328  
FNUS71 KLWX 191100  
FWSLWX  
 
SPOT FORECAST FOR BIG MOUNTAIN RX...USDA  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
700 AM EDT MON APR 19 2021  
 
FORECAST IS BASED ON IGNITION TIME OF 0700 EDT ON APRIL 19.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
 
DRY CONDITIONS AND LIGHT WINDS ARE EXPECTED TODAY. IT IS NOT  
COMPLETELY OUT OF THE QUESTION THAT THERE IS AN ISOLATED SHOWER,  
BUT THAT ACTIVITY IS MORE LIKELY TO STAY OFF TO THE SOUTH AND EAST.  
 
MORE DRY CONDITIONS ARE LIKELY TUESDAY AND THE MIXING HEIGHT SHOULD  
INCREASE TO ABOVE 7,000 FEET BY LATE MORNING. A SHOWER IS POSSIBLE  
IN THE EVENING (MOST LIKELY AFTER 5 PM), BUT MOST PLACES SHOULD END  
UP DRY.  
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (40-50 PERCENT).  
CWR.................10 PERCENT.  
MAX TEMPERATURE.....AROUND 66.  
MIN HUMIDITY........28 PERCENT.  
WIND (20 FT)........LIGHT WINDS BECOMING WEST 5 TO 9 MPH IN THE  
AFTERNOON.  
MIXING HEIGHT.......9900 FT AGL.  
TRANSPORT WINDS.....NORTHWEST 3 TO 12 MPH INCREASING TO AROUND 14  
MPH LATE IN THE AFTERNOON.  
SMOKE DISPERSAL.....POOR (0 KNOT-FT) EARLY IN THE MORNING  
INCREASING TO EXCELLENT (96100 KNOT-FT) IN THE  
AFTERNOON INCREASING TO EXCELLENT (111000  
KNOT-FT) LATE IN THE AFTERNOON.  
 
TIME (EDT) 7 AM 9 AM 11 AM 1 PM 3 PM 5 PM  
SKY (%).........57 47 30 35 38 40  
WEATHER COV.....  
WEATHER TYPE....NONE NONE NONE NONE NONE NONE  
CWR.............10 10 10 10 10 10  
TEMP............43 49 59 62 64 64  
RH..............84 66 39 32 29 28  
20 FT WIND......W 3 W 3 W 4 W 6 W 7 W 9  
20 FT WIND GUST.5 5 6 10 12 14  
MIX HGT (FT)....BLW100 2100 7100 8700 9600 9300  
MIXNG WIND......SW 3 W 3 NW 5 NW 8 NW 12 NW 14  
VRATE KT-FT/10000 6 29 61 96 111  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLEAR (15-25 PERCENT).  
CWR.................10 PERCENT.  
MIN TEMPERATURE.....AROUND 41.  
MAX HUMIDITY........76 PERCENT.  
WIND (20 FT)........WEST WINDS 7 TO 8 MPH EARLY IN THE EVENING  
BECOMING LIGHT.  
MIXING HEIGHT.......0 FT AGL.  
TRANSPORT WINDS.....WEST 6 TO 14 MPH.  
SMOKE DISPERSAL.....EXCELLENT (79000 KNOT-FT) EARLY IN THE EVENING  
DECREASING TO POOR (0 KNOT-FT) LATE IN THE  
NIGHT.  
 
TIME (EDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM  
SKY (%).........31 12 12 12 12 16  
WEATHER COV.....  
WEATHER TYPE....NONE NONE NONE NONE NONE NONE  
CWR.............10 0 0 0 0 0  
TEMP............62 56 51 47 45 45  
RH..............31 42 50 60 68 70  
20 FT WIND......W 8 W 4 W 4 SW 4 SW 4 SW 4  
20 FT WIND GUST.11 7 6 6 7 7  
MIX HGT (FT)....6600 500 BLW100 200 300 200  
MIXNG WIND......NW 14 W 10 W 7 W 6 W 8 W 9  
VRATE KT-FT/100079 4 0 1 2 2  
   
TUESDAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (25-35 PERCENT).  
CWR.................10 PERCENT.  
MAX TEMPERATURE.....AROUND 71.  
MIN HUMIDITY........29 PERCENT.  
WIND (20 FT)........LIGHT WINDS BECOMING SOUTHWEST 5 TO 6 MPH IN  
THE LATE MORNING AND AFTERNOON.  
MIXING HEIGHT.......8100 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST 10 TO 16 MPH.  
SMOKE DISPERSAL.....POOR (4300 KNOT-FT) EARLY IN THE MORNING  
INCREASING TO EXCELLENT (73100 KNOT-FT) IN THE  
AFTERNOON.  
 
TIME (EDT) 6 AM 9 AM NOON 3 PM  
SKY (%).........18 21 25 35  
WEATHER COV.....  
WEATHER TYPE....NONE NONE NONE NONE  
CWR.............0 10 10 10  
TEMP............44 52 66 71  
RH..............73 61 37 29  
20 FT WIND......SW 4G7 SW 4G8 SW 6G10 SW 6G11  
MIX HGT (FT)....400 1700 4700 7800  
MIXNG WIND......W 13 W 16 W 14 SW 10  
VRATE KT-FT/10004 23 56 70  
 

 
FORECASTER...LASORSA  
REQUESTED BY...JOHN FRY  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2109582.0/LWX  
.DELDT 04/19/21  
.FORMATTERVERSION 1.0.26  
 
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