142
FXUS65 KBOI 122119
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
219 PM MST WED NOV 12 2025
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
UPPER TROUGH OFF
THE COAST HAS CLOSED OF A LOW (NEAR 36N/138W AT 2 PM MST). THE
LOW IS HEADED TOWARD SOUTHERN CALIF WHILE THE NORTHERN PART OF
THE TROUGH MOVES RAPIDLY INLAND ALONG THE CANADIAN BORDER,
GETTING ALL THE WAY TO NORTH DAKOTA BY SATURDAY MORNING. THE
PORTION THAT COMES THROUGH OUR CWA WILL PROVIDE ONLY MINIMAL
SUPPORT FOR THE SURFACE COLD FRONT EXPECTED TO PASS THROUGH
OUR CWA LATE THURSDAY NIGHT AND FRIDAY MORNING. EVEN SO, THE
FRONT SHOULD STILL BE ABLE TO SCOUR OUR WEAK SURFACE INVERSION.
BUT BEFORE THAT HAPPENS THURSDAY WILL BE ANOTHER VERY MILD DAY
WITH HIGH TEMPS CLOSE TO RECORD HIGHS FOR NOV 13. PRE-FRONTAL
SOUTHWEST WINDS WILL GUST 25 TO 30 MPH THURSDAY AFTERNOON IN
EASTERN OR AND THE SOUTHWEST ID HIGHLANDS. THE WEAKENING FRONT
WILL BRING ONLY SLIGHT COOLING FRIDAY. PCPN FORECASTS HAVE
CHANGED ONLY SLIGHTLY BUT LOOK A LITTLE WETTER IN WESTERN ID
LATE THURSDAY NIGHT AND FRIDAY MORNING. TOTAL PCPN THURSDAY
THROUGH SATURDAY MORNING IS STILL EXPECTED TO RANGE FROM .25
TO .50 INCH IN THE BOISE MOUNTAINS AND WEST CENTRAL IDAHO
MOUNTAINS, WITH AROUND .10 INCH IN THE SNAKE BASIN, .05 TO
.15 INCH IN THE EASTERN OR VALLEYS, AND .15 TO .25 INCH IN
THE OR MOUNTAINS. SNOWFALL WILL BE MINIMAL WITH SNOW LEVELS
STAYING ABOVE 7000 FEET MSL DURING MOST OF THE PCPN.
LONG TERM...SATURDAY THROUGH WEDNESDAY
A BRIEF BREAK IN THE
UNSETTLED WEATHER IS ON TAP FOR SATURDAY; WITH THE JET STREAM TO
OUR NORTH, AND A CLOSED-LOW OFF THE SOCAL COAST, KEEPING MOST
OF OUR AREA DRY (ASIDE FROM ISOLATED SHOWERS OVER HIGHER TERRAIN
IN VALLEY COUNTY). THIS DRY PERIOD IS SHORTLIVED, HOWEVER, AS
THE SOCAL CLOSED LOW INTRODUCES SOME FUN INTO THE FORECAST. COME
SUNDAY, A TROUGH DIGGING DOWN FROM THE GULF OF ALASKA SWITCHES
FLOW ALOFT TO SOUTHWESTERLY, WHICH WILL HELP STEER THE SOCAL
LOW TO THE NORTHEAST AS IT FILLS IN AND EMBEDS BACK INTO THE
MAIN FLOW. THE MAJOR ENSEMBLE MEANS HAVE THIS BRINGING MOISTURE
AND DYNAMICS TO SUPPORT PRECIPITATION COME SUNDAY. THIS SYSTEM
WILL BE IMMEDIATELY FOLLOWED BY THE AFOREMENTIONED GULF OF
ALASKA TROUGH, PROLONGING THE UNSETTLED WEATHER INTO EARLY
NEXT WEEK. SNOW LEVELS WILL LOWER TO 4-5 KFT MSL THROUGH THE
DAY MONDAY ALLOWING FOR A COUPLE OF INCHES OF SNOW ALONG
RIDGELINES, AND PERHAPS EVEN A DUSTING IN HIGHER ELEVATION
TOWNS. TEMPERATURE WILL START OUT AT 5-10 DEGREES ABOVE NORMAL
ON SATURDAY, LOWERING TO NEAR NORMAL ON MONDAY FOLLOWING A COLD
FRONTAL PASSAGE.
AVIATION
VFR WITH HIGH CLOUDS. LLWS POSSIBLE OVERNIGHT IN
E-OREGON, ESPECIALLY NEAR KBNO. ISOLATED VIRGA SHOWERS THIS
AFTERNOON/EVENING. SURFACE WINDS: VARIABLE UP TO 10 KT. WINDS
ALOFT AT 10KFT MSL: SW 15-25 KT.
KBOI...VFR. SURFACE WINDS: SE 5-10 KT.
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
SHORT TERM...LC
LONG TERM....NF
AVIATION.....NF
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