it will be tough
to rule out some brief light accumulations on grassy/elevated
surfaces in any of the more significant snow showers.
Temperatures will be well below normal with daytime highs only
in the mid 30s to around 40 degrees. The snow shower activity
will slowly taper off heading into Monday evening with lows
Monday night in the mid 20s.
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.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
By Tuesday, the shortwave trough axis will have shifted southeast of
the region, however, much of the Great Lakes and Ohio Valley regions
remain within the longwave trough persisting over eastern North
America. The longwave trough lingers through Thursday before mid and
upper level flow temporarily becomes zonal. Conditions are expected
to remain dry through much of the week, but temperatures continue to
trend cooler toward the later half of the week as another surge of
cooler air drops in from the north. While Tuesday and Wednesday`s
high temperatures are near normal, Thursday afternoon will be a few
degrees below normal.
The next chance for precipitation arrives Thursday night into Friday
morning as a weak shortwave moving southeastward through the
longwave trough will supply weak synoptic lift. This will combine
with moisture sourced from a closed low passing the south of the
region. Overall, this leads to fairly lackluster precipitation
chances for the area through Friday. Heading into the weekend, a
longwave change appears to approach as a broad ridge opens up for
the central CONUS. This would suggest a gradual warming trend into
the weekend and early next week, with better rainfall chances
arriving next week.
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.AVIATION /06Z MONDAY THROUGH FRIDAY/...
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Main weather impact to the TAF sites over the 24-30 hour period
will be isolated to scattered snow showers Monday. These showers
are being produced by a mid-level trough which contains very
cold air aloft. This will cause the development of a broken
cumulus field and gusty (at times) winds from late morning into
the early evening hours, with best coverage likely in the mid-
to late-afternoon. The showers could also bring down visibility
and ceilings to MVFR levels, with localized visibility in
heavier showers down to IFR levels... especially at the
northern sites of DAY, CMH, and LCK.
The convection is likely to diminish after sunset as the trough
shifts to the east.
OUTLOOK...No significant weather.-- End Changed Discussion --
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.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
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$$
SYNOPSIS...JGL
NEAR TERM...AR
SHORT TERM...JGL
LONG TERM...McGinnis
AVIATION...