461
FNUS76 KSTO 120148
FWSSTO
SPOT FORECAST FOR CHALLENGE RX...USFS
NATIONAL WEATHER SERVICE SACRAMENTO CA
648 PM PDT MON MAY 11 2026
FORECAST IS BASED ON IGNITION TIME OF 0600 PDT ON MAY 12.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.
DISCUSSION
MOSTLY SUNNY AND DRY CONDITIONS AT THE BURN SITE ON TUESDAY, WITH DAYTIME
HUMIDITY VALUES IN THE UPPER 20S TO LOW 30S. LIGHT, EAST WINDS IN THE
MORNING WILL SHIFT TO THE SOUTH LATE MORNING/EARLY AFTERNOON WITH WIND
SPEEDS AROUND 4 TO 7 MPH, OCCASIONAL GUSTS UP TO AROUND 12 MPH. LATEST
MODEL RUNS HAVE BACKED DOWN ON THE CHANCES FOR SHOWERS AND THUNDERSTORMS
FOR WEDNESDAY, WITH NOW NEAR ZERO CHANCES FOR T-STORMS AND LESS THAN
10% FOR RAIN SHOWERS. A SLIGHT INCREASE IN DAYTIME HUMIDITY VALUES AND
SOUTHERLY WINDS ON WEDNESDAY, WITH HUMIDITY VALUES IN THE MID TO UPPER
30S FORECAST WITH SOUTH WINDS 6 TO 10 MPH, GUSTING UP TO AROUND 15
MPH. CONTINUED MOSTLY CLEAR CONDITIONS THURSDAY THROUGH THE WEEKEND AS
HIGH PRESSURE BUILDS OFFSHORE.
TUESDAY
SKY/WEATHER.........SUNNY.
MAX TEMPERATURE.....79-83.
MIN HUMIDITY........28-32 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......EAST WINDS UP TO 5 MPH EARLY IN THE MORNING
BECOMING LIGHT, THEN BECOMING SOUTH UP TO 6 MPH
IN THE LATE MORNING AND AFTERNOON.
RIDGETOP...........SOUTHEAST 7 TO 9 MPH SHIFTING TO THE SOUTH 9 TO
15 MPH LATE IN THE MORNING.
MIXING HEIGHT.......3900 FT AGL.
TRANSPORT WINDS.....EAST AROUND 9 MPH SHIFTING TO THE SOUTH 9 TO 15
MPH LATE IN THE MORNING.
CWR.................0 PERCENT.
CHANCE OF THUNDER...0 PERCENT.
TIME (PDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY COVER.......MCR MCR CLR CLR CLR CLR CLR CLR CLR CLR MCR MCR
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............67 69 72 73 74 74 77 79 80 81 81 79
RH..............43 44 46 46 44 43 41 36 34 32 31 30
SL/VL WIND DIR..E E E SE S S S S S S S S
SL/VL WIND SPD..5 3 3 3 5 6 6 6 6 6 6 6
SL/VL WIND GUST.8 7 6 7 12 14 15 15 16 17 17 17
RIDGE WIND DIR..E E SE SE SE S S S S S S S
RIDGE WIND SPD..9 9 7 7 7 13 13 13 15 15 15 9
MIX HGT (KFT)...0.4 0.4 1.2 1.2 1.2 3.2 3.2 3.2 3.9 3.9 3.9 2.4
TRANSP WIND DIR.E E SE SE SE S S S S S S S
TRANSP WIND SPD.9 9 7 7 7 13 13 13 15 15 15 9
TUESDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY THEN BECOMING MOSTLY CLOUDY THEN
BECOMING PARTLY CLOUDY.
MIN TEMPERATURE.....57-61.
MAX HUMIDITY........53-57 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......SOUTH WINDS 5 TO 6 MPH EARLY IN THE EVENING
BECOMING LIGHT.
RIDGETOP...........SOUTHEAST 8 TO 9 MPH.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....SOUTHEAST 8 TO 9 MPH.
CWR.................0 PERCENT.
CHANCE OF THUNDER...0 PERCENT.
TIME (PDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY COVER.......MCR MCR PC PC PC PC PC PC MC MC MC PC
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............79 75 72 71 70 68 67 65 64 61 61 59
RH..............30 36 39 41 42 44 45 47 48 50 52 55
SL/VL WIND DIR..S S SE SE SE SE SE SE SE SE SE SE
SL/VL WIND SPD..6 6 3 3 3 2 2 2 2 2 2 2
SL/VL WIND GUST.17 17 10 10 10 7 7 7 6 6 6 5
RIDGE WIND DIR..S S SE SE SE SE SE SE SE SE SE SE
RIDGE WIND SPD..9 9 8 8 8 9 9 9 8 8 8 8
MIX HGT (KFT)...2.4 2.4 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 SE SE SE SE SE SE SE SE SE SE
TRANSP WIND SPD.9 9 8 8 8 9 9 9 8 8 8 8
WEDNESDAY
SKY/WEATHER.........SUNNY. SLIGHT CHANCE OF RAIN LATE IN THE
MORNING.
MAX TEMPERATURE.....66-70.
MIN HUMIDITY........31-35 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......LIGHT WINDS BECOMING SOUTHWEST UP TO 6 MPH LATE
IN THE MORNING.
RIDGETOP...........SOUTH 8 TO 13 MPH SHIFTING TO THE SOUTHWEST 8
TO 14 MPH LATE IN THE MORNING.
MIXING HEIGHT.......5200 FT AGL.
TRANSPORT WINDS.....SOUTHEAST AROUND 8 MPH SHIFTING TO THE
SOUTHWEST 8 TO 14 MPH LATE IN THE MORNING.
CWR.................9 PERCENT.
CHANCE OF THUNDER...0 PERCENT.
TIME (PDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY COVER.......PC PC CLR CLR CLR PC PC PC PC PC PC MCR
CWR.............0 0 0 0 0 10 10 10 10 10 10 0
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............59 60 61 60 60 60 62 64 66 67 68 67
RH..............54 52 50 51 53 54 50 45 40 36 34 33
SL/VL WIND DIR..SE SE S S S SW SW SW SW SW SW W
SL/VL WIND SPD..2 2 2 2 2 6 6 6 5 5 5 5
SL/VL WIND GUST.5 5 5 5 5 14 14 14 14 14 14 10
RIDGE WIND DIR..SE SE S S S SW SW SW SW SW SW W
RIDGE WIND SPD..8 8 13 13 13 14 14 14 12 12 12 8
MIX HGT (KFT)...0.5 0.5 2.3 2.3 2.3 3.9 3.9 3.9 5.1 5.1 5.1 5.2
TRANSP WIND DIR.SE SE S S S SW SW SW SW SW SW W
TRANSP WIND SPD.8 8 13 13 13 14 14 14 12 12 12 8
FORECAST DAYS 3 THROUGH 7
THURSDAY
CLEAR. LOWS IN THE LOWER 50S. HIGHS IN THE MID 70S. LIGHT WINDS.
FRIDAY
CLEAR. LOWS IN THE UPPER 50S. HIGHS IN THE UPPER 70S. LIGHT
WINDS.
SATURDAY
MOSTLY CLEAR. LOWS IN THE UPPER 50S. HIGHS IN THE LOWER 70S.
LIGHT WINDS.
SUNDAY
MOSTLY CLEAR. LOWS IN THE MID 50S. HIGHS IN THE UPPER 70S.
MONDAY
MOSTLY CLEAR. LOWS IN THE LOWER 60S. HIGHS IN THE LOWER 80S.
FORECASTER...JW
REQUESTED BY...JASON MILLER
TYPE OF REQUEST...PRESCRIBED
.TAG 2613009.5/STO
.DELDT 05/12/26
.FORMATTERVERSION 2.0.0
.EMAIL JASON.T.MILLER@USDA.GOV,JAMES.LICO@USDA.GOV,JESSE.STEVENS@USDA.GOV
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