911
FXUS63 KEAX 230358
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1058 PM CDT Sun Jun 22 2025

...Updated 06z Aviation...

.KEY MESSAGES...

- Hot and humid conditions will continue through Monday, with
  only limited relief expected through the rest of the upcoming
  week.

- Chances for thunderstorms increase Monday afternoon and
  evening in far northeast Kansas and northwest Missouri. An
  isolated severe storm is possible (< 15% chance), with locally
  heavy rainfall and localized flooding a bigger concern (up to
  30% chance).

- Storm chances gradually increase for the rest of the region by
  late week, with low (< 15%) chances for severe weather.
  Locally heavy rainfall will remain the primary hazardous
  weather risk with any storms that occur.

&&

.DISCUSSION...
Issued at 147 PM CDT Sun Jun 22 2025

Another early-summer scorcher is in progress today across the
region, with temperatures in the 90s and heat indices
approaching/exceeding 100 degrees in much of the area. Despite
the reasonably similar tropospheric pattern in place versus that
of 24 hours ago, there are some subtle differences in sensible
weather today across the area. For areas south of the KC metro,
boundary-layer mixing has been more effective today in lowering
dew points this afternoon, with heat indices in these areas
primarily remaining in the 90s through 2 pm. Meanwhile, higher
dew points combined with slightly warmer temperatures have led
to widespread 100+ heat indices north of I-70 this afternoon. As
a synoptic front slowly approaches the region on Monday, expect
these spatial variations to persist, with perhaps even a
slightly more noticeable gradient in heat indices (highest north
to lowest south). Despite the marginal nature of the heat (at
least, compared to advisory criteria) in the southern parts of
the forecast area, the prolonged nature of the heat and lack of
overnight relief (lows in the mid to upper 70s) certainly
compensate, requiring continuation of the heat advisory through
Monday evening for the entire area.

Meanwhile, the aforementioned front will be approaching our far
northwest zones during peak heating on Monday. Proximity
soundings continue to indicate a moderate-to-very unstable
environment will be in place with little or no capping before
convective initiation. Convection-allowing models (CAMs)
initiate storms nearly universally between 2 and 4 pm near the
front (from north-central Kansas to far southeast Nebraska and
southern Iowa). With a lack of deep-layer shear, storm
organization will be limited, and fairly weak deep-layer flow
will keep storm motions relatively slow. With propagation
effects likely dominating convective evolution in an environment
of high (1.75-2.00") PWs, training storms producing bouts of
heavy rainfall will be the primary hazard with storms that
develop. However, water-loaded downdrafts will be capable of
producing sporadic damaging wind gusts, given dry midlevels and
high (900+ J/kg) DCAPE. This threat is outlined well by the
current slight-risk Day-2 severe weather outlook from the SPC
(mainly along/north of Doniphan County, KS, to Worth County,
MO). Though the marginal risk extends southward to the KC metro
and eastward to the Kirksville area, chances for storms rapidly
drop in these areas (and are generally lower than 20% farther
southeast). With CAMs in good agreement on the geographic
coverage/evolution of the storms, confidence is rather high that
any severe/flooding potential Monday and Monday night will
remain well northwest of the previously-mentioned KC to
Kirksville line.

One noticeable change with the convective evolution simulated by
the CAMs tomorrow is the lingering presence of storms overnight,
perhaps owing to a somewhat stronger trend with the nocturnal
low-level jet. The strongest convection should diminish by late
evening, but heavy rainfall will remain a threat with any storms
overnight. Localized totals in excess of 2 inches seem likely in
this environment, with the best chances of this just north of
our forecast area -- but high enough in our far north to warrant
mentioning here.

The forecast for Tuesday becomes murkier, owing to lingering
effects of the convection from Monday night, clashing with the
continued effects of upper ridging from the southeastern U.S.
Models have trended a little stronger with the ridging this
coming week, even extending its influence slightly farther west
in general Tuesday and Wednesday. Given the conflicting
influence of the antecedent convection and the perhaps re-
strengthening ridge, confidence was too low in any extension to
the heat advisory beyond Monday evening. However, it is not out
of the question extension of the current advisory or issuance of
subsequent advisories will be required for portions of the area
Tuesday and Wednesday given the increasingly-probable lingering
heat/humidity (especially for the southeastern half of the
CWA).

The more confident aspect of the stronger ridging is that
precipitation chances are lower for much of the forecast area
through midweek. Kept mentionable PoPs (15-40%) generally north
of U.S. Highway 36 Tuesday through Wednesday night as a result.
With a passing shortwave trough Monday night/Tuesday, the
expansion of ridging westward and even somewhat northward
Tuesday and Wednesday makes sense and would keep the storm track
to our north (and associated chances for more widespread
convection).

Ensembles are hinting at somewhat higher potential for
convection late in the week (Thursday and Friday), owing to a
perturbation ejecting into the northern/central Plains. However,
confidence is not particularly high on the southward extent of
storms, thanks to the strength of the southeast U.S. ridge. For
now, kept PoPs in the slight-chance to chance range (roughly 20
to 50 percent) during this time frame, but it is worth noting
that several deterministic runs from 12z have trended drier for
the area late this week. Should convection affect our area
during this time frame, the overall environment would again
favor sporadic downburst winds and locally heavy rainfall as the
main storm hazards.

Beyond the work week, models are trending toward retrogression
of the large-scale ridge in the southeastern U.S. This will keep
our region in the warmth and on the fringes of higher storm
potential (with rainfall chances continuing to be higher to our
north) for a while, but if retrogression is far enough west, we
may become more directly impacted by northwest upper-level
flow.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1057 PM CDT Sun Jun 22 2025

Gusty winds will continue through the overnight hours. This will
continue into Monday afternoon, but not expected to be as strong
Monday afternoon as they were the previous two days. High clouds
drift in through the afternoon, but will remain VFR. Scattered
shower activity starts to move toward the KC metro terminals
late Monday night into Tuesday morning.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 7 PM CDT Monday for MOZ001>008-011>017-
     020>025-028>033-037>040-043>046-053-054.
KS...Heat Advisory until 7 PM CDT Monday for KSZ025-057-060-102>105.

&&

$$

DISCUSSION...CMS
AVIATION...Krull