627
FXUS63 KEAX 152045
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
345 PM CDT Sat Jun 15 2024

.KEY MESSAGES...

- Isolated/Scattered Storms Possible This Evening

- Warm and Humid Conditions This Week

- Additional Shower/Storm Chances Throughout This Week

&&

.DISCUSSION...
Issued at 343 PM CDT Sat Jun 15 2024

Ridge axis has passed through the area with short-wave trough
working across the Central Plains this afternoon. An area of
stronger upper-level divergence appears to have aided in lift that
produced the thunderstorm and shower cluster early Saturday morning
across our western CWA. With the surface anticyclone shifting
eastward, weak southeasterly to southerly flow attempted to
push thermal boundary back northward as a warm front. However,
the outflow boundary for early morning convection has caused the
front to stall just south of Interstate 70. With weak dCVA,
expecting modest surface pressure falls through this evening and
persistent southerly flow to continue to provide more moisture
advection. Convergence along the warm front that appears to have
been strengthened through differential heating this afternoon
could provide a point of more convection initiation heading into
the evening hours. CAM solutions have been wavering on
redevelopment this afternoon, which is leading to lower forecast
confidence. Overall, mesoscale environment could support a few
stronger to low- end severe storms if storms are able to
develop. The boundary layer remains warm and moist, with
temperatures in the lower 90s and dewpoints crossing above 70
degrees. Mid-level lapse rates are looking more robust today
then they did yesterday, which is yielding greater MLCAPE values
for the southwestern third of the forecast area, current SPC
Mesoanalysis displaying 3000 J/kg. In this same area, where
strong differential heating occurred, visible satellite imagery
has been showing stronger cumulus clouds developing over the
past hours indicating the boundary destabilization on the warm
side of the boundary. The one limiting factor is that the better
deep layer shear is closer to the stronger mid-level flow,
which is more in northern Missouri and eastern Nebraska and
western Iowa. This may make it harder for convection to
organize, but the thermodynamics and lift with a second area of
upper-level divergence may lead to storms that could produce
some quarter size hail and downburst wind gusts. Low-level shear
and elevated SRH could be present along the boundary but will
remain very localized. Heading into this evening and overnight,
main mid-level vort max moves toward the area and provides
continued H5 height falls, and also shifts the warm front
northward. Additional development is possible, but the CAMs
have also been struggling to provide a consistent solution.
Given the high theta-e boundary layer, will keep POPs between 15
and 30 percent in western portions of the CWA through the
overnight hours where the instability axis will remain. Most of
these may end up just being general airmass thunderstorms. Far
northwestern counties may see more robust structure to
thunderstorms, but currently expecting supercell structure and
more prominent threat, including low-end tornado threat, to be
in eastern Nebraska and western Iowa. Will continue to monitor
northwest Missouri as the evening progresses.

Temperatures will remain above normal through the end of the week
with an anomalously strong ridge over the east coast helping to
set up persistent southwesterly flow through the week. Most
ensemble suites including those amongst most NBM members are
hold over 80 percent chances for exceeding 90 degrees on most
days through next week. The GEFS has been a bit cooler. The
extremes of the temperatures will depend on the how the strong
the ridge of the east is and where the PV anomaly over the
Pacific Northwest sets up. Within the southwesterly flow
expecting multiple embedded short-wave troughs and vort maxes to
ride through that will bring chances for precipitation.
Currently, the greatest signals and ensemble probabilities are
focused on Tuesday Night through Wednesday across most of our
forecast area with lower end chances continuing into Thursday.
Thermodynamically, the high theta-e boundary layer would be
supportive of stronger storms across eastern Kansas to central
Missouri. However, the stronger flow is currently progged to be
further west and northern of our area, which may limit severe
potential. Colorado State Machine Learning probabilities for
severe storms continue to favor a corridor from western Kansas
to the western Great Lakes for more active severe weather.
However, if stronger flow is able to sink further south, this
may be able to provide more organization to the storms during
midweek. While temperatures are very warm, precipitation may
help to provide some relief. Box and whiskers plots of
temperatures next week for medium range ensemble forecast do
show larger inner-quartile spreads for temperatures, likely due
to differences timing of shower activity.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1230 PM CDT Sat Jun 15 2024

VFR conditions prevail through the period as cloud coverage
continues to dissipate. Additional scattered to broken cloud
coverage is expected to move across the terminals throughout the TAF
interval, but these clouds will be above VFR thresholds. Scattered
showers are possible Sunday morning, but confidence is low at this
time. Winds will be out of the south-southeast at 10-15 knots
through the evening and overnight hours, possibly gusting over 20
knots within the first few hours of the period. Winds will
subsequently turn southwesterly in the early morning on Sunday.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Hayes