455
FXUS63 KLSX 211047
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
447 AM CST Sat Feb 21 2026

.KEY MESSAGES...

-There is a low chance (20-30%) of light rain or snow through
 early this afternoon south of I-70 with no accumulation
 expected.

-Cooler temperatures are expected through early next week before a
 warming trend starts on Tuesday.


&&

.SHORT TERM...  (Through Late Sunday Afternoon)
Issued at 337 AM CST Sat Feb 21 2026

Latest radar mosaic is showing one band of precipitation along the
Missouri/Arkansas border and another area of precipitation over
western Missouri/eastern Kansas early this morning.  This
precipitation is occurring ahead of shortwave trough seen on water
vapor over the central Plains that the HREF brings across Missouri
and Illinois this afternoon.  Even with the large areal extent of
the precipitation seen on radar, very few surface obs are reporting
rain or snow because of the dry low levels seen on the RAP
soundings. The RAP does show some modest moistening of the low
layers later this morning, particularly at Farmington which goes
along along with latest HREF which has 10-40% probabilities of
rain/snow south of I-70 today before dry weather is expected tonight
in the wake of the shortwave. With this said, will keep with the
going 20-30 PoPs along and south of I-70 with a chance of flurries
farther to north into the early afternoon.

Temperatures today will be slightly cooler with the clouds and
northwest winds with highs in the 30s and 40s.   Lows tonight will
drop in teens and 20s.

Britt

&&

.LONG TERM...  (Sunday Night through Friday)
Issued at 337 AM CST Sat Feb 21 2026

The dry weather is expected to continue from Sunday through
Wednesday as the LREF is showing that the upper low over the Great
Lakes will deepen over eastern CONUS before the pattern deamplifys
by midweek. We will be in deep northwesterly flow aloft Sunday and
Monday which will keep highs in the 30s before winds turn out of
the southwest by Tuesday helping highs climb into the 40s and 50s.
The LREF is showing a trough moving through Midwest mid-late week
which the determistic models each show slightly different timing
with how quickly the attendant front will move across the area
Wednesday into Wednesday night. Both the NBM/LREF are showing
20-40% of their members producing precipitation with this system
as it passes through the CWA. With no push of cold air behind this
front, highs mid to late week looks to be in the 50s and 60s.

Britt

&&

.AVIATION...  (For the 12z TAFs through 12z Sunday Morning)
Issued at 441 AM CST Sat Feb 21 2026

Dry and VFR conditions are expected through the period. The only
exception is a low chance (10-20% chance) for light rain or snow
through 15Z at COU/JEF and through 17Z at STL/SUS/CPS. Little if
any measurable accumulation is expected. Winds are expected to be
between 320 and 020 degrees at less than 10 knots except after
06Z when winds will increase at UIN/STL/SUS/CPS with gusts up to
20 knots.

Britt

&&

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

$$

WFO LSX