395
FXUS63 KLSX 101121
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
521 AM CST Mon Nov 10 2025

.KEY MESSAGES...

- Cold temperatures will continue through Tuesday morning before a
  warming trend starts Tuesday and continues into next weekend.

- The next best chance of rain will be next weekend.


&&

.SHORT TERM...  (Through Late Tuesday Afternoon)
Issued at 318 AM CST Mon Nov 10 2025

Spotty flurries have been moving south across the forecast area
this morning, driven by the center of the mid-level trough
dropping south from the Great Lakes region through the mid-
Mississippi Valley. These will end around sunrise as the low moves
into the Southeast US. The remainder of the day will be sunny but
cold, more reminiscent of January than mid November. 850 mb
temperatures in the negative low teens will result in high
temperatures in the 30s to near 40 degrees, despite the abundant
sunshine.

The mid-level trough will begin sliding east overnight and into
tomorrow morning, causing mid-level flow to become northwesterly.
Surface winds will become southwesterly by tomorrow morning, and
despite increased cloud cover, will help pull temperatures from
morning lows in the 20s back to the 50s.

Delia

&&

.LONG TERM...  (Tuesday Night through Sunday)
Issued at 318 AM CST Mon Nov 10 2025

Mid-level northwesterly flow will persist through the work week as
the exiting trough stalls over the East Coast and a ridge sits
over the West Coast. At the surface warmer morning starts and increasing
sunshine Wednesday and Thursday will push temperatures into the
60s area wide despite northwesterly low-level flow. By Friday the
mid-level pattern starts to become more progressive as the ridge
slides into the central CONUS and a trough comes onshore over the
West Coast. Southwesterly surface flow will push temperatures well
above normal, peaking in the upper 60s to 70s. The ridge shifts
eastward Friday into Saturday as the mid-level trough pushes into
the CONUS. By Saturday the system is expected to become a closed
low over the Four Corners region, with a surface low developing
over Texas in response. Strong southwesterly low-level flow ahead
of these features will keep the warming trend over our CWA going
into Saturday.

The mid-level and surface lows will move east and approach
the mid-Mississippi Valley Saturday night into Sunday. Current
guidance moves the center of the low just south of the forecast
area, which has the potential to limit how much precipitation we
receive from this system if the low stays to our south. Currently
ensemble guidance indicating a 60-70% chance of exceeding 0.25
inches of rain, and a 50% chance of exceeding 0.50 inches of rain
over a 24 hour period Sunday. As details in the timing, strength,
and position of the surface low come into focus over the next week
we`ll have a better understanding of how much rain we can expect
from this system.

Delia

&&

.AVIATION...  (For the 12z TAFs through 12z Tuesday Morning)
Issued at 520 AM CST Mon Nov 10 2025

Dry and VFR flight conditions will prevail through the end of the
TAF period. Northwesterly winds will be gusty across the St. Louis
metro and KUIN terminals, diminishing around sunset. Winds will
become light and variable overnight as a surface high passes near
the area and will pick up from the south to southwest Tuesday
morning.

Delia

&&

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

$$

WFO LSX