069
FNUS73 KUNR 210306
FWSUNR
SPOT FORECAST FOR SOUTH WESTON...BUREAU OF LAND MANAGEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
906 PM MDT THU AUG 20 2026
FORECAST IS BASED ON FORECAST START TIME OF 2100 MDT ON AUGUST 20.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE.
DISCUSSION
HOT AND DRY WEATHER IS EXPECTED TO CONTINUE AS A
RIDGE OF HIGH PRESSURE GENERALLY EXERTS CONTROL OVER THE REGION.
HIGH TEMPERATURES FRIDAY WILL REACH THE MID-90S WITH A MINIMUM
RELATIVE HUMIDITY AROUND 14% IN THE FIRE AREA. WINDS WERE FAIRLY
LIGHT TODAY, BUT WILL SWITCH TO NORTH AND COME IN A BIT STRONGER
FRIDAY AFTERNOON AS SHOWN BELOW. AT THIS TIME, CONSENSUS AMONG
OUR HIGH-RESOLUTION GUIDANCE IS EXCELLENT (LEADING TO HIGH
FORECAST CONFIDENCE) IN NO THUNDERSTORM DEVELOPMENT NEAR OR OVER
THE FIRE THROUGH AT LEAST SATURDAY MORNING. SOME UPPER-LEVEL
MOISTURE MAY TRY TO SPILL OVER THE RIDGE, BUT THIS WILL ONLY
MANIFEST AS SOME HIGH-LEVEL CLOUDS PASSING OVER THE REGION.
LOOKING AHEAD, ELEVATED FIRE WEATHER CONDITIONS ARE EXPECTED TO
CONTINUE INTO THE WEEKEND, ALTHOUGH HUMIDITY VALUES MAY INCREASE
SLIGHTLY WITH TIME. THE NEXT CHANCE OF THUNDERSTORMS WILL BE
SATURDAY AFTERNOON.
REST OF TONIGHT
SKY/WEATHER.........PARTLY CLOUDY (30-50 PERCENT).
MIN TEMPERATURE.....AROUND 61 DEGREES.
MAX HUMIDITY........50 PERCENT.
WIND (20 FT)........VARIABLE WINDS AROUND 8 MPH WITH GUSTS TO AROUND
15 MPH SHIFTING TO THE SOUTH LATE IN THE EVENING.
CWR.................0 PERCENT.
MIXING HEIGHT.......500 TO 1000 FT AGL.
TRANSPORT WINDS.....EAST AROUND 15 MPH SHIFTING TO THE SOUTH
OVERNIGHT.
SMOKE DISPERSAL.....POOR.
TIME (MDT) 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........22 36 48 50 46 45 45 42 40
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0
TEMP............79 76 73 71 69 68 66 64 63
RH..............25 30 34 39 41 43 45 49 50
20 FT WIND DIR..E E SE S S S S S S
20 FT WIND SPD..7 6 6 6 6 7 7 7 7
20 FT WIND GUST.17 15 14 9 15 15 15 14 14
MIX HGT (KFT)...0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
TRANSP WIND DIR.E E SE SE SE S S S S
TRANSP WIND SPD.13 13 12 12 12 13 13 13 12
FRIDAY
SKY/WEATHER.........MOSTLY SUNNY (30-40 PERCENT).
MAX TEMPERATURE.....AROUND 94 DEGREES.
MIN HUMIDITY........14 PERCENT.
WIND (20 FT)........SOUTH WINDS AROUND 10 MPH SHIFTING TO THE
NORTHWEST LATE IN THE MORNING, THEN SHIFTING TO
THE NORTH IN THE AFTERNOON. GUSTS UP TO 23 MPH.
CWR.................0 PERCENT.
MIXING HEIGHT.......9700 TO 10200 FT AGL INCREASING TO 10900 TO
11400 FT AGL LATE IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTH AROUND 15 MPH SHIFTING TO THE NORTHWEST
LATE IN THE MORNING, THEN SHIFTING TO THE NORTH
20 TO 25 MPH LATE IN THE AFTERNOON.
SMOKE DISPERSAL.....GOOD INCREASING TO EXCELLENT IN THE AFTERNOON.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........40 40 35 22 19 21 26 26 28 32 33 25
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............63 66 70 76 81 86 89 91 92 93 93 92
RH..............52 50 46 39 32 24 19 18 15 15 14 15
20 FT WIND DIR..S S S S SW NW N N N N N N
20 FT WIND SPD..6 7 7 7 6 6 6 8 10 12 13 14
20 FT WIND GUST.14 14 14 13 13 14 15 17 20 22 23 22
MIX HGT (KFT)...0.5 0.4 0.5 0.8 1.6 3.9 7.8 9.0 10 11 10 9.1
TRANSP WIND DIR.S S S S SW W NW NW NW NW N N
TRANSP WIND SPD.12 12 13 13 13 13 13 15 17 20 21 22
FRIDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY (25-35 PERCENT).
MIN TEMPERATURE.....AROUND 60 DEGREES.
MAX HUMIDITY........67 PERCENT.
WIND (20 FT)........NORTHEAST WINDS 10 TO 15 MPH WITH GUSTS TO
AROUND 22 MPH SHIFTING TO THE EAST 5 TO 10 MPH
WITH GUSTS TO AROUND 16 MPH IN THE LATE EVENING
AND OVERNIGHT.
CWR.................0 PERCENT.
MIXING HEIGHT.......400 TO 900 FT AGL.
TRANSPORT WINDS.....NORTHEAST 20 TO 25 MPH SHIFTING TO THE EAST 10
TO 15 MPH LATE IN THE EVENING.
SMOKE DISPERSAL.....FAIR DECREASING TO POOR IN THE LATE EVENING AND
OVERNIGHT.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........28 35 35 32 34 35 35 30 25 23 35 31
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............90 87 82 78 74 72 70 68 66 64 62 61
RH..............17 18 23 29 34 38 42 47 52 56 62 67
20 FT WIND DIR..N NE NE NE E E E E E E E E
20 FT WIND SPD..14 13 9 8 7 6 6 5 5 5 5 6
20 FT WIND GUST.22 21 20 18 16 15 14 12 12 10 10 12
MIX HGT (KFT)...7.9 5.4 3.0 0.6 0.6 0.5 0.5 0.5 0.5 0.5 0.5 0.4
TRANSP WIND DIR.N N NE NE NE E E E E E E E
TRANSP WIND SPD.22 22 21 18 16 14 12 10 9 9 9 9
FORECASTER...KSMITH
REQUESTED BY...FOX
TYPE OF REQUEST...WILDFIRE
.TAG 2620144.0/UNR
.DELDT 08/20/26
.FORMATTERVERSION 2.0.0
.EMAIL WYCPC@FIRENET.GOV
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