499
FXUS63 KLMK 161110
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
710 AM EDT Mon Jun 16 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Patchy dense fog is possible this morning.

* Unsettled weather continues today with afternoon/evening showers
  and thunderstorm chances. The greatest coverage of showers and
  storms should be across portions of southwest and south central
  KY, where localized swaths of heavy rainfall and flash flooding
  are possible.

* Additional showers and storms are expected Tuesday through
  Thursday, before warmer and drier weather arrives next weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 349 AM EDT Mon Jun 16 2025

This morning, mainly dry conditions are present across central
Kentucky and southern Indiana as most of the showers and
thunderstorms have dissipated over the past few hours. Nighttime
microphysics satellite imagery shows a mixture of low stratus and
fog as well as scattered mid- and high-level clouds. As we head
toward sunrise, low level moisture should settle into a stratus
layer, and given weak boundary layer flow, patchy, locally dense fog
will again be possible. For now, we`ll handle this with an SPS, but
stronger wording may be needed based on obs trends.

While the upper-level disturbance which has brought several days of
afternoon and evening showers and thunderstorms has now dissipated
and moved east of the area, another low pressure system has set up
over the Ozarks. This subtle troughing will move across the region
over the next 24-36 hours, exiting to the east of the region Tuesday
into Tuesday evening. With our area expected to be downstream of the
trough axis this afternoon and evening, better forcing will be in
place with around 30 kt of SW flow expected at 500 mb. Low-mid level
flow will also increase this afternoon and evening as a 25 kt LLJ
noses into the region from the SW. As daytime destabilization takes
place, more organized waves of showers and storms should lift from
SW to NE this afternoon and evening. Support for strong and severe
convection will still be weak to non-existent. Although there should
be 1400-1800 J/kg MLCAPE this afternoon and 20-25 kt of deep layer
shear, mid-level lapse rates will again be poor and tall, skinny
CAPE profiles will limit updraft strength.

As has been the case over the past few days, the main hazard
associated with showers and storms over the next 24 hours will be
heavy rainfall and localized flooding. Short range progs show even
higher PW values (between 1.9-2.2") than previous days, and warm
cloud depths around 14 kft will support efficient rainfall
processes. Storm motions should be faster than over the weekend,
with mean cloud layer winds out of the SW at around 20 kt. However,
better forcing may allow for multiple waves of training storms. 00Z
HREF guidance continues to pinpoint an area across western and south
central KY for swaths of locally heavier rainfall, on the order of 2-
4". Given the combination of ingredients listed above, think it
would be wise to have elevated messaging for flooding potential, so
we`ll issue a flash flood watch across our southwestern CWA for this
afternoon and evening after collaboration with WFO PAH. Within the
watch area, there will likely be many areas which do not see
flooding; however, confidence in exact placement of the heaviest
rainfall swaths is only medium, so the watch placement is broad to
account for uncertainty.

Tonight, additional waves of showers and a few storms are expected
to continue after sunset, supported by continued 20-25 kt of SW flow
within a LLJ. Convection should diminish after 06Z tonight, though
isolated showers are likely to linger into Tuesday morning.

Temperatures will be held in check today and tonight by the
continued moist air mass. Highs this afternoon should top out in the
low-to-mid 80s, with lows in the upper 60s and lower 70s Tuesday
morning.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 349 AM EDT Mon Jun 16 2025

Tuesday through Tuesday Night...

Tuesday should be another unsettled day as the mid- and upper-level
wave crosses into the central Appalachians. High PW values will
still be present, and with better forcing still in the region, would
expect another day of scattered to numerous afternoon and evening
showers and storms. The greatest coverage of showers/storms should
shift from western/southwestern KY on Monday to east central KY on
Tuesday. Depending on how much rain falls on Monday and how FFG
values change, the flood watch may need to be expanded in time and
area to account for additional rain on Tuesday. In general, heavy
rainfall will again be the greatest threat with storms, although
gusty winds will be possible with a few storms.

Wednesday through Saturday...

A quasi-zonal upper-level pattern will continue into Wednesday, with
additional shortwave troughs sliding quickly across the CONUS.
Medium-range guidance continues to suggest that the most potent of
these systems will cross just north of the Ohio Valley Wednesday
into Thursday, bringing stronger flow aloft and better forcing for
showers and thunderstorms, some of which could be strong. As
the pressure gradient strengthens ahead of the cold front on
Wednesday, increasing SW winds should make for a breezy and
warm day on Wednesday, with highs reaching into the upper 80s
to near 90.

AI/ML guidance and CIPS analogs continue to suggest that the
Wednesday evening into Thursday morning period could bring an
elevated potential for strong to severe storms, although the best
forcing may reside just to the north of our area. Additionally,
there is still some discrepancy on timing of the upper wave/surface
front for Wednesday evening into Thursday. Right now, the most
likely timing for FROPA would be early Thursday morning, during the
diurnal minimum in instability. This would limit the potential for
strong or severe storms, but slightly earlier or later timing could
increase the severe potential.

Thursday, additional showers and storms will be possible as the
tropical air mass slowly clears to the east of the region. While the
front Wednesday into Thursday will bring drier air behind it,
temperatures should not change much despite FROPA, as the air
mass behind the front will still be quite warm. As we head into
Friday and next weekend, upper ridging over the southwest US will
spread east of the Mississippi and build as troughing descends along
the west coast. This pattern shift should bring mostly dry and hot
weather into the Ohio Valley for next weekend as warm
temperatures/high heights aloft suppress instability and convection.
By Saturday and Sunday, we should see our best chances for
widespread low-to-mid 90s so far in 2025, though given elevated soil
moisture levels, temperatures may end up being lower than model
guidance would suggest, at least initially.

&&

.AVIATION /12Z TAFS THROUGH 18Z TUESDAY/...
Issued at 709 AM EDT Mon Jun 16 2025

Patchy fog and low stratus should scatter and lift over the next few
hours, with lingering MVFR stratus possible through the late morning
hours. This afternoon, VFR conditions and light winds are expected
outside of scattered showers and thunderstorms. The best chances for
SHRA/TSRA will lift northeast from BWG this afternoon to other
forecast sites this evening and into tonight. Within these heavier
showers and storms, TEMPO IFR/MVFR visibilities would be expected.
Tonight, lingering showers are possible, with additional reductions
in visibilities possible. Outside of showers and storms, ceilings
and visibilities are expected to drop in the late evening and
overnight hours tonight into Tuesday morning. Ceilings and
visibilities should gradually improve again after sunrise Tuesday.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Flood Watch from 11 AM CDT this morning through late tonight
     for KYZ023-024-026-027-061>063-070>074.
IN...None.

&&

$$

SHORT TERM...CSG
LONG TERM...CSG
AVIATION...CSG/JH