460
FXUS63 KLSX 301118
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
518 AM CST Fri Jan 30 2026

.KEY MESSAGES...

- Flurries are possible again this afternoon and evening, largely
south of I-70.

- Cold temperatures will persist through the weekend with wind
chills Saturday morning between -5 to -15 degrees.

- There is a slight chance for light snow Sunday and another,
  better chance for precipitation mid-week.



&&

.SHORT TERM...  (Through Late Saturday Afternoon)
Issued at 251 AM CST Fri Jan 30 2026

The band of low-level frontogenesis that produced flurries across
portions of the forecast area last night is exiting the southern
forecast area early this morning, and flurries are coming to an end.
Cold air advection behind yesterday`s front will result in cold
highs today, struggling to break 20 across much of the area as deep
mixing will allow access to 850 mb temperatures this afternoon near
-12 degrees.

This afternoon and evening an area of low-level moisture will advect
southward through the forecast area and combine with low-level weak
frontogenesis and steep low-level lapse rates into the DGZ to
produce another round of flurries. Flurries are most likely along
and south of I-70 where the overlap of these ingredients will be
greatest. Accumulations are not expected as LREF and HREF members
keep probabilities of greater than 0.01" of QPF around 50-60% and
probabilities of greater than 0.02" of QPF drop to spotty areas of
10%. Flurries will come to an end during the early morning as the
moisture continues to advect south out of the forecast area.

At the same time a surface high will be sliding southward from the
Upper-Midwest into the Kansas area. Winds overnight will remain
elevated from a relatively tighter surface pressure gradient, and
combined with the cold air advection will produce temperatures
reaching their minimums between 0-7 degrees and pushing wind chills
into the negative single digits to negative low teens Saturday
morning. While these wind chills are nothing to sneeze at,
confidence is around 40-50% that we will reach advisory criteria
Saturday. There is a narrow spread in wind speeds during this time,
only 2-3 mph, and temperatures are not expected to cool dramatically
under the elevated wind speeds.

Delia

&&

.LONG TERM...  (Saturday Night through Thursday)
Issued at 251 AM CST Fri Jan 30 2026

A mid-level trough will persist over the East Coast through the
weekend, exiting into the Atlantic at the beginning of next week,
only to be replaced by another strengthening mid-level trough during
the second half of next week. The result is multiple waves of
shortwaves and opportunities for precipitation throughout the week.
The first is Sunday as a surface low tracks eastward across the US-
Canada border, bringing another cold front into the region. LREF
guidance is a little more bullish than the NBM in the probability of
measurable precipitation, though the NBM is starting to incorporate
higher resolution guidance at this stage which leans towards a dryer
forecast across the forecast area. Have left the chance for
precipitation alone for now, but if any precipitation falls it is
expected to fall as snow.

The next chance for precipitation will come mid-week as another
surface low develops, this time over the southern US in response to
the strengthening mid-level trough. The track of this system will
allow for better moisture rebound across the region, resulting in
higher probabilities of at least some measurable precipitation. The
anticipated warming trend, combined with low-level warm air
advection ahead of the system increases the chances for rain and/or
snow across the area. Details on what will fall when will depend on
the strength of the airmasses at play, as well as the timing of the
system overall. Thus, there is low confidence in where specific
precipitation types fall. This system will depart the region and
allow a surface high to build in ahead of another potential system
towards the end of next work week.

Sunday will kick off a warming trend that will continue into next
week despite multiple cold fronts and chances for precipitation.
High temperatures are expected to push to near to above freezing
areawide, with portions of southern Missouri expected to rocket above
40 degrees at points during the week. The interquartile spread for
high temperatures is starting to narrow for next week, though is
still upwards of 8 degrees. This is reasonable for this part of the
extended forecast and speaks to the uncertainty in the strength and
timing of airmass changes.

Delia

&&

.AVIATION...  (For the 12z TAFs through 12z Saturday Morning)
Issued at 516 AM CST Fri Jan 30 2026

Dry and VFR flight conditions will continue ahead of MVFR ceilings
and a chance (30%) for flurries this afternoon and evening.
Moisture will move south through the area this afternoon and into
the evening, lowering clouds to MVFR flight conditions and
introducing a 30% chance for flurries. Any snow that falls is not
expected to be heavy enough to accumulate. The moisture will be
progressive and exit the terminals within a few hours, afterwhich
flight categories will improve back to VFR.

Winds will prevail from the north, generally around 10-12 kts.

Delia

&&

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

$$

WFO LSX