924
FXUS65 KPIH 291737
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
1137 AM MDT SAT MAR 29 2025
KEY MESSAGES
- A MIX OF RAIN/SNOW SHOWERS (~10-20% CHANCE OF THUNDERSTORMS
TODAY) ARE EXPECTED THROUGH SUNDAY WITH A CHANGEOVER TO ALL
SNOW EXPECTED TONIGHT INTO SUNDAY MORNING.
- A BRIEF RIDGE OF HIGH PRESSURE ON SUNDAY WILL BRING A RETURN
TO DRY CONDITIONS ACROSS THE SNAKE RIVER PLAIN AS SNOW SHOWERS
SHIFT INTO THE MOUNTAINS.
- DAILY PRECIPITATION CHANCES WILL CONTINUE FOR EARLY NEXT WEEK
AS A SERIES OF PACIFIC SYSTEMS SUPPORT A MIX OF RAIN/SNOW
SHOWERS AND NEAR NORMAL TO BELOW NORMAL TEMPERATURES.
UPDATE
ISSUED AT 813 AM MDT SAT MAR 29 2025
QUICK UPDATE THIS MORNING TO INCREASE POP SLIGHTLY FOR THE
MORNING TO ENCOURAGE MENTION OF SHOWERS ALONG THE WESTERN EDGES
OF THE FORECAST AREA. RADAR IMAGERY AND SURFACE OBSERVATIONS
HAVE PRECIPITATION FALLING, FASTER THAN EARLIER RUNS OF THE
HIGH-RES SOLUTIONS BROUGHT THE PRECIPITATION IN. LOWER ELEVATION
TEMPERATURES REMAIN WARM ENOUGH TO SUPPORT RAIN THIS MORNING,
THUS KEPT SNOW ABOVE VALLEY FLOORS.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 220 AM MDT SAT MAR 29 2025
EARLY MORNING SATELLITE IMAGERY SHOWS A NEGATIVELY TITLED
TROUGH WORKING EAST THROUGH THE PACNW AND NORTHERN GREAT BASIN
AS DRY CONDITIONS PREVAIL ACROSS EASTERN IDAHO OUT AHEAD OF IT.
A MIX OF ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WILL BUILD
IN WEST TO EAST BEGINNING AFTER SUNRISE THIS MORNING WITH
PRECIPITATION EXPANDING EAST THROUGHOUT THE DAYTIME HOURS. GIVEN
ONLY ~100-300 J/KG OF MUCAPE, ANY THUNDERSTORM DEVELOPMENT WILL
REMAIN ISOLATED IN NATURE WITH THE LATEST HREF MODEL PROBABILITY
OF THUNDER SHOWING A 10-20% CHANCE ACROSS MUCH OF OUR CWA WITH
BEST CHANCES IN THE CENTRAL MOUNTAINS AND ALONG THE MONTANA
DIVIDE AND IDAHO/UTAH BORDER REGION.
AS THIS TROUGH WORKS DIRECTLY OVERHEAD TONIGHT, SNOW LEVELS
WILL FALL TO VALLEY FLOORS AS A COLDER AIRMASS BUILDS IN
OVERNIGHT, SUPPORTING OVERNIGHT LOWS AT OR BELOW FREEZING. THIS
WILL BRING ABOUT A CHANGEOVER TO ALL SNOW HEADING INTO SUNDAY
MORNING AS BEST CHANCES SHIFT FURTHER NORTH AND EAST AS THIS
TROUGH WORKS EAST OVER THE CONTINENTAL DIVIDE. PRECIPITATION
TOTALS WITH THIS EVENT WILL REMAIN LIGHT WITH SNOW TOTALS ACROSS
OUR LOWER ELEVATIONS FURTHER NORTH AND EAST AROUND A T-2" WITH
1-6" IN THE MOUNTAINS. ACROSS THE LOWER SNAKE RIVER PLAIN AND
EASTERN MAGIC VALLEY IS WHERE WE ARE EXPECTING PREDOMINANT RAIN
WITH MORE LIMITED SNOW POTENTIAL.
AS THIS TROUGH WORKS EAST INTO WYOMING ON SUNDAY, A BRIEF
TRANSITORY RIDGE OF HIGH PRESSURE WILL BUILD IN FROM THE WEST AS
BEST CHANCES FOR SNOW SHIFT INTO THE MOUNTAINS AS PREDOMINANT
DRY CONDITIONS RETURN ACROSS THE SNAKE RIVER PLAIN. THIS BREAK
IN PRECIPITATION FOR MOST ON SUNDAY WILL BE SHORT-LIVED HOWEVER
AS OUR NEXT SYSTEM QUICKLY BUILDS IN FROM THE WEST SUNDAY NIGHT
INTO MONDAY WITH ANOTHER ROUND OF WIDESPREAD RAIN AND SNOW
CHANCES.
TEMPERATURES THIS WEEKEND WILL REMAIN NEAR SEASONAL NORMS WITH
HIGHS IN THE 40S/50S AND LOWS IN THE 20S/30S. WINDS WILL ALSO
REMAIN BREEZY BOTH DAYS WITH GUSTS PEAKING EACH AFTERNOON AROUND
20-40 MPH, STRONGEST ACROSS THE SNAKE RIVER PLAIN AND EASTERN
MAGIC/RAFT RIVER VALLEY REGION.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED AT 220 AM MDT SAT MAR 29 2025
MULTIPLE WEAKER SYSTEMS WILL BRING OCCASIONAL SHOWERS AND EVEN
A FEW THUNDERSTORMS OUR WAY THROUGH THE END OF NEXT WEEK. WE
WILL SEE A SHORT BREAK BETWEEN STORMS TUESDAY NIGHT/WEDNESDAY
BEFORE THE NEXT PERIOD OF MOISTURE BEGINS. AS WE HEAD INTO NEXT
WEEKEND, A BLOCKING PATTERN SETS UP OVER THE WESTERN STATES.
RIGHT NOW, THERE IS A PRETTY DECENT DIFFERENCE BETWEEN MODELS ON
WHERE THE LOW SETS UP SHOP. THE CLUSTER FORECASTS FIT NEATLY
INTO 3 CATEGORIES: NO CLOSED LOW (~25%), CLOSED LOW CENTERED
OVER NEVADA AND UTAH (~25%), AND CLOSED LOW NEAR THE FOUR
CORNERS (45-50%). THE GFS FITS INTO THE LAST SCENARIO, AND THE
ECMWF FITS THE SECOND ONE. THE FIRST "EVENT" FOR MONDAY-TUESDAY
YIELDS MOSTLY 6" OR LESS OF SNOW FOR THE MOUNTAINS. THE
EXCEPTIONS BEING THE SAWTOOTHS WHERE WE COULD SEE UPWARDS OF
9-10" IN SOME SPOTS, THE BEAR RIVER RANGE AND EASTERN HIGHLANDS
WHERE 10-16" ARE POSSIBLE ABOVE PASS LEVEL. LITTLE TO NO SNOW IS
FORECAST FOR LOWEST ELEVATIONS. SIMILARLY FOR WEDNESDAY-FRIDAY,
NO MUCH IF ANYTHING IMPACTFUL IS ANTICIPATED DOWN LOW. SNOW
AMOUNTS IN THE MOUNTAINS WILL BE ON THE LIGHT SIDE, WITH THE
SAWTOOTHS AND BEAR RIVER RANGE MAYBE HITTING 6". HIGH
TEMPERATURES MID-WEEK DIP DOWN INTO THE 40S FOR THE VALLEYS
BEFORE REBOUNDING A WEEK FROM NOW.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1133 AM MDT SAT MAR 29 2025
SHOWERS ARE CONTINUING TO WORK THEIR WAY THROUGH PART OF THE
EASTERN MAGIC VALLEY AND LOWER SNAKE RIVER PLAIN TODAY. MVFR TO
IFR CIGS WILL CONTINUE FOR THE NEXT FEW HOURS AROUND BYI AND PIH
BEFORE IMPROVING THIS AFTERNOON. WILL CONTINUE THE VCSH AT EACH
TAF SITE AND DROP CIGS AT IDA LIKE WE'VE SEEN AT BYI AND PIH SO
FAR AS THESE CLOUDS MOVE THROUGH, EVEN IF RAIN DOESN'T MAKE IT
TO THE GROUND. CIGS AT SUN CONTINUE TO HANG RIGHT ON THE EDGE OF
FEW TO SCT AT 010, SO WILL BE WATCHING THAT, TOO. AT BYI,
SHOWERS WILL COME TO AN END FIRST. WINDS WILL BE BREEZY AT TIMES
TODAY WITH GUSTS AROUND 20 KTS AT BYI, PIH, AND IDA. A FEW
SHOWERS WILL LINGER AROUND IDA AND DIJ EARLY SUNDAY, AND CAMS
ARE HINTING AT SOME LOW STRATUS/PATCHY FOG THROUGH THE SNAKE
RIVER PLAIN SUNDAY MORNING, TOO, SO HAVE SOME MVFR CIGS FOR PIH
AND IDA THEN.
PIH WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...DMH
SHORT TERM...MACKAY
LONG TERM...KEYES
AVIATION...AMM
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