Area Forecast Discussion
779
FXUS63 KLSX 281738
AFDLSX
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1138 AM CST Wed Jan 28 2026
.KEY MESSAGES...
- After today`s relative warmth, brutal cold will return to end
the week. Dangerous wind chills are possible Friday, Saturday,
and Sunday mornings.
- Very light snow is possible (80%) that this will be light. With how
cold it`s been, any snow that does fall will stick to the ground
and to untreated roads. Even a dusting may be enough to cause
isolated slick spots.Jaja
&&
.LONG TERM... (Thursday Night through Tuesday)
Issued at 353 AM CST Wed Jan 28 2026
The next wave will be much more potent. Guidance is centering in on
it passing late Friday into early Saturday. As it passes, the
feature will escort a blast of brutally cold Arctic air into the
region. Global models only keep intensifying the strength of the
airmass, now showing a 1045 mb surface high carrying 850 mb
temperatures of -20C into the Mid-Mississippi Valley. These values
register in the 99.5th and 0.5th percentiles of climatology,
respectively. Unsurprisingly, the Extreme Forecast Index for this
weekend reflects this, showing high confidence for a very unusual
to extreme event regarding both high and low temperatures. Though
exact air temperatures and wind chills are still uncertain, we`ve
got enough evidence to state the obvious. It`s going to be
dangerously cold again. The coldest morning is currently Saturday
morning with wind chills of -10 to -15 degrees areawide. These
values will wobble as models adjust the placement and intensity of
the surface high, but as for right now these are pretty safe
values to use for preparation of any kind.
The chance of snow increases again Sunday into Monday with the
passage of a couple more shortwaves. The LREF shows a 50% chance of
measurable precipitation in the northern CWA during this timeframe.
I think it`s important to add that this percentage comes from 2 very
deterministic forecasts from the ECMWF and GEFS, with the first
pushing out a 90% chance of snow and the second only reaching 10%.
So although the LREF`s 50% probability of measurable precipitation
would translate to a "high chance" in our terms, what it actually
reflects is an average of a few very different solutions that are
all possible at this range.
Jaja
&&
.AVIATION... (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1135 AM CST Wed Jan 28 2026
VFR flight conditions are expected to prevail through the period.
Light and variable winds will turn to the northeast overnight as
high pressure builds across the Midwest.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
NWS LSX Office Area Forecast Discussion