001
FNUS76 KSTO 090140
FWSSTO

Spot Forecast for Challenge RX...USFS
National Weather Service Sacramento CA
640 PM PDT Fri May 8 2026

Forecast is based on ignition time of 0600 PDT on May 09.
If conditions become unrepresentative...contact the National Weather
Service.

.DISCUSSION...
Dry conditions with a warming trend into early next week is
expected. Diurnal, terrain-driven winds into early next week with
occasional breezy afternoon winds up to 10-15 mph.

No precipitation is forecasted at this with daytime humidity values
in the 40s, lowering to the low 30s by Monday-Tuesday so Min RH
has seen a minor trend wetter from yesterday`s forecast. That
period will also be the hottest stretch over the next several
days.

.SATURDAY...

Sky/weather.........Sunny.
Max temperature.....77-81.
Min humidity........38-42 percent.
Wind (20 ft)........
 Slope/valley.......Light northeast-east winds shifting to the west
                    in the afternoon.
 Ridgetop...........East 5 to 10 mph shifting to the west 5 to 10 mph
                    late in the morning.
Mixing height.......2600 ft AGL.
Transport winds.....East 5 to 10 mph shifting to the west 5 to 10 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.......CLR CLR CLR CLR CLR CLR MCR CLR CLR CLR MCR MCR
Temp............61  63  66  67  69  71  74  77  77  78  79  78
RH..............48  45  44  48  46  46  47  44  43  41  40  40
SL/VL wind dir..NE  NE  E   E   SE  SW  W   W   W   W   W   W
SL/VL wind spd..5   3   3   3   3   3   5   5   5   5   5   2
SL/VL wind gust.9   9   8   7   7   8   10  10  12  10  10  8
Ridge wind dir..NE  NE  E   E   SE  SW  W   W   W   W   W   W
Ridge wind spd..9   9   7   7   7   5   5   5   6   6   6   5
Mix hgt (kft)...0.4 0.4 1.1 1.1 1.1 2.6 2.6 2.6 2.6 2.6 2.6 1.7
Transp wind dir.NE  NE  E   E   SE  SW  W   W   W   W   W   W
Transp wind spd.9   9   7   7   7   5   5   5   6   6   6   5

.SATURDAY NIGHT...

Sky/weather.........Mostly clear.
Min temperature.....60-64.
Max humidity........55-59 percent.
Wind (20 ft)........
 Slope/valley.......Light winds.
 Ridgetop...........West around 5 mph becoming light overnight.
Mixing height.......400 ft AGL.
Transport winds.....West around 5 mph becoming light overnight.
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 MCR MCR MCR CLR CLR CLR CLR CLR CLR CLR
Temp............77  75  72  71  70  67  67  66  64  64  63  62
RH..............40  51  51  53  54  57  57  57  56  55  54  55
SL/VL wind dir..W   W   E   E   E   NE  NE  NE  NE  NE  NE  NE
SL/VL wind spd..2   2   2   2   2   2   2   2   3   3   3   2
SL/VL wind gust.8   8   6   6   6   6   6   6   6   6   6   6
Ridge wind dir..E   E   E   E   E   SE  SE  S   S   S   S   S
Ridge wind spd..5   5   2   2   2   6   6   6   7   7   7   6
Mix hgt (kft)...1.7 1.7 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4
Transp wind dir.W   W   E   E   E   E   E   E   NE  NE  NE  NE
Transp wind spd.5   5   2   2   2   6   6   6   7   7   7   6

.SUNDAY...

Sky/weather.........Sunny.
Max temperature.....77-81.
Min humidity........40-44 percent.
Wind (20 ft)........
 Slope/valley.......Light winds becoming southwest 4 to 7 mph late
                    in the morning
 Ridgetop...........Northeast 4 to 6 mph shifting to the southwest
                    6 to 10 mph late in the morning.
Mixing height.......3000 ft AGL.
Transport winds.....Northeast 4 to 6 mph shifting to the southwest
                    6 to 10 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.......CLR CLR CLR CLR CLR CLR CLR CLR MCR MCR MCR MCR
Temp............64  66  69  70  70  70  73  76  78  79  79  79
RH..............52  50  50  52  54  55  53  49  46  43  42  42
SL/VL wind dir..NE  NE  NE  NE  NE  SW  SW  SW  SW  SW  SW  SW
SL/VL wind spd..2   2   1   1   1   5   5   5   3   3   3   3
SL/VL wind gust.6   6   3   3   3   9   9   9   10  10  10  9
Ridge wind dir..NE  NE  NE  NE  NE  SW  SW  SW  SW  SW  SW  SW
Ridge wind spd..6   6   5   5   5   6   6   6   7   7   7   7
Mix hgt (kft)...0.4 0.4 0.7 0.7 0.7 2.4 2.4 2.4 3.0 3.0 3.0 2.7
Transp wind dir.NE  NE  NE  NE  NE  SW  SW  SW  SW  SW  SW  SW
Transp wind spd.6   6   5   5   5   6   6   6   7   7   7   7

.FORECAST DAYS 3 THROUGH 5...
.MONDAY...
Mostly clear. Lows in the lower 60s. Highs in the mid 80s. Light
winds.
.TUESDAY...
Mostly clear. Lows in the mid 60s. Highs in the lower 80s. Light
winds.
.WEDNESDAY...
Not as warm. Mostly clear. Lows in the lower 60s. Highs in the
lower 70s. Light winds.

.OUTLOOK FOR SATURDAY MAY 16 THROUGH FRIDAY MAY 22...

$$
Forecaster...DA
Requested by...Jason Miller
Type of request...PRESCRIBED
.TAG 2613009.2/STO
.DELDT 05/09/26
.FormatterVersion 2.0.0
.EMAIL Jason.t.miller@usda.gov,james.lico@usda.gov,jesse.stevens@usda.gov