636
FXUS65 KBOI 261612
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1012 AM MDT SUN OCT 26 2025
DISCUSSION
REGIONAL SATELLITE AND RADAR IMAGERY SHOWING A
FAST AND MOIST WESTERLY FLOW EXTENDING FROM THE PACIFIC INTO
NORTHERN CA AND NV WITH A WEAK UPPER WAVE EVIDENT ALONG THE SW
OREGON COAST THIS MORNING. PRECIPITATION DEVELOPMENT IS FOCUSED
ALONG THE SOUTHERN OR/ID BORDER THIS MORNING WILL LIFT NORTH
THROUGH THE DAY AHEAD OF THE EASTWARD MOVING WAVE. THE UPPER
WAVE AND ACCOMPANYING COLD FRONT WILL CROSS SE OREGON THIS
EVENING (2000-2400MT), AND SW IDAHO OVERNIGHT (2300-0400MT).
EMBEDDED HEAVIER SHOWERS AND A PERIOD OF GUSTY WINDS WILL
ACCOMPANY THE PASSAGE WITH GUSTS TO 40 MPH POSSIBLE. WINDS WILL
REMAIN GUSTY FOR A FEW HOURS BEHIND THE FRONT ACROSS HIGHER,
OPEN TERRAIN OF SE OREGON, AND THE WESTERN MAGIC VALLEY/CAMAS
PRAIRIE. THE BEST CHANCE FOR ACCUMULATING SNOW COMES THIS
EVENING THROUGH MONDAY MORNING WITH SNOW LEVELS OF 4500-6000
FEET. STILL LOOKING AT UP TO AN INCH IN MTN VALLEYS WITH 2-5
INCHES ABOVE 6000 FEET. CURRENT FORECAST IS ON TRACK THROUGH
TONIGHT.
AVIATION
WIDESPREAD LIGHT PRECIPITATION IN FAR SE OR AND SW
ID WILL MOVE NORTH, REACHING THE TREASURE VALLEY AROUND NOON
AND KBKE/KMYL LATE THIS AFTERNOON/EARLY EVENING. PRECIP BECOMES
MORE SHOWERY AROUND SUNSET, WITH A LINE OF MODERATE RAIN/SNOW
SHOWERS DEVELOPING IN E OR AND MOVING TO W-CENTRAL ID. SNOW
LEVELS TODAY REMAIN AROUND 4-6 KFT MSL. IFR-LIFR IN MTN SNOW AND
MVFR-IFR IN VALLEY RAIN. SURFACE WINDS: SE-SW 5-15KT . WINDS
ALOFT AT 10KFT MSL:
SW-W 15-25KT.
KBOI...LIGHT STEADY RAIN ARRIVES JUST AFTER NOON, CONTINUING
THROUGH MON/02Z WHEN THE RAIN BECOMES SHOWERY AND SPORADIC.
CEILINGS DROP TO MVFR WHEN THE STEADY RAIN ARRIVES, WITH
POSSIBLE BRIEF REDUCTIONS TO IFR. RAIN LEAVES THE AREA AROUND
MON/09Z. SURFACE WINDS ARE SE 5-15 KT, BECOMING NW 10-15 KT
AROUND MIDNIGHT.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH TUESDAY NIGHT...SATURDAY EVENING'S
COLD FRONT MOVED RAPIDLY EASTWARD BUT ONLY AS FAR SOUTH AS THE
NV BORDER, WHERE IT HAS STALLED. MEANWHILE, VERY STRONG WESTERLY
FLOW OFF THE PACIFIC ALONG 40N WILL REDEVELOP SHOWERS IN OUR
SOUTHERN ZONES TODAY THROUGH EARLY THIS EVENING BEFORE EXITING
EASTWARD. MODELS ALSO MOVE A WEAK IMPULSE ACROSS OUR NORTHERN
ZONES THIS AFTERNOON AND EVENING. HRRR MODEL SHOWS A BRIEF
SURGE OF STRONGER WEST/NORTHWEST SURFACE WINDS AND MORE SHOWERS
AT THAT TIME, INDICATING PASSAGE OF A SECONDARY COLD FRONT, SO
OUR FORECAST INCLUDES THAT, TOO. LOWER ELEVATIONS SHOULD DRY
OUT THIS EVENING WHILE MOIST WESTERLY FLOW ALOFT CONTINUES TO
BRING SNOW SHOWERS TO THE IDAHO MOUNTAINS UNTIL EARLY MONDAY
MORNING. MCCALL SHOULD STILL GET ABOUT AN INCH OF SNOW SUNDAY
NIGHT, LESS THAN PREVIOUSLY FORECAST. LOW TEMPS MONDAY MORNING
WILL BE COLDER WITH THE UPPER TROUGH OVERHEAD, BUT WINDS AND
CLOUDS WILL PREVENT FULL RADIATIONAL COOLING. THAT WILL COME
TUESDAY MORNING WHEN WINDS ARE CALMER AND SKIES HAVE CLEARED.
LOW TEMPS TUESDAY WILL BE IN THE TEENS IN THE MOUNTAINS AND 20S
TO 32 IN THE VALLEYS. ANY SITE THAT HAS NOT YET REACHED FREEZING
CAN EXPECT TO FREEZE TUESDAY MORNING. TUESDAY LOOKS SUNNY, BREEZY,
AND COOL UNDER STRONG NORTHWEST FLOW ALOFT. TUESDAY NIGHT WILL
BEGIN A WARMING TREND AS THE NEXT UPPER RIDGE APPROACHES FROM
THE PACIFIC.
LONG TERM...WEDNESDAY THROUGH SUNDAY...GENERALLY DRY THROUGH
THE END OF THE WORK WEEK AS OUR AREA SITS UNDER THE PERIPHERY
OF A BUILDING RIDGE OVER THE GREAT BASIN. HOWEVER, BEING ON THE
PERIPHERY OF THE RIDGE PLACES US UNDER THE TRACK OF POTENTIAL
SHORTWAVES PROPAGATING THROUGH THE JET STREAM. THE FIRST OF
THESE SHORTWAVES IS LOOKING TO GRAZE OUR AREA TO THE NORTH
EARLY WEDNESDAY MORNING, THIS WILL GIVE WAY TO ISOLATED SHOWERS
MOSTLY CONFINED TO VALLEY COUNTY. FRIDAY INTO THE WEEKEND THE
SIGNAL REMAINS OF ANOTHER STREAM OF PACIFIC MOISTURE MAKING ITS
WAY INTO THE NORTHWEST/INTERMOUNTAIN WEST. UNCERTAINTY STILL
REMAINS ON WHERE THIS PLUME WILL SET UP. ROUGHLY 30% OF ENSEMBLE
MEMBERS (MOSTLY OUT OF THE GFS SUITE) FLATTEN OUT THE RIDGE AND
PUT THE MOISTURE OVER MUCH OF OUR AREA, WHEREAS THE REMAINING
70% KEEP THE HIGHER AMPLITUDE RIDGE AND SHUTTLE THE MOISTURE
MORE TO OUR NORTH. WHILE SOME UNCERTAINTY REMAINS, AM KEEPING
ELEVATED CHANCES OF PRECIPITATION PRIMARILY NORTH OF THE SNAKE
PLAIN. TEMPERATURES THROUGH THE LONG TERM WILL BE SEASONABLE
FOR THIS TIME OF YEAR, BUT WILL BEGIN LEANING ABOVE NORMAL BY
THE WEEKEND.
PRELIMINARY POINT TEMPS/POPS
BAKER CITY 27 48 23 52 / 80 0 0 0
BOISE 35 51 32 56 / 80 0 0 0
BURNS 21 48 20 55 / 50 0 0 0
CALDWELL 35 53 29 57 / 80 0 0 0
FAIRFIELD 27 42 12 47 / 90 0 0 0
IDAHO CITY 27 46 18 54 / 100 0 0 0
JEROME 32 44 27 50 / 80 0 0 0
MCCALL 25 38 14 44 / 100 10 0 0
MOUNTAIN HOME 34 51 27 56 / 60 0 0 0
ONTARIO 34 55 27 56 / 70 0 0 0
ROME 27 50 22 59 / 60 0 0 0
TWIN FALLS 33 44 27 50 / 80 0 0 0
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...DG
AVIATION.....JM
SHORT TERM...LC
LONG TERM....NF
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