697
FXUS65 KPIH 091056
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
456 AM MDT WED SEP 9 2026
KEY MESSAGES
- WARMING TREND THROUGH THURSDAY WILL DRIVE DOWN AFTERNOON
HUMIDITY READINGS TO CRITICAL FIRE WEATHER LEVELS AT LOWER
ELEVATIONS.
- APPROACHING TROUGH WILL INCREASE WIND ON THURSDAY AND FRIDAY
TO CRITICAL FIRE WEATHER LEVELS. RED FLAG WARNING MAY BE
NEEDED THURSDAY.
- SHOWERS AND THUNDERSTORMS MAY ARRIVE AS EARLY AS LATE THURSDAY
NIGHT/FRIDAY MORNING IN THE SOUTHERN AND EASTERN HIGHLANDS.
DISCUSSION
ISSUED AT 104 AM MDT WED SEP 9 2026
TODAY THROUGH FRI NIGHT...HIGH PRESSURE SLOWLY BREAKS DOWN IN
ADVANCE OF AN INCOMING TROUGH DURING THIS PERIOD, STARTING
THURSDAY. UNTIL THEN, EXPECT SUNNY SKIES AND TEMPERATURES
RETURNING IN LOWER ELEVATION TO ABOVE 80 DEG F STARTING TODAY,
AND EVEN WARMER THU. THE APPROACHING TROUGH BRINGS COOLER AIR
AND CLOUD COVER, AND TEMPERATURES WILL START TO COOL FROM THU TO
FRI. THERE IS A VERY WEAK CHANCE OF PRECPITATION, MAINLY SEEN ON
ECMWF MODEL RUNS, FOR THE SOUTHERN AND EASTERN HIGHLANDS,
SPILLING INTO THE SNAKE RIVER PLAIN.
WIND WILL BE LIGHT TODAY, BUT ON THU AFTERNOON, AS THE TROUGH
DRAWS CLOSER, WILL INCREASE SUBSTANTIALLY, WITH WINDY CONDITIONS
(20 TO 30 MPH WITH GUSTS TO 40 MPH) DEVELOPING. WIND WILL
CONTINUE TO BE AT THAT LEVEL FRI AFTERNOON.
SAT THROUGH TUE...THE TROUGH THAT BRINGS THE WIND AND A SLIGHT
CHANCE OF SHOWERS AND THUNDER ON THU NIGHT/FRI WILL CROSS OVER
THE FORECAST AREA. THIS WILL INCREASE THE THREAT OF SHOWERS AND
THUNDERSTORMS, WHICH WILL BRING SIGNIFICANT COOLING AFTER THE
TROUGH PASSES TO THE EAST ON SAT NIGHT. TEMPERATURES WILL COOL
BY 15 TO 20 DEG F FOR AFTERNOON HIGHS.
WIND WILL WEAKEN ON SAT, THEN INCREASE AGAIN ON SUN IN THE POST
TROUGH REGIME. MON WILL SEE THE DEPARTURE OF THE TROUGH'S
INFLUENCE, WITH TEMPERATURES STARTING A WARMING OR AT LEAST
BOTTOMING OUT, WITH ONCE AGAIN NEARLY CLEAR SKIES AND A RETURN
TO DRY CONDITIONS FOR MON TO THE END OF THE FORECAST PERIOD.
TEMPERATURES WILL WARM BACK TO NEAR NORMAL BY TUE/WED.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 454 AM MDT WED SEP 9 2026
NO CLOUDS, NO RESTRICTIONS TO VSBY UNDER HIGH PRESSURE.
WIND SHIFTS ARE THE ONLY SIGNIFICANT FORECAST, WITH ONLY 15KT
BEING REACHED AT KSUN. WIND TONIGHT IS NOT AS LIGHT AND
VARIABLE DUE TO A TROUGH STARTING TO INFLUENCE WIND ON THURSDAY.
FIRE WEATHER
ISSUED AT 104 AM MDT WED SEP 9 2026
A DRYING OUT AS TEMPERATURES WARM WILL PUSH WIDESPREAD
AFTERNOOON HUMIDITY READINGS AT LOWER ELEVATIONS BELOW THE 15
PERCENT CRITICAL CRITERIA. THIS WILL NOT BE SO BAD TODAY, AS
WIND WILL BE REMAINING LIGHT; HOWEVER AN APPROACHING LOW WILL
INCREASE THE WIND SO THAT G25KT TO G40KT WILL BE LIKELY FOR THU
AND FRI. THIS MAKES AN OVERLAP DAY OF GUSTY WIND AND VERY DRY
CONDITIONS OCCUR ON THU. THE LOW WILL START COOLING
TEMPERATURES, MAINLY IN THE WEST, ON FRI, ALONG WITH BRINGING IN
HIGHER HUMIDITY AIR. SO FRI IS LIKELY ONLY TO SEE CRITICAL FIRE
WEATHER CONDTIONS IN THE EASTERN PORTIONS, IF FUELS MEET
CRITICAL LEVELS STILL. AFTERNOON TEMPERATURES WILL COOL BY SUN
INTO THE 50S AND 60S, ENDING THE CRITICAL HUMIDITY THREAT, EVEN
IF SUN RETURNS TO BEING WIND LIKE THU AND FRI. WARMING AND
DRYING RETURN ON MON, WITH WIND STAYING LIGHT AS THIS IS CAUSED
BY HIGH PRESSURE RETURNING.
PIH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MESSICK
AVIATION...MESSICK
FIRE WEATHER...MESSICK
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