704
FXUS65 KPIH 011745
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
1145 AM MDT TUE SEP 1 2026
KEY MESSAGES
- RED FLAG WARNING & SCATTERED STORMS TODAY: OVERNIGHT SHOWERS
OVER THE SNAKE PLAIN AND EASTERN HIGHLANDS WILL CLEAR THIS
MORNING, FOLLOWED BY AN AFTERNOON FLARE-UP OF SHOWERS AND
THUNDERSTORMS. A **RED FLAG WARNING** REMAINS IN EFFECT FOR
FIRE ZONE 422 DUE TO SCATTERED THUNDERSTORM COVERAGE.
- BREEZY TO WINDY MID-WEEK: A TIGHT PRESSURE GRADIENT WILL
PRODUCE WIDESPREAD BREEZY TO WINDY CONDITIONS WEDNESDAY
THROUGH FRIDAY, WITH SOME VALLEY CORRIDORS FLIRTING WITH WIND
ADVISORY CRITERIA.
- BELOW-NORMAL TEMPERATURES: AFTERNOON HIGHS WILL REMAIN
SUPPRESSED IN THE MID-TO-UPPER 70S ACROSS LOWER VALLEYS AND
60S TO LOW 70S IN THE MOUNTAINS, THOUGH A BRIEF RECOVERY INTO
THE LOWER 80S IS EXPECTED TODAY AND POSSIBLE AGAIN ON
SATURDAY.
- UNSETTLED LABOR DAY WEEKEND OUTLOOK: UNSETTLED CONDITIONS AND
RAIN CHANCES INCREASE LATE IN THE HOLIDAY WEEKEND, WITH HIGH
CONFIDENCE IN COOL, BELOW-NORMAL TEMPERATURES PERSISTING INTO
THE FIRST WEEK OF SEPTEMBER.
DISCUSSION
ISSUED AT 155 AM MDT TUE SEP 1 2026
OVERNIGHT RAIN SHOWERS CONTINUE TO STREAM ACROSS THE SNAKE
PLAIN AND EASTERN HIGHLANDS EARLY THIS MORNING. HIGH-RESOLUTION
CONVECTIVE-ALLOWING MODELS (CAMS) SHOW THIS INITIAL WAVE EXITING
BY MID-MORNING, YIELDING A BRIEF LULL IN PRECIPITATION.
HOWEVER, INCOMING UPPER-LEVEL SHORTWAVE ENERGY AND LINGERING
ATMOSPHERIC MOISTURE WILL SPARK A SECONDARY ROUND OF SHOWERS AND
THUNDERSTORMS BY EARLY-TO-MID AFTERNOON. WHILE FORCING AND QPF
WILL FOCUS HEAVILY OVER THE CENTRAL MOUNTAINS AND ALONG THE
CONTINENTAL DIVIDE, LATEST MODEL TRENDS INDICATE AN ISOLATED
SHOWER OR STORM IS POSSIBLE NEARLY ANYWHERE ACROSS EASTERN
IDAHO. GIVEN THE SCATTERED NATURE OF LIGHTNING STRIKES ON DRY
FUELS, A RED FLAG WARNING REMAINS ACTIVE FOR FIRE ZONE 422
TODAY. CONVECTIVE ACTIVITY WILL TAPER OFF LATE THIS EVENING,
WITH MOST SHOWERS DIMINISHING BY MIDNIGHT.
BROAD UPPER-LEVEL TROUGHING ANCHORED OVER THE PACIFIC NORTHWEST
WILL DICTATE REGIONAL WEATHER THROUGH THE REMAINDER OF THE
WORKWEEK. EMBEDDED IMPULSES ROTATING AROUND THE PARENT LOW WILL
TRACK THROUGH THE FLOW, WITH ONE PROMINENT LOBE CROSSING THE
REGION ON WEDNESDAY. BECAUSE THE CORE ENERGY WILL REMAIN SHUNTED
TO OUR NORTH AND WEST, SHOWER AND THUNDERSTORM CHANCES
WEDNESDAY AND THURSDAY WILL BE LARGELY RESTRICTED TO THE CENTRAL
MOUNTAINS. THE MORE WIDESPREAD OPERATIONAL IMPACT MID-WEEK WILL
BE STRONG AFTERNOON WINDS DRIVEN BY A TIGHT REGIONAL PRESSURE
GRADIENT. SEVERAL WIND-PRONE VALLEY CORRIDORS WILL FLIRT WITH
WIND ADVISORY THRESHOLDS EACH AFTERNOON. FORTUNATELY,
UNSEASONABLY COOL AIR WILL HOLD MINIMUM RELATIVE HUMIDITY VALUES
ABOVE CRITICAL THRESHOLDS. AFTERNOON HIGHS WEDNESDAY THROUGH
FRIDAY WILL TOP OUT IN THE MID-TO-UPPER 70S IN LOWER ELEVATIONS
AND MID-60S TO LOWER 70S ACROSS MOUNTAIN ZONES.
LOWER ELEVATIONS MAY SEE A BRIEF TEMPERATURE RECOVERY INTO THE
LOWER 80S ON SATURDAY BEFORE THE NEXT WEATHER SYSTEM APPROACHES.
GUIDANCE INDICATES A POTENTIALLY UNSETTLED PATTERN TAKING HOLD
FOR THE LATTER HALF OF THE LABOR DAY HOLIDAY WEEKEND, WITH RAIN
CHANCES TRENDING UPWARD SUNDAY INTO MONDAY. WHILE GLOBAL MODELS
CONTINUE TO STRUGGLE WITH THE EXACT SYNOPTIC PLACEMENT OF THE
UPPER LOW AND DEEPEST MOISTURE PLUMES, CONFIDENCE REMAINS HIGH
THAT BELOW-NORMAL TEMPERATURES WILL PERSIST THROUGH MUCH OF THE
FIRST WEEK OF SEPTEMBER.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1138 AM MDT TUE SEP 1 2026
SHRA AND TSRA ARE RETURNING TONIGHT WITH PROBABILITIES IN THE
PROB30 THREAT, MOSTLY. BY 01/22Z SHRA/TSRA SHOULD BE DEVELOPING
EVERYWHERE, ALTHOUGH IT CAN BE SAID THAT AT KDIJ THE SHRA HASN'T
STOPPED WITH THE ON AND OFF CIG ISSUES THIS MORNING.
NOT EXPECTING FURTHER IMPACT TO CIG ANYWHERE DURING THE
AFTERNOON AND EVENING TONIGHT. HOWEVER, OVERNIGHT KDIJ WILL BE
ONCE MORE SUSCEPTIBLE TO MARGINAL VFR DUE TO SHRA.
VSBY IN TSRA COULD BE REDUCED, BUT STILL NOT EXPECTING ANYTHING
LOWER THAN MARGINAL VFR.
WITH AN APPROACHING LOW FROM THE SOUTH, MODERATE SOUTHERLY WIND
WILL DEVELOP OVERNIGHT, WITH A GENERAL G25KT LIKELY IN THE
NORMALLY CALM OR NEAR-CALM MORNING HOURS. G45KT LIKELY IN TSRA
OUTFLOW, ALTHOUGH THE FARTHER EAST THE LOWER THE GUSTS.
FIRE WEATHER
ISSUED AT 155 AM MDT TUE SEP 1 2026
THE PRIMARY OPERATIONAL FIRE HAZARD TODAY IS SCATTERED
THUNDERSTORM ACTIVITY ACROSS SOUTH-CENTRAL IDAHO, WHERE A RED
FLAG WARNING REMAINS ACTIVE FOR FIRE ZONE 422. WHILE WETTING
RAIN WILL ACCOMPANY STRONGER CORES, LIGHTNING IGNITIONS OUTSIDE
RAIN SHAFTS REMAIN A CONCERN. WEDNESDAY THROUGH FRIDAY WILL
BRING STRONG, BREEZY WEST-TO-SOUTHWEST WIND GUSTS ACROSS ALL
ZONES AS PRESSURE GRADIENTS TIGHTEN. HOWEVER, UNSEASONABLY COOL
TEMPERATURES HOLDING IN THE 60S AND 70S WILL KEEP DAYTIME
RELATIVE HUMIDITY RECOVERIES ELEVATED ABOVE CRITICAL THRESHOLDS.
PIH WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR IDZ422.
DISCUSSION...MCKAUGHAN
AVIATION...MESSICK
FIRE WEATHER...MCKAUGHAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page