086
FXUS63 KLSX 291708
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1208 PM CDT Fri May 29 2026

.KEY MESSAGES...

- There is a 60 to 80 percent chance of showers and isolated
  thunderstorms today over central and southeast Missouri. Lower chances
  linger through Monday, but there will be plenty of dry time.

- Temperatures will remain seasonable but variable through next week.


&&

.SHORT TERM...  (Through Late Saturday Afternoon)
Issued at 206 AM CDT Fri May 29 2026

Water vapor imagery is showing the Midwest remaining underneath a
ridge that is part of a large omega block early this morning.  An
elongated trough over the central and southern Plains along with low
level moisture convergence is responsible for the showers and
isolated thunderstorms that we are seeing over southern and western
Missouri. The HREF is showing this trough moving slowly east today
which will cause ascent to move slowly northwest and subsequently
bring the chance for showers and scattered thunderstorms into the
CWA. This chance will continue spread east tonight into Saturday
as the HREF is showing the trough eventually undercutting the
ridge resulting in chances (30-50%) across most of the area
tonight. The chances will continue into Saturday associated with
convection from MCVs or a weakening trough coming in from the
Plains.

The threat for severe thunderstorms remains relatively low through
Saturday as forecast soundings are showing relatively narrow,
elevated CAPE with deep layer shear staying under 30 knots.  There
is some potential for storms to produce some heavy downpours with
the HREF showing PWATS between 1.6-2.0" and the deep warm cloud
depths across central and southeast Missouri. The LPMM is showing
the highest amounts southwest of the area which should limit
flash flood potential.

Highs today and tomorrow will be in the upper 70s and lower 80s with
the coolest readings today over central and southeast Missouri where
the greatest coverage of rain and clouds are expected. Lows
tonight will be in the low to mid 60s.


Britt

&&

.LONG TERM...  (Saturday Night through Thursday)
Issued at 206 AM CDT Fri May 29 2026

Model guidance is in reasonable agreement that two additional
troughs will bring chances for showers and thunderstorms to the area
over the weekend.  The first will be on Saturday night with a trough
lifting northeast through Plains and Mid Missouri Valley which
the LREF shows 50-70% of its members producing rain across central
and northeast Missouri. The second is on Sunday night with a
system moving southeast across the across the Midwest with 40-60%
of the LREF members producing rain across the CWA. A ridge will
build over the area by the middle of next week bringing limiting
the chance for rain.

Britt

&&

.AVIATION...  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1203 PM CDT Fri May 29 2026

Showers and thunderstorms are expected to continue this afternoon,
mainly across central/southeast Missouri. Brief reductions in
visibility below 3SM are expected in any thunderstorms and did add
a TEMPO at KJEF/KCOU. If a storm directly impacts either
terminal, visibilities may very briefly drop below 1SM. Further
northeast, the terminals are expected to stay dry though not
ruling out a light shower or brief period of light rain this
afternoon. However, reductions in visibility below VFR thresholds
seem quite unlikely. The chances for showers (and especially
thunderstorms) drops this evening/overnight, though low chances
(20-30%) exist through Saturday morning. Similar to the ongoing
activity, the best chances should remain across central/southeast
Missouri. Ceilings are also expected to drop tonight in those
regions, with low MVFR conditions expected after midnight into
Saturday morning.

Gosselin

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$

WFO LSX