184
FNUS75 KCYS 220409
FWSCYS
SPOT FORECAST FOR SOUTH FORK WF...USWFS
NATIONAL WEATHER SERVICE CHEYENNE WY
1009 PM MDT SUN JUN 21 2026
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE AT (307) 772-2227
DISCUSSION
PREVAILING WINDS OUT OF THE SOUTHEAST THROUGH MUCH OF THE DAY
BETWEEN 5 TO 13 MPH, GUSTING TO 17 MPH. PATCHY FOG IS EXPECTED IN
THE MORNING, CLEARING UP MID MORNING. THUNDERSTORMS ARE POSSIBLE
IN THE AFTERNOON. WETTING RAINS MAY BE POSSIBLE WITH THESE STORMS
AND VARIABLE WIND SHIFTS. WINDS MAY GUST TO ABOVE 50 MPH AS STORMS
PASS NEARBY BETWEEN 3 PM AND 6 PM. A COLD FRONT PASSAGE IS
ANTICIPATED AROUND MIDNIGHT TUESDAY AND WILL SHIFT WINDS OUT OF
THE NORTHWEST. AN UPTICK IN WIND GUSTS MAY OCCUR WITH THIS FRONT TO
AROUND 25-30 MPH. SOME SHOWERS MAY BE PRESENT AT THE TIME OF THE
FRONT, BUT WETTING RAINS ARE UNLIKELY. WINDS GRADUALLY TURN MORE
EASTERLY THROUGH THE DAY. CHANCES OF SHOWERS AND STORMS INCREASE
IN THE EVENING AND EARLY NIGHTTIME HOURS TUESDAY.
MONDAY
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT) THEN BECOMING
MOSTLY SUNNY (30-40 PERCENT). PATCHY FOG EARLY
IN THE MORNING. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS EARLY IN THE AFTERNOON. RAIN
SHOWERS LIKELY AND CHANCE OF THUNDERSTORMS LATE
IN THE AFTERNOON.
CWR.................2 PERCENT INCREASING TO 21 PERCENT IN THE
AFTERNOON.
MAX TEMPERATURE.....AROUND 80.
MIN HUMIDITY........43 PERCENT.
WIND (20 FT)........LIGHT WINDS BECOMING SOUTHEAST 5 TO 10 MPH
EARLY IN THE MORNING. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS.
MIXING HEIGHT.......5600 FT AGL.
TRANSPORT WINDS.....SOUTHEAST 5 TO 13 MPH INCREASING TO 15 TO 17
MPH LATE IN THE AFTERNOON.
SMOKE DISPERSAL.....POOR (3100 KNOT-FT) EARLY IN THE MORNING
INCREASING TO GOOD (81000 KNOT-FT) IN THE
AFTERNOON.
HAINES INDEX........MISSING.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........81 76 65 42 33 35 21 27 21 37 50 33
WEATHER COV.....PTY PTY PTY SCH SCH SCH LKY LKY LKY
WEATHER TYPE....FOG FOG FOG RW RW RW RW RW RW
TSTM COV........ SCH SCH SCH CHC CHC CHC
CWR.............0 0 0 0 0 0 20 20 20 20 20 20
TEMP............50 53 56 60 65 68 72 74 75 77 75 74
RH..............99 96 88 77 65 58 50 49 46 43 47 53
20 FT WIND DIR..SE SE SE SE SE SE SE SE SE SE SE SE
20 FT WIND SPD..3 3 5 6 7 7 8 9 9 10 10 10
20 FT WIND GUST.7 8 9 10 13 15 16 17 18 20 20 20
MIX HGT (KFT)...0.8 0.8 1.1 1.6 2.1 2.9 3.3 4.3 5.0 5.6 3.4 3.2
TRANSP WIND DIR.SE SE SE SE SE SE SE S S S SE SE
TRANSP WIND SPD.5 5 6 6 7 9 10 13 15 15 16 17
HAINES INDEX....M M M M M M M M M M M M
SDSPL KT-FT/10004 4 6 10 15 27 34 51 73 81 56 53
MONDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY (25-35 PERCENT) THEN BECOMING
MOSTLY CLOUDY (65-75 PERCENT). SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS EARLY IN THE EVENING.
CHANCE OF RAIN SHOWERS AND SLIGHT CHANCE OF
THUNDERSTORMS OVERNIGHT, THEN SLIGHT CHANCE OF
RAIN SHOWERS AFTER 3 AM.
CWR.................7 PERCENT.
MIN TEMPERATURE.....AROUND 53.
MAX HUMIDITY........100 PERCENT.
WIND (20 FT)........SOUTHEAST WINDS 7 TO 10 MPH SHIFTING TO THE
SOUTHWEST 5 TO 7 MPH LATE IN THE EVENING, THEN
SHIFTING TO THE NORTH OVERNIGHT. GUSTY AND
ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS.
GUSTY AND ERRATIC WINDS EXPECTED NEAR
THUNDERSTORMS.
MIXING HEIGHT.......400 FT AGL.
TRANSPORT WINDS.....SOUTH 12 TO 17 MPH SHIFTING TO THE NORTH 9 TO
13 MPH OVERNIGHT.
SMOKE DISPERSAL.....FAIR (44600 KNOT-FT) EARLY IN THE EVENING
DECREASING TO POOR (3200 KNOT-FT) LATE IN THE
NIGHT.
HAINES INDEX........MISSING.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........27 37 45 33 34 17 21 23 27 54 70 84
WEATHER COV.....SCH SCH SCH CHC CHC CHC SCH SCH SCH
WEATHER TYPE....RW RW RW RW RW RW RW RW RW
TSTM COV........SCH SCH SCH SCH SCH SCH
CWR.............10 10 10 10 10 10 10 10 10 10 10 10
TEMP............73 72 68 65 63 62 61 60 58 56 56 55
RH..............56 53 63 70 74 77 81 83 87 92 95 98
20 FT WIND DIR..SE SE SE SE SE S S SW NW N N N
20 FT WIND SPD..10 10 10 9 8 7 6 5 5 5 6 7
20 FT WIND GUST.20 20 18 17 15 13 12 9 8 9 10 13
MIX HGT (KFT)...2.6 2.0 0.6 0.5 0.6 0.5 0.5 0.4 0.4 0.5 0.5 0.6
TRANSP WIND DIR.SE SE S S SE S S SW N N N NE
TRANSP WIND SPD.15 17 16 17 15 14 13 12 9 9 12 13
HAINES INDEX....M M M M M M M M M M M M
SDSPL KT-FT/100039 45 13 10 10 8 8 6 5 5 8 8
TUESDAY
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT) THEN BECOMING
MOSTLY SUNNY (30-40 PERCENT). SLIGHT CHANCE OF
RAIN SHOWERS EARLY IN THE MORNING.
CWR.................6 PERCENT.
MAX TEMPERATURE.....AROUND 74.
MIN HUMIDITY........43 PERCENT.
WIND (20 FT)........NORTHEAST WINDS 6 TO 8 MPH.
MIXING HEIGHT.......5800 FT AGL.
TRANSPORT WINDS.....NORTHEAST 10 TO 15 MPH.
SMOKE DISPERSAL.....POOR (10800 KNOT-FT) EARLY IN THE MORNING
INCREASING TO GOOD (66800 KNOT-FT) IN THE
AFTERNOON.
HAINES INDEX........MISSING.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........94 89 73 60 57 51 51 77 67 62 57 33
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............54 56 58 59 62 63 65 68 69 71 72 72
RH..............99 98 90 85 76 70 63 56 52 46 45 46
20 FT WIND DIR..N N N NE NE NE NE NE NE NE NE NE
20 FT WIND SPD..7 8 8 8 8 8 8 8 8 8 8 8
20 FT WIND GUST.15 16 16 16 16 16 16 16 16 15 16 16
MIX HGT (KFT)...0.9 1.3 1.4 1.9 2.7 3.5 3.8 4.3 4.6 4.4 5.1 5.8
TRANSP WIND DIR.N NE NE NE NE NE NE NE NE NE NE NE
TRANSP WIND SPD.14 15 15 15 13 13 12 12 14 10 13 13
HAINES INDEX....M M M M M M M M M M M M
SDSPL KT-FT/100013 17 21 28 36 39 41 50 64 46 59 67
FORECASTER...MCLAUGHLIN/VASQUEZ
REQUESTED BY...SIMON MADHAVAN
TYPE OF REQUEST...WILDFIRE
.TAG 2615942.0/CYS
.DELDT 06/22/26
.FORMATTERVERSION 2.0.0
.EMAIL SIMON_MADHAVAN@FIRENET.GOV
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page