122
FXUS63 KEAX 241954
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
254 PM CDT Fri May 24 2024

.KEY MESSAGES...

- Severe storms possible this afternoon/ early this evening in
central and northeastern MO. Large hail and damaging winds the main
hazards.

- Severe thunderstorms likely Saturday night - early Sunday morning.
Damaging winds are the most likely hazard. A few tornadoes are also
possible.

- Quiet weather expected for Memorial Day itself.

&&

.DISCUSSION...
Issued at 253 PM CDT Fri May 24 2024

This afternoon: Overnight and morning convection has left an outflow
boundary, evident on satellite imagery and surface observations,
across north central to northeastern MO. A cold front is moving
eastward across the area and as of 19Z is splitting Miami County,
through the southeastern KC metro area and into north central MO,
intersecting the outflow boundary near Sullivan to Putnam county.
The environment south of the outflow boundary and east of the
advancing cold front is characterized by very high CAPE with MLCAPE
in excess of 3000-3500 J/kg. Strong mid to upper-level flow is
evident moving along the base of a strong shortwave trough/ closed
upper-low spinning over South Dakota. This stronger flow is
resulting in deep-layer shear of 30-35 kts. Given the strong
instability present and the advancing cold front, storms that
develop south of the outflow boundary and ahead of the front will
have good potential to become severe. Convection coverage in this
"warm sector" may begin to increase in the next few hours as an area
of CAA begins to impinge on the area. Shear oriented nearly 90
degrees across the boundary would favor a period of discreet cells
with supercells possible. All hazard types look possible this
afternoon if storms can develop in this warm sector.

Saturday night - Sunday morning: The next upper-level shortwave
trough, which is currently moving ashore on California, will affect
the region Saturday night to Sunday morning. While most of the day
Saturday will be dry and we`ll start the day with lower dewpoints,
warm and moist advection will quickly alter the environment during
the afternoon and evening hours. Strong instability will build into
the area and overnight there may be 2000 to 3000 J/kg of MUCAPE
available. This is all within strong mid and upper-level flow that
will lead to deep-layer shear of 40-50 kts. With a warm front draped
over the area and nosing into north central to northeastern KS,
storms will likely initiate in that area, organize into a line of
storms, and then move along the CAPE gradient splitting the area
along the warm front. This line will very likely be severe with
damaging winds the main threat. But 0-3km shear vectors oriented
generally west to east at 30-40 kts suggest there will be potential
for QLCS mesovortices and associated tornadoes or enhanced wind
gusts. With this being in the middle of the night, and on a holiday
weekend with people camping and more exposed than usual, people
really need to be alert Saturday night and know where to shelter if
storms approach. As we`ve seen recently, these QLCS tornadoes
develop quickly and may not be able to be warned with much or any
lead time. So folks need to head any severe thunderstorm warnings
that are issued as well.

Sunday: The forecast for Sunday is fairly uncertain at this point
and mainly as a result of what may happen late Saturday night and
early Sunday morning. First, it looks like convection, or possibly
more stratiform rain, in the wake of the overnight MCS, may linger
through Sunday morning. This would limit potential instability later
in the day and thus limit potential for storms. Also, if a strong
MCS moves through, we`ll likely be more stable Sunday afternoon as
the atmosphere recovers and that would limit how much instability is
built during the day and potential additional storms. The current
forecast has chance to likely PoPs for Sunday afternoon. It`s very
possible this is overdone but is heavily dependent on how the
earlier storms evolve and affect the airmass over the area.

Memorial Day: Generally quiet weather is expected for the holiday
cooler/drier dewpoints moving into the region with northwesterly low-
level flow. This will limit the potential for precipitation. Highs
will be very close to normal with highs in the upper 70s to near 80
degrees.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1218 PM CDT Fri May 24 2024

There is an area of MVFR ceilings building southward behind a
cold front that will affect the terminals this afternoon before
either diminishing or moving away. Guidance is not handling this
area well so timing of when they move away or dissipate is
uncertain. Otherwise, VFR conditions are likely (>70%) through
the remainder of the forecast with high pressure moving through.
Winds become light overnight and then trend to the southeast
tomorrow morning and increase to 10-15 kts.

&&

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

&&

$$

DISCUSSION...CDB
AVIATION...CDB