A powerful winter storm brought snow and wind to the mountains with 5 to 10 inches of snow and many road closuures and accidents. Thunderstorms also accompanied the cold front with the storm with strong winds through the Snake River Plain as well along the front.
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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 PIH wrote it up.
A powerful winter storm brought snow and wind to the mountains with 5 to 10 inches of snow and many road closuures and accidents. Thunderstorms also accompanied the cold front with the storm with strong winds through the Snake River Plain as well along the front.
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 Pocatello, ID wrote its last area forecast discussion before the first event at Dec 20, 1:53 PM MST, 11 hours 7 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE POCATELLO ID 153 PM MST SUN DEC 20 2015 .SHORT TERM...TONIGHT THROUGH TUESDAY. A WEAK TROUGH WILL MOVE THROUGH THE REGION TONIGHT. THIS WILL PRODUCE SOME SNOW SHOWERS TONIGHT BUT AMOUNTS WILL REMAIN UNDER AN INCH FOR THE MOST PART. SLIGHTLY HEAVIER AMOUNTS ARE POSSIBLE NORTH AND EAST OF REXBURG WHERE 1 TO 3 INCHES ARE POSSIBLE TONIGHT. A WINTER WEATHER ADVISORY WAS IN EFFECT FOR THIS AREA BUT GIVEN THE STRONGER MORE SIGNIFICANT STORM APPROACHING MONDAY DECIDED TO JUST UPGRADE TO A WARNING TO AVOID HAVING AN ADVISORY WITH A BRIEF DRY PERIOD THEN A WARNING. A STRONG WARM FRONT WILL ARRIVE ON MONDAY. A BAND OF HEAVY SNOW WILL DEVELOP MONDAY MORNING ALONG THE SAWTOOTHS AND SMOKEY AND MOVE SOUTHEAST DURING THE AFTERNOON. HEAVY PRECIPITATION WILL OVERSPREAD THE MAGIC VALLEY DURING THE AFTERNOON BUT SNOW LEVELS WILL BE INCREASING DURING THIS TIME...SO EXPECT HEAVY SNOW ROUGHLY NORTH OF SHOSHONE WITH A MIX OF RAIN AND SNOW IN BURLEY WITH LITTLE OR NO SNOW ACCUMULATION. AREAS FROM AMERICAN FALLS TO POCATELLO TO BLACKFOOT WILL LIKELY SEE A DOWNSLOPE WIND WHICH WILL LIMIT PRECIPITATION AND RAISE TEMPS NOTICEABLY. A MIX OF RAIN AND SNOW WILL BREAK OUT ACROSS THE SOUTHERN AND EASTERN HIGHLANDS MONDAY AFTERNOON WITH SNOW LEVELS AROUND 5500FT OR SO. HEAVY SNOW WILL END ACROSS THE CENTRAL MOUNTAINS AND NORTHERN MAGIC VALLEY BY MID EVENING...BUT MAY PERSIST THROUGH MUCH OF THE NIGHT ACROSS THE SOUTHERN AND EASTERN HIGHLANDS. SNOW ACCUMULATIONS OF 5 TO 10 INCHES ALONG WITH BLOWING AND DRIFTING SNOW ARE LIKELY ACROSS MUCH OF THESE AREAS. LITTLE IF ANY SNOW IS EXPECTED FROM BURLEY THROUGH POCATELLO TO BLACKFOOT WITH 1 TO 3 INCHES POSSIBLE FROM IDAHO FALLS TO REXBURG. GIVEN THE SPEED AND INTENSITY OF THE SNOW ALONG WITH THE WIND...THINK ROAD CREWS COULD HAVE A HARD TIME KEEPING UP. THEREFORE WILL ISSUE WINTER STORM WARNINGS FOR MOST OF THESE AREAS. WILL CANCEL THE WATCH FOR THE POCATELLO AREA BECAUSE SNOW AMOUNTS WILL PROBABLY BE LIGHT BECAUSE OF DOWNSLOPE EFFECTS. DECIDED TO ISSUE A WINTER WEATHER ADVISORY FOR THE CACHE VALLEY INCLUDING PRESTON BECAUSE OF THE HUGE UNCERTAINTY AS TO WHERE THE SNOW LEVELS WILL SET UP THERE. CURRENT THINKING IS SNOW AMOUNTS OF 1 TO 5 INCHES THERE. THIS FORECAST IS HIGHLY DEPENDENT UPON SNOW LEVELS AND A HUGE CHANGE IN AMOUNTS IS LIKELY DEPENDING ON WHERE THE SNOW LEVELS ACTUALLY COME IN AT. THIS SYSTEM WILL EXIT THE AREA WITH TUESDAY. MOIST NORTHWEST FLOW WILL CONTINUE LIGHT SNOWFALL AMOUNTS ACROSS MOUNTAINS AND HIGHLANDS ON TUESDAY...BUT THIS WILL MAINLY BE SHOWERS. VALLE .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. THE MODELS STILL ARE OFF BY A FEW HOURS BUT IT LOOKS LIKE THE NEXT STORM IN THE SNOW TRAIN ARRIVES TUESDAY NIGHT AND WEDNESDAY. IT'S A FAST MOVER BUT MAY GIVE THE MOUNTAINS ANOTHER 2-6 INCHES WITH AN INCH OR TWO IN THE LOWER VALLEYS. WITH THE WINDY PATTERN CONTINUING...EXPECT SOME BLOWING AND/OR DRIFTING CONDITIONS EVEN WITH THE LIGHT AMOUNTS. CHRISTMAS EVE AND DAY STILL HAVE THE POTENTIAL TO BE SNOWY WITH SOME GUSTY WINDS...BUT THE MODELS ARE NOT KEYING ON JUST HOW MUCH RIGHT NOW. THAT IS BASED ON THE ONGOING THEME THIS FALL...SPLIT FLOW WITH A CLOSED DEVELOPING TO OUR SOUTH. THE GFS IS ALSO WETTER VS THE ECMWF. EITHER WAY...IT DOES LOOK LIKE TRAVEL COULD BE IMPACTED ESPECIALLY IN THE MOUNTAINS. LOWER ELEVATIONS WOULD BE MORE IMPACTED IF THE GFS IDEA COMES TRUE. FOR THE REST OF THE HOLIDAY WEEKEND...IT APPEARS THE LOW TO OUR SOUTH CONTINUES TO STRENGTH AND HEAD TOWARD THE SOUTHERN PLAINS. THAT...IN CONJUNCTION WITH A SYSTEM SWINGING TOWARD THE COAST WILL BUILD A RIDGE OF HIGH PRESSURE OVER US. WE COULD STILL SEE SOME LIGHT SNOW HERE AND THERE BUT THE IDEA WILL BE COLDER WITH INVERSION CONDITIONS. KEYES && .AVIATION...LOW CLOUDS AND FOG HAVE BEEN PRETTY STUBBORN TODAY ACROSS PORTIONS OF THE SNAKE PLAIN...BUT THINGS ARE FINALLY IMPROVING AT KBYI...KPIH AND KIDA. KSUN HAVE MANAGED TO AVOID ANY OF THIS SO FAR. THAT WON'T LAST LONG AS A WEAK STORM BRINGS A BAND OF SNOW LATE THIS AFTERNOON AND EVENING. WE ARE EXPECTING MVFR/IFR WEATHER WITH THIS BAND. WINDS WILL GRADUALLY PICK UP AT THE SAME TIME...BUT BLOWING SNOW SHOULDN'T BE AN ISSUE. AS QUICKLY AS THE BAND ARRIVES...IT'S GONE. WE SHOULD SEE IT END AT ALL TAF SITES SOMEWHERE BETWEEN 6-10Z...WITH KPIH AND KIDA BEING THE LAST. WE ARE CARRY VCSH AT KSUN...KPIH AND KIDA AS THERE COULD BE SOME LINGERING SNOW IN THE MOUNTAINS SURROUNDING THOSE SITES. WINDS WILL CONTINUE TO INCREASE AND REMAIN STRONG THROUGH MONDAY. THAT SHOULD HELP KEEP FOG AT BAY BUT NOT KEEP STRATUS FROM FORMING AHEAD OF THE NEXT STORM. ALL SITES HAVE MVFR/IFR CEILINGS AFTER THE SNOW ENDS. RAIN AND SNOW RETURNS TOMORROW AFTERNOON. WE ARE EXPECTING THINGS TO BEING CLOSE TO 18Z AT KSUN AND KIDA...WITH KSUN STAYING AS SNOW BUT KIDA GOING TO AT LEAST A MIX. THE THREAT OF RAIN WILL INCREASE IN THE AFTERNOON FOR KBYI AND KPIH. WINDS WILL PEAK AT 15-25KTS. KEYES && .PIH WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING FROM 8 PM THIS EVENING TO 5 AM MST TUESDAY FOR IDZ019-023. WINTER STORM WARNING FROM 11 AM MONDAY TO 5 AM MST TUESDAY FOR IDZ022-025. WINTER STORM WARNING FROM 8 AM TO 8 PM MST MONDAY FOR IDZ017-018- 031. WINTER WEATHER ADVISORY FROM 11 AM MONDAY TO 5 AM MST TUESDAY FOR IDZ024. &&
The Pocatello radar (KSFX), 30 km away, was scanning. The volume nearest the first event began at 03:50 UTC.
3 winter storm, 1 heavy snow, 1 thunderstorm wind. Local standard time, as filed.
Ten inches of snow fell at Chocolate Gulch with 12 inches at Galena and 10 inches at Galena Summit.
Only 4 to 8 inches of snow fell in the region but it was accompanied by very strong winds which closed US Route 30 between Lava Hot Springs and Soda Springs from the evening of the 21st around 11 pm to the morning of the 22nd. A Salt Lake City Express van flipped on its side on interstate 15 near McCammon around 5 pm on the 21st. No major injuries occurred due to the crash.
Ten inches of snow fell at Bostetter Ranger Station and 9 inches fell at Howell Canyon.
Six to 10 inches of snow fell in the Upper Snake Highlands on the 21st with 10 inches reported on Ashton Hill and 7 inches in Island Park. Winds were very strong causing limited visiblity and horrible driving conditions. Several slideoffs occurred in the Island Park including one semi on its side. Idaho Highway 32 was closed due to the conditions in between Ashton and Tetonia.
A thunderstorm moved through Pocatello and downed trees and power lines and thousands of people were reported without power in the Pocatello and Chubbuck area through 11 pm on the 21st.
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: 611596, 611597, 611602, 611599, 611605.