859  
FNUS73 KLSX 201409  
FWSLSX  
 
SPOT FORECAST FOR LOGAN UNIT A...MISSOURI DEPT. CONSERVATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
809 AM CST TUE JAN 20 2026  
 
FORECAST IS BASED ON IGNITION TIME OF 1100 CST ON JANUARY 20.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE  
NATIONAL WEATHER SERVICE.  
   
DISCUSSION
 
 
TEMPERATURES WILL WARM FROM THE TEENS AND INTO THE MID 30S BY THE  
AFTERNOON WITH LIGHT SOUTHERLY FLOW INCREASING IN MAGNITUDE  
THROUGHOUT THE DAY. WINDS WILL CONTINUE TO INCREASE IN STRENGTH  
THIS EVENING AND INTO TONIGHT AHEAD OF AN APPROACHING COLD FRONT  
TO THE WEST. THIS COLD FRONT IS FORECASTED TO MOVE THROUGH AROUND  
SUNRISE TOMORROW BRINGING ONLY A GRADUAL WIND SHIFT FROM SOUTHERLY  
TO THE WEST WHILE THE WIND SPEEDS WILL REMAIN THE SAME BEHIND THE  
FRONT ON WEDNESDAY. MINIMUM RELATIVE HUMIDITY VALUES ARE  
FORECASTED TO DROP TO AROUND 35 PERCENT THIS AFTERNOON WITH  
SLIGHTLY HIGHER VALUES AROUND 40 PERCENT WEDNESDAY AFTERNOON. THE  
LOWER TO MID-LEVEL CLOUDS CURRENTLY OVER THE AREA MAY SLOWLY BREAK  
THIS AFTERNOON BEFORE MORE MID-LEVEL CLOUDS MOVE IN TONIGHT INTO  
WEDNESDAY MORNING. THERE ARE NO CHANCES FOR PRECIPITATION NOW  
THROUGH WEDNESDAY.  
 
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (35-45 PERCENT).  
CWR.................10 PERCENT.  
CHANCE OF THUNDER...0 PERCENT.  
TEMPERATURE.........25 AT IGNITION...MAX 37.  
RH..................46 PERCENT AT IGNITION...MIN 40 PERCENT.  
EYE LEVEL WINDS.....WINDS SOUTH AT 5 MPH OR LESS AT IGNITION...OTHERWISE  
SOUTH WINDS 5 MPH. ADJUSTMENT FACTOR OF 0.3 USED.  
WIND (20 FT)........WINDS SOUTH AT 7 MPH AT IGNITION...OTHERWISE  
SOUTH WINDS 6 TO 8 MPH.  
MIXING HEIGHT.......1700 FT AGL AT IGNITION...OTHERWISE MAX 2900 FT  
AGL.  
TRANSPORT WINDS.....SOUTH 13 TO 21 MPH.  
SMOKE DISPERSAL.....POOR /4290 M/S-M/ AT IGNITION. MAX...GOOD /8310  
M/S-M/.  
 
TIME (CST) 11 AM 1 PM 3 PM 5 PM 7 PM 9 PM  
SKY (%).........48 36 28 32 42 48  
WEATHER COV.....  
WEATHER TYPE....NONE NONE NONE NONE NONE NONE  
TSTM COV........  
CWR.............10 0 0 0 0 0  
CHC OF THDR (%).0 0 0 0 0 0  
TEMP............25 32 36 34 30 30  
RH..............46 41 42 49 55 51  
20 FT WIND......S 7 SW 8 S 8 S 6 S 7 S 9  
20 FT WIND GUST.13 14 15 12 14 19  
EYE LEVEL WIND..S 3 SW 4 S 4 S 3 S 3 S 4  
EYE LVL WND GST.6 6 7 6 6 9  
MIX HGT (KFT)...1.7 2.4 2.9 0.6 0.5 0.7  
TRANSPORT WIND..S 18 SW 18 S 21 S 13 S 17 S 18  
VRATE KT-FT/1K..27 38 53 6 8 12  
VENTRATE CAT....POOR POOR FAIR POOR POOR POOR  
   
TONIGHT
 
 
SKY/WEATHER.........PARTLY CLOUDY (40-50 PERCENT) THEN BECOMING  
MOSTLY CLOUDY (65-75 PERCENT).  
CWR.................10 PERCENT.  
CHANCE OF THUNDER...0 PERCENT.  
TEMPERATURE.........MIN 27.  
RH..................MAX 81 PERCENT.  
EYE LEVEL WINDS.....SOUTHWEST WINDS 5 MPH OR LESS WITH GUSTS TO  
AROUND 7 MPH. ADJUSTMENT FACTOR OF 0.3 USED.  
WIND (20 FT)........SOUTHWEST WINDS 7 TO 10 MPH WITH GUSTS TO  
AROUND 21 MPH.  
MIXING HEIGHT.......MIN 500 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST 15 TO 20 MPH SHIFTING TO THE WEST  
AROUND 18 MPH EARLY IN THE MORNING.  
SMOKE DISPERSAL.....POOR (960 M/S-M).  
   
WEDNESDAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (25-35 PERCENT).  
CWR.................0 PERCENT.  
CHANCE OF THUNDER...0 PERCENT.  
TEMPERATURE.........MAX 40.  
RH..................MIN 46 PERCENT.  
EYE LEVEL WINDS.....WEST WINDS 5 MPH. GUSTS UP TO 8 MPH IN  
THE MORNING AND EARLY AFTERNOON. ADJUSTMENT  
FACTOR OF 0.3 USED.  
WIND (20 FT)........WEST WINDS 6 TO 9 MPH. GUSTS UP TO 23 MPH IN  
THE MORNING AND EARLY AFTERNOON.  
MIXING HEIGHT.......MAX 3100 FT AGL.  
TRANSPORT WINDS.....WEST 17 TO 24 MPH.  
SMOKE DISPERSAL.....POOR (1850 M/S-M) EARLY IN THE MORNING  
INCREASING TO GOOD MAX (10390 M/S-M) IN THE  
AFTERNOON.  
 

 
FORECASTER...PEINE/ELMORE  
REQUESTED BY...NICK LEMASTER  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2600604.0/LSX  
.DELDT 01/20/26  
.FORMATTERVERSION 2.0.0  
 
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