505
FXUS63 KLSX 150303
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
903 PM CST Fri Nov 14 2025

.KEY MESSAGES...

- Above normal temperatures will continue through Saturday.

- An active pattern will bring rain chances next week, though confidence
  in timing and placement of rainfall is low to medium.


&&

.SHORT TERM...  (Through Late Saturday Night)
Issued at 207 PM CST Fri Nov 14 2025

Present water vapor imagery depicts northwesterly flow over the
Middle Mississippi Valley as a trough slides off the East Coast and
a ridge amplifies over the Rockies and High Plains. Low-level
ridging just east of the region has low-level flow southwesterly,
which is advecting warmer air into the CWA. As a result,
temperatures this afternoon are running 10-15 degrees warmer than
yesterday and around record territory. See the climate section
for further details.

A surface low moving through the Great Lakes overnight will keep the
pressure gradient tight over the CWA and low-level winds maintained
out of the southwest. This will lead to anomalously warm overnight
lows, with a majority of locations failing to fall below the upper
50s.

Through Saturday, this surface low will swing a cold front through
the CWA from the northwest to the southeast. Moisture through the
low to mid levels will be lacking, leading to high confidence that
this will be a dry FROPA, with the most notable impact being winds
shifting to out of the west-northwest. While the front is expected
to clear much of the CWA prior to peak heating, weak northwesterly
flow and a slightly delayed low to mid-level response in the wind
field will lead to little to no impact in daytime temperatures.
Values will once again warm well above normal and approach daily
records.

Elmore

&&

.LONG TERM...  (Sunday through Next Friday)
Issued at 207 PM CST Fri Nov 14 2025

Early Sunday, guidance consensus is that a broad upper-level trough
will be over the eastern CONUS, an upper-level ridge over the
western CONUS, and the Middle Mississippi Valley beneath
northwesterly flow between these two features. This flow will keep
Saturday`s cold front progressing southward, with a seasonable and
very dry air mass advecting into the region. While confidence is
high in this general evolution, the exact progression of the
front varies slightly among guidance, leading to an approximately
5-degree spread among ensemble IQR of temperatures and even a
greater spread in dew points. However, this large spread is at
least partially driven by the deep-mixing bias of the GFS/GEFS,
and exactly how dry the post frontal air mass is will impact
temperatures as well as potentially lead to Elevated Fire Danger.
The 75th percentile of sustained wind speeds among ensemble
guidance topping out around 5 mph suggest this threat would be
mitigated, so confidence in it remains low.

The phasing of the upper-level pattern through the workweek remains
high variable among both deterministic guidance and ensemble
clusters, leading to low confidence in our local sensible weather.
Generally speaking, a shortwave undercutting the aforementioned
western ridge will phase with a trough digging into the Rockies to
weaken the ridge and push a surface low through the central CONUS
Monday into Tuesday. Southern solutions (favored by the GEFS) drag
the low through or very near to the CWA and have relatively
higher chances for rain across the CWA, while northern solutions
(favored by the ENS) push the low through the Central or Upper
Midwest and have a relatively lower chance of rain for the CWA.
The current NBM leans toward the GEFS and has a 50-70% chance of
rain across much of our CWA. Again, due to differences in the
strength and track of the upper-level wave and surface low, this
portion of the period remains volatile, reflected by the IQR among
both the NBM and global ensembles being 15-20 degrees for
temperatures on Tuesday.

Given the variability in the pattern among guidance on Tuesday, the
forecast for the rest of the week is just as uncertain, with
deterministic guidance and ensemble clusters not only showing
different solutions for the phasing of the upper-levels, but
solutions that give us notably different sensible weather day-to-
day. At the very least, confidence is high that the pattern will
be active, with a majority of guidance showing a series of waves
passing through the central CONUS Thursday into next weekend.
Where these waves pass, at least one round of soaking rain will
occur. Recent ensemble initializations favor the corridor of
greatest rainfall chances and highest accumulations to stretch
from the Southern Plains northeastward into the Ohio Valley;
though, run-to-run and source to source variability curtails
confidence.

Elmore

&&

.AVIATION...  (For the 06z TAFs through 06z Saturday Night)
Issued at 903 PM CST Fri Nov 14 2025

Dry and VFR flight condition are likely to persist through the TAF
period, but a few clouds around 3000 to 4000 ft are possible
Saturday morning. Southerly winds will veer to southwesterly and
strengthen with occasional 18 to 25 kt Saturday morning before
veering toward the northwest upon passage of a dry cold front
through midday and afternoon.

Pfahler

&&

.CLIMATE...
Issued at 429 AM CST Fri Nov 14 2025

Daily record high temperatures will be within range both today
(11/14) and tomorrow (11/15). Coincidentally, the daily record
high temperatures are the same both today and tomorrow at all
three sites, and are as follows:

St. Louis (STL): 81 degrees (1971), and 81 degrees (1971)
Columbia (COU): 78 degrees (1931), and 78 degrees (1950)
Quincy (UIN): 75 degrees (1971), and 75 degrees (1950)

BRC


&&

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

$$

WFO LSX