Area Forecast Discussion

908
FXUS63 KLSX 252318
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
518 PM CST Sun Jan 25 2026

.KEY MESSAGES...

- Dangerous cold will occur across the entire area tonight, with wind
  chills of -15 to 20 degrees expected through Monday morning.

-Temperatures will remain below freezing for most locations
 through the end of the week.


&&

.SHORT TERM...  (Through Late Monday Night)
Issued at 245 PM CST Sun Jan 25 2026

Regional radar imagery shows a weak frontogenetical band oriented
southwest to northeast roughly bisecting the CWA as of this
writing. This is collocated with a front aloft and is associated
with the clearing line of the stratus deck. This clearing line
will continue eastward through the remainder of the afternoon,
clearing the CWA by around 6pm. Any remaining snowfall will be
limited to flurries or light, unimpactful snowfall across far
southeastern Missouri and southwestern Illinois.

As the parent cyclone responsible for our departing snowfall
continues to deepen and shift further eastward, it will pull a
reinforcing shot of Arctic air southward into the Midwest, setting
the stage for a frigid night. High pressure sliding into the Central
Plains will maintain the pressure gradient enough to keep winds
mostly steady out of the north. With air temperatures falling to
around 0 degrees area wide, the winds support wind chills in the -15
to -20 range. Our current Cold Weather Advisory and Warning are on
track for tonight into tomorrow morning. In fact, temperatures may
not be cold enough, as our cooling trend this evening will have a
radiational component thanks to the clearing skies, and fresh snow
pack will aid in driving temperatures anomalously cold. If winds are
light enough, some areas could drop well below what is currently
forecast. Confidence in how much lower is low to medium, as a
majority of guidance shows a pocket of clouds moving overhead
tonight as the axis of the upper-level trough swings through, and
this may cut down on radiational cooling. Regardless, it will be
a very, very cold night and dangerous to individuals who are
exposed.

Temperatures on Monday rebound somewhat, as progressive flow aloft
shifts the core of the Arctic air mass eastward, allowing for low
to mid-level temperatures to warm relatively speaking. This
paired with mostly sunny skies will push temperatures into the
teens for most locations. The aforementioned high pressure will
edge eastward through the day, causing surface flow to become
southwesterly by the evening. This will keep temperatures Monday
night from getting quite as cold as the night prior, with guidance
favoring values in the single digits.

Elmore

&&

.LONG TERM...  (Tuesday through Next Sunday)
Issued at 245 PM CST Sun Jan 25 2026

For the entire extended period, a persistent upper-level trough over
southern Canada with ridging to the west will keep the region under
northwesterly flow. The result for us is that areawide temperatures
will remain well-below climatology with this flow regime in place.
In fact, confidence is low (30%) in high temperatures reaching 32
degrees for most the area, with the exception of Tuesday and
Wednesday, when parts of southern Missouri may reach the mid 30s
with light southwesterly surface winds in place. With the
continuation of cold temperatures this week, any melting of the
recent snow will be prolonged, with the exception of area roads that
should melt effectively on days with plenty of solar insolation.
This leads to an area of concern, which is with lows this week
reaching the single digits to near/below zero each night, refreezing
of area roads where any melting occurred the day before will be
likely, and will lead to isolated slick spots each night and morning
across the region.

Within the deep northwesterly flow regime, two mid-level shortwaves
will trek southeastward as weak clipper systems, with the first one
moving across the area on Wednesday and the second one on Friday.
Our precipitation chances this week will be limited to the approach
of these two shortwaves with the LREF showing a 20-40% for QPF
>0.01" on Wednesday evening and 10-20% for Friday. Given the bitter
cold that will be in place this week, any precipitation that occurs
would be of the frozen kind, so these clippers will need to be
monitored for trends. It is also important to note that amounts
would be light where any precipitation does fall from these clippers
as they almost always lack moisture given the flow regime they occur
within. When analyzing the low percentage of LREF members that have
any precipitation, ensemble maximums for 6 hourly QPF are all 

NWS LSX Office Area Forecast Discussion