062
FXUS65 KBOI 251550
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
950 AM MDT SAT OCT 25 2025
DISCUSSION
A BROAD AREA OF LIGHT TO MODERATE RAIN IS SPREADING EASTWARD
ACROSS THE SNAKE PLAIN. THE 12Z RAOB FROM BOI SAMPLED 0.66 INCH
OF PRECIPITABLE WATER - AROUND THE 90TH PERCENTILE FOR THE DATE.
EXPECTING SOME MODEST CLEARING TO OCCUR LATER THIS AFTERNOON
AHEAD OF THE BROAD STRATIFORM REGION OF RAIN, AND SHOULD LEAD TO
A NARROW AXIS OF DESTABILIZATION AHEAD OF A STRONG COLD FRONT.
MOST HI-RES MODELS ARE SHOWING A WELL-DEFINED FRONTAL BAND
MOVING EASTWARD LATER TONIGHT, AND WILL BE MOST PRONOUNCED
ACROSS EAST-CENTRAL OREGON INTO WEST-CENTRAL IDAHO. SPC IS
MAINTAINING A MARGINAL RISK OF SEVERE WIND GUSTS INCLUDING BAKER
CITY AND MCCALL, WITH THE PEAK PERIOD OF CONCERN BETWEEN
ROUGHLY 3 PM AND 9 PM PDT. STRONG WIND GUSTS ARE STILL LIKELY
ALL ALONG THE FRONTAL BAND, AS WELL AS AWAY FROM ANY CONVECTION,
AS A WIND ADVISORY GOES INTO EFFECT FOR SOUTHEAST OREGON AND
PARTS OF SOUTHWEST IDAHO STARTING AT 20Z. COOLER TEMPERATURES
ADVECT INTO THE REGION IN THE WAKE OF THE COLD FRONT, WITH SNOW
LEVELS FALLING TO 3500 FEET IN EASTERN OREGON TO 5000 FEET NEAR
THE NEVADA BORDER OVERNIGHT.
AVIATION
WIDESPREAD LIGHT PRECIPITATION WITH LOW CLOUDS BECOMES
MORE SCATTERED THIS AFTERNOON, BEFORE A LINE OF MODERATE-HEAVY
SHOWERS WITH EMBEDDED THUNDERSTORMS MOVES FROM E OR TO SW ID LATE
THIS AFTERNOON/EVENING. GUSTS TO 50 KT POSSIBLE ALONG THE LINE AS IT
MOVES FROM NW TO SE. SURFACE WINDS: S-SW 15-25 KT WITH GUSTS TO 30-
50 KT IN HIGHLANDS AND RIDGES, SE 10-30 KT IN THE SNAKE PLAIN. AREA-
WIDE W-SW 15-25 KT TONIGHT. WINDS ALOFT AT 10KFT MSL: SW 35-50 KT.
KBOI...LIGHT RAIN CONTINUES UNTIL ABOUT SAT/18Z, BRIEF PERIODS OF
DRIZZLE POSSIBLE UNTIL SUN/01Z WHEN A LINE OF STRONG WINDS, MODERATE-
HEAVY RAIN SHOWERS WITH EMBEDDED STORMS MOVES THROUGH. LOW CLOUDS
LIFT SLOWLY THIS MORNING, FOOTHILLS MAY BE OBSCURED. SURFACE WINDS:
BECOMING S-SE 10-15 KT WITH GUSTS UP TO 28 KT, BRIEFLY NW 10-20 KT
WITH BRIEF GUSTS UP TO 50 KT THIS EVENING AS THE HEAVY SHOWERS MOVE
THROUGH.
SUNDAY OUTLOOK...WIDESPREAD RAIN AND SNOW THROUGH SUNDAY. SNOW
LEVELS LOWERING TO 4 - 5.5 KFT MSL SUNDAY. AREAS OF MVFR/IFR FLIGHT
CATEGORIES IN LOW CLOUDS AND PRECIPITATION. MOUNTAINS FREQUENTLY
OBSCURED. PATCHY FOG/STRATUS IN VALLEYS THROUGH OVERNIGHT/EARLY
MORNING HOURS SUNDAY. SURFACE WINDS VARIABLE 5-15 KT, SW 5-15 KT
WITH GUSTS TO 25-30 KT AT KTWF/KJER AND IN SOUTHERN OWYHEE
COUNTY.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH MONDAY NIGHT...GULF OF ALASKA
UPPER TROUGH ON ITS WAY INTO OUR CWA. TWO SURFACE COLD FRONTS
EXPECTED: THE FIRST ONE ALREADY NEAR THE OR/ID BORDER AT 3 AM
MDT, AND A STRONGER ONE THIS AFTERNOON AND EARLY EVENING. THE
SECOND FRONT MAY BE ACCOMPANIED BY THUNDERSTORMS NORTH OF BOISE
(30 PERCENT CHANCE). THE PREVIOUSLY ISSUED WIND ADVISORY FOR
SOUTHEAST OR AND FAR SOUTHWEST ID REMAINS IN EFFECT BUT MOVED UP
AN HOUR TO 2 PM THROUGH 8 PM MDT. FORECAST GUSTS SHOULD EASILY
REACH ADVISORY CRITERIA IN SOUTHERN HARNEY AND MALHEUR COUNTIES
AND WESTERN OWYHEE COUNTY/ID, IF ANYTHING EVEN SLIGHTLY STRONGER
THAN FORECAST YESTERDAY. TOTAL PCPN TODAY THROUGH MONDAY NIGHT
HAS BEEN LOWERED SLIGHTLY -- NOW 0.75 TO 1.50 INCH IN IDAHO
NORTH OF THE SNAKE BASIN AND .20 TO .40 INCH ELSEWHERE, WITH
40 TO .75 INCH IN THE MOUNTAINS. TOTAL SNOWFALL HAS ALSO BEEN
LOWERED SLIGHTLY, NOW 4 TO 8 INCHES IN THE IDAHO MOUNTAINS NORTH
OF THE SNAKE BASIN. MCCALL/ID FORECAST TO RECEIVE 1.5 TO 2.0
INCHES SNOW ACCUMULATION, MOST OF IT FALLING SUNDAY NIGHT.
LITTLE CHANGE TO PREVIOUSLY FORECAST TEMPERATURES: HIGHS TODAY
45 TO 55 IN THE MOUNTAINS, 55 TO 65 IN THE SOUTHERN VALLEYS.
LOWS TONIGHT IN THE MID 20S TO LOWER 30S IN THE MOUNTAINS AND
MID 30S TO LOWER 40S IN THE VALLEYS. HIGHS SUNDAY AND MONDAY IN
THE 40S IN THE MOUNTAINS AND UPPER 40S TO MID 50S IN THE
VALLEYS. LOWS SUNDAY NIGHT IN THE 20S TO MID 30S, AND MONDAY
NIGHT 15 TO 25 IN THE MOUNTAINS AND HIGHER BASINS, AND MID 20S
TO LOWER 30S IN THE LOWER VALLEYS.
LONG TERM...TUESDAY THROUGH SATURDAY...THE FORECAST BEGINS TO DRY
OUT COME TUESDAY AS THE UPPER LEVEL TROUGH THAT BROUGHT ALL THE
ACTION IN THE SHORT TERM MOVES EAST OF OUR AREA. AS THIS TROUGH
MOVES OUT, ENSEMBLE ARE IN GENERALLY GOOD AGREEMENT OF OUR AREA
BEING PLACED UNDER THE NORTHERN PERIPHERY OF A RIDGE BUILDING OVER
THE GREAT BASIN. THIS SET UP PUTS US IN A POSITION WHERE SHORTWAVES
EMBEDDED IN THE JETSTREAM ALOFT COULD BRING PERIODIC CHANCES OF
PRECIPITATION. WEDNESDAY, DETERMINISTIC GUIDANCE IS RESOLVING ONE OF
THE AFOREMENTIONED SHORTWAVES GRAZING OUR NORTHERN AREA; THIS WAVE
WILL ALLOW FOR ISOLATED SHOWERS, MOSTLY CONFINED TO THE HIGHER
TERRAIN OF VALLEY COUNTY. TURNING THE ATTENTION TO LATE THIS COMING
WEEK. DETERMINISTIC GUIDANCE IS BEGINNING TO RESOLVE ANOTHER STREAM
OF INTEGRATED VAPOR TRANSPORT OVER OUR AREA AS A LOW DEEPENS IN GULF
OF ALASKA. THE GFS SOLUTION IS THE MOST BULLISH, WITH OUR ENTIRE
AREA UNDER THE MOISTURE PLUME BY SATURDAY (ALTHOUGH THE STRONGER
ADVECTION IS IN OUR NORTHERN COUNTIES); THE EURO SOLUTION IS A BIT
SLOWER AND KEEPS THE PLUME A FURTHER NORTH. IN EITHER CASE, BOTH OF
THE RESPECTIVE ENSEMBLES HAVE MEAN PWAT VALUES REACHING
05 TO .06 INCHES (WHICH WOULD BE AROUND THE 75TH PERCENTILE
CLIMATOLOGICALLY), SOME INDIVIDUAL ENSEMBLE MEMBERS REACH AROUND 1
INCH OF PWAT. WHILE THIS IS LATE IN THE PERIOD, AND LEAVES MUCH
UNCERTAINTY TO BE IRONED OUT IN THE DAYS TO COME, FOR NOW AM KEEPING
A 20-40% CHANCE OF PRECIPITATION IN OUR NORTHERN COUNTIES.
TEMPERATURES WILL REMAIN RIGHT AROUND NORMAL THROUGHOUT THE COMING
WEEK, LEANING ABOVE NORMAL COME SATURDAY.
PRELIMINARY POINT TEMPS/POPS
BAKER CITY 31 49 27 48 / 30 60 50 10
BOISE 41 53 36 51 / 90 40 50 0
BURNS 25 48 21 49 / 30 70 60 10
CALDWELL 40 55 35 53 / 70 40 50 0
FAIRFIELD 30 44 25 44 / 90 60 60 0
IDAHO CITY 29 48 26 48 / 100 70 80 10
JEROME 38 47 33 46 / 70 70 70 0
MCCALL 28 40 25 38 / 100 70 80 20
MOUNTAIN HOME 39 52 33 51 / 60 60 60 0
ONTARIO 39 55 33 54 / 60 30 50 0
ROME 33 52 27 53 / 70 70 60 0
TWIN FALLS 39 48 33 47 / 70 70 70 0
BOI WATCHES/WARNINGS/ADVISORIES
ID...WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM MDT THIS
EVENING IDZ015-029.
OR...WIND ADVISORY FROM 2 PM MDT /1 PM PDT/ THIS AFTERNOON TO 8 PM
MDT /7 PM PDT/ THIS EVENING ORZ061-063.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...JR
AVIATION.....JM
SHORT TERM...LC
LONG TERM....NF
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