898
FXUS63 KLSX 131130
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
530 AM CST Fri Feb 13 2026

.KEY MESSAGES...

- Widespread beneficial rainfall is forecast Saturday - Saturday night,
  with the heaviest amounts (>=1") most likely in southeast
  Missouri.

- Well-above normal temperatures are expected early/mid next week.


&&

.SHORT TERM...  (Through Late This Afternoon)
Issued at 259 AM CST Fri Feb 13 2026

Mild temperatures are expected this afternoon as low-level warm
air advection strengthens beneath a mostly sunny sky. Highs are
forecast to top out in the mid 50s to mid 60s from east to west,
or on average about 15 degrees above normal for the date.


Gosselin

&&

.LONG TERM...  (Tonight through Thursday)
Issued at 259 AM CST Fri Feb 13 2026

(Tonight - Sunday)

The main focus for this forecast package continues to be on what
should be the most widespread, significant rainfall across the area
since at least the middle of December. Rain is expected to enter
portions of central and southeast Missouri late tonight as low-level
warm/moist advection strengthens. Aloft, a lead midlevel impulse
also transverses the area along with enhanced divergence beneath the
right-entrance region of a jet streak across the Upper Midwest.
Persistent light to occasionally moderate rain should translate
east/northeast through the morning/early afternoon hours,
overspreading the entire region. The duration of rain should be
about 15-21 hours in any given location, with rain exiting from
west/northwest to east/southeast Saturday night into potentially
very early Sunday morning. By the time the rain ends, a vast
majority of the area is expected to see at least 0.50". Probabilities
on the latest LREF range are above 50% along/south of roughly a
Mexico, MO to Litchfield, IL line. For areas along/south of I-70,
chances increase to 70-90+%. For at least 1" of rain, the highest
probabilities (50-80%) are in parts of south central and southeast
Missouri. Given the ongoing dryness/drought, a widespread,
prolonged soaking rain is just what the doctor ordered. Soils
have dried out after the snow melt of the past couple of weeks, so
much of this rain is likely to go into moistening the soil.
However, there should be at least some modest runoff later on in
the event as well due to the persistence of the rainfall, aiding
in increasing local streamflows.


(Sunday Night - Thursday)

All signs continue to point toward a significant warming trend
early/mid next week as midlevel ridging moves into the Mississippi
Valley and 850-hPa temperatures climb above +10C. In fact, both the
GEFS/EPS mean 850-hPa temperature anomalies approach +15C above
normal, or near the 99th percentile of climatology. Highs above 60
degrees are a near certainty on at least one occasion Tuesday
through Thursday, if not multiple. There appears to be a cold
frontal passage associated with a surface low crossing the Upper
Mississippi Valley sometime Wednesday night into early Thursday.
This far out, there is a substantial amount of spread in terms of
the timing/track of the surface low, but at this point the warmest
day is expected to be on Wednesday ahead of the boundary. This is
when the chances of a high temperature at or above 70 degrees is
highest on the NBM (40-80+%). Thursday should be a bit cooler,
assuming the front does indeed actually make it through by mid to
late morning.

In terms of precipitation chances, much of the week looks dry though
low chances (~20%) exist between Wednesday and Thursday associated
with the frontal passage. Better chances are likely to move in
closer to Thursday night ahead of a more vigorous midlevel shortwave
trough.


Gosselin

&&

.AVIATION...  (For the 12z TAFs through 12z Saturday Morning)
Issued at 527 AM CST Fri Feb 13 2026

Quiet conditions are expected through this evening with a mostly
clear sky and light south/southeast winds. Winds are forecast to
become light/variable tonight. Look for increasing clouds and
decreasing ceilings ahead of the next weather system. Rain chances
will increase from southwest to northeast, but it looks like the
light to moderate rain will hold off until just after the end of
this TAF package at KCOU/KJEF.

Gosselin

&&

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

$$

WFO LSX