851
FXUS63 KPAH 212338
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
638 PM CDT Tue May 21 2024

.KEY MESSAGES...

- Heat continues today with highs in the upper 80s to lower 90s.
  Breezy today as well.

- Storms possible later this evening through the overnight. Some
  could be strong to severe.

- Storms possible again tomorrow afternoon through evening. Some
  could be strong to severe.

- Storms look to be possible each day through Sunday. Sunday
  looks to be the best chance for severe weather. Will need to
  watch Sunday closely.

&&

.DISCUSSION...
Issued at 235 PM CDT Tue May 21 2024

Aloft there is an upper low over Alberta/Saskatchewan with a trof
through MT and WY. A leading shortwave is moving through the
northern Plains and upper Midwest. The sfc low is intensifying and
moving through eastern NE, IA, and MN with an attendant cold front
running southwest to northeast. Good southerly flow at the sfc today
is helping to advect in higher dewpoints in the upper 60s and highs
in the upper 80s to lower 90s. Convection looks to initiate late
this afternoon along the cold front/dry line to the west over
central and southwestern MO and moves through towards our area this
evening. The cold front is then expected to stall to our north and
west this evening. Some of the anticipated storms this evening could
be strong to severe. Severe parameters look decent with 0-6 km shear
30-40 kts, 1,500-2,000 J/kg of MUCAPE, and mid level lapse rates
around 7.5-8 degC/km. The main threats would be wind and hail with a
low tornado risk.

Tomorrow the first upper level low moves north of MN with an
embedded shortwave moving through the upper Midwest in the
afternoon. Models mostly show a break in convection tomorrow morning
(with the exception of the EC). Storms tomorrow afternoon/evening
will be very contingent on there being this break during the
morning. More daytime heating will yield more instability. If storms
can take off (and several models suggest they do) then several could
become severe, though convection looks to be short lived and
only last through the evening. Models are showing 2,500-3,500
J/kg of MUCAPE, 45-50 kts of 0-6 km shear, and mid level lapse
rates of 6.5-7.5 degC/km. All modes of severe look to be
possible with supercells being the primary cause, though
coverage looks to be isolated to scattered. PWATs also look to
be in the 90th percentile both tonight and tomorrow. A Flood
Watch may not be necessary though due to the isolated nature and
brief duration of the the storms. However, localized flash
flooding is still possible with heavier downpours.

There is still a little bit of discrepancy between the EC and the
GFS with regards to precip on Thursday. The EC has more widespread
rain vs the GFS. The cold front which had stalled north and west of
the area, looks to maybe sag south slightly and then kind of wash
out over the area during the day. In the current pattern both models
show precip chances each day through Sunday. A few storms could be
strong to severe each day, but it`s hard to say for sure at the
moment. Sunday a more organized shortwave aloft comes out of the
central Plains. There is good consistency in the EC and GFS
with the presence and progression of this shortwave. The severe
threat on Sunday looks to be stronger than tonight or tomorrow.
0-6 km shear is 40-60 kts, MUCAPE is 2,500-3,500 J/kg, and mid
level lapse rates are an impressive 8.5-9.0 degC/km. This is
still quite a ways away though and will bear close watching.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 631 PM CDT Tue May 21 2024

There are two periods of convection that may impact the
terminals. The first is ongoing to the west, with a line of
SHRA/TSRA. This activity is expected to push into SEMO, and
portions of S IL overnight with a weakening trend. Reductions in
ceilings and visibility is likely near any shower activity or
thunderstorms. The highest confidence for tonight is at CGI and
MVN. Guidance favors MVFR CIGS by sunrise for most sites with
some IFR possible at CGI. The next period of SHRA/TSRA arrives
Wednesday afternoon. Gusty south winds will continue for a few
more hours this evening before relaxing to 5-10 knots for the
remainder of the period.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.

&&

$$

DISCUSSION...SHAWKEY
AVIATION...AD