576  
FNUS73 KLSX 221143  
FWSLSX  
 
SPOT FORECAST FOR MARK TWAIN LAKE - ROUTE N...U.S. ARMY CORPS OF ENGINEERS  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
643 AM CDT MON APR 22 2019  
 
FORECAST IS BASED ON IGNITION TIME OF 0700 CDT ON APRIL 22.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE  
NATIONAL WEATHER SERVICE.  
   
DISCUSSION
 
 
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF  
CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS THIS MORNING  
AND AGAIN LATER THIS AFTERNOON. OTHERWISE IT WILL BE A WARM DAY  
WITH ABOVE NORMAL TEMPERATURES AND GUSTY SOUTHERLY WINDS, BUT  
HUMIDITY VALUES WILL ALSO BE HIGHER. A COLD FRONT WILL MOVE THROUGH  
THE AREA TONIGHT ACCOMPANIED BY A SLIGHT CHANCE OF SHOWERS OR  
THUNDERSTORMS. COOLER TEMPERATURES ARE EXPECTED TUESDAY THROUGH  
THURSDAY WITH THE BEST RAIN POTENTIAL ACROSS SOUTHERN MISSOURI AND  
SOUTHWEST ILLINOIS.  
 
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY (65-75 PERCENT). ISOLATED SHOWERS  
AND THUNDERSTORMS LATE IN THE MORNING. ISOLATED  
SHOWERS AND THUNDERSTORMS LATE IN THE  
AFTERNOON.  
CHANCE OF PCPN......20 PERCENT.  
LAL.................NO TSTMS UNTIL 0900, THEN 1-8 STRIKES UNTIL  
1000, THEN NO TSTMS UNTIL 1600, THEN 1-8  
STRIKES.  
TEMPERATURE.........62 AT IGNITION...MAX 77.  
RH..................70 PERCENT AT IGNITION...MIN 52 PERCENT.  
WIND (20 FT)........WINDS SOUTH AT 10 MPH AT IGNITION...OTHERWISE  
SOUTHWEST WINDS 10 TO 13 MPH. GUSTS UP TO 24  
MPH IN THE LATE MORNING AND AFTERNOON. GUSTY  
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS  
LATE IN THE MORNING. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS LATE IN THE  
AFTERNOON.  
EYE LEVEL WINDS.....WINDS SOUTH AROUND 4 MPH AT IGNITION...OTHERWISE  
SOUTHWEST 4 TO 5 MPH USING AN ADJUSTMENT FACTOR  
OF 0.4.  
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME  
DOMINATED FIRE GROWTH.  
MIXING HEIGHT.......AROUND 200 FT AGL AT IGNITION,  
4000 FT AGL AT MAX HEATING.  
TRANSPORT WINDS.....SOUTHWEST AROUND 28 MPH.  
SMOKE DISPERSAL.....EXCELLENT (14940 M/S-M) AT MAX HEATING.  
 
TIME (CDT) 7 AM 9 AM 11 AM 1 PM 3 PM 5 PM  
SKY (%).........52 63 69 71 82 82  
WEATHER COV..... ISOLTD ISOLTD  
WEATHER TYPE....NONE RNSHWR NONE NONE NONE RNSHWR  
TSTM COV........ ISOLTD ISOLTD  
CWR.............10 20 10 10 10 20  
LAL.............1 2 1 1 1 2  
TEMP............62 66 72 76 77 75  
RH..............70 63 55 52 52 55  
20 FT WIND......S 10 S 11 S 13 S 13 SW 13 SW 12  
20 FT WIND GUST.13 16 18 21 20 18  
 

 
 
FORECASTER...GOSSELIN  
REQUESTED BY...ALLEN MEHRER  
TYPE OF REQUEST...PRESCRIBED  
.TAG 1906731.0/LSX  
.DELDT 04/22/19  
.FORMATTERVERSION 1.0.26  
 
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