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918
FXUS63 KLMK 040123
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
923 PM EDT Mon Jun 3 2024

.KEY MESSAGES...

*   Warm and muggy weather through midweek.

*   Scattered to numerous storms will be possible Tuesday and
    Wednesday. A few strong to severe storms Wednesday could produce
    heavy downpours and gusty winds.

&&

.UPDATE...
-- Changed Discussion --
Issued at 923 PM EDT Mon Jun 3 2024

Showers and storms are beginning to taper down as the nocturnal
inversion sets in. Outflow boundaries from prior convection could
still trigger some isolated activity for the next couple of hours,
but most of the overnight should feature dry/quiet weather. Forecast
remains on track.
-- End Changed Discussion --

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 257 PM EDT Mon Jun 3 2024

Quasi-zonal pattern aloft upstream with a few weak disturbances
making their way into the Plains, while a weak ridge builds over the
eastern CONUS. The resulting deep but weak S-SW flow will enhance a
juicy air mass, with PWATs ramping up to more than 1.5 inches on
Tuesday.

This afternoon`s cirrus should clear out this evening, making for a
mostly clear night. Not as concerned about fog tonight as we hold
onto a light SE breeze to keep a little mixing, and lower dewpoints
have mixed down over most of the area today.

Will start the day Tuesday with scattered showers and perhaps a T-
storm working their way into south central Kentucky. Precip chances
will increase and expand across Kentucky and southern Indiana
through the day, with 50-60% coverage in play. QPF will be fairly
spotty, but a in this air mass any storm could produce a brief
downpour. Decent CAPE exists per the forecast soundings, but mid-
level lapse rates will be weak, limiting our SVR potential. Still
could have a few gusty pulse storms with near-severe wind gusts, but
organized severe weather is not expected.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 257 PM EDT Mon Jun 3 2024

Tuesday Night through Friday Night...

Scattered showers thunderstorms will likely be in progress at the
beginning of the period (Tuesday Night) as a mid-level shortwave
trough axis will be pulling through the region.  NBM PoPs look too
high for the overnight hours, so will likely pull back on PoPs by
mid-late evening and then dry things out overnight.  Lows look to
dip into the 65-70 degree range.

By Wednesday, another mid-level shortwave trough axis will push
toward the region along with an associated surface cold front
passing in the afternoon and evening.  Model soundings across the
region show about 1500-2500 J/kg of MLCAPE with about 30-35 kts of
shear, though somewhat higher shear lags behind the front and just
to our north.  Nonetheless, we should have a decent amount of
convective coverage across the region, probably more north of the
Parkways with lesser amounts across southern KY. Some storms could
be strong, with some isolated severe storms possible.  Damaging
winds would be the main weather hazard along with heavy rainfall and
cloud to ground lightning.  Showers/storms should linger into
Wednesday night before the cold front pushes through overnight.
Highs on the day will be in the upper 70s to the lower 80s with
overnight lows in the low-mid 60s.

Surface cold front should be east of our region by sunrise Thursday
leaving us with a dryer and much cooler pattern for Friday and into
the weekend.  Highs Thursday will be in the lower 80s with overnight
lows in dipping into the low-mid 50s. Highs on Friday will be in the
mid-upper 70s with overnight lows in the low-mid 50s.

Saturday and Sunday...

Anomalous, closed upper low will spin across the northeastern US
this weekend resulting in a northwest flow regime across the Ohio
Valley.  Not seeing much of a signal in terms of rainfall for
Saturday, but we`ll have to be on guard for some weak perturbations
to come through late Sat/Sun within the northwest flow.  Highs
Saturday should warm into the 75-80 degree range with highs on
Sunday warming into the 78-82 degree range.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 710 PM EDT Mon Jun 3 2024

Spotty rain showers and storms near the KY/TN border should
gradually dissipate this evening with the setting sun, giving way to
mostly dry conditions overnight. Unlike this morning, think the fog
threat overnight into tomorrow morning will be lower, as surface
winds should be sustained (albeit light) while patchy cirrus drifts
in overhead, and most guidance does not hit fog potential at all.
Will run with a fog free forecast at TAF sites for now but will
monitor potential development.

Scattered showers and storms could fire off within a few hours after
dawn tomorrow and be a threat for the region for the remainder of
the day. PROB30 timing is based off a blend of high-res model
guidance, but confidence in a particular hour for showers/storm
potential remains low. Any TAF site that is impacted by a heavier
shower or storm will likely see briefly reduced cigs/vis and
erratic gusty winds.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE...DM
SHORT TERM...RAS
LONG TERM...MJ
AVIATION...DM