094
FXUS63 KEAX 300511
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1211 AM CDT Wed Jul 30 2025

.KEY MESSAGES...

- Widespread hazardous heat continues today. Heat index values
  range from 100-110. Hazardous heat continues for areas south
  of US-50 Wednesday.

- Isolated showers and storms are expected through the evening
  hours today. Additional storms are anticipated overnight
  tonight continuing through tomorrow morning. Another round of
  storms is expected during the afternoon and evening. A few
  strong storms are possible.

- Cooler conditions expected Thursday through the weekend.&&

.DISCUSSION...
Issued at 344 PM CDT Tue Jul 29 2025

A mesoscale convective system that traversed the central CONUS
overnight deviated around MO this morning only bringing some
interesting gravity wave features that could be seen on satellite
and radar. Hazardous heat continues to dominate the pattern and
generally south and southwesterly flow keep the train of warm air
and moisture flowing into the region. Heat index values once again
climb past 100 degrees with most areas around 105 to 110 with
locally higher heat index values possible.

Satellite imagery shows a band of clouds stretching from Maryville
SE through Warrensburg and Sedalia which is a focus point for the
development of pop-up showers this evening. Another boundary can be
seen extending from Cameron MO SW through Emporia, KS where
additional storms are developing. Isolated thunderstorms are
expected to continue through sunset. These storms are expected to
remain sub-severe; however, CAPE in excess of 4000 J/kg and PWATs
above 1.5 inches do show the potential for gusty winds and heavy
rainfall. Localized flooding is possible as saturated soils could
result in excessive runoff.

The weather pattern begins to overnight. The high pressure that
resides over the central and southern CONUS is slowly sliding
westward. As it does so, the more progressive zonal flow sinks
slightly southward. Simultaneously a shortwave trough, which can be
seen via water vapor imagery across the foothills of the Rockies,
encourages the development of an MCS which looks to track down the I-
80 corridor overnight with portions of this system stretching into
northern MO. Coverage of storms remains a little uncertain as models
have painted the southern extent of the precipitation potential
ranging from the MO/IA border all the way to the KC metro. Consensus
is that overnight showers and storms will likely reach to at least
the US-36 corridor. Storms are more likely to propagate southward
should the MCS be able to strengthen and take some MCV
characteristics leveraging subtle temperature differentials to
enhance the environment. The typical hazards of heavy rainfall and
potentially damaging winds continues. PWAT values continue to
average around 2 inches which breeds an environment conducive for
heavy rainfall. Flash flood guidance around 2 inches per 3 hours
certainly presents the opportunity for flooding. River flooding is
also possible as excessive runoff has the potential to fill creeks
and streams quickly.

The other effect of this MCS is the resultant cold pool that
emanates from it will bring cooler conditions across northern MO.
Unfortunately many south of I-70 will likely see muted effects from
this cold pool at best. Temperatures range from 80F in far NW MO to
95F across Bates and Henry counties. Heat indicies likewise range
from a pleasant sounding 85F to 105F across west central and
southern MO. Therefore, a heat advisory remains in effect for areas
south of US-50 for Wednesday. Depending on how the overnight MCS
plays out and the southward propagation of the cold pool, areas of
hazardous heat (and thus the heat advisory) may shift north or south.

This cold pool/outflow boundary will also serve as part of the
catalyst for storms Wednesday afternoon and evening. Winds ahead of
the outflow boundary continue to push a narrow corridor of warm air
and moisture back into the region attempting to destabilize the
atmosphere ahead of a synoptic cold frontal passage anticipated
Wednesday evening. Guidance continues to show varying scenarios.
There is consensus that there will likely be a second round of
storms; however, models differ in the vehicles which develop
convection. Many CAMs trigger storms along and ahead of the synoptic
cold front starting as isolated convection (with a couple supercells
possible) eventually congealing into a complex of storms. The
NAMnest paints a much more linear picture with a leeward low
manifesting across eastern Kansas draping a warm frontal boundary
along the I-70 corridor. The first scenario could result in isolated
supercells which given potentially 3000-4000 CAPE and 30-40 knots
shear paints a potential for all severe hazards; mainly damaging
winds. Fortunately, updraft helicity is not as strong downplaying
tornado potential, but the chances are not zero. The second scenario
yields high precipitation training storms emphasizing more
hydrological hazards; however, damaging wind and marginal tornado
hazards remain. The third scenario is the outflow sets up further
north or south than anticipated, the meso-low does not completely
manifest, and the initiation area of storms shifts by several miles
east or west. Unfortunately, that uncertainty will not be able to be
refined until we see how the MCS overnight tonight plays out.

Once we get past tomorrow, the outlook is much better for late
summer. 500mb flow becomes more zonal before high pressure from the
north begin to push in bringing a much needed cool down across the
region. Northwest flow aloft and easterly flow at the surface keeps
highs Thursday through Sunday average in the upper 70s to low 80s.
Southerly low level flow returns early next week; however, upper
level flow continues its NW to SE orientation as the upper level
high stalls across the SW CONUS. This combats low level warm
advection resulting in a slow warm up throughout next week. Several
embedded shortwaves bring opportunities for precipitation next
week.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1211 AM CDT Wed Jul 30 2025

VFR conds are expected thru 11Z when bkn cigs around 4kft are
expected at he TAF sites with lgt shra poss reducing vis to 5SM
btn 11Z-13Z. Aft 16Z bkn cigs around 4kft are fcst with a chc
for ocnl mod thunderstorms at the TAF sites btn 21Z-01Z which
may reduce vis to 2-4SM in stronger storms. Byd 01Z...cigs are
expected to remain bkn at 4kft thru the remainder of the TAF
pd. Winds will be out of the south around 5kts thru 16Z briefly
shifting to the north around 10kts btn 11Z-13Z as showers mov
thru the terminals. Aft 16Z...winds will veer to the SW around
10kts til 21Z when a storms ahead of a cold front will shift
winds to the N around 10kts.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 7 PM CDT this evening for MOZ043>046-053-
     054.
KS...Heat Advisory until 7 PM CDT this evening for KSZ057-060.

&&

$$

DISCUSSION...Pesel
AVIATION...73