Expires:No;;873575
FXUS63 KLMK 061743
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
143 PM EDT Sun Apr 6 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Areal flooding will slowly diminish today but river flooding will 
  continue into the second half of April.

* Patchy frost will be possible early tomorrow morning in southern 
  Indiana.

* A hard freeze is expected for Monday night and again Tuesday 
  night, with many locations dropping into the middle and upper 20s. 
  A Freeze Watch has been issued for Monday night. Tuesday night may 
  also require one in future forecasts.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 310 AM EDT Sun Apr 6 2025

The surface boundary that has been plaguing us recently has slipped 
to the southeast, but not by much, and waves of low pressure will be 
riding northeastward along the boundary today. As a result, clouds 
and showers will continue. Instability will be meager, with just a 
few rumbles of thunder possible in the Lake Cumberland and Blue 
Grass regions. Rainfall totals will be light, around a third of an 
inch or less after 12Z...though a few spots in the Blue Grass could 
approach half an inch. Because of the light QPF, and because we're 
past the "watch" phase of this flood event, will let the Flood Watch 
expire on time this morning and will let the already established 
flooding be covered by areal and river Flood Warnings. 

The rain will end (!) this evening, followed by partially clearing 
skies and light winds overnight. Temperatures will fall into the 30s 
by morning. There may be just enough clearing skies and light winds 
to lead to some patchy frost formation in southern Indiana.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 310 AM EDT Sun Apr 6 2025

Monday - Tuesday

Strong Canadian high pressure will push a cold front ahead of it as 
the high drops SSE from Saskatchewan to the Great Lakes. Fropa in 
the Ohio Valley will occur Monday evening, and will likely be dry, 
though there is a very small chance of an isolated shower or two, 
especially in the Blue Grass, a couple hours either side of sunset. 
After highs in the 50s on Monday, the front will usher in much 
colder air. By Tuesday morning the mercury will have tumbled into 
the middle and upper 20s for most...lower 30s in the Bowling Green 
region. This will bring many locations a hard freeze, and the 
coldest readings since at least March 21. Confidence in a freeze is 
fairly high due to model consistency over the past several runs, 
progged temps well below freezing, and ECMWF EFI showing a signal 
for unusual cold. So, after coordinating with neighbors, will go 
ahead and hoist a 4th period Freeze Watch for Monday night.

Tuesday will be chilly but mostly sunny as the high sinks farther to 
the south. Afternoon temperatures will range from the upper 40s to 
middle 50s, which is about 15 degrees below normal. This will be 
followed by another chilly night, though a couple degrees warmer 
than Monday night as the high moves off to our east and clouds begin 
to increase from the northwest as the next system approaches. Still, 
most locations will see another freeze Tuesday night.

Wednesday - Thursday

A clipper type low will quickly cruise from around Omaha Wednesday 
morning to near Cleveland by Thursday evening pulling its trailing 
cold front through the Ohio Valley. This system will bring a period 
of showers to the region Wednesday night through Thursday night. 
There should be enough instability and deep layer shear for 
organized convection Thursday afternoon ahead of the cold front, 
though so far severe storms look unlikely. QPF for this system is on 
the order of half an inch over 24-48 hours so no impact on river 
flooding is expected.

Friday - Saturday

Confidence decreases quite a bit for the end of the week as models 
diverge. In general it looks like the 5H trough that brought us the 
showery weather Thursday will push to the East Coast by Saturday as 
ridging moves into the Plains.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 142 PM EDT Sun Apr 6 2025

Impacts to cigs will continue through this evening and most of the 
overnight, with IFR clouds handing around. Light precip will also 
continue for this evening, but the stalled front will finally shift 
off to the east by tomorrow. Some drizzle will be possible as cigs 
hang on, but an overall drier trend will settle in by tomorrow. 
Flight conditions will be improving to MVFR or VFR by the end of the 
TAF period, but this will be dependent on location. HNB/SDF/BWG will 
likely scatter out the cloud deck, but LEX/RGA will likely hold onto 
a MVFR cig through the end of this period. Wind will be light and 
from the NNE.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Freeze Watch from late Monday night through Tuesday morning 
     for KYZ023>043-045>049-053>057-061>067-070>078-081-082.
IN...Freeze Watch from late Monday night through Tuesday morning 
     for INZ076>079-083-084-089>092.

&&

$$

SHORT TERM...13
LONG TERM...13
AVIATION...CJP