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000
FXUS63 KLMK 182345
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
745 PM EDT Thu Apr 18 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Strong to severe storms possible Thursday night. Highest risk of
    severe storms will be generally west of I-65.

*   Much cooler weather this weekend. Next chance of rain arrives in
    the Tuesday/Wednesday timeframe.

&&

.UPDATE...
Issued at 744 PM EDT Thu Apr 18 2024

A Severe Thunderstorm Watch is now in effect until 3am EDT for
portions of central Kentucky and southern Indiana, generally west of
I-65.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 346 PM EDT Thu Apr 18 2024

Currently, satellite imagery is showing a warm front stretching to
the northwest through southern Indiana and central Kentucky. This
front arches to the west into a surface low in western Missouri. To
the north of this front, dew points are in the 40s and 50s. To the
south of the front, mid 60s, and as we head through the afternoon
and evening hours, the surface low, part of a larger cold front
extending to the north and south, will begin moving towards
Indianapolis. This will cause the warm front and cold front to
develop an inverted "V" look by 0z over southern Illinois, eastern
Missouri and western Kentucky. Dew points over southern Indiana and
central Kentucky will likely drop into the 50s as the region becomes
better mixed.

As 1-2z approaches, the surface low will be moving from Illinois
into central Indiana. The area under the aforementioned inverted "V"
will see dew points in the mid 60s. Again, this is the area in
between the warm and cold fronts. On the leading edge, the warm
front will likely kick off convection over western Kentucky and
southward while the cold front running through Chicago arches
southward through southern Illinois. As these two lines continue
eastwards. The front line could become the dominate line for
southern part of the cold front over Missouri and could combine with
the northern half of the cold front, or it could remain as two
separate lines and join with the cold front over southern Indiana.
It doesn`t make much of a difference, except some over central
Kentucky could get one or two lines of convection.

The timing is going to help us from a severe weather standpoint.
Since the fronts won`t move through until after sunset, an inversion
is expected to develop and make any convection elevated. This will
limit potential wind energy from reaching the ground. Overall shear
is fairly weak. Think the current SPC outlook is a little bullish
over our CWA.

Winds tonight will remain out of the south to southwest around 5-10
mph. A few gusts around 30 mph will be possible as the line of
convection passes, and as the cold front begins to move through
during the morning on Friday, winds will quickly veer towards the
north-northwest increasing cold air advection into the area. Winds
tomorrow will stay around 10 mph as they gust to 15-20 mph.

WAA will keep temperatures warm tonight, only dropping into the 50s
to low 60s. Tomorrow, the sun is expected to return, but CAA will
limit temperatures to the 60s. A few in the Lake Cumberland region
could hit the low 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 346 PM EDT Thu Apr 18 2024

Friday Night through Monday Night..

Dry conditions are expected Friday night and into Saturday as a
surface high pressure system builds into the region with a dry zonal
flow pattern aloft.  A southern stream system may graze the far
southern part of KY Saturday night and Sunday morning, but the
latest trends in the data suggests a drier forecast may end up
prevailing.  Lows Friday night will dip into the upper 30s and lower
40s.  Highs Saturday will be cool highs in the 60-65 degree range.
Lows Saturday night should be a bit cooler with lows in the upper
30s across much of the region.  Areas south of the Cumberland
Parkway may only drop into the lower 40s.  Continued cool conditions
are expected for Sunday with highs in the upper 50s to near 60.
Depending on cloud cover conditions Sunday night, we could see some
patchy frost in southern IN and the KY Bluegrass region as lows dip
into the mid 30s.  Monday will see warmer conditions returning to
the area with temps warming up into the mid-upper 60s.

Tuesday through Thursday...

Forecast confidence continues to increase in another chance of
showers and storms coming into the region in the late Tuesday/early
Wednesday time frame as a shortwave trough aloft moves through the
region.  The previous forecast of solid PoP coverage still looks
good here.  Temperatures through the period will warm into the upper
60s to the lower 70s with overnight lows in the low-mid 40s.

&&

.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 744 PM EDT Thu Apr 18 2024

VFR conditions will deteriorate this evening as showers and
thunderstorms approach the region ahead of a cold front. Expect
impacts to ceilings and vis as thunderstorms roll through from west
to east, first at HNB in the next few hours, and later tonight at
LEX and RGA. The peak for convective activity will be from 02-09z
tonight. After the storms pass, ceilings will lower to MVFR and
likely below the 2k ft fuel alternate threshold near the pre-dawn
hours. There appears to be a short window where ceilings could drop
to IFR, so included a TEMPO group at all terminals for that as well.
We`ll gradually improve to VFR conditions again by late tomorrow
morning or early afternoon, with post-frontal winds from the north.

&&

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

&&

$$

UPDATE...CJP
SHORT TERM...KDW
LONG TERM...MJ
AVIATION...CJP