578
FNUS75 KCYS 272146
FWSCYS
SPOT FORECAST FOR CHALK MOUNTAIN...CASPER DISPATCH
NATIONAL WEATHER SERVICE CHEYENNE WY
346 PM MDT THU AUG 27 2026
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE AT (307) 772-2227
DISCUSSION
WEST WINDS THIS AFTERNOON WILL BECOME VARIABLE THIS EVENING AND
OVERNIGHT WITH A FEW HIGH-BASED LIGHT SHOWERS IN THE AREA. EXPECT
HUMIDITY RECOVERIES TO AROUND 45 PERCENT.
THE PRIMARY CONCERNS ON FRIDAY WILL BE INCREASING PREVAILING WINDS
WITH WEST-SOUTHWEST WINDS SUSTAINED 10 TO 20 MPH, GUSTING TO AROUND
30 MPH, AND THE POTENTIAL FOR GUSTY SHOWERS/THUNDERSTORMS. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP EARLY FRIDAY AFTERNOON.
LOCALIZED WIND GUSTS UP TO AROUND 50 MPH WILL BE POSSIBLE NEAR AND
UNDER THIS ACTIVITY, BUT THE CHANCE FOR WETTING RAINFALL REMAINS
LOW. THE MOST LIKELY TIMING FOR GUSTY THUNDERSTORM WINDS IS BETWEEN
2PM AND 6PM. IMPROVED MOISTURE WILL BE MOVING IN ALOFT, BUT THE LOWER
ATMOSPHERE WILL REMAIN SOMEWHAT DRY, WITH MINIMUM RH AROUND 20 TO 25
PERCENT. EXPECT WEST-SOUTHWEST WINDS TO CONTINUE FRIDAY NIGHT. WHILE
MOST GUSTS WILL BE AROUND 20 MPH, THE CHANCE FOR A FEW GUSTY SHOWERS
WILL CONTINUE THROUGH THE OVERNIGHT HOURS. GUSTS OF 30 TO 40 MPH
WILL BE POSSIBLE AGAIN LATE IN THE EVENING OR EARLY MORNING IF THIS
SECOND ROUND MATERIALIZES.
TONIGHT
SKY/WEATHER.........PARTLY TO MOSTLY CLOUDY.
CWR.................1 PERCENT.
MIN TEMPERATURE.....AROUND 61.
MAX HUMIDITY........AROUND 45 PERCENT.
WIND (20 FT)........WEST WINDS AROUND 5 TO 10 MPH, BECOMING VARIABLE.
MIXING HEIGHT.......6800 FT AGL DECREASING TO 500 FT AGL EARLY IN
THE EVENING.
TRANSPORT WINDS.....WEST 6 TO 9 MPH SHIFTING TO THE SOUTH 7 TO 12
MPH EARLY IN THE EVENING.
SMOKE DISPERSAL.....GOOD (90600 KNOT-FT) EARLY IN THE EVENING
DECREASING TO POOR (3600 KNOT-FT) LATE IN THE
NIGHT.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........23 35 54 60 57 38 47 41 43 44 41 48
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............80 78 74 69 68 66 65 64 63 63 63 62
RH..............17 19 23 28 31 34 37 38 39 39 39 41
20 FT WIND DIR..W W SW S S S S S SW SW SW SW
20 FT WIND SPD..5 5 6 7 7 7 7 7 7 8 9 9
20 FT WIND GUST.9 9 10 12 12 13 13 14 15 15 17 18
MIX HGT (KFT)...11 6.8 0.6 0.6 0.6 0.5 0.5 0.5 0.5 0.5 0.5 0.5
TRANSP WIND DIR.W W S SE SE S S S SW S SW SW
TRANSP WIND SPD.9 6 7 8 8 12 12 10 10 10 12 12
SDSPL KT-FT/100091 34 4 4 4 5 5 5 5 4 5 6
FRIDAY
SKY/WEATHER.........MOSTLY SUNNY (40-50 PERCENT) THEN BECOMING
MOSTLY CLOUDY (70-80 PERCENT). SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.
CWR.................4 PERCENT.
MAX TEMPERATURE.....AROUND 80.
MIN HUMIDITY........20 TO 25 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 10 TO 20 MPH WITH GUSTS TO
AROUND 30 MPH. GUSTY AND ERRATIC
WINDS EXPECTED NEAR THUNDERSTORMS IN THE
AFTERNOON.
MIXING HEIGHT.......10200 FT AGL INCREASING TO 11400 FT AGL LATE IN
THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 12 TO 21 MPH SHIFTING TO THE WEST 23
TO 26 MPH IN THE AFTERNOON.
SMOKE DISPERSAL.....POOR (5500 KNOT-FT) EARLY IN THE MORNING
INCREASING TO EXCELLENT (242200 KNOT-FT)
IN THE AFTERNOON.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........37 66 35 42 55 52 26 28 45 61 83 66
WEATHER COV..... SCH SCH SCH SCH SCH SCH
WEATHER TYPE.... RW RW RW RW RW RW
TSTM COV........ SCH SCH SCH SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............62 61 63 66 69 72 76 78 78 79 78 77
RH..............41 44 41 38 36 33 28 26 25 24 25 26
20 FT WIND DIR..SW SW SW SW SW SW W W W W W W
20 FT WIND SPD..10 10 9 10 12 12 14 15 16 16 16 16
20 FT WIND GUST.18 18 18 18 20 23 25 28 29 30 30 29
MIX HGT (KFT)...0.5 0.5 0.6 1.3 3.3 6.1 8.4 10 11 11 11 7.0
TRANSP WIND DIR.SW SW SW SW SW W W W W W W W
TRANSP WIND SPD.13 13 12 15 16 18 21 23 24 26 26 26
SDSPL KT-FT/10006 6 6 17 46 98 151 204 234 262 242 161
FORECASTER...NATOLI
REQUESTED BY...CASPER DISPATCH
TYPE OF REQUEST...WILDFIRE
.TAG 2620632.1/CYS
.DELDT 08/27/26
.FORMATTERVERSION 2.0.0
.EMAIL MWENGERT@BLM.GOV,EFOWLER@BLM.GOV,WYCPC@FIRENET.GOV
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