340
FXUS65 KBOI 191632
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
932 AM MST WED NOV 19 2025
DISCUSSION
MORNING RADAR SHOWED A BAND OF RAIN SHOWERS
EXTENDING FROM NEAR CASCADE/ID THROUGH VALE/OR TO SOUTH OF
BURNS/OR. LATEST HRRR MOVES THE SHOWERS INTO THE WEST- CENTRAL
ID MOUNTAINS BY NOON AND OUT OF OUR CWA BY 2PM MST. EXTENSIVE
VALLEY STRATUS AND PATCHY FOG WILL DECREASE LATER TODAY AND
SHOULD BE LESS PREVALENT THURSDAY MORNING. NORTH PACIFIC COLD
FRONT NEAR 130W THIS MORNING WILL MOVE ONSHORE LATE TODAY AND AS
FAR INLAND AS EASTERN OR OVERNIGHT, THEN DISSIPATE IN WESTERN
ID THURSDAY MORNING. THE SUPPORTING UPPER TROUGH WILL ALSO SPLIT
WITH THE STRONGER PART AGAIN BECOMING A CLOSED LOW THAT MOVES
DOWN THE WEST COAST THURSDAY THROUGH FRIDAY. CURRENT FORECAST IS
SLIGHTLY COOLER THAN NBM TODAY AS THE STRATUS AND FOG MAY NOT
FULLY CLEAR THIS AFTERNOON ESPECIALLY IN HARNEY COUNTY. BEST
CHANCE OF PCPN WILL COME OVERNIGHT AND THURSDAY MORNING IN
EASTERN OR, AND THURSDAY IN WESTERN ID. CURRENT FORECAST IS ON
TRACK WITH THAT. NO UPDATES.
AVIATION
MVFR-LIFR IN AREAS OF FOG AND LOW STRATUS. SE OREGON
FOG WILL STICK AROUND THROUGH THE DAY, WITH SOME AREAS LIFTING
TO LOW STRATUS BEFORE FOG BECOMES POSSIBLE AGAIN TONIGHT. LIGHT
PRECIPITATION IS MOVING TO THE NE TODAY FROM KONO TO KMYL. LOW
CLOUDS MVFR-VFR ARE MOSTLY WITHIN AND TO THE SE OF THE
PRECIPITATION. SURFACE WINDS: LIGHT AND VARIABLE. WINDS ALOFT AT
10KFT MSL: SW 10-15 KT.
KBOI
LOW CLOUDS PERSIST THIS MORNING, BUT WILL REMAIN MVFR-VFR.
CLOUDS ARE EXPECTED TO BREAK LATE THIS AFTERNOON INTO THIS EVENING.
FOG/LOW STRATUS CHANCES TOMORROW ARE LOWER AT 30%. SURFACE WINDS:
LIGHT AND VARIABLE.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH FRIDAY NIGHT...LIGHT RAIN SHOWERS
AND STRATUS CONTINUE ACROSS MUCH OF THE REGION THIS MORNING
AHEAD OF A WEAK UPPER LEVEL TROUGH SLOWLY MOVING EAST. MAINLY
LOW STRATUS IS TRAPPED IN THE LOWER VALLEY THIS MORNING,
STRETCHING FROM BURNS, OREGON THROUGH THE WESTERN MAGIC VALLEY.
LIGHT SHOWERS ASSOCIATED WITH THE WEAK TROUGH HAVE HELPED
DISSIPATE THE LOW STRATUS IN BAKER VALLEY AND WILL LIKELY HELP
DISSIPATE THE STRATUS IN THE LOWER TREASURE VALLEY AND THE WEST
CENTRAL MOUNTAINS LATER THIS MORNING. FOG IS NOT EXPECTED TO BE
A WIDESPREAD ISSUE THIS MORNING ALONG THE I-84 CORRIDOR, THOUGH
LIGHT SHOWERS COULD BRING SOME WET ROADS DURING THE MORNING
COMMUTE.
STRATUS IS LIKELY TO REMAIN ACROSS MUCH OF THE WESTERN SNAKE
PLAIN INTO THE AFTERNOON BEFORE INCREASED WINDS ALOFT ASSOCIATED
WITH THE NEXT UPPER LEVEL SYSTEM HELP ERODE THE REMAINING
CLOUDS. THE ONLY AREA THAT MAY NOT SEE ANY IMPROVEMENT OR BRIEF
IMPROVEMENT WILL BE NEAR BURNS, WHERE STRATUS COULD REMAIN IN
PLACE THROUGH THE LATE EVENING. THIS WILL PRIMARILY AFFECT HIGH
TEMPERATURES TODAY, AS THE DELAYED STRATUS DISSIPATION COULD
KEEP THE VALLEY A FEW DEGREES COOLER THAN YESTERDAY.
THE NEXT SYSTEM WILL BRING SCATTERED SHOWERS ACROSS MUCH OF
THE AREA STARTING LATE TONIGHT AS THE UPPER LEVEL TROUGH
REACHES THE PACIFIC NORTHWEST COAST. THIS WILL CONTINUE THROUGH
THURSDAY AS A CLOSED LOW FORMS TO THE WEST AND MOVES SOUTH
SOUTHEAST INTO SOUTHERN CALIFORNIA/ARIZONA THURSDAY NIGHT.
THE BEST CHANCE FOR PRECIPITATION WILL BE THURSDAY MORNING WITH
A 20 TO 40 PERCENT CHANCE FOR LIGHT ACCUMULATIONS. SNOW LEVELS
REMAIN BETWEEN 6000 TO 7000 FEET MSL.
A WEAK RIDGE BUILDS ACROSS THE AREA FOLLOWING THE LOW MOVING
SOUTH FOR FRIDAY, WHICH COULD RETURN AN INVERSION FOR VALLEY
STRATUS AND FOG. PEAK DAYTIME VALLEY TEMPERATURES ARE EXPECTED
TO REMAIN IN THE LOWER 50S TODAY THROUGH FRIDAY, WITH NIGHTTIME
TEMPERATURES DROPPING INTO THE UPPER 30S. AGAIN, LOW CLOUDS,
ESPECIALLY THURSDAY AND FRIDAY MORNING, COULD KEEP TEMPERATURES
WARMER OVERNIGHT.
LONG TERM...SATURDAY THROUGH WEDNESDAY...AN UPPER-LEVEL RIDGE
AXIS WILL BE OVERHEAD TO BEGIN SATURDAY, WITH FLOW BEING WEAK
ALOFT. THIS SHOULD PERSIST OUR CURRENT PATTERN OF VALLEY
FOG/STRATUS OVERNIGHT AND EARLY MORNING. GETTING INTO SUNDAY,
THE CLOSED LOW THAT TRAVERSED CALIFORNIA WILL CONTINUE ITS TREK
EAST INTO THE FOUR CORNERS REGION, WITH AN UPPER-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE U.S./CANADA BORDER. THIS PROVIDES A
MORE ZONAL FLOW PATTERN INTO MONDAY. AT SOME POINT IN TIME AFTER
MIDDAY MONDAY, THE SHORTWAVE UPPER-LEVEL TROUGH TRAVERSING THE
U.S./CANADA BORDER WILL SAG A COLD FRONT THROUGH THE REGION. AS
IS TYPICAL THIS FAR OUT, TIMING IS QUITE VARIED BETWEEN LONG
RANGE MODELS, BUT THEY DO SEEM TO AGREE BETWEEN EVENING MONDAY
AND OVERNIGHT INTO TUESDAY. THIS WILL CREATE A CHANCE OF RAIN
AND SNOW OVER HIGHER TERRAIN, AND CLOSER TO NORMAL TEMPERATURES.
UPPER- LEVEL RIDGING LOOKS TO BUILD FOLLOWING INTO WEDNESDAY.
BOI WATCHES/WARNINGS/ADVISORIES
ID...NONE.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...LC
AVIATION.....JM
SHORT TERM...JDS
LONG TERM....CH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page