502  
FNUS73 KLSX 161012  
FWSLSX  
 
SPOT FORECAST FOR CANAAN FIELDS BURN...MISSOURI DEPARTMENT OF CONSERVATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
512 AM CDT WED SEP 16 2026  
 
FORECAST IS BASED ON IGNITION TIME OF 0700 CDT ON SEPTEMBER 16.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE  
NATIONAL WEATHER SERVICE.  
   
..HEAT ADVISORY IN EFFECT UNTIL 8 PM CDT FRIDAY
 
 
   
DISCUSSION
 
 
A WEAK COLD FRONT THAT IS SLOWLY PUSHING SOUTH THIS MORNING HAS  
PASSED THROUGH THE BURN AREA WITHIN THE LAST FEW HOURS. SURFACE  
WINDS WILL BE LIGHT TO SOMEWHAT VARIABLE GENERALLY OUT OF THE  
NORTHEAST THIS MORNING, POTENTIALLY BECOMING LIGHT AND SOUTHERLY  
BY THE AFTERNOON. SCATTERED TO BROKEN LOW/MID-LEVEL CLOUDS WILL  
MOVE IN FROM THE NORTHWEST AROUND SUNRISE WITH GRADUAL DISPERSION  
OF THIS CLOUD COVER ANTICIPATED THROUGHOUT THE DAY. THERE MAY BE  
SOME ADDITIONAL LOW-LEVEL CLOUDS THAT DEVELOP LATER TODAY WITH A  
20-30% CHANCE FOR AN ISOLATED SHOWER OR SUB-SEVERE THUNDERSTORM  
THIS AFTERNOON AND EVENING. ASIDE FROM THOSE LOW PRECIPITATION  
CHANCES, DRY CONDITIONS SHOULD PREVAIL WHILE THE MORE WIDESPREAD  
RAIN THIS MORNING STAYS TO THE NORTH ACROSS NORTHERN MO. MINIMUM  
RELATIVE HUMIDITY VALUES TODAY SHOULD REACH THE MID 50S BRIEFLY  
THIS AFTERNOON WITH SLIGHTLY LOWER VALUES IN THE MID 40S POSSIBLE  
THURSDAY AFTERNOON. MIXING HEIGHTS COULD BE SLOWER TO INCREASE  
THIS MORNING WITH LIGHTER SURFACE WINDS AND ESPECIALLY IF CLOUD  
COVER IS MORE PREVALENT. ASSUMING AN AFTERNOON HIGH IN THE LOW  
90S, MIXING HEIGHTS BRIEFLY REACH AROUND 5KFT BEFORE QUICKLY  
LOWERING BELOW 1KFT AFTER SUNSET. RELATIVELY STEEP LOW-LEVEL LAPSE  
RATES THIS AFTERNOON WILL ALLOW FOR EFFICIENT VERTICAL MIXING OF  
SMOKE. HOWEVER, ANY SCATTERED MID/LOW-LEVEL CLOUDS THAT MOVE PAST  
THE BURN AREA WILL TEMPORARILY LOWER THAT EFFICIENCY. THURSDAY  
SHOULD FEATURE MORE SUNSHINE, WARMER AFTERNOON TEMPERATURES (HIGHS  
MID 90S), POSSIBLY LEADING TO SLIGHTLY HIGHER AFTERNOON MIXING  
HEIGHTS (>5KFT) ALONG WITH LIGHT AND VARIABLE SURFACE WINDS.  
 
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (30-40 PERCENT). SLIGHT CHANCE OF  
SHOWERS AND THUNDERSTORMS EARLY IN THE MORNING.  
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN  
THE AFTERNOON.  
CWR.................11 PERCENT.  
CHANCE OF THUNDER...23 PERCENT.  
TEMPERATURE.........75 AT IGNITION...MAX 92.  
RH..................87 PERCENT AT IGNITION...MIN 56 PERCENT.  
EYE LEVEL WINDS.....LIGHT AND GENERALLY SOUTHERLY.  
WIND (20 FT)........WINDS EAST AT 4 MPH AT IGNITION...OTHERWISE  
LIGHT WINDS BECOMING SOUTHEAST AROUND 5 MPH  
LATE IN THE MORNING, THEN BECOMING LIGHT LATE  
IN THE MORNING. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS EARLY IN THE  
MORNING. GUSTY AND ERRATIC WINDS EXPECTED NEAR  
THUNDERSTORMS IN THE AFTERNOON.  
MIXING HEIGHT.......1200 FT AGL AT IGNITION...OTHERWISE MAX 5600 FT  
AGL.  
TRANSPORT WINDS.....EAST 7 TO 8 MPH SHIFTING TO THE SOUTHWEST 6 TO  
9 MPH IN THE LATE MORNING AND AFTERNOON.  
SMOKE DISPERSAL.....POOR /1080 M/S-M/ AT IGNITION. MAX...MARGINAL  
/5810 M/S-M/.  
 
TIME (CDT) 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 6PM  
SKY (%).........56 46 35 21 16 10 13 13 29 53 59 52  
WEATHER COV.....SCH SCH SCH SCH SCH SCH SCH SCH CHC  
WEATHER TYPE....RW RW RW RW RW RW RW RW RW  
TSTM COV........SCH SCH SCH SCH SCH SCH SCH SCH CHC  
CWR.............10 10 10 10 10 10 10 10 10 10 10 10  
CHC OF THDR (%).20 20 10 10 10 20 20 20 20 20 20 30  
TEMP............75 75 79 82 86 88 90 92 92 92 91 89  
RH..............87 90 82 77 70 63 62 56 56 56 56 61  
20 FT WIND DIR..E E SE SE S S SW SW S S E SE  
20 FT WIND SPD..4 4 4 5 4 4 4 4 3 3 4 4  
20 FT WIND GUST.8 8 8 9 8 8 8 8 7 7 7 7  
EYE LVL WND DIR.E E SE SE S S SW SW S S E SE  
EYE LVL WND SPD.2 2 2 2 2 2 2 2 1 1 2 2  
EYE LVL WND GST.4 4 4 4 4 4 4 4 3 3 3 3  
MIX HGT (KFT)...1.2 1.0 1.2 1.4 2.5 3.2 4.4 5.3 5.6 4.7 2.6 1.0  
TRANSP WIND DIR.E E SE S SW SW SW SW SW S S SE  
TRANSP WIND SPD.7 8 8 7 9 9 8 8 6 6 7 7  
VRATE KT-FT/1K..7 7 8 9 20 25 31 37 28 24 16 6  
VENTRATE CAT....PR PR PR PR PR PR PR PR PR PR PR PR  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY (55-65 PERCENT) THEN BECOMING  
PARTLY CLOUDY (20-30 PERCENT). CHANCE OF  
SHOWERS AND THUNDERSTORMS EARLY IN THE EVENING.  
CWR.................12 PERCENT.  
CHANCE OF THUNDER...27 PERCENT.  
TEMPERATURE.........MIN 76.  
RH..................MAX 79 PERCENT.  
EYE LEVEL WINDS.....LIGHT AND GENERALLY SOUTHERLY.  
WIND (20 FT)........LIGHT WINDS. GUSTY AND ERRATIC WINDS EXPECTED  
NEAR THUNDERSTORMS EARLY IN THE EVENING.  
MIXING HEIGHT.......MIN 400 FT AGL.  
TRANSPORT WINDS.....SOUTH 7 TO 10 MPH SHIFTING TO THE SOUTHWEST 10  
TO 12 MPH AFTER 3 AM.  
SMOKE DISPERSAL.....POOR (420 M/S-M).  
   
THURSDAY
 
 
SKY/WEATHER.........SUNNY (10-20 PERCENT). SLIGHT CHANCE OF SHOWERS  
AND THUNDERSTORMS EARLY IN THE AFTERNOON.  
CWR.................6 PERCENT.  
CHANCE OF THUNDER...22 PERCENT.  
TEMPERATURE.........MAX 95.  
RH..................MIN 48 PERCENT.  
EYE LEVEL WINDS.....LIGHT AND SOUTHERLY IN THE MORNING TURNING  
WESTERLY AROUND THE MIDDLE OF THE DAY AND  
NORTHERLY BY THE AFTERNOON.  
WIND (20 FT)........LIGHT WINDS. GUSTY AND ERRATIC WINDS EXPECTED  
NEAR THUNDERSTORMS EARLY IN THE AFTERNOON.  
MIXING HEIGHT.......MAX 6500 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST 10 TO 13 MPH SHIFTING TO THE  
NORTHWEST 6 TO 12 MPH IN THE AFTERNOON.  
SMOKE DISPERSAL.....POOR (690 M/S-M) EARLY IN THE MORNING  
INCREASING TO FAIR MAX (7320 M/S-M) IN THE  
AFTERNOON.  
 

 
FORECASTER...PEINE  
REQUESTED BY...RYAN WESTCOTT  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2621976.0/LSX  
.DELDT 09/16/26  
.FORMATTERVERSION 2.0.0  
 
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