412
FNUS73 KUNR 190022
FWSUNR
SPOT FORECAST FOR GREYHOUND FIRE...SD-BKF
NATIONAL WEATHER SERVICE RAPID CITY SD
522 PM MST THU DEC 18 2025
FORECAST IS BASED ON FORECAST START TIME OF 1800 MST ON DECEMBER 18.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE.
DISCUSSION
WARMER AIR WILL FLOW INTO THE AREA OVERNIGHT TONIGHT
WITH MUCH WARMER TEMPERATURES FOR FRIDAY AHEAD OF A COLD FRONT
WHICH WILL BRING GUSTY SOUTHWEST WINDS. THIS COLD FRONT MOVES
THROUGH FRIDAY EVENING SHIFTING WINDS TO THE NORTHWEST AND
BRINGING A CHANCE OF RAIN. COOLER WEATHER IS EXPECTED SATURDAY
WITH A BUMP IN TEMPERATURES FOR SUNDAY.
FOR TONIGHT, EXPECT MOSTLY CLOUDY SKIES WITH LOWS IN THE MID 20S
AND FAIR RELATIVE HUMIDITY RECOVERY AROUND 60%. SOUTHWEST WINDS AT
5 TO 15 MPH WILL BECOME WEST 10 TO 20 MPH AFTER MIDNIGHT WITH
GUSTS AROUND 30 MPH.
FRIDAY, EXPECT MOSTLY SUNNY SKIES AND HIGHS IN THE UPPER 50S WITH
MINIMUM RELATIVE HUMIDITIES AROUND 28%. WEST WINDS WILL BLOW AT 15
TO 20 MPH WITH GUSTS FROM 30 TO 45 MPH. THERE IS A SMALL CHANCE OF
RAIN LATE IN THE AFTERNOON.
FRIDAY NIGHT, AS THE COLD FRONT MOVES THROUGH THERE WILL BE A
CHANCE OF RAIN EARLY AND THEN SNOW WILL BECOME LIKELY. SNOW
ACCUMULATIONS WILL BE LESS THAN AN INCH. LOWS FRIDAY NIGHT WILL BE
IN THE MID 20S WITH FAIR TO GOOD RELATIVE HUMIDITY RECOVERY
(66-72%). NORTHWEST WINDS AT 10 TO 15 MPH WITH GUSTS AROUND 30 MPH
ARE EXPECTED.
SATURDAY WILL BE MOSTLY SUNNY WITH HIGHS IN THE UPPER 30S AS
MINIMUM RELATIVE HUMIDITIES DROP TO AROUND 31%. EXPECT WEST WINDS
AT 5 TO 15 MPH WITH GUSTS TO 15 TO 25 MPH.
SATURDAY NIGHT INTO SUNDAY WILL BE MOSTLY CLEAR AND DRY WITH
WEST/SOUTHWEST WINDS AT 5 TO 15 MPH. LOWS SATURDAY NIGHT WILL BE
AROUND 20 WITH FAIR RELATIVE HUMIDITY RECOVERY (60%). HIGHS SUNDAY
WILL JUMP TO THE UPPER 40S WITH MINIMUM RELATIVE HUMIDITY FROM
30-35%.
TONIGHT
SKY/WEATHER.........MOSTLY CLOUDY (50-60 PERCENT).
MIN TEMPERATURE.....AROUND 24.
MAX HUMIDITY........60 PERCENT.
WIND (20 FT)........SOUTH WINDS 5-15 MPH BECOMING WEST
AFTER MIDNIGHT AT 10-20 MPH WITH GUSTS
AROUND 30 MPH.
CWR.................0 PERCENT.
MIXING HEIGHT.......400 TO 900 FT AGL.
TRANSPORT WINDS.....SOUTH 10 TO 15 MPH SHIFTING TO THE SOUTHWEST
AROUND 20 MPH LATE IN THE EVENING, THEN
INCREASING TO WEST 25 TO 35 MPH AFTER 3 AM.
SMOKE DISPERSAL.....POOR.
TIME (MST) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........58 59 52 38 46 51 65 70 59 50 50 42
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............26 24 24 24 25 26 28 30 32 36 39 41
RH..............54 60 59 57 55 52 49 49 49 47 47 47
20 FT WIND DIR..S S S S S S S S SW SW W W
20 FT WIND SPD..3 3 3 3 5 6 7 8 9 10 13 15
20 FT WIND GUST.8 10 12 14 16 17 18 21 22 26 30 32
MIX HGT (KFT)...0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
TRANSP WIND DIR.S S S S S S SW SW SW W W W
TRANSP WIND SPD.7 8 10 13 15 17 18 17 18 23 28 32
FRIDAY
SKY/WEATHER.........MOSTLY SUNNY (40-50 PERCENT). CHANCE OF RAIN
LATE IN THE AFTERNOON.
MAX TEMPERATURE.....AROUND 57.
MIN HUMIDITY........28 PERCENT.
WIND (20 FT)........WEST WINDS 15 TO 20 MPH WITH GUSTS
FROM 30 TO 45 MPH.
CWR.................0 PERCENT.
MIXING HEIGHT.......1900 TO 2400 FT AGL.
TRANSPORT WINDS.....WEST 35 TO 45 MPH INCREASING TO 50 TO 60 MPH IN
THE LATE MORNING AND EARLY AFTERNOON, THEN
DECREASING TO 45 TO 50 MPH LATE IN THE
AFTERNOON.
SMOKE DISPERSAL.....VERY GOOD.
TIME (MST) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........47 53 41 32 31 34 39 45 59 54 56 59
WEATHER COV..... CHC
WEATHER TYPE.... RN
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............42 43 46 50 53 55 55 56 56 55 54 53
RH..............45 46 42 35 32 30 29 28 30 31 32 35
20 FT WIND DIR..W W W W W W W W W W W W
20 FT WIND SPD..17 18 18 20 20 18 20 18 17 17 16 15
20 FT WIND GUST.36 38 38 41 44 44 44 44 41 39 37 35
MIX HGT (KFT)...0.5 0.6 0.6 0.9 1.5 1.9 2.1 2.2 2.4 1.9 1.5 1.0
TRANSP WIND DIR.W W W W W W W W W W W W
TRANSP WIND SPD.35 35 37 44 51 56 56 54 51 49 46 43
FRIDAY NIGHT
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT). CHANCE OF RAIN
EARLY IN THE EVENING, THEN SNOW LIKELY.
MIN TEMPERATURE.....AROUND 26.
MAX HUMIDITY........66-72 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 10 TO 15 MPH WITH GUSTS
AROUND 30 MPH.
CWR.................40 PERCENT.
MIXING HEIGHT.......600 TO 1100 FT AGL.
TRANSPORT WINDS.....WEST 30 TO 40 MPH SHIFTING TO THE NORTHWEST
LATE IN THE EVENING, THEN DECREASING TO AROUND
30 MPH AFTER 3 AM.
SMOKE DISPERSAL.....POOR.
TIME (MST) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........61 63 51 59 71 82 77 73 68 62 57 51
WEATHER COV.....CHC CHC CHC CHC CHC LKY LKY LKY LKY LKY LKY
WEATHER TYPE....RN RN RS SN SN SN SN SN SN SN SN
TSTM COV........
CWR.............40 40 40 40 40 40 40 40 40 40 40 40
TEMP............50 47 44 40 37 34 32 31 31 30 29 28
RH..............38 44 50 56 64 69 68 65 59 56 52 50
20 FT WIND DIR..W NW NW NW NW N N NW NW NW NW W
20 FT WIND SPD..13 12 12 12 10 10 9 9 8 7 6 6
20 FT WIND GUST.33 32 30 29 29 28 26 25 23 21 18 17
MIX HGT (KFT)...0.9 0.7 0.6 1.0 1.3 1.7 1.8 2.0 2.2 1.8 1.4 1.1
TRANSP WIND DIR.W W W NW NW NW NW NW NW NW NW NW
TRANSP WIND SPD.37 31 28 30 36 39 38 35 30 29 26 26
SATURDAY
SKY/WEATHER.........MOSTLY SUNNY (25-35 PERCENT).
MAX TEMPERATURE.....AROUND 38.
MIN HUMIDITY........31 PERCENT.
WIND (20 FT)........WEST WINDS 5 TO 15 MPH WITH GUSTS
15 TO 25 MPH.
CWR.................0 PERCENT.
MIXING HEIGHT.......6100 TO 6600 FT AGL.
TRANSPORT WINDS.....NORTHWEST 25 TO 35 MPH INCREASING TO 35 TO 40
MPH LATE IN THE MORNING, THEN BECOMING WEST 20
TO 25 MPH LATE IN THE AFTERNOON DECREASING TO
AROUND 15 MPH LATE IN THE AFTERNOON.
SMOKE DISPERSAL.....VERY GOOD INCREASING TO EXCELLENT LATE IN THE
MORNING, THEN DECREASING TO POOR LATE IN THE
AFTERNOON.
TIME (MST) 6 AM 10 AM 2 PM
SKY (%).........44 21 13
WEATHER COV.....
WEATHER TYPE....NONE NONE NONE
TSTM COV........
CWR.............0 0 0
TEMP............28 33 38
RH..............52 40 31
20 FT WIND......W 6G17 W 9G25 W 10G25
MIX HGT (FT)....1100 3900 6600
TRANSPORT WIND..NW 24 NW 31 NW 32
FORECASTER...EH
REQUESTED BY...LOGAN BROWN
TYPE OF REQUEST...WILDFIRE
.TAG 2527911.1/UNR
.DELDT 12/18/25
.FORMATTERVERSION 2.0.0
.EMAIL LOGAN_BROWN@FIRENET.GOV
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