093
FNUS76 KSTO 181644
FWSSTO
SPOT FORECAST FOR TWAIN FIRE...USFS
NATIONAL WEATHER SERVICE SACRAMENTO CA
944 AM PDT SAT JUL 18 2026
FORECAST IS BASED ON FORECAST START TIME OF 0600 PDT ON JULY 19.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.
DISCUSSION
MAIN NOTE IN THE FORECAST IS THAT THERE IS A 10 TO 15% CHANCE OF
THUNDERSTORMS EARLY ON SUNDAY, THOUGH THERE IS UNCERTAINTY ON WHETHER THE
STORMS WILL GET ENOUGH FORCE BEHIND THEM TO DEVELOP INTO THUNDERSTORMS
OR IF THEY WILL SIMPLY RESULT IN SOME VIRGA AND LIGHT RAINFALL. CURRENTLY,
HIGH RESOLUTION MODELS SHOW A LINE OF LIGHT RAIN MOVING OVER THE GENERAL
AREA OF THE FIRE AROUND 4 TO 6 AM, RATHER THAN ACTUAL THUNDERSTORMS, BUT
THE UNCERTAIN POTENTIAL FOR LIGHTNING STILL REMAINS. AFTER SUNDAY MORNING,
POTENTIAL FOR THUNDERSTORMS NEAR THE FIRE CURRENTLY REMAINS BELOW 10% THROUGH
MID TO LATE WEEK. OTHERWISE, A PUSH OF MONSOONAL MOISTURE WILL INCREASE BOTH
DAYTIME AND OVERNIGHT HUMIDITY FOR MUCH OF THE UPCOMING WEEK. DAYTIME
MINIMUMS WILL HOVER WITHIN THE 20S, WITH MODERATE RECOVERIES THE NEXT COUPLE
OF NIGHTS TRANSITIONING TO EXCELLENT RECOVERIES FOR THE REMAINDER OF THE WEEK.
HIGH TEMPERATURES WILL REMAIN IN THE LOW 90S AND WINDS WILL GENERALLY BE
LIGHT AND TERRAIN DRIVEN OVERNIGHT WITH STRONGER SOUTHWEST WINDS IN THE
AFTERNOON (GUSTS UP TO 15 MPH).
SUNDAY
SKY/WEATHER.........MOSTLY SUNNY. SLIGHT CHANCE OF RAIN EARLY IN
THE MORNING.
MAX TEMPERATURE.....88-98.
MIN HUMIDITY........19-23 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......LIGHT TERRAIN DRIVEN WINDS BECOMING WEST UP TO 7 MPH
IN THE AFTERNOON WITH GUSTS UP TO 15 MPH.
RIDGETOP...........EAST AROUND 3 MPH SHIFTING TO THE SOUTHWEST 8
TO 15 MPH LATE IN THE MORNING.
MIXING HEIGHT.......7600 FT AGL.
TRANSPORT WINDS.....EAST AROUND 3 MPH SHIFTING TO THE SOUTHWEST 8
TO 15 MPH LATE IN THE MORNING.
CWR.................5 PERCENT.
CHANCE OF THUNDER...15 PERCENT.
TIME (PDT) 6 AM 9 AM NOON 3 PM
SKY COVER.......PCLDY PCLDY MCLEAR PCLDY
CWR.............5 5 0 0
CHC OF THDR (%).15 12 0 0
TEMP............60 67 85 91
RH..............65 48 27 21
SL/VL WIND......NE 1G3 E 2G5 SW 2G8 W 6G14
RIDGETOP WIND...NE 15 SE 12 S 9 SW 12
MIX HGT (FT)....300 1400 6000 7600
TRANSPORT WIND..NE 3 SE 3 S 8 SW 12
SUNDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY THEN BECOMING MOSTLY CLOUDY.
MIN TEMPERATURE.....62-67.
MAX HUMIDITY........52-60 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......SOUTHWEST WINDS UP TO 7 MPH IN THE EVENING WITH
GUSTS UP TO 15 MPH, THEN BECOMING LIGHT AND
TERRAIN DRIVEN OVERNIGHT.
RIDGETOP...........SOUTHWEST TO SOUTHWEST 3 TO 12 MPH.
MIXING HEIGHT.......300 FT AGL.
TRANSPORT WINDS.....SOUTHWEST TO SOUTHWEST 3 TO 12 MPH.
CWR.................2 PERCENT.
CHANCE OF THUNDER...2 PERCENT.
TIME (PDT) 6 PM 9 PM MIDNGT 3 AM
SKY COVER.......PCLDY MCLDY MCLDY MCLDY
CWR.............0 0 0 0
CHC OF THDR (%).0 0 0 0
TEMP............89 78 72 68
RH..............24 36 46 52
SL/VL WIND......SW 7G14 SW 5G9 SW 2G5 S 2G3
RIDGETOP WIND...S 9 S 12 SW 9 S 9
MIX HGT (FT)....4900 700 300 300
TRANSPORT WIND..SW 12 SW 9 SW 6 S 3
MONDAY
SKY/WEATHER.........MOSTLY CLOUDY THEN BECOMING MOSTLY SUNNY.
MAX TEMPERATURE.....86-96.
MIN HUMIDITY........22-28 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......LIGHT TERRAIN DRIVEN WINDS BECOMING SOUTHWEST
UP TO 7 MPH IN THE AFTERNOON WITH GUSTS UP TO
15 MPH.
RIDGETOP...........SOUTH 6 TO 12 MPH.
MIXING HEIGHT.......7000 FT AGL.
TRANSPORT WINDS.....SOUTH TO SOUTHWEST 3 TO 12 MPH.
CWR.................1 PERCENT.
CHANCE OF THUNDER...1 PERCENT.
TIME (PDT) 6 AM 9 AM NOON 3 PM
SKY COVER.......MCLDY MCLDY MCLDY PCLDY
CWR.............0 0 0 0
CHC OF THDR (%).0 0 0 0
TEMP............65 69 83 90
RH..............57 52 30 23
SL/VL WIND......NE 1G2 NE 1G2 SW 2G5 SW 6G13
RIDGETOP WIND...S 9 S 6 S 6 SW 8
MIX HGT (FT)....300 400 3500 7000
TRANSPORT WIND..S 3 SW 3 SW 6 SW 8
FORECASTER...SP
REQUESTED BY...ISABELLA GIACOMANGELI
TYPE OF REQUEST...WILDFIRE
.TAG 2617670.0/STO
.DELDT 07/18/26
.FORMATTERVERSION 2.0.0
.EMAIL IZZIEG.64@GMAIL.COM,JORDAN.TOWNSEND@USDA.GOV,ISABELLA.GIACOMANGELI@USDA.GOV
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