627
FXUS63 KLMK 131933
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
333 PM EDT Wed Aug 13 2025

.KEY MESSAGES...

* Warm and humid with isolated to scattered showers and
  thunderstorms, tonight into tomorrow. The risk for severe weather
  is low, though some storms could produce locally heavy downpours
  and frequent lightning.

* Hot and humid this weekend with highs in the low to mid 90s.
  Triple digit heat index values possible at times.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 332 PM EDT Wed Aug 13 2025

Positively tilted mid level trough stretching from the northeast US
back into the Ohio Valley, along with a slow moving sfc boundary
will keep the scattered showers/storms over the area this afternoon,
tonight and into the day tomorrow. The main threat remains the same,
heavy rainfall, thanks to PWAT values ranging between 1.50" to
2.00". Localized flooding, lightning and some gusty winds will
remain the main threat with any storms we see develop over the next
24 hours. Shear remains light and weak over the area so there
appears little to no threat of organized convection.

Radar mosaic this afternoon shows scattered showers and isolated
storms developing along both a weak sfc trough across southern and
central KY and the weak sfc boundary across southern IN. As
mentioned above, main threat this afternoon, remains locally heavy
rainfall, lightning and gusty winds. While most of this activity is
expected to diminish with the loss of daytime heating later this
evening, like last night, some activity may linger overnight into
the early morning hours. Patchy fog will once again be possible as
we go overnight and into the early morning hours. Where and how
dense the fog is will likely be determined on where it rains this
afternoon and evening and how much clearing we can get overnight.

Tomorrow looks like another wash, rinse and repeat kind of day but
the PoPs as well as location of rain/storm looks to be lower (20-
30%) as well as further south with areas from Lexington to
Louisville and points northward into southern IN look to remain
mainly dry.

It will remain warm and humid with overnight lows in the upper
60s/low 70s and highs tomorrow upper 80s to low 90s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 332 PM EDT Wed Aug 13 2025

For the end of the week and into the weekend, ridging will expand
from the central Plains and over the Ohio Valley along with strong
sfc high pressure will be positioned to our east and out into the
Atlantic Ocean. Other than just a slight chance of an isolated
shower or storm across the far southeastern corner of our CWA on
Friday, the forecast looks dry but hot. Highs will climb from the
low 90s on Friday and into the mid 90s by Sunday, we should see
enough mixing to keep dewpoints in the upper 60s to near 70
producing heat index values into the upper 90s with a few locations
seeing it feel like 100.

Ridging over the central US will weaken some for the start of next
week as a weak upper trough works over the top of the ridge and into
the Great Lakes and Ohio Valley. This will push another sfc boundary
southward towards southern IN and KY but how far south it reaches is
still in question. Given the mid-level trough and proximity of sfc
boundary, along with very warm temperatures in the low 90s.
Diurnally driven convection is possible each afternoon.

&&

.AVIATION /18Z TAFS THROUGH 00Z FRIDAY/...
Issued at 152 PM EDT Wed Aug 13 2025

Weak sfc cold front is across southern Indiana as it slowly drops
southward towards the Commonwealth of KY. There is also a weak sfc
boundary across south-central KY which has been firing some isolated
showers/storms. BWG may end up seeing 1 or 2 of these this evening
or afternoon. Them and RGA seem to have the highest chance of seeing
this kind of activity this afternoon and evening. The other story
has been some stubborn BKN MVFR clouds over a few location this
morning, we still anticipate a return to VFR flight categories later
this afternoon and evening. Then our attention turns to the prospect
of fog in the early morning hours of Thursday. Decided to bring all
TAF sites down in VIS but didn`t go to far to allow other shifts to
get a better look at the signal. I think alot of this will be
determine by rain that falls today and clearing overnight.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...BTN
AVIATION...BTN