855
FXUS63 KEAX 011128
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
628 AM CDT Tue Jul 1 2025

...12z Aviation Update...

.KEY MESSAGES...

* Pleasant conditions today, with near-normal highs in the mid 80s,
  but comfortable dew points in the low 60s.

* Gradual warming and increasing humidity through remainder of week.
  - 4th of July: Heat index values creep back toward the upper 90s

* Next chances for showers/storms may return as early as 4th of
  July evening, but best chances may hold off until the weekend.

&&

.DISCUSSION...
Issued at 338 AM CDT Tue Jul 1 2025

After the last few days, a welcome couple/few days of quiet and
largely seasonably pleasant conditions have arrived.

Upper level pattern has broadly transitioned from the zonal flow of
recent days to more of a western ridge - eastern trough pattern,
though a weakly closed low is situated just off the California coast
as well. This has placed the region within NW upper level flow and
quiet, clear conditions. Surface high development on the heels of
the mid-upper trough has dropped into the Central Plains, broadly
centered over central to eastern Nebraska early this morning. Given
the lack of strong features/disturbances in the flow, this surface
high is quite broad and surface pressure gradient rather weak.
Because of that, air mass change has been slow and gradual,
predominantly in the form of falling/drier dew points. Do continue
to expect dew points to fall into the upper 50s to low 60s across
the area today, which will be noticeably more comfortable. Modest
850mb cooling, only into the mid-teens deg C, and strong diurnal
heating under clear skies this time of the year will keep
temperatures seasonable in the mid 80s ("normal" this time of the
year is mid 80s for the most part). But again, more comfortable with
the lower dew points.

Upper level pattern gradually shifts eastward through the week,
pushing ridging across the central CONUS. Fortunately, EML is not
expected to substantial locally, even as the upper ridge becomes
centered overhead around Friday/4th of July. Expectation for mid-
upper teens 850mb values locally, but into the lower 20s deg C just
to our west. At the surface, eastward departing surface high will
allow southerly winds to return Wednesday onward, aiding in gradual
warming and increasing dew points. Given the lack of substantial
thermal ridging and ho-hum southerly flow there is no current
expectation for oppressive heat and humidity. It will be seasonably
warm though with a moderate to high confidence in high temperatures
climbing back into the upper 80s to low 90s by Thursday/Friday and
dew points creeping back into the low 70s pushing heat index values
to the mid-upper 90s. Again, not truly oppressive, but enough to
warrant at least some caution given the plethora of outdoor
activities expected with the 4th of July Holiday.

With the upper level pattern gradually shifting, so too does the
previously mentioned cutoff upper low off the California Coast. This
too is where uncertainty begins to grow in the forecast. Confidence
is high in this feature gradually being absorbed into the larger
pattern, but given its rather weak nature in the first place,
synoptic guidance is not full lock-step with one another in how this
feature evolves through the week, including timing. This results in
reintroduction of low end (<30%) NBM PoPs as early as Friday PM over
western areas of the CWA, and further spreading eastward into the
weekend. Whether or not Friday evening may remain dry for various
pyrotechnic activities will likely hinge on arrival time of remnant
upper cutoff low (by then a broad and filling open wave) for broad
scale lift to overcome an expected CAP. Point soundings that far out
depict a weak CAP in place Friday and weak overall deep layer shear,
suggesting more of an air mass thunderstorm potential vs widespread.
Should convective activity not result for much (or all) of the area
Friday evening, chances will carry through the weekend as this
broad/weak lift overspreads and passes the area. The threat for any
strong/severe appears quite low at this point, but the plethora of
outdoor activities expected Friday (4th) through the weekend would
still warrant paying attention to forecasts and storms for
lightning.

Temperatures and heat index values into the weekend similar to the
4th Holiday, upper 80s/lower 90s and mid-upper 90s respectively as
upper levels appear poised to transition back toward a more zonal
stance and jet displaced across the Northern Plains/Southern Canada.
A likely weak frontal passage late weekend into next week will allow
for additional shower/storm chances, but confidence at this distance
is quite low for its location/progression.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 626 AM CDT Tue Jul 1 2025

Generally patchy fog has developed across the area in the wake
of showers and cloud cover that departed overnight. As such, TAF
sites KSTJ/KIXD have been most adversely affect. Those IFR/LIFR
conditions will continue early this morning, but should give way
quickly with much of this activity fairly shallow and rapid
diurnal heating this time of the year underneath otherwise clear
skies. Otherwise, quiet VFR conditions will prevail during the
period with light NNW/N winds.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...Curtis