638
FXUS63 KLMK 101032
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
632 AM EDT Sun Aug 10 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Mostly dry conditions today, with an isolated shower or
  storm possible this afternoon.

* Shower and storm chances increase again early next week as cold
  front approaches the region. Severe weather chances are unlikely.

* Daily high temperatures in the upper 80s to lower 90s expected all
  week. With muggy dewpoints, could end up with heat indices
  approaching 100 degrees each afternoon.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 252 AM EDT Sun Aug 10 2025

The positively tilted upper ridge axis will be shifting slightly to
the east today, though sfc high pressure over the mid-Atlantic
coastline will keep a mostly dry influence across the region. Temps
are forecast to reach the upper 80s to lower 90s, and with sfc
dewpoints expected to hit the lower 70s, we will likely see heat
indices peak in the upper 90s this afternoon.

Similar to previous days, a few isolated showers or storms could pop
up this afternoon despite not much of any trigger in place. RAP
soundings do indicate pretty steep low level lapse rates to help
agitate some cu, though they will have to deal with a pretty healthy
mid-level inversion this afternoon. As a result, any storms that can
fire would likely struggle or top out at 15k feet or so. Will
mention a 15% chance to cover for the isolated chance this
afternoon, but majority of the area will keep dry today, with mostly
sunny skies.

The cu field and any isolated showers will dissipate with the loss
of peak heating. Mostly clear skycover is expected overnight, with
temps dropping into the upper 60s to lower 70s.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 252 AM EDT Sun Aug 10 2025

===== Monday through Thursday =====

Monday will mostly be a transition day between upper level features,
with the upper ridge departing to the northeast, and upper level
troughing set to spread across the Midwest. At the sfc, high
pressure looks to remain anchored to the mid-Atlantic coast one last
day, which will continue to influence a warm return flow regime into
the TN Valley. Moisture transport will begin to increase on Monday,
though above average PWATS will mostly be limited to Kentucky, which
is where the best chance for any scattered showers and storms to pop-
up during the afternoon. Model soundings indicate dry mid-levels,
supporting higher DCAPEs, though weak wind profiles lead to meager
shear parameters and sluggish storm motions. Given the potential for
DCAPEs over 1000 J/kg, microburst winds could occur with any
stronger storms that can overcome unimpressive mid-level lapse
rates. Any precip activity should dwindle into the nighttime hours
as heating is lost, but the moisture transport will continue into
Tuesday morning.

PWATs ramp up to near 2" by Tuesday, with the upper trough axis
pivoting towards the Great Lakes. At the sfc, an associated cold
front will be sweeping through the mid-Mississippi River Valley,
which will provide better forcing and moisture convergence in the
region. Showers and storms are expected to be more scattered
throughout the forecast area, with peak coverage during the
afternoon thanks to daytime heating.

The frontal boundary becomes more stationary north of the region for
Wednesday and Thursday, which will continue to provide ample
moisture and forcing for additional diurnally-driven showers and
storms. PoPs will peak on Wednesday due to the upper trough axis
swinging directly overhead. Some strong storms capable of producing
gusty winds, heavy rainfall, and frequent lightning will be possible
during this time. Storm motions will also be slow, leading to the
concern of localized flooding issues with storms feeding off PWATs
over 2 inches. As such, WPC has a marginal risk for excessive
rainfall for Wednesday and Thursday.

For this stretch, daily high temps are expected to reach the low to
mid 90s. The warmest day of the week may end up being Monday as we
will still be within the return flow from the sfc high to the east
and not much after precip to cool down the afternoon. Daily
dewpoints creeping into the low 70s are possible, which would end up
yielding heat indices in the upper 90s to around 100 degrees each
afternoon.


===== Friday and Saturday =====

The trough will push through the region Thursday night, allowing
weak ridging to move over the region. However, the stationary sfc
front will linger across Ohio, which could help provide some
additional precip activity for the end of the week and into the
weekend. Some afternoon scattered precip will remain in the
forecast, but overall decreasing PoPs are to be expected. Forecast
highs remain in the 90s as we get into the weekend, and with
dewpoints still in the 70s during the daytime, we have a good chance
for heat indices near 100.

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
Issued at 630 AM EDT Sun Aug 10 2025

VFR conditions are across the region this morning, with only some
mid-level clouds near BWG at this time. Expect afternoon scattered
diurnal cu filed to develop later today, with VFR and light winds.
We could have a few isolated showers this afternoon, but coverage
will be minimal, and not enough to include any mention in the TAFs
at this time. By this evening, cloud cover will begin to diminish
with the loss of daytime heating. VFR is expected to continue
overnight.

&&

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

&&

$$

SHORT TERM...CJP
LONG TERM...CJP
AVIATION...CJP