339
FXUS63 KEAX 301120
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
620 AM CDT Tue Sep 30 2025

...12z Aviation Update...

.KEY MESSAGES...

* No hazardous weather is expected thru the work week and weekend
  - Above normal fall temps, mainly mid-upper 80s
  - Predominantly dry conditions

* Some regression toward normal (cooler) temperatures likely
  and precipitation chances by early next week.

&&

.DISCUSSION...
Issued at 403 AM CDT Tue Sep 30 2025

Just how many different ways can you describe a quiet, dry, and
fairly stagnant weather pattern? Probably not too many more... but
at least there is some change signaled during latter portions of the
forecast. So off we go...

Mid-upper level ridging remains the primary driver of sensible
weather conditions in the region, even though its axis has slid
eastward some by this point. Early morning conditions remain largely
the same as the previous few mornings, including mostly clear skies
and light/variable to calm winds. Little noticeable fog activity in
river valleys or otherwise prone areas with the amply dry
conditions of late exerting ever increasing influence there.
Otherwise, only perceivable change over previous days and nights
tends to be the smattering of high level cloud cover as S/SW upper
level flow moves into the Plains. For today, high level clouds will
continue to stream into the area, but too will be eaten away as they
migrate into drier air. Eventually, open wave lifting out of the
TX/OK regions will overspread strong/deeper lift and likely yield
broken to overcast skies by this evening and overnight. The effect
of cloud cover can be teased out in the high temperature forecasts
today, with far western Missouri and into Kansas a few to handful of
degrees cooler than eastern Missouri... low to mid 80s vs upper 80s.
Overall inconsequential, but of casual note should expansive cloud
cover either be earlier and more expansive or slower and less
expansive.

Looking through the majority of the rest of the work week,
deterministic and ensemble synoptic guidance remains in very strong
agreement in pattern evolution and resulting sensible weather. In
effect, the mid-upper ridge finds itself only gradually spreading
eastward from the Mid-Missippi Valley to the Ohio Valley as Tropical
Storm Imelda and Hurricane Humberto play out in the Atlantic basin.
And as the previously mentioned open wave lifting out of TX/OK lifts
N/NE, a deep western CONUS trough will begin to dig in and
exert/amplify ridging into the southern central Plains. All of this
to say that there will be no significant changes to ongoing
conditions. Expect dry conditions and high temperatures to largely
remain in the mid to upper 80s and mostly light southerly winds.

Through the weekend, pattern still hints at more significant pattern
shift as western CONUS trough moves across Inter-Mountain West and
into the central Plains, but has slowed down in recent synoptic
runs. This keeps the area on the warm side of the SW flow pattern
with warm (mid-upper 80s) and dry conditions continuing. More
noticeable will be increasing southerly winds as surface pressure
gradient increases in response to Lee Cyclogenesis. Precipitation
chances previously suggested as early as Friday night, look to be
pushed back towards Sunday or later.

Into early next week, flagship deterministic guidance are in fair
agreement on finally pushing a cold frontal boundary across the area
as the upper wave translates NE. Unfortunately, ensembles are not
necessarily as confident as spread increases significantly here on
out. Even so, there is fair to good confidence in a cooling trend
when observing the ensemble output, even with the increased spreads.
There is less confidence in appreciable precipitation though,
especially given existing dry air mass, limited low level moisture
return depicted, and potential reliance of mid-upper level moisture
streaming in from the Pacific. Current takeaways for this time frame
are a likely cooling trend (think 70s to low 80s) and uncertain
precipitation opportunities (best chances N/NW).

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 614 AM CDT Tue Sep 30 2025

VFR conditions to prevail throughout the TAF period across all
sites. During daytime hours, SE winds to prevail across the area
but remain on the lighter side around 4-8kts. Otherwise expect
light and variable winds during early morning, post- dusk, and
overnight hours. SCT250 to BKN250 high level cloud cover
streams in today, likely increasing to BKN/OVC200 during latter
half of the TAF period. Also may see periods of diurnal CU,
FEW/SCT070 today.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...Curtis