245  
FNUS71 KRNK 080919  
FWSRNK  
 
SPOT FORECAST FOR COBBLER MOUNTAIN RX...USFS  
NATIONAL WEATHER SERVICE BLACKSBURG VA  
519 AM EDT THU APR 8 2021  
 
FORECAST IS BASED ON IGNITION TIME OF 0600 EDT ON APRIL 08.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
 
EXPECTING INCREASING CLOUDS AND MOISTURE TODAY. CLOUD HEIGHTS  
WILL BE LOWERING THIS AFTERNOON. WINDS BECOME EAST THEN SOUTHEAST  
AFTER 11AM WITH THE PASSAGE OF A FRONT. THE CHANCE OF RAIN ARRIVES  
AFTER 2PM WITH THE CHANCE IMPROVING AFTER 6PM.  
 
MINIMUM RH THIS AFTERNOON 45 TO 50 PERCENT.  
RAINFALL AMOUNTS BY FRIDAY MORNING WILL BE AROUND 0.25 INCHES.  
 
AT IGNITION TIME, PARTLY CLOUDY, TEMP 63, RH 56, WIND E 5MPH  
 
   
TODAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (40-50 PERCENT) THIS MORNING.  
BECOMING MOSTLY CLOUDY (75-85 PERCENT)THIS  
AFTERNOON. SCATTERED RAIN SHOWERS LATE IN  
THE AFTERNOON.  
CWR (0.01 IN).......10 PERCENT INCREASING TO 40 PERCENT.  
MAX TEMPERATURE.....AROUND 73.  
MIN HUMIDITY........47 PERCENT.  
WIND (20 FT)........LIGHT WINDS BECOMING SOUTHEAST 5 TO 7 MPH LATE  
IN THE MORNING.  
MIXING HEIGHT.......3100 FT AGL.  
MIXING WINDS........EAST 2 TO 9 MPH IN THE MORNING BECOMING SOUTHEAST  
13 TO 20 MPH IN THE AFTERNOON.  
SMOKE DISPERSAL.....POOR (600 MPH-FT) EARLY IN THE MORNING  
INCREASING TO GOOD (53500 MPH-FT) IN THE  
AFTERNOON.  
LVORI...............3.  
ADI.................1 INCREASING TO 48.  
HAINES INDEX........3 TO 5 OR VERY LOW TO MODERATE POTENTIAL FOR  
LARGE PLUME DOMINATED FIRE GROWTH.  
 
TIME (EDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........28 38 44 40 33 30 39 57 66 72 82 87  
WEATHER COV..... ISO ISO SCT SCT  
WEATHER TYPE.... RW RW RW RW  
TSTM COV........  
CWR.............0 0 0 0 0 0 10 10 20 20 30 40  
TEMP............57 52 54 58 60 63 65 66 68 69 68 67  
RH..............64 62 60 58 57 56 54 51 48 47 49 51  
20 FT WIND DIR..NE NE NE NE E E E E SE SE SE SE  
20 FT WIND SPD..3 3 3 3 4 5 5 6 6 7 7 7  
20 FT WIND GUST.5 5 6 6 7 8 10 12 13 14 14 14  
MIX HGT (KFT)...0.3 0.3 0.3 0.7 1.1 1.5 2.1 2.6 3.1 3.1 3.1 3.1  
MIXNG WIND DIR..NE NE E E E SE SE SE SE SE SE SE  
MIXNG WIND SPD..2 3 3 3 5 6 9 13 15 17 20 20  
LVORI...........3 4 4 3 3 2 2 2 1 1 1 1  
ADI.............1 4 4 4 7 11 23 28 37 42 48 48  
HAINES INDEX....5 5 5 5 5 5 5 5 5 4 4 3  
VRATE MPH-FT/1K.1 1 1 3 5 9 19 33 47 54 61 62  
   
TONIGHT
 
 
SKY/WEATHER.........CLOUDY (90-100 PERCENT). SCATTERED  
THUNDERSTORMS IN THE EVENING. NUMEROUS RAIN  
SHOWERS THROUGH THE NIGHT.  
CWR (0.01 IN).......60 PERCENT.  
MIN TEMPERATURE.....AROUND 49.  
MAX HUMIDITY........95 PERCENT.  
WIND (20 FT)........EAST WINDS 5 TO 6 MPH. GUSTY AND ERRATIC  
WINDS EXPECTED NEAR THUNDERSTORMS EARLY IN THE  
EVENING.  
MIXING HEIGHT.......1300 FT AGL.  
MIXING WINDS........SOUTHEAST 10 TO 18 MPH DECREASING TO 6 TO 9 MPH  
OVERNIGHT.  
SMOKE DISPERSAL.....GOOD (44100 MPH-FT) EARLY IN THE EVENING  
DECREASING TO POOR (6700 MPH-FT) LATE IN THE  
NIGHT.  
LVORI...............4.  
ADI.................42 DECREASING TO 4.  
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME  
DOMINATED FIRE GROWTH.  
 
TIME (EDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM  
SKY (%).........90 99 95 95 96 97  
WEATHER COV.....SCTTRD NUMRUS NUMRUS NUMRUS SCTTRD NUMRUS  
WEATHER TYPE....RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR  
TSTM COV........ISOLTD SCTTRD  
CWR.............50 60 60 60 50 60  
TEMP............67 60 57 54 53 52  
RH..............56 80 86 89 93 93  
20 FT WIND......SE 6 SE 6 E 5 E 5 E 5 E 4  
20 FT WIND GUST.14 10 9 9 9 8  
MIX HGT (FT)....2800 2000 1600 1300 1300 1300  
MIXING WIND.....SE 18 SE 15 SE 13 SE 10 SE 8 E 6  
LVORI...........1 4 5 5 6 6  
ADI.............42 10 8 7 5 4  
HAINES INDEX....3 3 3 3 3 3  
VRATE MPH-FT/1K.51 29 20 14 10 8  
   
FRIDAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY (65-75 PERCENT). SCATTERED RAIN  
SHOWERS IN THE MORNING  
CWR (0.01 IN).......50 PERCENT DECREASING TO 20 PERCENT.  
MAX TEMPERATURE.....AROUND 63.  
MIN HUMIDITY........67 PERCENT.  
WIND (20 FT)........LIGHT WINDS.  
MIXING HEIGHT.......2500 FT AGL.  
MIXING WINDS........SOUTHEAST 3 TO 7 MPH.  
SMOKE DISPERSAL.....POOR (4500 MPH-FT) EARLY IN THE MORNING  
INCREASING TO FAIR (14700 MPH-FT) IN THE  
AFTERNOON.  
LVORI...............5.  
ADI.................3 INCREASING TO 20.  
HAINES INDEX........3 TO 4 OR VERY LOW TO LOW POTENTIAL FOR LARGE  
PLUME DOMINATED FIRE GROWTH.  
 
TIME (EDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM  
SKY (%).........92 79 80 71 56 52  
WEATHER COV.....SCTTRD CHANCE CHANCE S CHC S CHC S CHC  
WEATHER TYPE....RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR  
TSTM COV........  
CWR.............50 30 30 20 20 20  
TEMP............52 53 54 57 61 61  
RH..............94 91 91 81 67 67  
20 FT WIND......E 3 SE 3 SE 3 SE 3 SE 3 SE 3  
20 FT WIND GUST.6 6 5 6 7 7  
MIX HGT (FT)....1400 1500 1500 1800 2500 2300  
MIXING WIND.....E 6 E 5 SE 3 SE 5 S 7 SE 5  
LVORI...........6 5 5 4 3 3  
ADI.............3 9 7 11 20 12  
HAINES INDEX....3 3 3 3 3 4  
VRATE MPH-FT/1K.8 7 5 8 17 10  
 

 
FORECASTER...SILVERMAN  
REQUESTED BY...LARAE GUILLORY  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2108283.1/RNK  
.DELDT 04/08/21  
.FORMATTERVERSION 1.0.26  
 
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