052
FXUS65 KBOI 250928
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
328 AM MDT SAT OCT 25 2025
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.
AVIATION
INCREASING LOW TO MID CLOUDS AND PRECIPITATION IN
E-OREGON CONTINUING TO MOVE EAST INTO SW-IDAHO THROUGH THE
MORNING. MVFR CONDITIONS POSSIBLE IN PRECIP AND LOW CEILNGS.
LLWS THIS MORNING. ISOLATED THUNDERSTORMS DEVELOPING AFTER 20Z,
CAPABLE OF GUSTS TO 50 KT. SURFACE WINDS: S-SE 10-15 KT WITH
GUSTS 20-25 KT THIS MORNING, BECOMING SW 10-15 KT WITH GUSTS
30-40 KT. WINDS ALOFT AT 10KFT MSL: SW 35-50 KT.
KBOI...VFR. INCREASING LOW CLOUDS THROUGH THE MORNING WITH
PRECIPITATION AFTER 10Z. MVFR CONDITIONS POSSIBLE IN PRECIP
AND FOOTHILLS OBSCURED. LLWS POSSIBLE THIS MORNING. A 30%
CHANCE OF THUNDERSTORMS IMPACTING TERMINAL BETWEEN SUNDAY/00Z
TO 04Z. SURFACE WINDS: VARIABLE UNDER 10 KT EARLY THIS MORNING,
BECOMING S-SE 10-15 KT WITH GUSTS UP TO 28 KT AFTER 17Z.
SUNDAY OUTLOOK...WIDESPREAD RAIN AND SNOW LATE SATURDAY THROUGH
SUNDAY. SNOW LEVELS LOWERING TO 3500-5000 FEET MSL SUNDAY. AREAS
OF MVFR/IFR FLIGHT CATEGORIES IN LOW CLOUDS AND PRECIPITATION.
MOUNTAINS FREQUENTLY OBSCURED. PATCHY FOG 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.
PRELIMINARY POINT TEMPS/POPS
BAKER CITY 57 31 49 27 / 100 30 60 50
BOISE 63 41 53 36 / 70 90 40 50
BURNS 58 25 48 21 / 90 30 70 60
CALDWELL 64 40 55 35 / 60 70 40 50
FAIRFIELD 52 30 44 25 / 70 90 60 60
IDAHO CITY 56 29 48 26 / 100 100 70 80
JEROME 58 38 47 33 / 10 70 70 70
MCCALL 45 28 40 25 / 100 100 70 80
MOUNTAIN HOME 64 39 52 33 / 20 60 60 60
ONTARIO 64 39 55 33 / 80 60 30 50
ROME 63 33 52 27 / 50 70 70 60
TWIN FALLS 61 39 48 33 / 10 70 70 70
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
SHORT TERM...LC
LONG TERM....NF
AVIATION.....NF
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