A strong Pacific storm spread heavy snow across the mountains of western Idaho including power outages over parts of the area.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BOI wrote it up.
A strong Pacific storm spread heavy snow across the mountains of western Idaho including power outages over parts of the area.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Boise, ID wrote its last area forecast discussion before the first event at Dec 12, 2:44 PM MST, 1 hour 16 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
244 PM MST SAT DEC 12 2015
.SHORT TERM...FORECAST MODELS CONTINUE TO SUPPORT WINTER STORM
WARNING FOR THE WEST CENTRAL IDAHO MOUNTAINS AND BOISE MOUNTAINS
TONIGHT THROUGH SUNDAY NIGHT...WITH TOTAL SNOWFALL ESTIMATES
STILL 6 TO 12 INCHES IN THE VALLEYS ABOVE 4000 FEET AND 12 TO 24
INCHES IN THE MOUNTAINS. LATEST MODELS RAISE THE SNOW LEVEL TO 4500
TO 5500 FEET FOR A FEW HOURS SUNDAY BEFORE LOWERING IT TO VALLEY
FLOORS AGAIN SUNDAY EVENING WHEN THE STORM/S COLD FRONT COMES
THROUGH. SOUTHEAST WINDS WILL INCREASE TONIGHT AND SUNDAY MORNING TO
15 TO 30 MPH...THEN DECREASE LATER SUNDAY BEFORE SHIFTING TO WEST OR
NORTHWEST 15 TO 30 MPH WITH GUSTS TO 40 MPH LATE SUNDAY AND SUNDAY
EVENING WITH THE COLD FRONT. SNOW AND WIND WILL CONTINUE SUNDAY
NIGHT INTO MONDAY MORNING IN THE IDAHO HIGHLANDS SOUTH OF THE SNAKE
BASIN. TEMPS A LITTLE WARMER TONIGHT AND SUNDAY THEN COLDER SUNDAY
NIGHT AND MONDAY. WEST WINDS WILL APPROACH ADVISORY SPEEDS MONDAY
IN THE UPPER TREASURE VALLEY...WESTERN MAGIC VALLEY...AND SOUTH TO
THE NEVADA BORDER.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY. UPPER TROUGH TO OUR EAST
WILL KEEP COLD NORTHWESTERLY FLOW OVER THE FORECAST AREA THROUGH
WEDNESDAY FOR BELOW NORMAL TEMPERATURES. MODELS...TO VARYING DEGREES
...ARE SHOWING A WEAK EMBEDDED SHORTWAVE PASSAGE ON WEDNESDAY
IMPACTING THE IDAHO CENTRAL MOUNTAINS WITH SNOW. LOWER CONFIDENCE
FROM THURSDAY INTO THE WEEKEND AS THE LATEST MODELS HAVE DIVERGED
WITH THE NEXT LARGE TROUGH. THE 12Z ECMWF IS THE OUTLIER WITH
AMPLIFYING THE RIDGE OVER THE INTERMOUNTAIN WEST AND SHIFT THE
MOISTURE FURTHER NORTHWEST LEAVING THE FORECAST AREA UNDER THE RIDGE
INTO THE WEEKEND. THIS WOULD KEEP THE LOWER VALLEYS IN AN INVERSION
FOR BELOW TEMPERATURES. THE 12Z GFS/CANADIAN ARE STILL SHOWING A MORE
PROGRESSIVE PATTERN WITH MOISTURE ASSOCIATED WITH A WARM FRONT
MOVING ACROSS THE REGION THURSDAY AFTERNOON/EVENING FOR A WINTRY
MIX BELOW 4500 FEET FOLLOWED BY WARM MOIST SOUTHWESTERLY FLOW
FRIDAY/SATURDAY WITH SNOW LEVELS AROUND 5500 FEET. HAVE TRENDED
FORECAST TOWARD THE GFS/CANADIAN SOLUTIONS SINCE THEY HAVE HAD
BETTER CONSISTENCY SO FAR. TEMPERATURES CLIMB BACK ABOVE NORMAL
THURSDAY THROUGH SATURDAY.
&&
.AVIATION...ISOLATED SHOWERS THROUGH THIS EVENING IN SW IDAHO.
WIDESPREAD PRECIPITATION WITH GUSTY WINDS BEGINNING IN SE OREGON
THIS AFTERNOON AND SW IDAHO THIS EVENING. SNOW LEVELS 3000-4000 FT
TODAY WILL RISE TO AROUND 5000 FT BY SUNDAY AFTERNOON...THEN FALL
BACK TO VALLEY FLOORS SUNDAY EVENING WITH COLD FRONT PASSAGE.
MOSTLY VFR IN RAIN AREAS...WITH MVFR/IFR IN AREAS OF SNOW WITH MTN
OBSCURATION. SURFACE WINDS GENERALLY 10 KTS OR LESS INCREASING
TONIGHT THROUGH SUNDAY TO 15-25 KTS WITH GUSTS TO 20-25 KTS. WINDS
ALOFT NEAR 10K FT MSL...WSW 15-20 KTS...INCREASING TO 45-55 KTS
AFTER 00Z SUNDAY. RAIN WILL CHANGE TO SNOW SUNDAY EVENING IN THE
VALLEY WITH PASSAGE OF THE COLD FRONT THOUGH LITTLE SNOW
ACCUMULATION IS EXPECTED.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM MST
SUNDAY IDZ028-029-033.
WINTER WEATHER ADVISORY FROM 5 PM SUNDAY TO 11 AM MST MONDAY
IDZ015-030.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM MST MONDAY
IDZ011-013.
OR...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM PST
SUNDAY ORZ062.
&&
WEATHER.GOV/BOISE
SHORT TERM...LC
LONG TERM....JDS/DD
AVIATION.....JDSThe national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
Various sources reported 10 to 17 inches of new snow around the McCall, New Meadows and Council areas.
A trained spotter at Pine, Idaho reported 8 inches of new snow and Bogus Basin Ski Area measured 15 inches of snowfall.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2015Every state in 2015This day in weather historyWarnings in Idaho, December 2015
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 612373, 612369.