857
FXUS65 KPIH 151817
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
1217 PM MDT TUE JUL 15 2025
KEY MESSAGES
- COLD FRONT LATER TODAY WILL SUPPORT ISOLATED TO SCATTERED
THUNDERSTORMS, BREEZY WINDS, AND NEAR CRITICAL TO CRITICAL
FIRE WEATHER CONDITIONS.
- ISOLATED STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE THIS
AFTERNOON AND EVENING, CAPABLE OF PRODUCING WIND GUSTS UP TO
AROUND 50-60 MPH, UP TO 1-1.5" DIAMETER SIZED HAIL, MODERATE
TO HEAVY RAIN, AND FREQUENT LIGHTNING.
- COOLER AND DRIER CONDITIONS ON WEDNESDAY.
- WARMING TREND TO FINISH OUT THE WEEK WITH ANY SHOWER AND
THUNDERSTORM DEVELOPMENT REMAINING ISOLATED.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 245 AM MDT TUE JUL 15 2025
EARLY MORNING SATELLITE IMAGERY SHOWS A CLOSED MID/UPPER-LEVEL
LOW DIVING SOUTHEAST OUT OF BRITISH COLUMBIA, TRACKING SOUTHEAST
INTO THE IDAHO PANHANDLE AND WESTERN MONTANA. AS THIS TROUGH
WORKS EAST THROUGH MONTANA THROUGHOUT THE DAY, A COLD FRONT THIS
AFTERNOON AND EVENING WILL SUPPORT ANOTHER ROUND OF ISOLATED TO
SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT ALONG WITH BREEZY
WINDS. OUT AHEAD OF THIS FRONT, ISOLATED SHOWERS WILL REMAIN
POSSIBLE THIS MORNING AHEAD OF CONVECTIVE INITIATION THIS
AFTERNOON AND EVENING. FOR LATER TODAY, WE ARE LOOKING AT TWO
MAIN AREAS FOR STRONGER STORMS: ONE IN THE EAST-CENTRAL
MOUNTAINS ACROSS THE UPPER SNAKE RIVER PLAIN AND EASTERN
HIGHLANDS STARTING FIRST AND A SECONDARY AREA SOUTHEAST OF THE
SNAKE RIVER PLAIN SOUTH INTO UTAH STARTING SECOND. THESE AREAS
ARE WHERE THE HREF MODEL PROBABILITY OF WINDS GREATER THAN 35
MPH SHOWS A 70-90%+ CHANCE, INCLUDING A 10-30% CHANCE OF WINDS
GREATER THAN 58 MPH SOUTHEAST OF THE SNAKE RIVER PLAIN.
GIVEN TODAY'S ENSEMBLE CONVECTIVE ENVIRONMENT SUPPORTING
500-1000 J/KG OF MUCAPE, 25-40 KTS OF 0-6 KM SHEAR (PUSHING
40-50 KTS FURTHER NORTH), AND 6-10 DEGREE/KM 700-500 MB LAPSE
RATES, ISOLATED TO SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE
EXPECTED THIS AFTERNOON AND EVENING. AS EVIDENT BY STRONGER
THUNDERSTORMS YESTERDAY OUT ACROSS THE SHOSHONE/ARCO/MUD LAKE
DESERT AND SOUTH HILLS/RAFT RIVER VALLEY REGIONS PRODUCING WIND
GUSTS OF 45-65 MPH, STRONG TO SEVERE STORMS TODAY WILL BE
CAPABLE OF PRODUCING WIND GUSTS UP TO 50-70 MPH, UP TO 1-1.5"
DIAMETER SIZED HAIL, MODERATE TO HEAVY RAIN, AND FREQUENT
LIGHTNING. GIVEN THIS INCREASING CONFIDENCE, THE STORM
PREDICTION CENTER HAS EXPANDED THEIR MARGINAL RISK (5-14%
CHANCE) OF SEVERE THUNDERSTORMS TODAY TO INCLUDE EVERYWHERE
OUTSIDE THE WEST- CENTRAL MOUNTAINS AND WESTERN MAGIC VALLEY.
STAY TUNED FOR ADDITIONAL FORECAST INFORMATION, WARNINGS, AND
ALERTS LATER TODAY AS WE TRACK THIS THUNDERSTORM DEVELOPMENT. WE
WILL ALSO SEE A MIX OF WET AND DRY THUNDERSTORMS TODAY WHICH
COUPLED WITH SCATTERED COVERAGE, HAS PROMPTED A RED FLAG WARNING
FOR IDAHO FWZ 410/411/413/427 FROM 12-9 PM MDT TODAY. MORE ON
THAT IN THE FIRE WEATHER DISCUSSION BELOW. BEHIND THE COLD
FRONTAL PASSAGE TONIGHT, SHOWERS AND STORMS WILL BECOME
INCREASINGLY ISOLATED AFTER MIDNIGHT AND SHIFT EAST AHEAD OF DRY
CONDITIONS BACK REGIONWIDE FOR WEDNESDAY. PRECIPITATION TOTALS
TODAY WILL RANGE FROM A T-0.25" FOR MOST, LOCALLY HIGHER IN THAT
0.25-1.00" RANGE WHERE STRONGER THUNDERSTORMS PASS OVER. HIGHS
TODAY WILL BE IN THE 80S/90S AS SYNOPTIC WINDS OUTSIDE OF ANY
CONVECTION WILL SUPPORT GUSTS PEAKING AROUND 25-45 MPH THIS
AFTERNOON.
WEDNESDAY IS SHAPING UP TO COOLER AND DRIER WITH LIGHTER WINDS
OVERALL BEHIND THE COLD FRONT, AS ZONAL FLOW FILLS IN BEHIND THE
EXITING BOUNDARY. THIS WILL LEAD TO HIGHS IN THE 70S/80S (90S
FURTHER SOUTH) WITH WIND GUSTS PEAKING AROUND 15-25 MPH. THE
FORECAST FOR TOMORROW HAS ALSO TRENDED DRIER, WITH LESS THAN A
10% CHANCE OF ANY SHOWER AND THUNDERSTORM DEVELOPMENT DURING THE
DAYTIME HOURS WEDNESDAY INTO WEDNESDAY NIGHT. |
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 245 AM MDT TUE JUL 15 2025
NEAR NORMAL TO ABOVE NORMAL TEMPERATURES AND MOSTLY DRY
CONDITIONS WILL PREVAIL THROUGHOUT THE LONG TERM PERIOD AS W/SW
FLOW DOMINATES THE OVERALL MID/UPPER-LEVEL FLOW PATTERN. A
SERIES OF SHORTWAVE TROUGHS LATER THIS WEEK INTO EARLY NEXT WEEK
WILL HELP TRIGGER A 5- 20% CHANCE OF AFTERNOON SHOWERS AND
THUNDERSTORMS EACH DAY (PRIMARILY IN THE MOUNTAINS), AS
CONDITIONS REMAIN VERY DRY OVERALL OUTSIDE OF ANY OF THIS
ISOLATED ACTIVITY. AS OF THE LATEST ENSEMBLE MODEL GUIDANCE,
COVERAGE OF THESE SHOWERS AND STORMS WILL PEAK ON FRIDAY AND
SATURDAY, WITH VERY ISOLATED COVERAGE EXPECTED OTHER DAYS. HIGHS
EACH DAY WILL BE IN THE 80S/90S IN THE VALLEYS WITH BREEZY
WINDS EXPECTED EACH AFTERNOON, SUPPORTING GUSTS UP TO AROUND
20-40 MPH. A COMBINATION OF BREEZY WINDS AND LOW RELATIVE
HUMIDITY WILL NEED TO BE MONITORED LATER THIS WEEK FOR ANY
OVERLAP FOR RED FLAG WARNING CRITERIA. MORE ON THAT IN THE FIRE
WEATHER DISCUSSION BELOW.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1209 PM MDT TUE JUL 15 2025
HOURLY PROBABILITY OF THUNDERSTORMS IN THE NBM HOURLY OUTPUT
INDICATES A MINOR CHANCE OF TSRA THAT WOULD RATE FOR MOST
AIRDROMES A PROB30 GROUP OF VARYING INTERVALS. SHORTEST IS KSUN,
THEN KBYI, WITH THE LONGEST FOR KDIJ. KDIJ HAS HIGH ENOUGH
PROBABILITIES DURING THE AFTERNOON FOR GREATER THAN 50 PERCENT
RISK, SO HAVE FOR AN INTERVAL AT KDIJ A TEMPO GROUP. TSRA ENDS
FROM WEST TO EAST, WITH KBYI ENDING PRIOR TO 16/00Z, AND FOR
KDIJ ENDING AFTER 16/06Z. SEE NO IMPACT TO VSBY OR CIG, WITH THE
MAIN ISSUE BEING OUTFLOW WIND AND THE TS HAZARDS. THERE IS THE
POTENTIAL AT ALL BUT KSUN FOR SEVERE TSRA, WHICH WILL MAINLY
MEAN G50KT OR MORE IS POSSIBLE. CONDITIONS SETTLE DOWN IN THE
LATE EVENING FOR LIGHT WIND AND UNLIMITED CIG/VSBY. NOT
EXPECTING A RETURN OF IMPACTFUL WEATHER FOR AVIATION INTERESTS
ON WED.
FIRE WEATHER
ISSUED AT 245 AM MDT TUE JUL 15 2025
TODAY WILL BE ANOTHER CRITICAL FIRE WEATHER DAY ACROSS EASTERN
IDAHO AS A COLD FRONT PASSES OVERHEAD LATER IN THE DAY,
SUPPORTING GUSTY WINDS, LOW RH, AND ISOLATED TO SCATTERED
THUNDERSTORMS. ASIDE FROM ISOLATED SHOWERS THIS MORNING,
CONVECTIVE INITIATION WILL BEGIN AROUND 12-3 PM AND CONTINUE
THROUGH 9 PM TO MIDNIGHT, AHEAD OF DRY CONDITIONS BACK FOR
WEDNESDAY. AS EVIDENT BY STRONGER THUNDERSTORMS YESTERDAY OUT
ACROSS THE SHOSHONE/ARCO/MUD LAKE DESERT AND SOUTH HILLS/RAFT
RIVER VALLEY REGIONS PRODUCING WIND GUSTS OF 45-65 MPH, STRONG
TO SEVERE STORMS TODAY WILL BE CAPABLE OF PRODUCING WIND GUSTS
UP TO 60-70 MPH, 1-1.5" DIAMETER SIZED HAIL, MODERATE TO HEAVY
RAIN, AND FREQUENT LIGHTNING. WHILE MOST THUNDERSTORMS WILL
REMAIN WET, WE WILL ALSO SEE ISOLATED DRY THUNDERSTORMS AT TIMES
AS WELL. AS A RESULT, A RED FLAG WARNING REMAINS IN EFFECT FOR
IDAHO FWZ 410/411/413/427 TODAY WITH ELEVATED TO NEAR CRITICAL
FIRE WEATHER CONDITIONS EXPECTED REGIONWIDE DUE TO A COMBINATION
OF GUSTY WINDS AND LOW RH IN THE TEENS/20S. HIGHS TODAY WILL BE
IN THE 80S/90S AS SYNOPTIC WINDS OUTSIDE OF ANY CONVECTION WILL
SUPPORT GUSTS PEAKING AROUND 25-45 MPH THIS AFTERNOON.
WEDNESDAY IS SHAPING UP TO COOLER AND DRIER WITH LIGHTER WINDS
OVERALL BEHIND THE COLD FRONT, AS ZONAL FLOW FILLS IN BEHIND THE
EXITING BOUNDARY. THIS WILL LEAD TO HIGHS IN THE 70S/80S (90S
FURTHER SOUTH) WITH WIND GUSTS PEAKING AROUND 15-25 MPH. THE
FORECAST FOR TOMORROW HAS ALSO TRENDED DRIER, WITH LESS THAN A
10% CHANCE OF ANY SHOWER AND THUNDERSTORM DEVELOPMENT DURING THE
DAYTIME HOURS WEDNESDAY INTO WEDNESDAY NIGHT.
LOOKING AHEAD TOWARDS LATER THIS WEEK INTO EARLY NEXT WEEK,
NEAR NORMAL TO ABOVE NORMAL TEMPERATURES AND MOSTLY DRY
CONDITIONS WILL PREVAIL AS W/SW FLOW DOMINATES THE OVERALL
MID/UPPER-LEVEL FLOW PATTERN. A SERIES OF SHORTWAVE TROUGHS
DURING THIS TIMEFRAME WILL HELP TRIGGER A 5-20% CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS (PRIMARILY IN THE MOUNTAINS)
EACH DAY, AS CONDITIONS REMAIN VERY DRY OVERALL OUTSIDE OF ANY
OF THIS ISOLATED ACTIVITY. AS OF THE LATEST ENSEMBLE MODEL
GUIDANCE, COVERAGE OF THESE SHOWERS AND STORMS WILL PEAK ON
FRIDAY AND SATURDAY, WITH VERY ISOLATED COVERAGE EXPECTED OTHER
DAYS. HIGHS EACH DAY WILL BE IN THE 80S/90S IN THE VALLEYS WITH
BREEZY WINDS EXPECTED EACH AFTERNOON, SUPPORTING GUSTS UP TO
AROUND 20-40 MPH. A COMBINATION OF BREEZY WINDS AND LOW RELATIVE
HUMIDITY WILL NEED TO BE MONITORED LATER THIS WEEK FOR ANY
OVERLAP FOR RED FLAG WARNING CRITERIA. STAY TUNED.
PIH WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR IDZ410-411-
413-427.
SHORT TERM...MACKAY
LONG TERM...MACKAY
AVIATION...MESSICK
FIRE WEATHER...MACKAY
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