588
FXUS65 KPIH 292354
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
554 PM MDT SAT MAR 29 2025
KEY MESSAGES
- RAIN AND SNOW SHOWERS WILL SLOWLY DIMINISH THIS EVENING,
CONTINUING THROUGH SUNDAY MORNING IN THE MOUNTAINS EAST OF
I-15 TO THE WYOMING BORDER. OVERALL IMPACTS WILL BE VERY
LIMITED.
- A BRIEF RIDGE OF HIGH PRESSURE ON SUNDAY WILL BRING A RETURN
TO MOSTLY DRY CONDITIONS ACROSS THE SNAKE RIVER PLAIN AS
LOCALIZED SNOW SHOWERS CONTINUE IN SOME MOUNTAIN AREAS.
- DAILY PRECIPITATION CHANCES WILL INCREASE FOR EARLY NEXT WEEK
AS A SERIES OF PACIFIC SYSTEMS SUPPORT A MIX OF RAIN/SNOW
SHOWERS AND NEAR NORMAL TO BELOW NORMAL TEMPERATURES.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 117 PM MDT SAT MAR 29 2025
SATELLITE IMAGERY SHOWS WEAKLY CLOSED LOW SPINNING THROUGH IDAHO
EARLY THIS AFTERNOON. MIX OF CLOUDS AND SUN HAVE ALLOWED FOR A
FEW SHOWERS TO DEVELOP AHEAD OF THE LOW, AND A FEW THUNDERSTORMS
WILL STILL BE POSSIBLE THIS AFTERNOON IN AREA OF BEST
INSTABILITY NORTH OF THE LOW. SNOW LEVELS HAVE RISEN SLIGHTLY
WITH THE WARMER TEMPERATURES OF THE DAY, RISING TO 6000-6500 FT
AHEAD OF THE TROUGH AXIS ASSOCIATED WITH THE LOW, AND 5500-6000
FT BEHIND IT THIS AFTERNOON. LOWER ELEVATIONS SHOULD SEE RAIN,
AND THOUGH MOST OF THE SNAKE PLAIN SHOULD BE THE DRIEST OF EAST
IDAHO, CAN'T REALLY RULE OUT A SHOWER ANYWHERE TODAY. SNOW
LEVELS FALL BACK TO VALLEY FLOORS OVERNIGHT TONIGHT WITH LOW
TEMPERATURES BACK TO OR JUST BELOW FREEZING. WRAP AROUND
MOISTURE LINGERS ACROSS THE CENTRAL MOUNTAINS AND ALONG THE
DIVIDE OVERNIGHT, WHILE THE TROUGH STILL LINGERS ALONG THE
EASTERN HIGHLANDS. THERE IS STILL A VERY LOW CONFIDENCE CHANCE
OF LIGHT SNOWS FROM THE WRAP AROUND MOISTURE MAKING IT INTO THE
NORTHERN PORTIONS OF THE SNAKE PLAIN, WITH THE NAM NEST BRINGING
A VERY HINT OF LIGHT PRECIP AS FAR SOUTH AS THE MUD LAKE AREA.
THE LATEST RUNS OF THE OTHER HIGH-RES MODELS HAVE REMAINED DRY
THAT FAR SOUTH, SO HAVE LEFT OUT FOR NOW, BUT THIS MAY BE AN
IMPACT TO WATCH FOR GOING FORWARD INTO TONIGHT. SNOW TOTALS
REMAIN LIGHT, MAXING OUT ROUGHLY 3-5" HIGHER ELEVATIONS ALONG
THE MONTANA BORDER.
SUNDAY STARTS OUT DRY FOR MOST AREAS, BUT WEAK SHORTWAVE EJECTS
NORTHEAST ACROSS IDAHO VERY LATE IN THE DAY. THERE SHOULD BE
ENOUGH SUNSHINE AVAILABLE DURING THE AFTERNOON, THAT AFTERNOON
BUILD-UPS OVER THE SNOWPACK COULD DROP A WEAK SHOWER ACROSS
HIGHER TERRAIN. NOT A SURPRISE THAT THE NBM DEVELOPED BARELY-
THERE 15% POPS ACROSS HIGHER TERRAIN THIS TIME OF YEAR AHEAD OF
THIS SHORTWAVE FEATURE FOR SUNDAY AFTERNOON. BETTER POP AND MORE
ORGANIZED QPF DEVELOP DURING THE EVENING AND OVERNIGHT ACROSS
EAST IDAHO LEADING INTO EARLY NEXT WEEK. TEMPERATURES WARM UP
FOR OVERNIGHT LOWS, SO RAIN WOULD BE EXPECTED AT MOST LOWER
ELEVATIONS.
LONG TERM /MONDAY THROUGH SATURDAY/
ISSUED AT 117 PM MDT SAT MAR 29 2025
THE EXTENDED FORECAST REMAIN AN ACTIVE ONE AS WE WRAP UP MARCH AND
HEAD INTO APRIL. MONDAY WILL STILL BE A "WARMER" DAY WITH HIGHS IN
THE LOW 50S IN THE EASTERN MAGIC VALLEY AND SNAKE RIVER PLAIN WITH
PRECIPITATION CHANCES MAKING THEIR RETURN EARLY MONDAY MORNING AS
THE FIRST WAVE OF ENERGY IS EJECTED FROM A LOW SITTING OFF THE COAST
OF THE PNW MOVES THROUGH OUR AREA. WITH TEMPERATURES WELL ABOVE
FREEZING ON MONDAY AND FALLING TO VERY NEAR FREEZING BY TUESDAY
MORNING, VERY LITTLE TO NO SNOW ACCUMULATION IS EXPECTED DOWN IN THE
EASTERN MAGIC VALLEY AND SNAKE RIVER PLAIN AND ANY SNOW THAT DOES
FALL IN THE UPPER SNAKE RIVER PLAIN WOULD MOSTLY LIKELY STAY BELOW
AN INCH. AS YOU WOULD VENTURE TO GUESS, SNOW TOTALS WILL BE
INCREASING AS YOU GO UP IN ELEVATION WITH THE NBM SHOWING ABOUT A 20
TO 30 PERCENT CHANCE OF AT LEAST 6 INCHES OF SNOW AT GALENA SUMMIT,
A 50 TO 60 PERCENT CHANCE OF AT LEAST 6 INCHES OF SNOW IN THE ISLAND
PARK AREA, AND A 50 TO 60 PERCENT CHANCE OF AT LEAST 8 INCHES OF
SNOW AT EMIGRATION SUMMIT IN THE 48 HOURS FROM MONDAY TO WEDNESDAY
MORNING. THE COLD FRONT THAT COMES THROUGH ON MONDAY WILL BRING
AFTERNOON HIGHS BACK DOWN INTO THE 40S FOR TUESDAY, WEDNESDAY, AND
THURSDAY. LOOK FOR WIND GUSTS TO INCREASE ON TUESDAY, TOO, INTO THE
35 TO 40 MPH RANGE IN THE EASTERN MAGIC VALLEY AND LOWER SNAKE RIVER
PLAIN. WE WILL SEE A BRIEF LULL IN THE ACTIVITY ON WEDNESDAY, BUT
THEN THE NEXT SYSTEM MOVES RIGHT INTO FOR THE SECOND HALF OF THE
WEEK, SO THE OVERALL ACTIVE PATTERN CONTINUES. MODELS ARE SHOWING A
PRETTY SOLID BLOCKING PATTERN SETTING UP OVER THE WEST NEXT WEEKEND
TO GIVE US A BREAK FROM THE PRECIPITATION, BUT WE WILL HAVE TO SEE
HOW THE FORECAST HOLDS BETWEEN NOW AND THEN.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 554 PM MDT SAT MAR 29 2025
THE "MOST-LIKELY" SCENARIO FOR AVIATION ACROSS SOUTHEAST IDAHO IS
LOW-IMPACT, VFR CONDITIONS OVER THE NEXT 24-36 HOURS...BUT WITH SOME
MESSINESS AND PERHAPS BRIEF EXCEPTIONS. TRENDS FOR THE EVENING INTO
THE FIRST PART OF THE OVERNIGHT WILL GENERALLY BE DIMINISHING
SHOWERS, VERY SLOWLY DECREASING WINDS, AND CLOUD COVER TRENDING
TOWARD SCT. WE LARGELY FOCUSED ON REFINING TIMING ON END OF VCSH AND
STEPPING THE WINDS DOWN IN THE 00Z TAFS JUST ISSUED. COULD STILL SEE
A BRIEF PERIOD OF -SN AT KDIJ SOMETIME BETWEEN 04Z/10PM AND 09Z/3AM
PER A COUPLE OF THE CAMS, SO KEPT THE TEMPO GOING THERE. THE HREF
DOES SUPPORT A FAIRLY MOIST LOW-LEVEL AIRMASS TONIGHT WITH GOOD
COVERAGE OF RH VALUES OVER 90%, AND BOTH THE HRRR AND NBM ARE
RESPONDING WITH SOME COMBINATION OF LOW STRATUS AND/OR BR/FOG, BUT
IT'S A REALLY MESSY SETUP. A BREAK IN HIGH-LEVEL CLOUDS FOR THE
FIRST HALF OF THE NIGHT MAY ALLOW FOR A PERIOD OF BETTER RADIATIONAL
COOLING, BUT ANOTHER SHIELD OF SCT TO BKN HIGH-LEVEL CLOUDS IS
FORECAST TO ARRIVE FROM THE PACIFIC BY EARLY MORNING, WHICH WOULD
TEND TO FAVOR STRATUS OVER FOG AND MAY EVEN KEEP ANY STRATUS
DEVELOPMENT A BIT HIGHER OFF THE SFC. MEANWHILE, BOTH THE HRRR AND
NBM FOCUS BEST FOG/STRATUS POTENTIAL OUT OVER THE SNAKE PLAIN AND
SHOSHONE LAVA BEDS NE TO THE ARCO DESERT, KEEPING KBYI, KPIH, AND
KIDA RIGHT ON THE EDGE. AND, A TREND TOWARD BREAKING ANY DEVELOPMENT
UP IS NOTED EARLY TO MID-MORNING SUNDAY...PERHAPS IN RESPONSE TO THE
ADVANCING HIGH-LEVEL CLOUD SHIELD. ALSO MEANWHILE, MOS GUIDANCE
SHOWS NO HITS TO CIGS/VSBYS ANYWHERE, AND SFC WINDS STAY A BIT
ELEVATED FOR A GOOD PORTION OF THE NIGHT AT KPIH AND KIDA WHICH
ISN'T FAVORABLE FOR FOG. ALL THINGS CONSIDERED...WE HAVE NO
CONFIDENCE ON HOW THIS WILL PLAY OUT. WENT AHEAD AND HINTED AT A
PERIOD OF LOWER CLOUDS (FEW015) AT KBYI/KPIH/KIDA ROUGHLY TIMED OUT
WITH NBM/HRRR GUIDANCE FOR START TIMES, AND JUST LET IT RIDE UNTIL
AFTERNOON WIND/VCSH FM GROUPS KICK IN SUNDAY. SUNDAY IN SOME
RESPECTS SHOULD BROADLY SERVE AS A BREAK BETWEEN SYSTEMS, BUT THERE
IS JUST ENOUGH MOISTURE/INSTABILITY THAT WE ARE CARRYING SOME
GENEROUS VCSH SUNDAY AFTERNOON. OVERALL FORECAST CONFIDENCE IS HIGH
IN LOW-IMPACT, VFR CONDITIONS AT THE TAF TERMINALS AFTER ABOUT 16-
17Z/10-11AM SUNDAY, AND WINDS REGIONWIDE LOOK LIGHTER SUNDAY
AFTERNOON WITH JUST THE NORMAL DIURNAL PATTERN AT KSUN (NO
CROSSWINDS). LOOKING AHEAD, MONDAY WILL FEATURE A RETURN OF MORE
WIDESPREAD RAIN/SNOW, AND LOWER CIGS, AS A MORE SUBSTANTIAL LOW
PRESSURE SYSTEM MOVES INTO THE REGION.
PIH WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...DMH
LONG TERM...AMM
AVIATION...KSMITH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page