337
FXUS63 KLMK 230721
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
321 AM EDT Thu May 23 2024

.KEY MESSAGES...

*   Strong/severe storms possible region wide this afternoon with
    damaging winds, hail, and very heavy rainfall being the main
    threats.

*   Stormy pattern with a risk for localized flooding Thursday
    through Tuesday with strong/severe storms possible Sunday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 320 AM EDT Thu May 23 2024

Remainder of the Overnight and into the Morning...

A 35-40kt LLJ located over the KY/TN border and a stalled surface
front over the Ohio River has allowed for convective initiation
within the last hour. As these showers and storms move NE, they will
be separated from the best (although weak) forcing and have very
limited instability to work with. Low stratus over the I-64 corridor
and north will remain until sunrise. Patchy fog is possible in low
lying areas.

Mid-morning through Early Afternoon...

Model guidance is not initiating well with current early morning
convection. However, given radar trends, much of the morning and
into the afternoon will likely remain dry. Drier conditions will
allow for increased heating and increased instability potential. Mid
60s dew points and high temperatures in the upper 70s and low 80s
will lead to muggy conditions.

Late Afternoon - Evening...

Weak shortwave troughing and CVA will move over the region in the
afternoon. This feature, coupled with the stalled surface front and
ample moisture will allow for scattered convective initiation over
the region. Weak, but sufficient shear will keep convection
disorganized and pulse-like. Main threats will be gusty to damaging
winds, heavy rain with downbursts, and marginal hail. Very limited
tornado threat due to weak low-level shear.

Thursday Night into Friday Morning...

With sunset, the nocturnal inversion will settle into the region and
convection will dissipate. The remainder of the night will feature
weak ridging, thinning skies, and calm to light winds. These
conditions coupled with recent precip will likely bring some patchy
fog to the region in the early morning hours.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 320 AM EDT Thu May 23 2024

Overall unsettled pattern through the holiday weekend, with multiple
waves of showers and storms, but also dry periods in between. Best
chances for dry weather will be Saturday and Saturday night, with
fairly widespread showers and storms for portions of Friday and
especially Sunday. Organized severe weather is also in play on
Sunday.

The upper pattern Friday is quasi-zonal without much phasing between
the northern and southern streams. Sfc warm sector will push PWATs
up to 1.5 inches or more, with decent instability but not much
shear. Could see gusty winds, perhaps near-severe, with the steep
low-level lapse rates, as well as brief heavy rainfall resulting in
localized flooding.

Can`t rule out isolated/scattered convection on Saturday but that
should be a mostly dry day. Sunday is the most interesting day with
a sub-1000mb sfc low tracking to our north, moderate instability and
strong speed and directional shear. Organized severe weather is
possible with all modes on the table including tornadoes. SPC
extended outlook highlights central and western Kentucky, so all
interests in the lower Ohio Valley should remain weather aware
through the holiday weekend.

Cold front pushes through early Monday, but cyclonic flow will mean
a slow exit for precipitation. Better chances for dry weather Tue-
Wed under a more NW flow regime, with temps on the lower side of
climo.

&&

.AVIATION /06Z TAFS THROUGH 12Z FRIDAY/...
Issued at 320 AM EDT Thu May 23 2024

Low stratus is building over I-64 terminals and will continue
through the remainder of the early morning. Radar shows some
convection beginning to develop over north-central TN and southern
IL along a cold front and weak LLJ, respectively. As these showers
and storms move NE through the Ohio Valley, they will incur very
limited instability and little forcing for sustainability. Showers
and storms are most likely to impact BWG and HNB, while keeping
other terminals precip free until the afternoon.

In the afternoon, instability will increase over the region and
coupled with a frontal boundary and mid-level shortwave will allow
for convective initiation. VCTS is expected at all terminals with
some TSRA possible. Further TAF issuances will be able to narrow a
timeframe for convective impacts.

&&

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

&&

$$

SHORT TERM...SRM
LONG TERM...RAS
AVIATION...SRM