Area Forecast Discussion

295
FXUS63 KLSX 020422
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1022 PM CST Thu Jan 1 2026

.KEY MESSAGES...

- Near normal temperatures will continue through Sunday with a 20
  percent chance of rain Friday afternoon/evening across parts of
  southeast Missouri.

- The weather pattern will shift next week bringing above normal
  temperatures to the region.


&&

.SHORT TERM...  (Through Late Friday Night)
Issued at 217 PM CST Thu Jan 1 2026

A cold front moved through the area last night and has become
nearly stationary over southern Missouri. A weak wave of low
pressure is drifting along it, and is trying to move it back to
the north a little. Warm moist air to the south of the front
interacting with the cooler air to the north is producing a deck
of low stratus that is blanketing the northern 3/4 of the forecast
area. There`s some slow erosion from the south but recent pireps
suggest the stratus is 1500-2000 feet thick so it looks very
unlikely that the majority of the stratus will break up before
sunset.

It`s very likely the stratus will spread south again with
the loss of daytime heating, and there could also be some fog
overnight, primarily across central Missouri. Low clouds are likely
to linger through most if not all day Friday as well with low level
flow from the northeast continuing to reinforce the cooler air.
Temperatures through Friday will be very similar to today`s with the
exception of southeast Missouri where prevailing clouds will limit
diurnal rises.  Even if the stratus deck doesn`t build that far
south, there will be clouds and possibly some showers from a low
moving across Arkansas.  Most deterministic guidance keeps the
precip out of our area Friday, but the NBM and LREF continue to show
low probabilities for light rain, and a few CAMs also show
some light rain, mainly just for Reynolds county.  Any rain that
does fall should end by early Friday evening as the low finally
drags drier air into the area behind it.

Carney

&&

.LONG TERM...  (Saturday through Next Thursday)
Issued at 217 PM CST Thu Jan 1 2026

Near normal temperatures and quiet weather continue Saturday and
Sunday under a ridge of high pressure.  Winds turn to the southeast
Sunday afternoon as the ridge moves into the Ohio Valley which will
bring temperatures up a few degrees over Saturday`s highs, most
notably across central Missouri where the wind shift will happen
first.  Guidance continues to show an upper level pattern shift from
northwest flow to zonal flow by Monday.  The GFS and ECMWF show
persistent zonal flow across the central U.S. at least through
midweek which will keep the truly cold air locked up across Canada.
Deterministic guidance does show a couple of weak short waves moving
quickly across the Midwest Monday night and Wednesday.  These waves
push a weak cold front into the Mid Mississippi Valley, which
continues to add uncertainty to the temperature forecast.  LREF
temperature IQRs increase from 4 degrees or less Saturday through
Monday to as much as 8 degrees Tuesday through Thursday. Regardless,
even the 25th percentile is warmer than normal.  Guidance shows a
more substantial short wave moving into the Central U.S. Thursday,
although they differ on its timing and amplitude.  Regardless,
southwest flow ahead of the wave finally taps some Gulf moisture and
brings us our next best chance for measurable precipitation. Current
forecast temperatures will be warm enough to rule out wintry precip.

Carney

&&

.AVIATION...  (For the 06z TAFs through 06z Friday Night)
Issued at 1015 PM CST Thu Jan 1 2026

Low stratus and fog will be the primary concerns overnight tonight
through the day on Friday. The low stratus should be the primary
driver of flight conditions, with ceilings mostly in the 300-600
feet AGL range overnight. Visibilities in fog are expected to be
mostly low MVFR, though some brief periods of IFR visibilities may
occur, especially at KJEF and KSUS. Gradual improvement is likely
from the north and east, but it should be slow. As the past 24
hours has shown, it can be hard to be pessimistic enough with the
improvement in stratus near the winter solstice.

Gosselin

&&

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

$$

WFO LSX

NWS LSX Office Area Forecast Discussion