933
FNUS75 KCYS 281111
FWSCYS
SPOT FORECAST FOR CHALK MOUNTAIN...CASPER DISPATCH
NATIONAL WEATHER SERVICE CHEYENNE WY
511 AM MDT FRI AUG 28 2026
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE AT (307) 772-2227
DISCUSSION
DRY AND BREEZY CONDITIONS ANTICIPATED TODAY WITH AFTERNOON MINIMUM
HUMIDITY VALUES DROPPING TO AROUND 20-25%. LIGHT AND VARIABLE WINDS
ARE EXPECTED THROUGH 8AM THEN WINDS START PICKING UP FOR THE REMAINDER
OF THE DAY. EXPECTING WINDS SOUTHWESTERLY WINDS 10 TO 15MPH THROUGH 1PM.
WINDS INCREASE THIS AFTERNOON WITH SUSTAINED WINDS 20 TO 25MPH GUSTING UP
TO 40MPH FROM 1PM THROUGH 7PM. WINDS DECREASE AFTER SUNSET TO LIGHT AND
VARIABLE, BUT ARE EXPECTED TO INCREASE AGAIN ON SATURDAY. WITH THE STRONGER
WINDS THIS AFTERNOON, HUMIDITY VALUES WILL REACH 20-25%, LEADING TO ELEVATED
FIRE CONCERNS, BUT NOT RED FLAG CRITERIA. AFTERNOON SHOWERS AND STORMS WILL
DEVELOP AROUND 2PM, BRINGING ISOLATED CHANCES FOR PRECIPITATION AND LIGHTNING.
GUSTY AND ERRATIC WINDS ARE ANTICIPATED AROUND ANY SHOWER OR STORM THAT FORMS
THIS AFTERNOON, SO WIND DIRECTION MAY CHANGE SUDDENLY WHEN SHOWERS ARE NEARBY.
OVERNIGHT HUMIDITY RECOVERIES WILL BE DECENT, IN THE 55-60% RANGE. ANOTHER
DRIER DAY IS EXPECTED FOR SATURDAY, THOUGH AFTERNOON HUMIDITY VALUES WILL
ONLY DROP TO AROUND 30-35%. WINDS WILL BE BREEZY AGAIN, SUSTAINED 20 TO 25
MPH GUSTING UPWARDS OF 40 MPH IN THE AFTERNOON. ISOLATED SHOWERS AND STORMS
EXPECTED AGAIN SATURDAY WITH GUSTY AND ERRATIC WINDS LIKELY IN AND AROUND
ANY SHOWERS AND STORMS.
TODAY
SKY/WEATHER.........PARTLY SUNNY (50-60 PERCENT). SLIGHT CHANCE OF
SHOWERS EARLY IN THE AFTERNOON. CHANCE OF
SHOWERS AND SLIGHT CHANCE OF THUNDERSTORMS LATE
IN THE AFTERNOON.
CWR.................6 PERCENT.
MAX TEMPERATURE.....AROUND 81.
MIN HUMIDITY........22 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 9 TO 16 MPH SHIFTING TO THE
WEST 17 TO 21 MPH WITH GUSTS TO AROUND 37 MPH
LATE IN THE AFTERNOON. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS LATE IN THE
AFTERNOON.
MIXING HEIGHT.......9800 FT AGL INCREASING TO 11000 FT AGL LATE IN
THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 12 TO 18 MPH INCREASING TO WEST 23 TO
30 MPH IN THE LATE MORNING AND AFTERNOON.
SMOKE DISPERSAL.....POOR (4900 KNOT-FT) EARLY IN THE MORNING
INCREASING TO GOOD (65800 KNOT-FT) IN THE
AFTERNOON INCREASING TO VERY GOOD (121600
KNOT-FT) EARLY IN THE MORNING INCREASING TO
EXCELLENT (197600 KNOT-FT) IN THE AFTERNOON
LATE IN THE MORNING, THEN INCREASING TO
EXCELLENT (244800 KNOT-FT) EARLY IN THE
AFTERNOON DECREASING TO VERY GOOD (102800
KNOT-FT) EARLY IN THE MORNING INCREASING TO
EXCELLENT (179300 KNOT-FT) IN THE AFTERNOON
LATE IN THE AFTERNOON.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........37 67 46 42 47 52 35 52 58 67 72 70
WEATHER COV..... SCH SCH SCH CHC CHC CHC
WEATHER TYPE.... RW RW RW RW RW RW
TSTM COV........ SCH SCH SCH
CWR.............0 0 0 0 0 0 10 10 10 10 10 10
TEMP............61 61 64 66 70 73 77 79 79 80 77 77
RH..............42 42 38 36 32 30 26 24 24 22 26 28
20 FT WIND DIR..SW SW SW SW SW SW SW SW W W W W
20 FT WIND SPD..9 10 10 12 12 13 14 16 20 21 20 17
20 FT WIND GUST.17 18 18 20 22 23 25 30 35 37 35 31
MIX HGT (KFT)...0.5 0.5 0.5 1.5 3.3 5.8 8.2 9.8 11 11 6.9 4.1
TRANSP WIND DIR.SW SW SW SW W W W W W W W SW
TRANSP WIND SPD.12 15 14 18 23 24 28 29 30 29 30 29
SDSPL KT-FT/10005 6 7 24 66 122 198 245 285 261 179 103
TONIGHT
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT). SLIGHT CHANCE OF
SHOWERS EARLY IN THE EVENING.
CWR.................5 PERCENT.
MIN TEMPERATURE.....AROUND 59.
MAX HUMIDITY........57 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 7 TO 15 MPH.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 14 TO 23 MPH.
SMOKE DISPERSAL.....FAIR (59700 KNOT-FT) EARLY IN THE EVENING
DECREASING TO POOR (6900 KNOT-FT) LATE IN THE
NIGHT.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........68 80 79 71 67 68 72 74 63 61 55 52
WEATHER COV.....SCH SCH SCH
WEATHER TYPE....RW RW RW
TSTM COV........
CWR.............10 10 10 10 10 10 0 0 0 0 0 0
TEMP............76 73 69 67 66 65 65 63 63 63 61 61
RH..............31 34 40 43 43 45 45 48 48 48 51 51
20 FT WIND DIR..W SW SW SW SW SW SW SW SW SW SW SW
20 FT WIND SPD..15 12 9 7 7 7 7 7 7 8 9 9
20 FT WIND GUST.26 22 17 14 13 12 12 13 14 15 16 17
MIX HGT (KFT)...3.0 2.9 1.0 0.6 0.6 0.6 0.5 0.5 0.9 0.5 0.5 0.5
TRANSP WIND DIR.W W W SW SW SW SW SW SW SW SW SW
TRANSP WIND SPD.23 17 14 15 15 16 17 17 16 15 17 17
SDSPL KT-FT/100060 44 12 8 8 8 8 8 13 7 8 8
SATURDAY
SKY/WEATHER.........MOSTLY SUNNY (35-45 PERCENT) THEN BECOMING
MOSTLY CLOUDY (70-80 PERCENT). SLIGHT CHANCE OF
THUNDERSTORMS EARLY IN THE AFTERNOON. CHANCE OF
RAIN SHOWERS IN THE AFTERNOON. CHANCE OF
THUNDERSTORMS LATE IN THE AFTERNOON.
CWR.................4 PERCENT.
MAX TEMPERATURE.....AROUND 75.
MIN HUMIDITY........33 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 10 TO 17 MPH INCREASING TO 18
TO 21 MPH WITH GUSTS TO AROUND 39 MPH IN THE
AFTERNOON. GUSTY AND ERRATIC WINDS EXPECTED
NEAR THUNDERSTORMS EARLY IN THE AFTERNOON.
GUSTY AND ERRATIC WINDS EXPECTED NEAR
THUNDERSTORMS LATE IN THE AFTERNOON.
MIXING HEIGHT.......9100 FT AGL INCREASING TO 11000 FT AGL IN THE
AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 15 TO 23 MPH SHIFTING TO THE WEST 24
TO 32 MPH LATE IN THE MORNING.
SMOKE DISPERSAL.....POOR (7500 KNOT-FT) EARLY IN THE MORNING
INCREASING TO GOOD (94500 KNOT-FT) IN THE
AFTERNOON INCREASING TO EXCELLENT (174400
KNOT-FT) LATE IN THE MORNING, THEN INCREASING
TO EXCELLENT (219200 KNOT-FT) EARLY IN THE
AFTERNOON DECREASING TO GOOD (80900 KNOT-FT)
EARLY IN THE MORNING INCREASING TO EXCELLENT
(152000 KNOT-FT) IN THE AFTERNOON LATE IN THE
AFTERNOON.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........50 51 41 35 29 39 48 45 70 84 78 68
WEATHER COV..... CHC CHC CHC CHC CHC CHC
WEATHER TYPE.... RW RW RW RW RW RW
TSTM COV........ SCH SCH SCH CHC CHC CHC
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............60 59 63 64 68 71 73 74 73 72 71 70
RH..............53 57 50 50 42 38 35 33 34 34 36 38
20 FT WIND DIR..SW SW SW SW SW SW SW SW W W W SW
20 FT WIND SPD..10 12 12 13 15 17 20 21 21 21 21 18
20 FT WIND GUST.18 21 22 24 28 31 35 37 38 39 37 33
MIX HGT (KFT)...0.5 0.6 1.0 2.3 4.7 7.3 9.1 11 9.0 7.8 6.1 3.9
TRANSP WIND DIR.SW SW SW SW SW W W SW W W W W
TRANSP WIND SPD.16 15 17 21 23 28 32 31 29 32 29 24
SDSPL KT-FT/10008 8 15 41 95 174 256 297 226 219 152 81
FORECASTER...MOSE
REQUESTED BY...CASPER DISPATCH
TYPE OF REQUEST...WILDFIRE
.TAG 2620632.2/CYS
.DELDT 08/28/26
.FORMATTERVERSION 2.0.0
.EMAIL MWENGERT@BLM.GOV,EFOWLER@BLM.GOV,WYCPC@FIRENET.GOV
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