910
FNUS75 KCYS 200443
FWSCYS
SPOT FORECAST FOR BRITTANIA MOUNTAIN...USFS
NATIONAL WEATHER SERVICE CHEYENNE WY
1043 PM MDT WED AUG 19 2026
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE AT (307) 772-2227
DISCUSSION
LIGHT WINDS ARE EXPECTED OVERNIGHT THROUGH 2PM THURSDAY AFTERNOON, GENERALLY
OUT OF THE WEST, AROUND 5 TO 7 MPH. AFTER 2PM, WINDS PICK UP OUT OF THE NORTH
TO NORTHWEST BETWEEN 8 TO 10 MPH WITH NO SIGNIFICANT GUSTS EXPECTED. LIGHT
AND VARIABLE WINDS RETURN THURSDAY EVENING, GENERALLY OUT OF THE SOUTH, FROM
5 TO 7 MPH THROUGH THE NIGHT. WINDS PICK BACK UP AGAIN EARLY FRIDAY MORNING.
OVERNIGHT RECOVERIES TONIGHT ARE EXPECTED TO BE BETWEEN 55 AND 60 PERCENT
WITH AFTERNOON HUMIDITY VALUES DROPPING INTO THE 15 TO 20 PERCENT RANGE.
PRECIPITATION CHANCES ARE MINIMAL TO NONE THROUGHOUT THE ENTIRE PERIOD WITH
MOSTLY CLEAR SKIES BECOMING PARTLY CLOUDY THURSDAY AFTERNOON.
REST OF TONIGHT
SKY/WEATHER.........MOSTLY CLEAR (5-15 PERCENT).
CWR.................0 PERCENT.
MIN TEMPERATURE.....AROUND 58.
MAX HUMIDITY........57 PERCENT.
WIND (20 FT)........NORTHWEST WINDS AROUND 5 MPH SHIFTING TO THE
WEST 5 TO 7 MPH OVERNIGHT.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....NORTHEAST AROUND 6 MPH SHIFTING TO THE WEST 6
TO 12 MPH OVERNIGHT.
SMOKE DISPERSAL.....POOR (2600 KNOT-FT).
TIME (MDT) 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........12 9 10 11 7 11 14
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0
TEMP............65 62 62 60 59 59 59
RH..............45 49 49 53 57 55 56
20 FT WIND DIR..NW W W W W W W
20 FT WIND SPD..5 5 5 5 7 7 7
20 FT WIND GUST.7 7 7 7 8 9 10
MIX HGT (KFT)...0.5 0.5 0.5 0.5 0.5 0.5 0.5
TRANSP WIND DIR.NE NW W W W W W
TRANSP WIND SPD.6 6 6 7 8 10 12
SDSPL KT-FT/10003 3 3 3 4 5 5
THURSDAY
SKY/WEATHER.........SUNNY (5-15 PERCENT).
CWR.................0 PERCENT.
MAX TEMPERATURE.....AROUND 82.
MIN HUMIDITY........20 PERCENT.
WIND (20 FT)........WEST WINDS 5 TO 7 MPH SHIFTING TO THE NORTH
AROUND 7 MPH LATE IN THE AFTERNOON.
MIXING HEIGHT.......9700 FT AGL INCREASING TO 11600 FT AGL LATE IN
THE AFTERNOON.
TRANSPORT WINDS.....WEST 9 TO 17 MPH.
SMOKE DISPERSAL.....POOR (4000 KNOT-FT) EARLY IN THE MORNING
INCREASING TO GOOD (84500 KNOT-FT) IN THE
AFTERNOON INCREASING TO VERY GOOD (126400
KNOT-FT) EARLY IN THE MORNING INCREASING TO
EXCELLENT (174100 KNOT-FT) IN THE AFTERNOON IN
THE AFTERNOON.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........12 16 7 7 5 5 4 6 8 8 20 14
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............58 60 63 66 71 75 77 79 81 81 81 82
RH..............55 52 50 43 36 31 28 24 21 21 21 20
20 FT WIND DIR..W W W W W W W NW NW NW N N
20 FT WIND SPD..7 7 7 5 5 5 5 6 7 7 7 7
20 FT WIND GUST.12 12 10 9 8 7 7 8 10 12 12 12
MIX HGT (KFT)...0.5 0.5 0.4 1.1 4.7 7.2 8.5 9.7 11 11 12 12
TRANSP WIND DIR.W W W W W W W W W NW NW NW
TRANSP WIND SPD.13 12 10 9 9 9 12 15 15 17 17 16
SDSPL KT-FT/10006 5 4 9 38 58 85 126 139 167 174 162
THURSDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY (25-35 PERCENT).
CWR.................1 PERCENT.
MIN TEMPERATURE.....AROUND 61.
MAX HUMIDITY........45 PERCENT.
WIND (20 FT)........NORTH WINDS AROUND 7 MPH SHIFTING TO THE
NORTHEAST AROUND 5 MPH EARLY IN THE EVENING,
THEN BECOMING LIGHT EARLY IN THE EVENING
BECOMING SOUTH AROUND 5 MPH LATE IN THE EVENING
SHIFTING TO THE SOUTHWEST.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....NORTHWEST AROUND 12 MPH SHIFTING TO THE EAST
EARLY IN THE EVENING, THEN SHIFTING TO THE
SOUTH 8 TO 12 MPH LATE IN THE EVENING SHIFTING
TO THE SOUTHWEST 10 TO 15 MPH OVERNIGHT.
SMOKE DISPERSAL.....GOOD (93600 KNOT-FT) EARLY IN THE EVENING
DECREASING TO POOR (3000 KNOT-FT) LATE IN THE
NIGHT.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........22 27 36 24 26 34 31 32 27 21 24 31
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............80 78 76 71 70 69 67 66 65 63 63 63
RH..............23 27 29 32 32 33 39 40 41 45 45 45
20 FT WIND DIR..N NE SE SE S SW SW SW SW SW SW W
20 FT WIND SPD..7 5 3 5 5 5 7 7 9 10 10 10
20 FT WIND GUST.12 12 10 10 10 12 13 13 15 16 16 17
MIX HGT (KFT)...9.4 2.0 0.5 0.5 0.5 0.5 0.6 0.5 0.6 0.5 0.5 0.5
TRANSP WIND DIR.NW E E SE S S S SW W W SW W
TRANSP WIND SPD.12 8 7 8 9 12 10 10 12 13 13 15
SDSPL KT-FT/100094 14 3 4 4 5 5 5 6 6 5 7
FORECASTER...MOSE
REQUESTED BY...BURKE
TYPE OF REQUEST...WILDFIRE
.TAG 2620067.0/CYS
.DELDT 08/19/26
.FORMATTERVERSION 2.0.0
.EMAIL WYCPC@FIRENET.GOV
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