874
FNUS76 KSTO 192239
FWSSTO
SPOT FORECAST FOR TWAIN FIRE...USFS
NATIONAL WEATHER SERVICE SACRAMENTO CA
339 PM PDT SUN JUL 19 2026
FORECAST IS BASED ON FORECAST START TIME OF 1600 PDT ON JULY 19.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.
DISCUSSION
BIGGEST CHANGE FROM PREVIOUS SPOT IS THE SLIGHT INCREASE IN THE
POTENTIAL FOR THUNDERSTORM DEVELOPMENT (UP TO A 20% CHANCE) IN THE
VICINITY OF THE FIRE THIS EVENING ROUGHLY BETWEEN 6-10 PM.
CURRENTLY THERE IS A 10-20% CHANCE FOR ISOLATED SHOWERS AND
THUNDERSTORMS THIS EVENING INTO MONDAY EARLY AFTERNOON WITH BEST
CHANCES FOR OCCURRENCE THIS EVENING INTO EARLY MONDAY MORNING AND
AGAIN MONDAY AFTERNOON. LATEST MODELS SHOW A SLIGHT INCREASE IN
THE AVAILABLE ENERGY NEEDED FOR THUNDERSTORM DEVELOPMENT TONIGHT,
BUT GIVEN THE NATURE OF MONSOONAL MOISTURE THERE IS STILL A LEVEL
OF UNCERTAINTY. AFTER TUESDAY, BETTER THUNDERSTORM CHANCES SHIFT
TO THE SIERRA AND DRIER CONDITIONS DEVELOP.
HUMIDITY VALUES TREND HIGHER LATER THIS WEEK INTO THE LOW TO MID
20S. DIURNAL ONSHORE FLOW EXPECTED WITH AFTERNOON GUSTS UP TO
15-20 MPH, OUTSIDE OF GUSTY OUTFLOW WINDS FROM ANY
THUNDERSTORM/DECAYING STORM.
REST OF TODAY
SKY/WEATHER.........MOSTLY SUNNY. 10% CHANCE OF SHOWERS AND
THUNDERSTORMS LATE IN THE AFTERNOON.
MAX TEMPERATURE.....87-97.
MIN HUMIDITY........19-23 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......WEST TO SOUTH WINDS UP TO 8 MPH. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS LATE IN THE
AFTERNOON.
RIDGETOP...........SOUTH 8 TO 12 MPH.
MIXING HEIGHT.......5600 FT AGL.
TRANSPORT WINDS.....SOUTHWEST AROUND 12 MPH.
CWR.................4 PERCENT.
CHANCE OF THUNDER...10 PERCENT.
TONIGHT
SKY/WEATHER.........MOSTLY CLOUDY. SLIGHT (10-20%) CHANCE OF
SHOWERS AND THUNDERSTORMS.
MIN TEMPERATURE.....61-65.
MAX HUMIDITY........57-61 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......WEST WINDS UP TO 6 MPH EARLY IN THE EVENING
BECOMING LIGHT. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS.
RIDGETOP...........SOUTH 4 TO 7 MPH BECOMING LIGHT.
MIXING HEIGHT.......300 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 8 TO 12 MPH SHIFTING TO THE NORTHEAST
AROUND 2 MPH EARLY IN THE MORNING.
CWR.................4 PERCENT.
CHANCE OF THUNDER...10-20 PERCENT.
MONDAY
SKY/WEATHER.........PARTLY SUNNY.
MAX TEMPERATURE.....84-94.
MIN HUMIDITY........25-29 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......LIGHT WINDS BECOMING SOUTHWEST UP TO 7 MPH IN
THE AFTERNOON.
RIDGETOP...........SOUTHWEST AROUND 8 MPH.
MIXING HEIGHT.......5700 FT AGL.
TRANSPORT WINDS.....SOUTHWEST AROUND 10 MPH.
CWR.................5 PERCENT.
CHANCE OF THUNDER...5-10 PERCENT.
FORECASTER...KF
REQUESTED BY...ISABELLA GIACOMANGELI
TYPE OF REQUEST...WILDFIRE
.TAG 2617670.2/STO
.DELDT 07/19/26
.FORMATTERVERSION 2.0.0
.EMAIL IZZIEG.64@GMAIL.COM,JORDAN.TOWNSEND@USDA.GOV,ISABELLA.GIACOMANGELI@USDA.GOV
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