511
FXUS63 KEAX 301137
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
637 AM CDT Mon Jun 30 2025

...12z Aviation Update...

.KEY MESSAGES...

* Chances for storms this morning thru the afternoon, gradually
  shifting eastward.
  - There is a Marginal Risk for Severe Storms, mainly east of
    I-35 and I-49 corridors

* Generally comfortable early work week, including less
  humidity, then gradually warming and more humid thru the 4th
  of July Holiday.

&&

.DISCUSSION...
Issued at 332 AM CDT Mon Jun 30 2025

The good news, forecast confidence is greater than last night at
this point in time. But that on its own is not necessarily saying
much considering how low confidence the situation was yesterday
early morning. Though, with a changing upper level pattern
(shortwave trough) moving into the region this morning/today,
confidence is at least moderate in the general convective
progression through the day today.

The largely zonal/stagnant upper level flow pattern of late has
begun to see more substantial change as a shortwave trough continues
to drop out of the Northern Plains and towards the Great Lakes and
Mid-Mississippi Valley Regions. This will both provide large
scale/broad lift and push a cold frontal boundary through as a
surface high builds into the western Northern Plains.

As such, this pattern progression has produced a fairly persistent
low-end severe MCS overnight, currently tracking across central and
south-central Nebraska early this morning within an unstable MUCAPE
environment of >2000 J/kg. Additionally, a modest 20-30kt LLJ has
blossomed scattered convection across portions of northwest and
north-central Kansas. All of this activity should continue to track
SE, and is largely well depicted within recent hi-res/CAM guidance,
following the MUCAPE gradient. Given the continued weak steering
flow otherwise, do not see much ability/potential for deviation from
this preferred solution. So, that pushes convective activity toward
Missouri in the couple/few hours around/after sunrise but should be
on a weakening trend given a general of substantial environmental
factors pointing towards sustained strong cold pool generation. As
of now, a window of arrival to the western CWA of between 8-10am is
favored. Not out of the question for a couple/few enhanced stronger,
borderline severe, down bursts with wind profiles favoring precip
loading and HRRR/RAP depictions of at least some modest dry air in
the 900-700 layer. Otherwise, activity should continue to be on a
gradually weakening trend initially thru the morning.

By around mid to late morning, surface cold front begins to push
into portions of NW Missouri and NE Kansas and will meander across
the state through the day and evening hours. This, along with the
broader lift with the approach/arrival of the upper shortwave
trough, remains expected to trigger off additional scattered
convection across the area through the remainder of the day. This
includes potential for both pre and post frontal convection
considering the lack of substantial air mass change. There is an SPC
Marginal Risk, for strong/damaging winds, mainly for areas east of
the I-35 and I-49 corridors. Environment may not be wholly different
than yesterday, being marginally supportive for periodic enhanced
downdrafts/wet-microbursts. This may be most prevalent with post-
frontal convection as some drying in the lowest levels will occur.
One potential bug in the ointment will inevitably be how initial MCS
evolves this morning. Should it "hang on" longer, that may limit the
generation of moderate instability (~1500-2000 J/kg) depicted in
various CAM guidance. Not necessarily a substantial consequence
(unlike what transpired just yesterday), given the already marginal
environment. Conditions then dry out from NW to SE evening and
overnight tonight.

Upper level pattern continues to transition away from the recent
zonal flow, taking on a more amplified look as the shortwave trough
pushes eastward and digs a bit further southward. This places the
region within a NW flow regime and initially pleasant conditions
with surface high influence and northerly winds through Tuesday.
Expect temperatures predominantly in the mid 80s with pleasant dew
points in the upper 50s/lower 60s. Surface high glides E/SE,
allowing southerly winds to return by Wednesday, which too will push
temperatures and dew points gradually warmer. Upper level pattern
shifts eastward during this time as well, building in ridging across
the central CONUS. From Wednesday thru Friday/4th of July, if not
into the weekend, southerly winds are expected to prevail and push
highs back towards the lower 90s and dew points back into the lower
70s. This may see heat index values flirt with 100 by Friday.
Precipitation chances begin to creep back into the picture late
week, though prevailing sentiment of synoptic guidance currently
keeps the area on the dry side through Friday/4th of July.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 630 AM CDT Mon Jun 30 2025

First half of the TAF period will carry all the potential non-
VFR conditions. MCS gliding eastward out of Kansas, along with
widely scattered convection ahead of it, will affect all TAF
sites this morning. Progression of this activity should be TSRA
to SHRA over a period of 2-4 hours. Have done best to time the
activity to the TAF sites, limiting prevailing TSRA to 2 hrs or
less then transitioning to SHRA as depicted on KTWX radar. A
break mid-late morning then may give way to scattered pre and
post frontal convection this afternoon and early evening. Have
addressed this with PROB30s at all sites. Once that activity
wanes, VFR conditions to prevail remainder of period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch until 1 PM CDT this afternoon for MOZ001>005-
     011>014-020>022-028>030-037-038-043-044-053-054.
KS...Flood Watch until 1 PM CDT this afternoon for KSZ025-057-060-
     102>105.

&&

$$

DISCUSSION...Curtis
AVIATION...Curtis