912
FXUS65 KPIH 152054
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
154 PM MST FRI NOV 15 2024
SHORT TERM
TONIGHT AND SATURDAY
WINTER WEATHER IS POISED TO IMPACT ALL OF EASTERN IDAHO TONIGHT
AND INTO SATURDAY AS A POTENT UPPER LEVEL FEATURE MOVES THROUGH
THE REGION. AFTERNOON SATELLITE IMAGERY ALREADY SHOWS WIDESPREAD
CLOUD COVER ACROSS THE REGION AND THIS WILL BE THE NORM FOR THE
NEXT 24 HOURS OR SO. RADAR IS BEGINNING TO PICKUP ON SOME LIGHT
RETURNS THIS AFTERNOON BUT THE LOWER LEVELS OF THE ATMOSPHERE
REMAIN DRY SO IT'LL STILL TAKE A FEW MORE HOURS BEFORE WE SEE ANY
APPRECIABLE PRECIP AT THE SURFACE. SPEAKING OF WHICH, THERE
REMAINS THE POSSIBILITY FOR A BRIEF PERIOD OF RAIN OR A RAIN/SNOW
MIX IN THE MAGIC VALLEY AND SNAKE PLAIN THIS AFTERNOON BUT THIS
SHOULD QUICKLY CHANGEOVER TO ALL SNOW AROUND SUNSET, IF NOT
SOONER. HASN'T BEEN MUCH CHANGE TO THE FORECAST THINKING AND
LATEST STORM TOTAL ACCUMULATIONS REMAIN SIMILAR TO THE PREVIOUS
FORECAST. THERE REMAINS SOME UNCERTAINTY IN THE PLACEMENT OF A
POTENTIAL CONVERGENCE BAND OF SNOWFALL LATER THIS EVENING AND HI-
RES MODELS STILL HAVE DIFFERENCES OF OPINION AS TO WHERE THIS WILL
SETUP. NEVERTHELESS, A WINTER WEATHER ADVISORY REMAINS IN EFFECT
FOR THE EASTERN MAGIC VALLEY, SOUTH HILLS, LOWER SNAKE AND THE
HIGHER TERRAIN AREAS AROUND THESE LOCATIONS. 1 TO 4 INCHES OF
SNOWFALL IS EXPECTED IN THESE AREAS WITH AMOUNTS CLOSER TO THAT
3-4 INCH RANGE, PERHAPS LOCALLY HIGHER, WHEREVER OUR CONVERGENCE
BAND ULTIMATELY SETS UP. IT'S STILL A WAIT AND SEE APPROACH AT
THIS TIME THOUGH AS WE STILL DON'T HAVE A GOOD FEEL FOR WHERE THAT
WILL BE. THE WINTER WEATHER ADVISORY ALSO CONTINUES ACROSS THE
BEAR RIVER RANGE AND AROUND MONIDA PASS WHERE 4-7 INCHES WILL BE
POSSIBLE.
NO MATTER WHERE THE HEAVIER BAND OF SNOW SETS UP, ANYONE IN THE
AFOREMENTIONED AREAS WILL STILL SEE SNOW. SO IF YOU'RE PLANNING TO
BE OUT AND ABOUT TONIGHT OR VERY EARLY SATURDAY MORNING, PLAN TO
ENCOUNTER WINTER DRIVING CONDITIONS. THIS WILL BE ESPECIALLY TRUE IN
THE EASTERN MAGIC VALLEY AND SOUTH HILLS WHERE WINDS WILL INCREASE
TONIGHT WITH GUSTS RANGING FROM 30 TO 40 MPH AT TIMES. OUTSIDE OF
THE ADVISORY, SNOW IS STILL EXPECTED EVERYWHERE ELSE JUST TO A
LESSER EXTENT WITH A TRACE TO 1 INCH IN THE VALLEYS AROUND STANLEY
AND SUN VALLEY, 1 TO 2 INCHES IN THE UPPER SNAKE PLAIN AND 2-4
INCHES ACROSS THE EASTERN HIGHLANDS. SNOWFALL IS EXPECTED TO
CONTINUE THROUGH LATE MORNING TOMORROW AND BEGIN TO TAPER OFF
REGIONWIDE. SKIES WILL BEGIN TO BRIEFLY CLEAR BY MID/LATE AFTERNOON
BUT IT WILL REMAIN COLD THROUGHOUT THE DAY WITH DAYTIME HIGHS
STRUGGLING TO GET MUCH ABOVE THE FREEZING MARK. SOME PLACES WILL,
BUT MOST SPOTS WILL ONLY TOP OUT IN THE MID TO UPPER 30S ON
SATURDAY. ANOTHER SYSTEM WILL IMPACT US FOR SUNDAY AND INTO THE
START OF THE WORKWEEK. MCKAUGHAN
LONG TERM
SUNDAY THROUGH FRIDAY
THROUGH SUNDAY, THE BULK OF THE MOISTURE FALLS ACROSS THE
SAWTOOTHS, WOOD RIVER VALLEY, AND SURROUNDING MOUNTAINS. MUCH
LIGHTER PRECIPITATION IS EXPECTED ACROSS THE REST OF THE CENTRAL
MOUNTAINS AND INTO THE ISLAND PARK AREA. TRENDS ARE A SLIGHT BIT
SLOWER, BUT STILL SPREAD PRECIPITATION ACROSS THE REST OF EASTERN
IDAHO THROUGH AROUND NOON MONDAY. UNTIL THE FRONT SWINGS THROUGH
MONDAY, WE CAN EXPECT UPSLOPE TO ENHANCE SNOWFALL FROM THE WOOD
RIVER VALLEY THROUGH ISLAND PARK...DOWNSLOPE TO CUT DOWN ON
AMOUNTS FROM BURLEY THROUGH THE TETON VALLEY. IT DOES LOOK PRETTY
BREEZY AHEAD OF THE FRONT, AND ESPECIALLY AFTER IT PASSES. SO THIS
STORM MIGHT HAVE A LITTLE BETTER POTENTIAL OF BLOWING SNOW. WE
WILL NEED WATCH TRENDS OVER THE NEXT 36 HOURS TO SEE IF THAT HOLDS
UP. SNOW WILL CONTINUE IN THE MOUNTAINS THROUGH TUESDAY MORNING
BEFORE TAPERING OFF. WE ARE STILLING FLUCTUATIONS FROM MODEL RUN
TO MODEL RUN IN TERMS OF PRECIPITATION AMOUNTS. THE LATEST THROUGH
STILL KEEPS AMOUNTS AT 0.33" OR LESS FOR MOST AREAS OUTSIDE OF
THE SAWTOOTHS AND EASTERN HIGHLANDS. AMOUNTS ACROSS THOSE
LOCATIONS ARE PUSHING 0.75-1.0" IN SOME SPOTS. THERE IS A 15-30%
CHANCE OF SEEING MORE THAN 1" WITH THE LATEST PROBABILITY
FORECASTS. IN TERMS OF SNOW, THAT EQUATES FROM A TRACE-4" FOR MOST
FOLKS. WE COULD SEE 5-12" ACROSS THE EASTERN HIGHLANDS AND
SAWTOOTHS WITH LOCALLY HIGHER AMOUNTS. THERE IS A 40-60% CHANCE OF
MORE THAN 12" ACROSS THE SPINE OF THE SAWTOOTHS AND THE HIGHER
ELEVATIONS AROUND ISLAND PARK. WE DO EXPECT THESE NUMBERS TO
BOUNCE AROUND A BIT MORE HEADING INTO THE WEEKEND. TRENDS HEADING
THROUGH NEXT WEEK CONTINUE TO SHOW A SHIFT IN THE PATTERN ACROSS
THE PACIFIC AND LOWER 48. THE BLOCKING PATTERN IS STILL FORECAST,
BUT IT SEEMS THE STRENGTH OF THE RIDGE AND LOCATION ARE TRENDING
SOUTH (SHOWING A WEAKER RIDGE) AND EAST (SHIFTING THE CENTER EAST
OF THE DIVIDE). INITIALLY, THIS TREND SHOWS UP IN 90-95% OF THE
CLUSTER FORECASTS. BY FRIDAY, THE CLUSTER FORECASTS ARE ALL OVER
THE PLACE. YOU HAVE AROUND 40% OF THE CLUSTERS SHOWING THE WEAKER
RIDGE IN PLACE, A THIRD HAVE A STRONGER RIDGE STILL AROUND, 15%
KEEP THE RIDGE CENTERED TO THE WEST, AND THE REST HAVE A BROAD
TROUGH/LOW OVER THE WESTERN AND CENTRAL U.S. THE LATEST BLEND OF
MODELS FOLLOWS BASICALLY THE WEAKER RIDGE SCENARIO AND KEEP SOME
MOISTURE THE REST OF THE WEEK AROUND CENTRAL AND EASTERN IDAHO,
ESPECIALLY THE CENTRAL MOUNTAINS AND EASTERN HIGHLANDS. THIS ALSO
REFLECTS WARMER TEMPERATURES POTENTIALLY IN THE FORECAST. KEYES
AVIATION
ALL TERMINALS CAN EXPECT GRADUALLY DETERIORATING CONDITIONS OVER
THE HOURS AHEAD AS A ROUND OF SNOWFALL IS EXPECTED REGIONWIDE.
KSUN WILL BE THE TERMINAL LIKELY LEAST IMPACTED BY THIS BUT THERE
COULD STILL BE A BRIEF PERIOD OF SNOW RELATED IMPACTS. KPIH, KBYI,
KIDA, KDIJ WILL LIKELY BE THE MOST PROBLEMATIC TERMINALS OVER THE
NEXT 6-18 HOURS WITH A PERIOD OF SNOWFALL EXPECTED IN THESE
AREAS. MVFR TO IFR CIGS AND VSBYS WILL BE POSSIBLE THROUGHOUT MUCH
OF THE EVENING AND OVERNIGHT WITH THINGS SLOWLY IMPROVING AFTER
DAYBREAK SATURDAY. ONCE GREATER CONFIDENCE EXISTS WITH PLACEMENT
AND TIMING OF HEAVIER SNOW BANDS, TEMPOS OR PREVAILING IFR WILL
LIKELY BE NEEDED TO ACCOUNT FOR THE PERIOD OF WORST CONDITIONS.
FOR NOW, HAVE PREVAILING MVFR CONDITIONS IN PLACE FOR THESE SITES
FOR A GOOD CHUNK OF THE PERIOD BUT AGAIN, IFR IS PROBABLE (IF NOT
LIKELY) FOR AT LEAST SOME PERIOD OF TIME. WINDS LOOK BREEZIEST AT
KBYI WHERE 15-25 KTS IS LIKELY; ELSEWHERE, IT'LL FALL MORE IN THE
10-15 KT RANGE. MCKAUGHAN
PIH WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM MST
SATURDAY FOR IDZ054-058-060.
WINTER WEATHER ADVISORY UNTIL 8 AM MST SATURDAY FOR IDZ055>057-
067.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page