Area Forecast Discussion

582
FXUS63 KLSX 011135
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
535 AM CST Thu Jan 1 2026

.KEY MESSAGES...

-Temperatures are expected to be near normal through the weekend.
 Temperatures will likely (60-70%) climb above normal early next
 week, though by how much is uncertain.


&&

.SHORT TERM...  (Through Late Friday Afternoon)
Issued at 326 AM CST Thu Jan 1 2026

The latest surface analysis is showing a cold front extending across
central Illinois through northern Missouri which the HREF shows
moving south across the CWA this morning.  Satellite imagery is
showing a post-frontal band of low clouds that will move into all
but the far southern CWA this morning before scattering out this
afternoon. The combination of the low clouds and cold air advection
behind the front will bring highs a few degrees cooler than
yesterday except in the far south.  There will be increasing high
clouds tonight ahead of southern stream shortwave which will help
keep lows in the 20s and lower 30s.

Britt

&&

.LONG TERM...  (Friday Night through Wednesday)
Issued at 326 AM CST Thu Jan 1 2026

The aforementioned southern stream shortwave seen in the NAM/GFS
will move across the Mid South on Friday night.  The southern
counties will be on the northern periphery of the precipitation
shield with the CAMS showing light QPF over this region.  With
northeasterly dry advection cutting into any amounts, I will keep
with the NBM`s 20% PoPs.  Thereafter, generally dry weather is
expected through the upcoming weekend as the western CONUS ridge
will deamplify and move east across the Midwest while the LREF is
showing a weak front moving across the Midwest early next week.
Less than 10% of the ensemble members are producing any
precipitation over the weekend into next Wednesday over the CWA.
After that, precipitation chances will increase Wednesday night
and Thursday with the approach of an upper trough.

Highs will stay close to seasonal normals through the weekend before
climbing into the 50s and 60s next week.  The LREF does show some
spread in the timing and strength with the weak front that will move
across the area early next week with the NBM IQR spread at STL going
from 3-5 degrees over the weekend to 10 degrees by next Wednesday.

Britt

&&

.AVIATION...  (For the 12z TAFs through 12z Friday Morning)
Issued at 528 AM CST Thu Jan 1 2026

Low clouds with IFR/low MVFR ceilings between 500-1500 feet will
affect all of the terminals this morning, clearing out of UIN by
15Z, and JEF/COU around 18Z, and the St. Louis metro terminals
around 20Z. Winds will intially be out of the north to northeast
at 5 to 10 knots before become light and variable around 18Z.


Britt

&&

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

$$

WFO LSX

NWS LSX Office Area Forecast Discussion