Area Forecast Discussion

592
FXUS63 KLSX 130851
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
251 AM CST Tue Jan 13 2026

.KEY MESSAGES...

- Unseasonably warm and dry conditions are expected to yield
  elevated fire conditions along/south of I-70 in Missouri this
  afternoon.

- Multiple cold fronts are expected to move through over the next
  4-5 days, with temperatures getting progressively colder behind
  each front.


&&

.SHORT TERM...  (Through Late Tonight)
Issued at 251 AM CST Tue Jan 13 2026

The latest surface analysis shows a cold front draped from the
Upper Midwest into the mid-Missouri Valley early this morning.
This front will continue to progress eastward through tonight,
moving into the lower Ohio Valley by 1200 UTC Wednesday. Our
region will be ahead of the front during the day today, with
continued low-level warm air advection. Temperatures at 850 hPa
peak just above 10C this afternoon in southwestern sections of the
area, or around the 95th percentile of climatology. Surface winds
are expected to veer ahead of the front. This is critical as a
west/southwest wind is ideal for downsloping off of the Ozark
Plateau. This should lead to enhanced warming across portions of
central, east central, and southeast Missouri. It is very
difficult to forecast warm enough temperatures with this type of
setup, so leaned toward the 90th percentile of the NBM for highs
today. For those areas detailed above which should experience the
most pronounced downsloping, leaned closer to the 95th percentile
where widespread low to mid 60s are forecast. Some spots may even
pop into the upper 60s. Further north, thicker cirrus should
arrive sooner, with cloud bases lowering gradually during the day.
Highs in the mid to upper 50s are forecast further north as a
result. Today`s highs at all three climate stations may threaten
daily records for the date (KSTL: 67-1952, KCOU: 66-1952, and
KUIN:
58-1932). Of the three official climate sites, St. Louis appears to
be the most prone to potentially tying or just breaking their
record.

Precipitation chances are expected to increase this evening as
surface convergence increases along the front, a weak midlevel
vorticity maxima moves through the region, and divergence
strengthens beneath the right-entrance region of an upper-level jet
streak. There is plenty of antecedent dry air, but the forcing
appears deep and long enough to produce an area of light rain. The
best chances (40-60%) are south of I-70/I-64 in Missouri/Illinois
respectively. Any rain that does fall tonight does look very light
however, with amounts under a tenth of an inch expected.


Gosselin

&&

.LONG TERM...  (Wednesday through Monday)
Issued at 251 AM CST Tue Jan 13 2026

(Wednesday - Friday)

Low-level cold air advection strengthens Wednesday morning, and
peaks early afternoon. This is a strong indicator for falling
temperatures at least through the morning hours, with readings
dropping into the 30s. Decreasing clouds are expected though, with
plenty of sunshine by mid-late afternoon. This should help
temperatures level off by afternoon. Seasonably cold conditions are
forecast Wednesday night, with a surface ridge moving into
central/northeast Missouri by 1200 UTC Thursday. The combination of
a clear sky, low dewpoints (

NWS LSX Office Area Forecast Discussion