521
FXUS65 KPIH 182053
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
153 PM MST WED DEC 18 2024
SHORT TERM
TONIGHT AND THURSDAY
AFTERNOON SATELLITE IMAGERY SHOWS A WEAK SHORTWAVE MOVING WELL TO
THE NORTH OF THE AREA ACROSS WESTERN MONTANA. THIS FEATURE IS
PUSHING SOME ADDITIONAL CLOUDS THROUGH EASTERN IDAHO BUT NOT MUCH
IN THE WAY OF APPRECIABLE PRECIPITATION. THERE REMAINS A SLIGHT
CHANCE WE GET A BRIEF SNOW SHOWER ACROSS THE CENTRAL MOUNTAINS AND
NEAR THE MONTANA DIVIDE BUT FOR THE MOST PART, THINGS WILL REMAIN
DRY. HI-RES CAMS AREN'T TOO EXCITED ABOUT THE POTENTIAL BUT THE
FORECAST AT LEAST SHOWS A BRIEF PERIOD WHERE SOME PRECIPITATION
COULD BE REALIZED. FOR THE OVERNIGHT, THE ONLY WEATHER CONCERN
WILL BE FOR STRATUS/FOG ACROSS PARTS OF THE UPPER SNAKE PLAIN,
UPPER SNAKE HIGHLANDS AND INTO THE ARCO DESERT. THERE REMAINS
ABUNDANT MOISTURE IN THE LOWER LEVELS IN THESE AREAS AND WITH HIGH
PRESSURE BUILDING OVER THE REGION, THERE IS AT LEAST SOME
POTENTIAL. FORECAST SHOWS AT LEAST SOME PATCHY FREEZING FOG
WORDING AS SUCH. HIGH PRESSURE RIDGE CONTINUES TO BUILD OVER THE
REGION TOMORROW KEEPING THINGS DRY AND TEMPERATURES ON THE WARMER
SIDE OF NORMAL. MCKAUGHAN
LONG TERM
FRIDAY THROUGH NEXT WEDNESDAY
NO CHANGES NOTED IN THE LONG-TERM AS A RIDGE OF HIGH PRESSURE
BRINGS QUIET WEATHER THROUGH SATURDAY, FOLLOWED BY A TRANSITION
BACK TO AN ACTIVE PATTERN WITH SHORTWAVE TROUGHS BRINGING
ELEVATION-DEPENDENT RAIN AND SNOW CHANCES SATURDAY NIGHT AND
SUNDAY, THEN AGAIN SUNDAY NIGHT AND MONDAY, THEN AGAIN TUESDAY
NIGHT AND WEDNESDAY. THESE FEATURES CONTINUE TO LOOK RELATIVELY
SHORT-DURATION WITH LITTLE WIND AND ONLY MODEST RAINFALL/SNOWFALL
AMOUNTS, PERHAPS SUPPORTING SLICK CONDITIONS AT SOME MOUNTAIN
PASSES WITH EACH WAVE. THE TUESDAY NIGHT/WEDNESDAY SYSTEM
CONTINUES TO LOOK THE WETTEST, BUT WITH HIGH TEMPERATURES TOPPING
OUT IN THE UPPER 30S TO LOWER 40S EACH DAY OVER THIS ENTIRE
PERIOD, CHANCES FOR A WHITE CHRISTMAS DO NOT LOOK GREAT FOR MOST
LOWER-ELEVATION POPULATION CENTER...ESPECIALLY FROM THE SNAKE
PLAIN SOUTH AND WEST.
AVIATION
VFR CONDITIONS HAVE GENERALLY RETURNED TO THE REGION AND SHOULD
DOMINATE THE TAF PERIOD. QUITE A BIT OF MOISTURE REMAINS IN THE LOW-
LEVELS, SO OF COURSE WE NEED TO TALK ABOUT FOG AND LOW STRATUS
POTENTIAL. ON THE ONE HAND...IMPACTS WERE A BIT LESS THAN FORECAST
THIS MORNING, TONIGHT AND THURSDAY MORNING MAY BE SLIGHTLY DRIER,
WINDS MAY REMAIN A TOUCH MORE ELEVATED/BREEZIER AT LEAST INTO EARLY
TONIGHT, AND THERE ISN'T STRONG SUPPORT FOR FOG/STRATUS IN MOST OF
OUR GUIDANCE. ON THE OTHER HAND, THE HRRR AND NBM STILL DO FEATURE
SOME DEVELOPMENT OUT OVER THE SNAKE PLAIN PERHAPS GETTING CLOSE TO
KPIH AND KIDA, SURFACE RH VALUES WILL REMAIN QUITE SATURATED, AND
OVERALL CLOUD COVER AT ALL LEVELS SHOULD BE LESS TONIGHT, WHICH
CONCEPTUALLY COULD SUPPORT BETTER RADIATIONAL COOLING AND GIVE FOG A
BETTER CHANCE TO COALESCE. THIS ALL LEADS TO A SOMEWHAT LOW-
CONFIDENCE FORECAST FOR CIGS/VSBYS. BEST POTENTIAL APPEARS TO BE AT
KIDA, SO FOR NOW HAVE HINTED AT VCFG AND SCT008 STARTING AROUND
09Z/2AM. FUTURE SHIFTS WILL CONTINUE TO EVALUATE THIS POTENTIAL.
KPIH AND KDIJ CAN'T COMPLETELY BE RULED OUT EITHER, WHILE CONFIDENCE
IS HIGHER IN NO FOG/STRATUS IMPACTS FOR KBYI AND KSUN.
PIH WATCHES/WARNINGS/ADVISORIES
NONE.
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