Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

772
FXUS63 KLSX 121817
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
117 PM CDT Thu Mar 12 2026

.KEY MESSAGES...

- A Wind Advisory is in effect for tonight into Friday morning
  across parts of northeast Missouri and west central/southwest
  Illinois. Wind gusts up to 45 mph are expected in the advisory
  area.

- Severe thunderstorms will be possible on Sunday across southwest
  MO. SPC`s 15% area for severe weather includes southwest MO.

- Behind a cold front on Sunday, expect precipitation to switch
  over to snow with light accumulations possible Sunday night.
  Highs will only be in the mid 20s to mid 30s on Monday.


&&

.SHORT TERM...  (Through Late Friday Night)
Issued at 117 PM CDT Thu Mar 12 2026

The forecast for tonight includes increasing winds as a low
pressure system moves from the Dakotas into the Great Lakes
region. Expect winds to increase from the south and southwest to
15-30 mph, with gusts to 45 mph. The HREF mean 10m wind gusts
increase to over 40 mph after 8 pm, peaking around midnight
tonight. Winds decrease late in the night/early tomorrow morning.

Temperatures will not fall much tonight given the relatively warm
south to southwesterly winds ahead of the cold front. The front
will pass through the area late tonight and into Friday morning.
However, temperatures will rebound back into the 50s and 60s on
tomorrow. High pressure will then settle into the area for Friday
night.

WFO ILX

&&

.LONG TERM...  (Saturday through Next Thursday)
Issued at 117 PM CDT Thu Mar 12 2026

A warm front will lift north across the area on Saturday ahead of
a low pressure system moving out of the Rockies and into the
Central Plains. Expecting highs in the 60s across much of the area
on both Saturday and Sunday ahead of the low as it moves out of
the plains and across MO. This is a strong system with a deep
upper trough and a strong temperature gradient at the surface.
Expect a chance for severe storms on Sunday afternoon with the
best chance south of St Louis. However, the timing and exact track
of this system will likely fluctuate a bit as we are still four
days out. Potential exists for CAPEs and 0-6km shear appear to be
in the 500-1000J/kg and 50-60kt ranges, respectively.

After the cold frost pushes through on Sunday afternoon/evening,
expect rain to change to snow, with light accumulations possible.
(Generally thinking an inch or two of snow right now.) Gusty
northwest winds of 20-30 mph with gusts to 40 mph are expected on
Monday, with wind chills in the single digits (both above and
below zero). Monday will feel like a change back to winter with
some snow accumulations and relatively cold wind chills.

High pressure will move into the area by mid week, with a slow
warm up expected. A return to 60s and 70s is expected by Thursday.

WFO ILX

&&

.AVIATION...  (For the 18z TAFs through 18z Friday Morning)
Issued at 1255 PM CDT Thu Mar 12 2026

VFR conditions will persist at all TAF sites through Friday
afternoon. Winds become stronger and gustier from the south-
southwest later this afternoon. Low level winds will increase
notably this evening as a low level jet develops with 60 kt
southwesterly flow at around 3-4 kft. Given the height of the low
level winds, left LLWS out of the TAFs for now, but the strong winds
aloft may cause low level wind shear concerns if surface wind
speeds/gusts decrease noticeably overnight. There are some
differences among forecasts of low level stability and the low level
inversion height overnight, but we currently anticipate wind speeds
to remain enhanced at the surface. A cold front will move into
northern MO/central IL late tonight, turning the wind more to the
west before 12Z Friday.

WFO ILX

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory from 10 PM this evening to 11 AM CDT Friday for
     Audrain MO-Boone MO-Callaway MO-Cole MO-Knox MO-Lewis MO-
     Lincoln MO-Marion MO-Moniteau MO-Monroe MO-Montgomery MO-
     Pike MO-Ralls MO-Shelby MO.

IL...Wind Advisory from 10 PM this evening to 11 AM CDT Friday for
     Adams IL-Brown IL-Calhoun IL-Greene IL-Jersey IL-Macoupin
     IL-Montgomery IL-Pike IL.

&&

$$

WFO LSX