585
FXUS63 KEAX 052317
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
617 PM CDT Tue Aug 5 2025

.KEY MESSAGES...

- Gradually getting warmer through Friday. Highs in the upper
  80s to lower 90s F. Heat Index values in the upper 90s to
  around 100 F.

- Lower chances (around 20 to 30%) for precipitation tonight
  through midday Wednesday across northern Missouri.

- Wednesday Night - Thursday Morning: Increasing signal for
  scattered thunderstorms as far south as the Missouri River.

- Unsettled pattern arrives for the weekend. 30 to 40%
  precipitation chances Sunday into Monday.

&&

.DISCUSSION...
Issued at 258 PM CDT Tue Aug 5 2025

Generally quiet across the region this afternoon. Weak surface
ridging remains extending from northern Illinois and southwest
across northern Missouri into eastern Kansas. A gradually
strengthening surface trough remains oriented along the western High
Plains of NE/KS/CO. Increased southerly surface flow across the
central Plains has allowed temperatures to push 90 in several
locations. Easterly winds across our area has kept temps more
moderate, in the lower to mid 80s through 18Z.

Through this morning and continuing this afternoon, a MCS has
continued east across North Dakota. Supported by a negatively tilted
H500 short wave lifting northeast across the Canadian Prairie. With
strong WAA south of this complex and increasing convergence through
the lower levels, most short range solutions continue to key in on
new CI through this evening across South Dakota, developing into an
MCS overnight, advancing southeast into NE/IA through tonight. As
ongoing convection through daybreak moves across Iowa, it will be
encountering a less favorable environment, weaker shear and
instability, with lingering showers and isolated thunder possible
(20-40%) across northern Missouri through at least midday,
Wednesday.

Through Wednesday afternoon, the eastern blocking pattern will stand
pat with the larger H500 trough anchored over NM/WTX, but with a bit
more access to the southwesterly flow, especially through the lower
levels, with H850 temps pushing 20 C. Temps will respond to the
increased WAA, pushing highs into the lower 90s along the MO/KS
border region. This persistent synoptic pattern is interesting,
looking lower at tonight through Wednesday, H700 relative vorticity,
H850 heights/winds, etc. One could make the assumption we have a
pacific front pushing east, with a much greater dew point response
than temps in it`s passage through Wednesday into Thursday morning.
Paired with an enhancement of the moisture return through Wednesday
night, pwats remain ample, 1.25 to 1.75" within a ribbon of moisture
stretched from the Upper Midwest through KC into southeastern Iowa.
This combined with an increase in the LLJ and broad warm sector
forcing for ascent, while the effective boundary remains to the west
in central and western Kansas, it`s appearing more likely the latest
NBM is under-performing with PoPs, which is supported by the 90-10
(~0.00 to 0.10) and max-min (~0.00-0.73") spreads of the NBM
members. 18Z HRRR has come in a bit more bullish, suggesting some
guidance is catching on. A fly in the ointment is where and how
storms evolve tomorrow night given CI is likely going to be tied to
remnant outflow boundary placement from earlier convection, but the
greatest potential will be north of the Missouri River, where modest
elevated instability, ~1500 J/KG will pool. I cannot find fault with
SPCs Marginal given a few robust elevated updrafts may develop
posing a wind risk.

Through Thursday into Friday, the H500 ridge axis will begin to tilt
more SW to NE, with increased southwesterly flow into the region.
Temperatures will respond accordingly, with highs pushing the lower
90s both days, with heat index values in the upper 90s to around 100
F. As discussed yesterday, a more active pattern develops over the
weekend, as a stout upper trough wraps up and east along the CAN/US
border through the weekend, with a developing swath of convergence
along an outstretched surface boundary through the Midwest. This
will be the focus for near daily precipitation chances, especially
Sunday into early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 614 PM CDT Tue Aug 5 2025

VFR conditions through the period. Decaying showers and
thunderstorms are possible across northern Missouri 15-18Z
Wednesday morning. This activity is expected to be northeast of
St Joeseph, so the terminals remain thunderstorm free.

&&

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

&&

$$

DISCUSSION...Kurtz
AVIATION...BT