395  
FNUS74 KMOB 202023  
FWSMOB  
 
SPOT FORECAST FOR DESOTO SITE PREP COMP. 20...USFS  
NATIONAL WEATHER SERVICE MOBILE AL  
323 PM CDT WED OCT 20 2021  
 
FORECAST IS BASED ON IGNITION TIME OF 1600 CDT ON OCTOBER 20.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
 
...LOW DISPERSION INDEX AROUND 20 EXPECTED THURSDAY AFTERNOON OVER THE  
BURN AREA...  
   
DISCUSSION
 
 
FOR THE REST OF THIS AFTERNOON, EXPECT FAIR DISPERSIONS WITH  
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA.  
PRECIPITATION CHANCES INCREASE FOR THURSDAY, WITH SCATTERED TO AT  
TIMES NUMEROUS SHOWER AND THUNDERSTORM COVERAGE EXPECTED. MINIMUM  
RELATIVE HUMIDITY VALUES REMAIN WELL ABOVE CRITICAL THRESHOLDS.  
SOUTHEAST TRANSPORT WINDS TODAY BECOME SOUTHERLY FOR THURSDAY  
MORNING, THEN WESTERLY BY THURSDAY AFTERNOON AND EVENING.  
 
FOG POTENTIAL AND OTHER REMARKS...SOME PATCHY FOG BECOMES POSSIBLE  
OVERNIGHT TONIGHT INTO THURSDAY MORNING, WITH LOCAL REDUCTIONS IN  
VISIBILITY POSSIBLE.  
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY (80-90 PERCENT). SHOWERS LIKELY  
AND CHANCE OF THUNDERSTORMS.  
CHANCE OF PCPN......60 PERCENT.  
LAL.................9-15 STRIKES.  
MAX TEMPERATURE.....AROUND 79.  
MIN HUMIDITY........72 PERCENT.  
WIND (20 FT)........SOUTHEAST WINDS AROUND 5 MPH. GUSTY AND ERRATIC  
WINDS EXPECTED NEAR THUNDERSTORMS.  
MIXING HEIGHT.......1800 FT AGL.  
MIXING HEIGHT (M)...549 METERS AGL.  
TRANSPORT WINDS.....SOUTHEAST AROUND 15 MPH.  
TRANSPORT WINDS M/S.SOUTHEAST AROUND 7 METERS/SECOND.  
DISPERSION INDEX....26.  
LVORI...............3.  
STABILITY CLASS.....4.  
 
TIME (CDT) 4 PM  
SKY (%).........87  
WEATHER COV.....LIKELY  
WEATHER TYPE....RNSHWR  
TSTM COV........CHANCE  
CHC OF PCPN (%).60  
LAL.............3  
TEMP............76  
RH..............82  
20 FT WIND DIR..SE  
20 FT WIND SPD..5  
20 FT WIND GUST.7  
MIX HGT (FT)....1800  
MIX HGT (M).....550  
TRANSP WIND DIR.SE  
TRANSP WIND SPD.15  
TRANS WIND DIR..SE  
TRANS SPD (M/S).7  
DISPERSION IDX..26  
LVORI...........3  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY (80-90 PERCENT). SHOWERS LIKELY  
AND CHANCE OF THUNDERSTORMS EARLY IN THE  
EVENING, THEN CHANCE OF SHOWERS AND SLIGHT  
CHANCE OF THUNDERSTORMS. PATCHY FOG OVERNIGHT.  
CHANCE OF PCPN......60 PERCENT.  
LAL.................9-15 STRIKES UNTIL 1900, THEN 1-8 STRIKES.  
MIN TEMPERATURE.....AROUND 67.  
MAX HUMIDITY........100 PERCENT.  
WIND (20 FT)........LIGHT WINDS. GUSTY AND ERRATIC WINDS EXPECTED  
NEAR THUNDERSTORMS.  
MIXING HEIGHT.......200 FT AGL.  
MIXING HEIGHT (M)...61-549 METERS AGL.  
TRANSPORT WINDS.....SOUTHEAST 6 TO 15 MPH DECREASING TO 1 TO 5 MPH  
EARLY IN THE EVENING.  
TRANSPORT WINDS M/S.SOUTHEAST 0 TO 3 METERS/SECOND.  
DISPERSION INDEX....26 DECREASING TO 3.  
LVORI...............7.  
STABILITY CLASS.....4.  
 
TIME (CDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM  
SKY (%).........86 87 83 78 76 77  
WEATHER COV.....LIKELY CHANCE CHANCE CHANCE CHANCE CHANCE  
WEATHER TYPE....RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR  
TSTM COV........CHANCE S CHC S CHC S CHC S CHC S CHC  
CHC OF PCPN (%).60 40 40 40 50 50  
LAL.............3 2 2 2 2 2  
TEMP............73 71 68 70 68 68  
RH..............90 97 100 97 100 100  
20 FT WIND DIR..SE SE SE SE SE SSE  
20 FT WIND SPD..4 3 3 3 2 1  
20 FT WIND GUST.6 5 4 4 2  
MIX HGT (FT)....1800 300 300 300 300 200  
MIX HGT (M).....550 90 90 90 90 60  
TRANSP WIND DIR.SE SE SE SE SE SSE  
TRANSP WIND SPD.15 5 5 5 3 2  
TRANS WIND DIR..SE SE SE SE SE SSE  
TRANS SPD (M/S).7 2 2 2 1 1  
DISPERSION IDX..26 4 3 3 2 2  
LVORI...........4 9 9 9 9 10  
   
THURSDAY
 
 
SKY/WEATHER.........PARTLY SUNNY (60-70 PERCENT). PATCHY FOG EARLY  
IN THE MORNING. SHOWERS LIKELY AND CHANCE OF  
THUNDERSTORMS THROUGH THE DAY.  
CHANCE OF PCPN......60 PERCENT.  
LAL.................1-8 STRIKES UNTIL 0700, THEN 9-15 STRIKES.  
MAX TEMPERATURE.....AROUND 82.  
MIN HUMIDITY........67 PERCENT.  
WIND (20 FT)........LIGHT WINDS. GUSTY AND ERRATIC WINDS EXPECTED  
NEAR THUNDERSTORMS EARLY IN THE MORNING. GUSTY  
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS.  
MIXING HEIGHT.......3800 FT AGL.  
MIXING HEIGHT (M)...61-1158 METERS AGL.  
TRANSPORT WINDS.....SOUTHEAST 1 TO 2 MPH SHIFTING TO THE WEST 5 TO  
8 MPH IN THE LATE MORNING AND AFTERNOON.  
TRANSPORT WINDS M/S.SOUTHEAST AROUND 0 METERS/SECOND BECOMING 0 TO  
1 METERS/SECOND EARLY IN THE MORNING, THEN  
SHIFTING TO THE WEST 2 TO 4 METERS/SECOND IN  
THE LATE MORNING AND AFTERNOON.  
DISPERSION INDEX....4 INCREASING TO 18 IN THE LATE MORNING AND  
AFTERNOON.  
LVORI...............7.  
STABILITY CLASS.....2.  
 
TIME (CDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM  
SKY (%).........77 74 69 63 57 52  
WEATHER COV.....CHANCE LIKELY LIKELY LIKELY CHANCE CHANCE  
WEATHER TYPE....RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR  
TSTM COV........S CHC CHANCE CHANCE CHANCE CHANCE CHANCE  
CHC OF PCPN (%).50 60 60 60 40 40  
LAL.............2 3 3 3 3 3  
TEMP............67 68 75 78 82 82  
RH..............100 100 90 79 67 67  
20 FT WIND DIR..SE SSE SSW WSW WSW SW  
20 FT WIND SPD..1 1 2 3 3 2  
20 FT WIND GUST.2 2 4 4  
MIX HGT (FT)....200 500 1300 3000 3500 2900  
MIX HGT (M).....60 150 400 910 1070 880  
TRANSP WIND DIR.SE SSE WSW W W WSW  
TRANSP WIND SPD.1 2 7 7 6 5  
TRANS WIND DIR..SE SSE WSW W W WSW  
TRANS SPD (M/S).0 1 3 3 3 2  
DISPERSION IDX..1 3 13 21 20 18  
LVORI...........10 9 5 3 3 3  
 

 
FORECASTER...25  
REQUESTED BY...CLIFF WILLIS  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2119768.1/MOB  
.DELDT 10/20/21  
.FORMATTERVERSION 1.0.26  
.EMAIL CLIFTON.WILLIS@USDA.GOV  
 
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