349
FNUS76 KOTX 151920
FWSOTX
SPOT FORECAST FOR UPPER SMITH...USFS
NATIONAL WEATHER SERVICE SPOKANE WA
1220 PM PDT SAT AUG 15 2026
FORECAST IS BASED ON FORECAST START TIME OF 1300 PDT ON AUGUST 16.
DISCUSSION
209:
THE UPPER SMITH FIRE SAW CLOUDS INCREASING THROUGH THE EARLY
PART OF THE DAY, BUT HAS BEEN TRENDING WARMER THAN THE PREVIOUS
DAY WITH HIGHS CLIMBING IN THE UPPER 60S TO UPPER 70S, WITH HUMIDITY
VALUES UPPER 30S TO MID-40S. THE EARLY PART OF THE DAY SAW SHOWERS
NEARBY WITH 10% RISK, THEN A SLIGHTLY BETTER POTENTIAL FOR SHOWERS
AND NEARBY THUNDERSTORMS PUSHED IN FOR THE LATE AFTERNOON TO EVENING
AT AROUND A 15-20% CHANCE. WINDS REMAINED LIGHT AND PRIMARILY TERRAIN
DRIVEN.
SUNDAY REMAINS MILD WITH UPPER 60S TO 70S. CLOUDS INCREASE THROUGH
THE DAY, WITH A 10-15% CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS.
HEADING INTO THE EARLY PART OF THE WEEK THE LOOK FOR A MIX OF SUN
AND AFTERNOON CLOUDS, WITH MILD TEMPERATURES AND GENERALLY
LIGHTER TERRAIN DRIVEN WIND, WITH GOOD HUMIDITY RECOVERIES AT NIGHT.
A 10% CHANCE OF SHOWERS AND THUNDERSTORMS REMAINS IN THE FORECAST
THROUGH TUESDAY EACH AFTERNOON BUT FOR THE LARGE PART IT REMAINS DRY.
DISCUSSION:
EXPECT MILD TEMPERATURES THROUGH THE NEXT SEVERAL DAYS, WITH
RECURRING CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY, PEAKING
DURING THE AFTERNOON AND EVENING HOURS. LIGHTNING CHANCES WILL
CONTINUE TO WEAKEN EACH DAY. THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING BRIEF HEAVY DOWNPOURS AND GUSTY, ERRATIC WINDS. WINDS
WILL GENERALLY BE LIGHT AWAY FROM THUNDERSTORMS. PRECIP AMOUNTS
ARE EXPECTED TO BE A FEW HUNDREDTHS AT MOST. RELATIVE HUMIDITY
RECOVERIES WILL BE GOOD.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE.
***************************************************************
FORECASTS FOR 20 FOOT WIND SPEEDS (VALLEYS AND RIDGE TOPS) ARE
10 MINUTE AVERAGES REFLECTING RAWS WIND.
***VENTILATION INDEX IS DERIVED FROM TRANSPORT WIND
MULTIPLIED BY THE MIXING HEIGHT DIVIDED BY 100.
CATEGORIES: LOW (< 200), MODERATE (200-500),
HIGH (500-800), AND VERY HIGH (> 800).
***************************************************************
SUNDAY
SKY/WEATHER.........PARTLY SUNNY. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS.
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.15 PERCENT.
MAX TEMPERATURE.....68 RIDGETOP TO 82 VALLEY BOTTOM.
MIN HUMIDITY........38-44 PERCENT.
WIND (20 FT)........SOUTHWEST DOWNSLOPE/DOWN VALLEY AT 4 TO 8 MPH WITH
GUSTS TO 13 MPH IN THE MORNING...BECOMING UPSLOPE/
UPVALLEY AFTER 1100 4 TO 8 MPH. GUSTY AND ERRATIC
WINDS EXPECTED NEAR THUNDERSTORMS IN THE AFTERNOON.
MIXING HEIGHT.......1000 FT AGL AT 0800 INCREASING TO 7500 FT AGL IN
THE AFTERNOON.
TRANSPORT WINDS.....LIGHT WINDS BECOMING SOUTHWEST AROUND 10 MPH IN
THE AFTERNOON.
VENTILATION INDEX...MODERATE (220) INCREASING TO HIGH (763) IN THE
AFTERNOON.
SUNDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE EVENING.
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.15 PERCENT.
MIN TEMPERATURE.....AROUND 54.
MAX HUMIDITY........67 PERCENT. GOOD RECOVERY.
WIND (20 FT)........DOWNSLOPE/DOWNVALLEY 2 TO 6 MPH. GUSTY AND
ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS
IN THE EVENING.
MIXING HEIGHT.......3500 FT AGL FALLING TO 500 FT AGL.
TRANSPORT WINDS.....NORTHWEST 6 TO 7 MPH.
VENTILATION INDEX...MODERATE (296) DECREASING TO LOW (24)
OVERNIGHT.
MONDAY
SKY/WEATHER.........MOSTLY SUNNY...BECOMING PARTLY CLOUDY WITH
A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS
IN THE AFTERNOON
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.15 PERCENT.
MAX TEMPERATURE.....69 RIDGETOP TO 84 VALLEY BOTTOM.
MIN HUMIDITY........36-44 PERCENT.
WIND (20 FT)........DOWNSLOPE/DOWNVALLEY 2 TO 4 MPH IN THE MORNING
...BECOMING VARIABLE 2 TO 4 MPH IN THE AFTERNOON.
GUSTY AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS
IN THE AFTERNOON.
MIXING HEIGHT.......4000 FT AGL INCREASING TO 7000 FT AGL IN THE
AFTERNOON.
TRANSPORT WINDS.....WEST 5 TO 11 MPH.
VENTILATION INDEX...MODERATE (239) INCREASING TO HIGH (732) IN THE
AFTERNOON.
FORECASTER...MSC
REQUESTED BY...DAVID PEARSON
TYPE OF REQUEST...WILDFIRE
.TAG 2619090.10/OTX
.DELDT 08/15/26
.FORMATTERVERSION 2.0.0
.EMAIL DAVID_PEARSON@FIRENET.GOV,IDCDC@FIRENET.GOV,2026.UPPERSMITH.PLANS@FIRENET.GOV
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