253
FNUS73 KLSX 181341
FWSLSX

Spot Forecast for Jennings Hill Prairie...IDNR
National Weather Service Saint Louis MO
841 AM CDT Wed Mar 18 2026

Forecast is based on ignition time of 0900 CDT on March 18.
If conditions become unrepresentative, contact the
National Weather Service.

.DISCUSSION...
Light south winds this morning will slowly shift to the southwest
near or just prior to noon, and eventually to the due west by mid
afternoon. Otherwise, moderate humidity is expected throughout
the day with relatively mild temperatures, with almost full sun
and no precipitation. In spite of the full sun, mixing heights are
not expected to be particularly high, which will likely limit
smoke dispersion along with the light winds. Winds will be nearly
calm overnight with good humidity recovery. Tomorrow, warm
even warmer temperatures are expected with moderate humidity once
again. Winds will begin the day light and southwesterly, but will
switch to the northwest as a weak front moves through the area
during the day.

.REST OF TODAY...

Sky/weather.........Mostly sunny (20-30 percent).
CWR.................1 percent.
Chance of thunder...2 percent.
Temperature.........37 at ignition...Max 62.
RH..................75 percent at ignition...Min 48 percent.
Eye level winds.....Winds south 0 to 2 mph at ignition...and will
                    shift slowly to the southwest 1 to 4 mph by 11 am, and
                    due west 1 to 4 mph by 2 PM.
Wind (20 ft)........Winds south 1 to 4 mph at ignition...and will
                    shift slowly to the southwest 4 to 8 mph by noon, and
                    due west 4 to 8 mph by 2 PM.
Mixing height.......900 ft AGL at ignition...otherwise max 2400 ft
                    AGL.
Transport winds.....Southwest 12 to 14 mph shifting to the west 8
                    to 10 mph in the afternoon.
Smoke dispersal.....Poor /1680 m/s-m/ at ignition. Max...poor /3330
                    m/s-m/.

TIME (CDT)      9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 6PM 7PM 8PM
Sky (%).........26  5   6   7   8   4   10  23  47  48  60  61
Weather cov.....
Weather type....
Tstm cov........
CWR.............0   0   0   0   0   0   0   0   0   0   0   0
Chc of thdr (%).0   0   0   0   0   0   0   0   0   0   0   0
Temp............37  43  48  52  55  58  61  61  62  60  57  54
RH..............75  67  63  56  57  53  48  51  50  55  62  66
20 FT wind dir..S   S   SW  SW  SW   W   W   W   W   W   SW  S
20 FT wind spd..5   5   5   5   5   5   5   4   3   2   2   2
20 FT wind gust.13  13  12  12  11  11  10  10  8   6   5   5
Eye lvl wnd dir.S   SW  W   W   W   W   W   W   W   W   SW  S
Eye lvl wnd spd.2   2   2   2   2   2   2   2   1   1   1   1
Eye lvl wnd gst.6   6   6   6   5   5   5   5   4   3   2   2
Mix hgt (kft)...0.9 1.3 1.5 2.0 2.1 2.2 2.4 2.4 1.9 0.7 0.5 0.5
Transp wind dir.SW  SW  W   W   W   W   W   W   W   SW  SW  S
Transp wind spd.14  14  12  10  9   9   10  10  8   6   6   6
Vrate kt-ft/1K..11  16  15  18  17  17  21  21  14  4   3   2
Ventrate Cat....PR  PR  PR  PR  PR  PR  PR  PR  PR  PR  PR  PR

.TONIGHT...

Sky/weather.........Partly cloudy (45-55 percent) then becoming
                    mostly cloudy (65-75 percent).
CWR.................2 percent.
Chance of thunder...3 percent.
Temperature.........Min 41.
RH..................Max 96 percent.
Eye level winds.....Light winds.
Wind (20 ft)........Light winds.
Mixing height.......Min 400 ft AGL.
Transport winds.....South 6 to 10 mph.
Smoke dispersal.....Poor (380 m/s-m).

.THURSDAY...

Sky/weather.........Mostly cloudy (70-80 percent) then becoming
                    mostly sunny (25-35 percent).
CWR.................3 percent.
Chance of thunder...3 percent.
Temperature.........Max 70.
RH..................Min 51 percent.
Eye level winds.....1 to 2 mph, shifting from southwest to northwest.
Wind (20 ft)........2 to 4 mph, shifting from southwest to northwest.
Mixing height.......Max 3500 ft AGL.
Transport winds.....Southwest 8 to 10 mph shifting to the north 9
                    to 12 mph in the afternoon.
Smoke dispersal.....Poor (600 m/s-m) early in the morning
                    increasing to marginal max (5280 m/s-m) in the
                    afternoon.

$$
Forecaster...19
Requested by...Geroff
Type of request...PRESCRIBED
.TAG 2606288.0/LSX
.DELDT 03/18/26
.FormatterVersion 2.0.0