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240
FXUS63 KEAX 071137
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
637 AM CDT Fri Jun 7 2024

.KEY MESSAGES...

- Showers and thunderstorms are expected this evening into
  tonight. Locally heavy rain and straight line winds are
  possible.

- A second round of thunderstorms and locally heavy rain is
  possible Saturday night. This rain should be shifted south but
  may still lead to flooding issues.

&&

.DISCUSSION...
Issued at 326 AM CDT Fri Jun 7 2024

Quiet morning across the forecast area with clear skies and
seasonably low dewpoints in the 40s and 50s. Changes are expected by
late afternoon into the evening hours. Moisture will gradually
build back into the CWA as modest southerly flow returns, with
dewpoints potentially in the lower to middle 60s across eastern
Kansas and western Missouri by sunset. Two zones of precipitation
are expected by late afternoon; elevated convection associated with
warm air advection within the warm sector over eastern Kansas and
western Missouri, and well upstream over north central Nebraska
associated with a strong LLJ and weak upper disturbance.

Northwest flow aloft will tend to take the Nebraska convection
southeastward towards Missouri during the evening hours, all the
while convection grows upscale and more linear with time. While deep
layer shear is impressive (60 kts), the general environment over
much of the CWA does not look particularly notable, especially
for early June, with the bulk of instability primarily residing
over eastern Kansas and far western Missouri, with a sharp drop
off with eastern extent. This is further complicated by the
late arrival of upstream convection between 10 PM and 2 AM as
cold pool/shear balance and available instability begins to
wane. With the anticipated storm mode and timing, large hail
and tornado threat appear considerably low, with localized
damaging wind gusts the primary concern with the most robust
convection. This will likely be confined to areas of far
northwestern Missouri and northeastern Kansas, where
shear/instability and storm organization are juxtaposed.
Confidence for severe weather in other areas south/east is
fairly low.

Moderate to heavy rainfall is expected tonight, with a basin
average of 0.5 to 1 inch of precipitation expected. The zone
with the most robust updrafts may be able to produce 1 to 2
inches of rainfall. Still, this is well shy of the 3-hour RFC
flash flood guidance, and with the progressive nature of this
thunderstorm cluster, the overall threat for flash flooding
should be low. The exception would be in any localized spot
where updraft regeneration can occur near the state line of
KS/MO as the LLJ gradually veers and noses into the area.

While a lull in thunderstorm activity can be expected for the first
half of Saturday, a much more volatile atmosphere may emerge by late
afternoon into the evening as strong instability and deep layer
shear reside ahead of a southward sagging cold front and shortwave
trough. A few supercell storms may develop near the Interstate 70
corridor over central Missouri during the evening hours, with all
hazards possible with these storms. Further upstream, a thunderstorm
complex originating off the Cheyenne Ridge and Palmer Divide will
shift into central Kansas. With time, convection may attempt to fill
in between these two areas, although the severity becomes much more
in question by late evening. Attention instead may turn to the hydro
side of things, as a corridor of heavy rainfall is possible over the
southern sections of the CWA. Depending on the rainfall tonight,
this could result in both localized flash flooding and river/stream
flooding.

The latter half of Sunday is expected to be quiet, with mild
temperatures on tap to start the week. While weak shortwave troughs
provide some potential for precipitation in the upcoming week, model
spread is high, owing to a low confidence forecast for rain. The
overall severe weather threat looks low during the mid/long range.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
-- Changed Discussion --
Issued at 630 AM CDT Fri Jun 7 2024

VFR conditions expected during the daylight hours. Light
southerly winds continue until the afternoon when they start
accelerating ahead of expected storms later today. Some
isolated storms are possible during the afternoon/evening;
however, a larger complex of thunderstorms is expected overnight Friday
into early Saturday morning. RA exits just beyond the TAF period.
-- End Changed Discussion --

&&

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

&&

$$

DISCUSSION...Blair
AVIATION...Pesel