-- Discussion containing changed information from previous version are highlighted. --
688
FXUS61 KILN 270137
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
937 PM EDT Sun May 26 2024

.SYNOPSIS...
Widespread showers and thunderstorms are expected tonight in
the moist and unstable circulation around low pressure to the
northwest. The threat for showers and thunderstorms is forecast
to diminish Monday as the low moves east. Showers will be
possible on Tuesday due to a disturbance crossing Northern Ohio.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
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Broad mid level trof over the Upper MS Valley and the Great
Lakes. Initial shortwave brought a round of strong to severe
storms to the area this afternoon. In the wake of these storms
the airmass was worked over and stabilized. ILN/s 00Z sounding
shows this CAP. This has left a dry period as we progressed into
the evening.

Low level theta-e advection is working to erode this CAP as
evident with latest ACARS data from CVG. Thunderstorm complex
moving across southern Illinois will continue to progress east
as the CAP continues to erode. The storms will eventually move
into a less favorable environment. The best threat for severe
storms will occur across ILN/s southwest counties - where the
low level theta-e advection will be most favorable. Further
north - storms will occur but severe threat will be limited due
to lack of favorable thermodynamics.

Heavy downpours could lead to localized flooding - especially
over the southwest.

All locations will see mild low temperatures in the lower and
middle 60s.
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&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
As a cold front containing plentiful moisture continues to
progress to Eastern Ohio, the threat for showers and
thunderstorms will decrease through the day on Monday, with dry
weather arriving by Monday evening. The dry period is expected
to last through Monday night in most locations as weak high
pressure pushes in from the southwest. The exception may be over
far northern counties where a weak disturbance could trigger a
few showers.

Temperatures will slip a bit due to cold advection, with highs
in the 70s followed by lows in the upper 50s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
No large scale changes were made to the extended forecast for this
period. Getting forecast out early to focus on ongoing weather this
afternoon. For Tuesday/Wednesday, did not see the overall threat of
thunder in the weather pattern with most unstable CAPE values <500
J/kg with a brief localized area just above this value skimming
central OH in the morning. Have removed thunder in favor of shower
activity for this period as thunder will not be the primary weather
type.

A couple of upper level disturbances will interact with an
overturning lower atmosphere due to cold advection. Some shower
activity is expected from Tuesday through the day Wednesday. A dry
period will be found from Wednesday night through the day on
Saturday as high pressure dominates the synoptic pattern. S/w energy
butting into the western edge of the upper ridge with a southerly
flow ahead of it and a trailing surface cold front will bring the
next threat of shower and thunderstorm activity beginning Saturday
night. Models are not in much agreement in timing and evolution of
the mass fields beginning Saturday night with the Euro and Canadian
models outpacing the GFS.

With the passage of the cold front prior to the long term time
period, temperatures will be cooler. High temperatures in the 60s
and 70s with lows in the 40s and 50s will begin to rebound Saturday,
then rise to near 80 as lows drop to the low 60s for Sunday and
Monday.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Broad mid level trof over the Upper MS Valley and the Great
Lakes. Initial shortwave and associated convection pivoted thru
the area this afternoon leaving MVFR clouds. As we head into
mid evening ceilings may improve to VFR prior to the development
of additional convection.

Next shortwave to rotate thru the Great Lakes overnight.
Additional thunderstorms are forecast to develop between 02Z-04Z
into the far southwest and overspread ILN/s area into the
eastern TAF sites by 06Z-07Z. Some of these storms will have
severe weather potential - especially across the southwest
overnight. Ceilings are expected to drop into MVFR category and
remain there thru Monday morning. Surface cold front to sweep
east thru the TAF sites early Monday.

VFR is likely to return Monday afternoon as clouds lift and
scatter out.

Southerly winds at 10 to 15 kts with gusts to 25 kts to veer
southwesterly overnight and then westerly Monday. Winds may gust
up to 25 to 30 kts on Monday.

OUTLOOK...MVFR conditions possible Tuesday afternoon into
Tuesday night.

&&

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

&&

$$
SYNOPSIS...Coniglio
NEAR TERM...AR
SHORT TERM...Coniglio
LONG TERM...Franks
AVIATION...AR