472
FXUS63 KEAX 201941
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
Issued by National Weather Service Louisville KY
241 PM CDT Mon May 20 2024

.KEY MESSAGES...

- Enhanced risk of severe storms Tuesday afternoon into the
  evening hours, with all severe hazards possible.

- Active weather pattern for Friday through the Memorial Day
  weekend. Showers and storms possible each day with some
  potentially strong to severe.

&&

.DISCUSSION...
Issued at 237 PM CDT Mon May 20 2024

On the synoptic scale, upper level ridging extends across the
eastern U.S. from a large high pressure system anchored over Mexico,
while deep troughing extends across the western U.S. from deep low
pressure over central Canada. This general setup remains largely
unchanged throughout the forecast period, which will allow for a
progression of depressions to pass through our region bringing
unsettled weather throughout the week.

Latest surface analysis places a low pressure center over southern
MN with a serpentine warm front extending east across the Great
Lakes and a cold front extending SW into KS. This places our area
well within the warm sector, allowing for increasing moist air
advection and further destabilization ahead of the cold front.

Current radar shows mostly dissipating convection across our eastern
CWA as cloud temps continue to warm as evidenced by GOES-16 IR
imagery. Latest CAMs continue to show discrete convection initiating
into tonight as the environment boasts 2000 - 3000 J/kg of SBCAPE
and sufficient moisture as PWATs reside around 1.4 inches, which is
above the 90th percentile for this time of the year. Low confidence
continues in exact timing or placement of potential storms this
evening.

Further complicating tomorrow`s forecast is the possibility of
residual convective debris from any overnight storms upstream. Some
models do indicate a layer of low clouds lingering from sunrise into
the late morning, which could delay convective onset, especially in
our western counties. As the cold front approaches, diurnal
destabilization will result in steepening low to mid level lapse
rates as strong low and mid level jetting persists into the
afternoon hours. Upstream convection will likely evolve into a QLCS
with the southern portion of this line of storms strengthening into
the late afternoon and early evening hours Tuesday. Environmental
parameters suggest the possibility of all severe hazards with this
feature, and SPC has placed our area in a Day 2 Enhanced Risk. As of
now, the best timing appears to be from 3pm to midnight.

Showers and storms will linger Wednesday morning as the sfc cold
front works to the southeast and stalls along the I-44 corridor.
Most locations will dry out during the day as a weak area of sfc
high pressure builds in over the area, a few showers/storms will be
possible for our far southern and eastern parts of the CWA through
the afternoon thanks to their proximity to the stalled boundary. Dry
weather will continue into Thursday but turn warmer as the sfc high
works eastward into the Ohio Valley as a weak upper shortwave ridge
moves over the Upper Mississippi Valley. Temperatures will go from
the low/mid 70s on Wednesday climbing back into the upper 70s/low
80s for Thursday thanks to return flow behind the sfc high and the
area of ridging.

The pattern becomes active for the end of the week into the holiday
weekend as a series of shortwave troughs work out of the
Intermountain West along a quasi-zonal southwest oriented upper
flow. Showers and storms will be possible each day as forecast
soundings show good amount of instability and shear each afternoon
with CIPS analog and CSU Machine learning keying in on at least a 15
percent probability of severe weather across the central plains over
this time period.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1241 PM CDT Mon May 20 2024

Low-confidence forecast continues due to varying model guidance and
conditionally unstable environment. Latest surface analysis places a
low pressure center over southern MN with a warm front extending
east and a cold front extending to the SW, placing TAF sites within
a warm sector with general S-SW flow. Current radar shows a few
areas of convection moving eastward across the area. So far these
have been short lived, modest cells that have produced little
lightning. Began all TAF sites with VCTS to account to potential for
convection to generate this afternoon. Otherwise, VFR conditions
should prevail outside of convection with winds backing to SE this
evening and overnight. Winds do pick up by Tuesday morning out of
the south with gusts around 20kt. Enough models are also suggesting
the possibility of a layer of MVFR stratus to advect over the TAF
sites Tuesday morning, which could linger into the late morning
hours.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.

&&

$$

DISCUSSION...CG/BTN
AVIATION...CG