Celestine, Indiana Weather Forecast Discussion

279
FXUS63 KLMK 201033
AFDLMK
Area Forecast Discussion
National Weather Service Louisville KY
633 AM EDT Sat Sep 20 2025
...Updated Aviation Discussion...
.KEY MESSAGES...
*  Mainly dry and unseasonably warm today with highs in the upper
   80s and low 90s.
*  Rain chances increase during the day Sunday with scattered
   showers and thunderstorms. Some storms may become strong, with
   gusty winds and hail possible.
*  Daily rain chances through next week. Beneficial rain ranging
   from 2.0" to as high as 3.50" along and north of the Ohio River
   by Friday afternoon.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 314 AM EDT Sat Sep 20 2025
Troughing is moving east into the Midwest and Ohio Valley this
morning. The lower Ohio Valley will just be on the periphery of the
larger troughing through the short term.
Through the day, convective debris clouds and a thin afternoon Cu
field will work over the region. Expecting to see high temperatures
in the upper 80s and low 90s. In the late afternoon and into the
evening hours, some showers and storms may develop to the west of
the region, but will quickly dissipate as they encounter dry air
still in place over the region. Some sprinkles or light rain isn`t
ruled out over the far western areas.
In the overnight hours, vorticity traveling along the upper
troughing will approach the region from the northwest. Additionally,
a 25-30kt LLJ will overspread the Ohio Valley, which will usher in
better moisture. This will develop scattered showers and storms
northwest of the region. In the early morning hours, we will begin
to see some showers move into southern Indiana. The majority of the
night will remain dry with increasing cloud coverage. Expecting to
see low temperatures in the low-to-mid 60s and some cooler spots in
the upper 50s.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 314 AM EDT Sat Sep 20 2025
Sunday...
Troughing will continue to slowly shift east and mostly remain to
the northwest of the region on Sunday. By Sunday afternoon,
southerly flow will have ushered in PWATs around 1.6 inches. This
moisture coupled with continued vorticity streaming over the region
will allow for showers and storms to develop. Best chances for
showers/storms will be over the northwestern half of the region.
Forcast soundings show modest CAPE (1500-1700 J/kg), weak
unidirectional shear, and modest lapse rates. As storms develop, we
could see some stronger storms capable of gusty winds and hail. Best
timing is Sunday late afternoon through the evening. HREF LPMMs show
a few bullseyes of about 2.0 inches over southern Indiana and along
the Ohio River.
In the overnight, a 25-30kt LLJ will once again overspread the Ohio
Valley and help to promote overnight showers and few storms. Storms
will remain limited given the weak instability profile, though
elevated convection is possible.
Monday through Tuesday...
The main trough axis will slowly swing through the region Monday
afternoon and evening. Forecast soundings continue to show modest
CAPE and increased shear. Showers and stroms will move through the
region Monday afternoon through the evening, where some storms could
become strong to severe.
On Tuesday, upper flow becomes messy and mostly zonal with a
continued vorticity stream from a developing cut-off low over the
central Plains. Showers and storms will remain over the region on
Tuesday.
Wednesday - The End of the Work Week...
The cut-off low over the central Plains will begin to work eastward
and interact with the troughing in place over the Great Lakes
region. Some long range guidance is suggesting these two features
eventually creating a Fujiwhara interaction over the mid-Mississippi
and Ohio Valleys. This Fujiwhara interaction would then develop a
surface low pressure system that moves through the region. During
this time, we will see continued shower and storm chances and near
normal temperatures.
Precip Chances Through the Long Term...
Over the last several days, we have seen guidance trend with
increased precipitation. Each day we have seen probabilities of
(much needed) rainfall increase. LREF probabilities now stand at 40-
60% of exceeding 2.0 inches of rainfall, and a 30% chance of
exceeding 3.0 inches of rainfall (mostly over the northwestern half
of the region). Current forecast shows a widespread 2-3 inches, with
locally higher amounts over the northwestern half of the region.
&&
.AVIATION /12Z TAFS THROUGH 18Z SUNDAY/...
Issued at 632 AM EDT Sat Sep 20 2025
Convective debris clouds stream over the region this morning and
winds are calm or light and variable. By mid-morning, winds will
begin to pick up out of the SSE around 5-7kts. In the afternoon, a
thin Cu field around 6-8kts will likely develop. In the overnight,
some isolated to scattered showers and storms will approach the
region from the west. These will begin to dissipate, though showers
are possible at BWG/HNB.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Air Quality Alert until midnight EDT tonight for KYZ029>031.
IN...Air Quality Alert until midnight EDT tonight for INZ077>079-
     090>092.
&&
$$
SHORT TERM...SRW
LONG TERM...SRW
AVIATION...SRW

NWS LMK Office Area Forecast Discussion