003
FXUS63 KEAX 031852
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
152 PM CDT Sun Aug 3 2025

.KEY MESSAGES...

- Temperatures will remain cooler than seasonal normals on
  Monday, but a stout warm-up will commence for the rest of the
  week.

- Mainly dry conditions are expected through the upcoming work
  week.

- The pattern looks to become more unsettled next weekend and
  beyond.

&&

.DISCUSSION...
Issued at 122 PM CDT Sun Aug 3 2025

The summertime doldrums are here across the country, with fairly
stagnant flow for much of the southern two-thirds of the U.S.
and faster flow confined to the Canadian border vicinity.
Convectively-augmented vorticity maxima are on the southern
fringes of the faster flow, with one approaching the central
Plains this afternoon, resulting in a shield of decaying
precipitation in eastern Nebraska and central/eastern Kansas. As
alluded to yesterday, convection-allowing models were a little
more aggressive in bringing precipitation to our doorstep, and
this seems to have come to fruition. Lower levels are fairly
unsaturated, though, so precipitation is having a difficult
time reaching the ground, and large-scale descent on the western
fringes of a broad high in the eastern U.S. is countering the
precipitation push well. Nevertheless, felt inclined to include
a mention of sprinkles in far eastern Kansas and far western
Missouri through the early evening hours. It is not even out of
the question a spot or two gets measurable precipitation, but I
think overall chances remain below 15% (mentionable) in our
forecast area this evening.

The main weather players in the central U.S. this week will be
a broadening upper ridge in the southwestern U.S., and
additional convectively-augmented perturbations to its north.
The ridge will be our forecast area`s main concern, with a deep
trough in the Pacific Northwest allowing for ridge amplification
downstream (allowing for rising heights in much of the
southern/central U.S. Tuesday onward). As this process begins, a
key aspect to our forecast will be the presence of any shortwave
troughs moving into the northern/central Plains. Ensembles and
bias-corrected guidance are rather muted with precipitation
chances Tuesday through Thursday during this pattern evolution.
This lack of forecast precipitation is likely a little overdone,
given rather consistent/persistent deterministic solutions
depicting diurnally-driven rounds of convection attendant to
these perturbations. The 12z GFS and EC-AIFS suggest convection
on our doorstep or even in our northwestern zones Tuesday and
Wednesday night, for example. However, just like what we are
seeing today, there is a sharp gradient between sufficient lift
and thermodynamics for convection (in the High Plains to the
mid-Missouri Valley) to little-or-no lift and resultant
convection (Mississippi Valley). Timing will be key here, as if
the upper ridge expands faster than anticipated, our area would
most likely be dry. However, if the perturbation is stronger and
the upper ridge is weaker, some convection may end up occurring
in our northern/western zones. As mentioned, ensembles are
leaning dry at this point, so will refrain from going on the
aggressive side with precipitation chances. It is worth
mentioning, I think, as a potential source of forecast changes
early this week, however.

What is far more certain to occur during the next few days is
a return to warm/humid conditions, as the ridge expands into the
central U.S. by mid-to-late week. Forecast highs do not look
overly unbearable through most of the week, though we will most
likely be flirting with mid 90s by the close of the week, as the
ridge maximizes its amplification in the central U.S. Enjoy
these cooler days while you can!

The pattern looks to change gradually next weekend and beyond,
as a series of perturbations near the International Border area
begin to dampen the central U.S. ridging. Deterministic and
ensemble guidance are hinting at a slowly sagging front in the
northern Plains during the weekend into early next week, meeting
the usual brick wall of ridging in the southern U.S. System
after system will glance the increasingly zonally-oriented
front, leading to rounds of convection in the central/eastern
U.S. thereafter. The main concern for the next few days of
forecasts will be how fast this process occurs. Some of the 12z
guidance suggests this may happen as early as Saturday, but the
majority of ensemble members and time-lagged deterministic
members are slower. A couple of countering model biases are at
play here. (1) Models tend to be too aggressive breaking down
amplified ridges and overall stagnant/blocky patterns. (2)
Models are often a little conservative with the influence of
convection on frontal timing. This makes the long-range forecast
rather uncertain, so have kept close to consensus/bias-
corrected guidance for the time being. However, expect the
general pattern to get gradually stormier by or a little after
next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 101 PM CDT Sun Aug 3 2025

Stagnant conditions will continue across the region the next
24 hours, with BKN to OVC midlevel clouds and a light east
wind (5 to 10 kt). Some light precipitation may approach
far eastern Kansas this afternoon and evening, but currently
think any showers will remain west of the terminals.

&&

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

&&

$$

DISCUSSION...CMS
AVIATION...CMS