424
FXUS63 KEAX 181749
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1249 PM CDT Mon Aug 18 2025

.KEY MESSAGES...

- Several uncertainties continue in this forecast regarding
  both heat and storms.

- Scattered showers and storms are expected today. Coverage is
  expected to range from isolated to small complexes. Storms are
  possible most of the day; however, chances are higher during
  the afternoon continuing through Tuesday. Heavy rainfall and
  gusty winds are possible.

- Hot and humid conditions some areas may see heat index values
  near 100-105F (mainly south of US-50). Other areas will see
  heat index values near 100F. Cloud cover and scattered storms
  may affect heat forecasts.

&&

.DISCUSSION...
Issued at 135 AM CDT Mon Aug 18 2025

The weather pattern continues to be quite complex. Satellite imagery
shows several waves around a small high pressure system across
eastern MO and western IL. This lies underneath a weakening upper
level ridge centered across the Ouachita Mountains and Ozark
Plateau. Several waves and mesoscale convective systems dot the
central and southern CONUS. The most prominent system being across
the Sand Hills of Nebraska extending into northern Iowa and northern
Illinois. A few smaller systems occupy north central KS and southern
MO. While those systems are not as strong, the residual outflow
boundaries of these systems will affect the precipitation outlooks
for today. One of these outflow boundaries could be seen on KEAX
radar from 03-06Z moving westward across MO. Several upper level
waves are progressing through the flow along the NW side of the
upper level high. These waves are tapping into the moisture rich
slightly destabilized air initiating thunderstorms across eastern
Nebraska.

Satellite imagery as of 0530Z shows a developing lee
trough in the SW Sand Hills. Subtle boundaries can be seen extending
along the NE/SD border with another from Sioux Falls, SD south
through Salina, KS. More waves can be seen across western SD and
eastern MT. Over the course of the day, the wave from eastern MT is
expected to become more dominant descending from the NW into the
region. Frontogenesis combined with the residual outflow boundaries
from convection over the past few days is creating a fairly
challenging environment around the region. Upper level ridging,
southerly midlevel flow, and warm air advection from the Gulf
continue to dominate the region. The continued flow of warm air and
moisture will A) keep hot and humid conditions around and B) prime
the environment for which pressure perturbations will try to develop
scattered thunderstorms. Model guidance has struggled to resolve the
short term forecast. Low resolution (broad spatial scale) guidance
maintains the upper level ridge with upper level shortwaves passing
throughout the day. This corridor of upper level waves gradually
slides south and eastward through the afternoon and evening hours.
This southeastward movement thanks to a combination of a large scale
cooler air mass to the north, several NW to SE moving low level
waves, and gradual weakening of the previously mentioned ridge.
While low res guidance has been picking up on the multitude of short
waves across the pressure levels, high resolution CAMs have been
doing their best to try to resolve all of these interactions to
varying degrees of plausibility. As mentioned, multiple surface
level outflow boundaries interacting with midlevel systems and upper
level shortwaves over an already warm and saturated environment
creates a favorable setup for both scattered air mass convection and
organized thunderstorms complexes. The fact that there are so many
interactions and variations in timing and location of these
boundaries and waves makes predicting when and where storms will
develop quite challenging. All of these have to line up to get
convection to form and sustain. There is also higher confidence in
showers and storms later this evening continuing through Tuesday.
The uncertainty lies with how much of Monday (today) could be stormy.

Model guidance is really struggling to resolve the multiple layers
of boundary interactions that are ongoing. Looking empirically at
satellite and radar at the time of initial AFD drafting (~06Z), a
westward moving surface outflow bounday from storms Sunday afternoon
looks to settle along to just west of the I-35 corridor. This might
interact with the eastward moving midlevel wave across northern KS
sparking convection this morning across areas along and west of the
I-35 corridor. These storms will likely output an outflow boundary
of there own which will interact with upper level shortwaves
expected later today; thus, potentially sparking more convection
throughout the daytime hours. Another solution is that the outflow
boundary retreats eastward and the eastward moving wave over KS
weakens upon entering far NW MO. This will likely delay the
convection until upper level CVA arrives later this
afternoon/evening.

While there continues to be much uncertainty in when and where
storms will form, where there is higher confidence is in expected
impacts. Scattered disorganized convection is likely to bring the
potential for heavy downpours as well as gusty winds. More organized
complexes will likely bring the same hazards on a larger geographic
scale. Severe weather risk remains marginal. CAPE around 1500 - 2500
show the potential for some robust updrafts, but low shear and high
LCLs and LFCs limit severe weather concerns. PWATs remain elevated
(around 2 inches) which couple with the increased CAPE presents the
potential for heavy rainfall. The good news is that storms look to
be fairly transient limiting flooding concerns.

Hazardous heat is possible once again today. All of the variables
described above add some uncertainty to the forecast with higher
confidence in hazardous heat being across the southern and
southeastern portions of the coverage area. However, a larger area
of potentially hazardous heat is possible across a larger area
should storms/clouds not progress as anticipated. Heat index values
of 100-105 are possible; however, the duration of those values looks
to be limited to an hours or so during the afternoon. Some area may
experience longer durations of higher heat index values; however,
convective and cloud cover uncertainty means that any heat headline
decisions will likely be short fused once there is a better
understanding of storm/cloud progression.

The good news is that these waves are the preamble to a much cooler
air mass entering the region. High temperatures Wednesday and beyond
are expected to reside toward seasonal normals in the upper 80s.
Long term guidance keeps this cooler air mass around through the
rest of the week with the next notable chances for precipitation
coming towards next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1244 PM CDT Mon Aug 18 2025

Mostly VFR conditions anticipated for the entire forecast
period. Winds will stay out of the south until late this
evening. There is a chance for thunderstorms early tomorrow
morning, however confidence is low in the location of storm
initiation. Decided to leave in a PROB30 group for now.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 7 PM CDT this evening for MOZ025-032-033-
     039-040-043>046-053-054.
KS...Heat Advisory until 7 PM CDT this evening for KSZ060.

&&

$$

DISCUSSION...Pesel
AVIATION...Collier