335
FXUS63 KEAX 221108
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
608 AM CDT Fri Aug 22 2025

...Updated 12z Aviation...

.KEY MESSAGES...

- Rain Showers and Isolated Thunderstorms Late Friday Into Early
  Saturday

- Cooler This Week; Low End Precipitation Chances Along Missouri-
  Kansas Sate Line and Westward

- Precipitation chances expand eastward into Central Missouri
  Toward End of Week

&&

.DISCUSSION...
Issued at 316 AM CDT Fri Aug 22 2025

H5 flow across the central CONUS will primarily be northwesterly for
several days, with a closed-low system sitting between the Northern
Great Lakes and Hudson, and 594dam high sitting over the southwest
CONUS. A few short-wave perturbations are progged to ride through
this flow over the next several days, especially as the cloesd-low
system sinks southward for a few days. This flow regime will help
keep temperatures fairly mild, ranging between the mid 70s to mid
80s. Throughout the week, there is decent spread between the inner-
quartile values for high temperatures especially beyond the weekend,
likely due to inconsistency in the timing of passing short-waves
through the mid-level flow.

For today, broad surface anticyclone across the Midwest to the
eastern Great Lakes Region will keep conditions mild and clear for
most of the day. The main feature to track will be a cold front
dropping southward from the Canadian Prairie Provinces, being driven
by the low that is south of Hudson Bay and strong surface
anticyclone in the Canadian Rockies. Most deterministic model
guidance depicts the strongest temperature gradient occurring around
H85 level, with a weak mid-level vort max helping to guide it
southward. This should begin to approach northwest Missouri and
northeast Kansas late Friday evening, perhaps in the 03-06z
timeframe, then eventually stall, and be forced more due east as the
low south of Hudson Bay wobbles back northward. Convergence should
increase ahead of this front, with potential for some moisture
pooling ahead of that should be enough to generate light shower
activity heading into the overnight hours, especially north of Hwy.
36. Most synoptic scale ensemble systems depict elevated
probabilities for measurable rainfall north of Hwy. 36, with lower
probabilities to around the Interstate 70 corridor. HREF mean QPF
suggests most activity stays along Hwy. 36 and northward, with this
second area focused over Central Kansas and into the Flint Hills. A
few isolated thunderstorms may be possible ahead of the approaching
thermal boundary depending on how much instability can be realized.
RAP suggests MUCAPE around 1500-1750 J/kg is possible directly ahead
of the front where that had depicted notable moisture pooling in the
axis of moisture convergence. 00z HREF mean MUCAPE values are lower
though, just under 1000 J/kg. There may be some deep layer shear
present in close vicinity of the thermal boundary, with 0-6km bulk
shear values around 30 kts. However, if the bulk of the forcing is
at 850mb and above, the effective shear may be considerably less.
Therefore, any strong storm or low-end severe threat with isolated
storms will be very minimal. Portions of Atchison [MO] and Nodaway
[MO] counties have been included in the 06z issuance of the SWODY1
under a marginal risk. The bulk of the stronger to low-end severe
threat will be more centered in Nebraska where the front will be
able to push up against a boundary layer that should be more
unstable from the late afternoon hours.

Saturday, ridge axis over the southwest CONUS shifts eastward which
will stall southeastward progress of the cold front, and will
attempt to push it back eastward. During the morning hours,
lingering convergence may present isolated to scattered showers,
perhaps as far south as Interstate 70. This may go further south if
a more organized system over Nebraska brings remnants into eastern
Kansas and western Missouri. By the afternoon to evening hours,
surface anticyclone should move from the Nebraska Sandhills toward
the lower Missouri River Valley, keeping conditions in extreme
eastern Kansas to Central Missouri mostly dry. Deterministic guidance
has been depicting a mid-level short-wave trough moving through
western and Central Kansas that develops as the southwestern CONUS
ridge axis makes a subtle shift eastward. This does appear to align
with low-lever axis of convergence caused by a weak surface low
developing over western Kansas with the anticyclone northeast of it
across the Nebraska Sandhills. Low end precipitation chances may
clip portions of Linn [KS] and Bates [MO] counties Saturday
afternoon, but most guidance keeps better precipitation chances from
the Flint Hills and westward.

Sunday and beyond, H5 closed-low make subtle shift eastward along
with the H5 ridge axis shifting toward the Rockies. Dominant AVA
regime sets up from the Midwest to lower Missouri River Valley and
eastward, developing a broad surface anticyclone across roughly the
eastern third of the CONUS. Deterministic guidance depicts several
mid-level short-waves traversing the northwesterly flow just
downstream from the ridge axis, promoting lift mainly across Central
Kansas through much of the start of the of the work week. Ensemble
suites have also depicted multiple opportunities for rain shower
activity primarily for central Kansas, though there are a few members
that indicate this may reach just east of the Kansas-Missouri state
line. For the KC metro, this may bring some isolated activity
through Tuesday, with areas then east of Interstate 35 remaining
mostly dry. This will also help keep temperatures mild. Eventually
the closed-low system gets forced eastward, and more activity in the
Pacific Northwest breaks the ridge down which should shift
persistent forcing eastward into Central Missouri for rain shower
activity toward end of the forecast period. Temperatures still look
to remain mild through this pattern.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 606 AM CDT Fri Aug 22 2025

Patchy fog possible in some parts of eastern Kansas to Central
Missouri this morning, this conditions should clear up. High
pressure this afternoon will keep conditions mild. Next feature
to watch will be cold front late tonight moving southward from
Nebraska and Iowa. Expecting shower activity in northern
Missouri. Uncertain at this time how far south showers will make
it, so there will not be any mention of activity in 12z TAFs for
STJ and KC Metro TAF sites.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Krull