592 
FXUS63 KLSX 040949
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
349 AM CST Thu Dec 4 2025

.KEY MESSAGES...

- Cold temperatures are expected through tomorrow morning with 
potentially record breaking lows in Quincy, IL.

- Dry weather is expected through Saturday before there is a chance 
for a wintry mix (20-40% chance) Saturday night and Sunday.

&&

.SHORT TERM...  (Through Late Friday Afternoon)
Issued at 346 AM CST Thu Dec 4 2025

regional radars are showing some weak banding over the CWA early 
this morning, but very little is reaching the ground.  MVN reported 
a brief shower in the last hour, and the FAM RAP sounding supports 
sprinkles or flurries the next few hours.  After that, dry weather 
is expected through tonight as the southern stream shortwave is 
staying south of the area tonight as a surface ridge moves south 
into the Midwest.

Temperatures have already fallen into the teens and 20s across 
the area early this morning behind a cold front that has now 
moved into southern Illinois and southeast Missouri. Lows this 
morning will still likely drop down into the single digits over 
northeast Missouri and west central Illinois. We will still be 
close to the daily record low of +2F set back in 2006 at Quincy. 
Even though there will be some clearing today, highs will only 
reach the teens and the 20s with the cold air advection and the 
snow cover. By tonight, the ridge will move off to the southeast 
allowing for some return flow over the western CWA which will 
allow for quite a range in lows from west to east. Here again, we 
will be close to the daily record low at Quincy on Thursday night 
of +6F set back in 2005.

Britt

&&

.LONG TERM...  (Friday Night through Wednesday)
Issued at 346 AM CST Thu Dec 4 2025

The ensemble guidance is consistent over the weekend into early next 
week that there will be a series of troughs moving through the area 
in northwesterly flow aloft.  The first will be on Friday night when 
a shortwave trough will move through the Upper Midwest which will 
bring a weak front down into the area.   None of the LREF member are 
producing precipitation over the area with this first system. The
NBM has pushed chances up to 20-40% on Saturday night with a more
pronounced trough late in the weekend, and expect these PoPS will
go higher as more of the LREF members are producing precipitation
Saturday night and Sunday. Precipitation types from both the LREF
and NBM are pointing toward a wintry mix of light snow and rain 
with possible freezing rain on Saturday night and Sunday. QPF 
amounts look to be light at this point (<0.05"), but this still 
may change has as the surface low track comes into better 
agreement in the models. Additional weaker troughs will move 
through the area early next week, though <15% of the LREF members 
are producing precipitation over the area at this time.

With the northwesterly flow aloft, below normal air is expected to 
continue to linger over the region through at least Monday before 
southwesterly low level flow sets up over the area by midweek. This 
is supported by the NBM temperatures which has an IQR at STL which 
is only 2-6 degrees for highs through Tuesday.

Britt

&&

.AVIATION...  (For the 06z TAFs through 06z Thursday Night)
Issued at 1024 PM CST Wed Dec 3 2025

A cold front is moving slowly southeast through the region. MVFR
ceilings will clear from northwest to southeast behind the front.
There may still be some very light snow or flurries across parts
of east central and southeast Missouri into southwest Illinois
between now and 08-09Z, however the chance for snow is only 20-30
percent. VFR flight conditions are expected to prevail after the
MVFR clears out.

Carney

&&

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

$$

WFO LSX