193  
FNUS73 KLSX 160809  
FWSLSX  
 
SPOT FORECAST FOR WHITE RIVER TRACE GRASSLAND RXB...MISSOURI DEPARTMENT OF CONSERVATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
309 AM CDT WED APR 16 2025  
 
FORECAST IS BASED ON IGNITION TIME OF 0800 CDT ON APRIL 16.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE  
NATIONAL WEATHER SERVICE.  
   
DISCUSSION
 
 
LIGHT AND VARIABLE WINDS THIS MORNING WILL BECOME SOUTHERLY BY  
MID MORNING, INCREASING IN SPEED THROUGH MID AFTERNOON. RH VALUES  
WILL REACH THEIR MINIMUM AROUND 30% DURING THE EARLY AFTERNOON,  
THOUGH SURROUNDING AREAS ARE FORECAST TO DROP INTO THE LOW TO MID  
20S. IF THE LOCAL AREA IS A LITTLE WARMER AND/OR A LITTLE DRIER  
THAN CURRENTLY EXPECTED, RH VALUES COULD DROP AS LOW AS 20%.  
 
BY 11 AM THE ATMOSPHERE WILL BE MIXING TO 1200-2000 FT, AND WILL  
REACH ITS MAXIMUM MIXED HEIGHT AROUND 5,000 FT BY 3-5 PM.  
 
BY 4 PM A 15-20% CHANCE FOR SHOWERS AND THUNDERSTORMS WILL MOVE  
INTO THE AREA, THOUGH CONFIDENCE IN DEVELOPMENT IS LOW AT THIS  
POINT.  
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (20-30 PERCENT). SLIGHT CHANCE OF  
RAIN SHOWERS LATE IN THE AFTERNOON.  
TEMPERATURE.........43 AT IGNITION...MAX 72.  
RH..................57 PERCENT AT IGNITION...MIN 25 PERCENT.  
WIND (20 FT)........WINDS SOUTH AT 3 MPH AT IGNITION...OTHERWISE  
LIGHT WINDS BECOMING SOUTH 5 TO 9 MPH IN THE  
LATE MORNING AND AFTERNOON.  
EYE LEVEL WINDS.....1-4 MPH USING AN ADJUSTMENT FACTOR OF 0.4.  
MIXING HEIGHT.......2100 FT AGL AT IGNITION...OTHERWISE MAX 4600 FT  
AGL.  
TRANSPORT WINDS.....SOUTH 8 TO 17 MPH INCREASING TO AROUND 20 MPH  
LATE IN THE AFTERNOON.  
SMOKE DISPERSAL.....POOR /420 M/S-M/ AT IGNITION. MAX...GOOD /11990  
M/S-M/.  
 
TIME (CDT) 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 6PM 7PM  
SKY (%).........2 2 6 6 22 35 33 41 50 46 54 54  
WEATHER COV..... SCH SCH SCH SCH SCH  
WEATHER TYPE.... RW RW RW RW RW  
TSTM COV........ SCH  
TEMP............43 53 61 66 68 71 72 72 72 72 70 66  
RH..............57 46 35 30 27 25 26 25 26 27 30 38  
20 FT WIND DIR..S S S S S S S S S S S S  
20 FT WIND SPD..3 4 5 6 8 9 9 9 9 9 9 9  
20 FT WIND GUST.9 9 8 11 12 13 14 15 14 16 17 20  
EYE LVL WND DIR.S S S S S S S S S S S S  
EYE LVL WND SPD.1 2 2 3 4 4 4 4 4 4 4 4  
EYE LVL WND GST.4 4 4 5 6 6 6 7 6 7 8 9  
MIX HGT (KFT)...0.4 0.7 2.1 2.9 3.6 4.1 4.5 4.2 4.6 4.5 1.9 0.7  
TRANSP WIND DIR.SW S S S S S S S S S S S  
TRANSP WIND SPD.8 8 9 12 15 15 16 16 17 20 17 15  
VRATE KT-FT/1K..3 5 17 29 47 54 63 59 69 76 29 9  
VENTRATE CAT....PR PR PR PR FR FR GD FR GD GD PR PR  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT). SLIGHT CHANCE OF  
SHOWERS AND THUNDERSTORMS IN THE EVENING, THEN  
CHANCE OF SHOWERS AND THUNDERSTORMS OVERNIGHT.  
TEMPERATURE.........MIN 52.  
RH..................MAX 77 PERCENT.  
WIND (20 FT)........SOUTH WINDS 9 TO 10 MPH WITH GUSTS TO AROUND 24  
MPH. GUSTY AND ERRATIC WINDS EXPECTED NEAR  
THUNDERSTORMS.  
EYE LEVEL WINDS.....4-10 MPH, USING AN ADJUSTMENT FACTOR OF 0.4.  
MIXING HEIGHT.......MIN 500 FT AGL.  
TRANSPORT WINDS.....SOUTH 15 TO 20 MPH.  
SMOKE DISPERSAL.....POOR (1180 M/S-M).  
   
THURSDAY
 
 
SKY/WEATHER.........PARTLY SUNNY (50-60 PERCENT) THEN BECOMING  
SUNNY (15-25 PERCENT). RAIN SHOWERS LIKELY AND  
CHANCE OF THUNDERSTORMS IN THE MORNING.  
TEMPERATURE.........MAX 78.  
RH..................MIN 47 PERCENT.  
WIND (20 FT)........SOUTH WINDS 10 TO 18 MPH. GUSTS UP TO 33 MPH  
INCREASING TO 38 MPH IN THE AFTERNOON. GUSTY  
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS  
EARLY IN THE MORNING. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS LATE IN THE  
MORNING.  
EYE LEVEL WINDS.....4-7 MPH, GUSTING 13-15 MPH, USING AN ADJUSTMENT  
FACTOR OF 0.4.  
MIXING HEIGHT.......MAX 4100 FT AGL.  
TRANSPORT WINDS.....SOUTH 20 TO 26 MPH INCREASING TO 31 TO 39 MPH  
LATE IN THE MORNING.  
SMOKE DISPERSAL.....POOR (1480 M/S-M) EARLY IN THE MORNING  
INCREASING TO GOOD MAX (12820 M/S-M) IN THE  
AFTERNOON INCREASING TO GOOD (14060 M/S-M)  
EARLY IN THE MORNING INCREASING TO EXCELLENT  
MAX (20440 M/S-M) IN THE AFTERNOON IN THE  
AFTERNOON.  
 

 
FORECASTER...DELIA  
REQUESTED BY...MATTHEW PETER  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2510569.0/LSX  
.DELDT 04/16/25  
.FORMATTERVERSION 2.0.0  
 
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