Spot Forecast
Issued by NWS St. Louis, MO
Issued by NWS St. Louis, MO
Versions:
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FNUS73 KLSX 201258
FWSLSX
Spot Forecast for Mark Twain Lake...U.S. Army Corps of Engineers
National Weather Service Saint Louis MO
758 AM CDT Tue Oct 20 2026
Forecast is based on ignition time of 1200 CDT on October 20.
If conditions become unrepresentative, contact the
National Weather Service.
.DISCUSSION...
Winds will be light from the south or south-southeast this afternoon
with relative humidity bottoming out between 30 and 35 percent. Light
winds in the mixed layer will produce poor ventilation rates, though
the low levels will be unstable which will help smoke to rise quickly.
.REST OF TODAY...
Sky/weather.........Sunny (0-10 percent).
CWR.................0 percent.
Chance of thunder...0 percent.
Temperature.........67 at ignition...Max 72.
RH..................47 percent at ignition...Min 35 percent.
Eye level winds.....Light south wind.
Wind (20 ft)........Winds south at 4 mph at ignition...otherwise
Light winds becoming south around 5 mph late in
the afternoon, then becoming light late in the
afternoon.
Mixing height.......3000 ft AGL at ignition...otherwise max 4500 ft
AGL.
Transport winds.....South 6 to 7 mph.
Smoke dispersal.....Poor /2370 m/s-m/ at ignition. Max...poor /4210
m/s-m/.
TIME (CDT) NOON 2 PM 4 PM 6 PM 8 PM 10 PM
Sky (%).........1 0 5 13 25 24
Weather cov.....
Weather type....NONE NONE NONE NONE NONE NONE
Tstm cov........
CWR.............0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0
Temp............67 71 72 69 61 58
RH..............47 38 35 40 61 65
20 ft wind......S 4 S 5 S 5 SE 3 SE 1 SE 1
20 ft wind gust.7 6 7 6 5 5
Eye level wind..S 2 S 2 S 2 SE 1 SE 0 SE 0
Eye lvl wnd gst.3 3 3 3 2 2
Mix hgt (kft)...3.0 4.4 4.3 0.6 0.4 0.4
Transport wind..S 6 S 7 S 7 SE 6 SE 8 SE 8
Vrate kt-ft/1K..15 26 26 3 3 3
Ventrate Cat....POOR POOR POOR POOR POOR POOR
$$
Forecaster...Carney
Requested by...Aaron Eckelkamp
Type of request...PRESCRIBED
.TAG 2624124.0/LSX
.DELDT 10/20/26
.FormatterVersion 2.0.0