An arctic front moved into the area on the 13th. Moisture from a storm system over California overspread this arctic air resulting in heavy snow across the Beartooth and Absaroka Mountains and adjacent foothills.
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 BYZ wrote it up.
An arctic front moved into the area on the 13th. Moisture from a storm system over California overspread this arctic air resulting in heavy snow across the Beartooth and Absaroka Mountains and adjacent foothills.
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 Billings, MT wrote its last area forecast discussion before the first event at Dec 13, 6:38 PM MST, 1 hour 22 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
638 PM MST SUN DEC 13 2009
.SHORT TERM...VALID FOR MON AND TUE...
UPDATED FORECAST TO DROP LOW TEMPERATURES OVER WESTERN AND
NORTHERN AREAS TONIGHT. TEMPERATURES ARE IN THE -5 TO -12 RANGE
ALREADY IN THESE AREAS...AND ARE BELOW FORECAST LOWS IN SOME WESTERN
AREAS. WENT 5 TO 8 DEGREES BELOW CURRENT TEMPERATURES FOR MOST
LOCATIONS. THE CENTER OF HIGH PRESSURE WHERE THE COLDEST AIR IS
LOCATED IS STILL WELL NORTH OF THE AREA AND IS PROGGED TO SLIP
SOUTH LATER TONIGHT. THUS SHOULD SEE TEMPERATURES DROP A BIT MORE
DESPITE CLOUD COVER.
RADAR SHOWING AREAS OF MODERATE TO HEAVY SNOWFALL OVER PORTIONS OF
THE FORECAST AREA...WITH CLOUD TOPS COOLING CENTRAL AND WEST AS AN
AREA OF QG FORCING AND 700MB FRONTOGENESIS MOVES INTO THE AREA.
THE HEAVIEST SNOW IS FROM HARLOWTON TO ROUNDUP AND INTO NORTHERN
ROSEBUD COUNTY...WHERE SNOWFALL RATES ARE 1 TO 2 INCHES AN HOUR AT
TIMES. ADDITIONAL MODERATE SNOWFALL IS FROM WHEATLAND COUNTY SOUTH
TO BIG TIMBER...ALONG WITH AREAS OF SOUTHERN BIG HORN INTO POWDER
RIVER AND SHERIDAN COUNTY. WITH SHALLOW NATURE OF THE ARCTIC
AIRMASS...MOUNTAIN LOCATIONS CURRENTLY IN THE MID 20S...STILL
BEING IMPACTED BY SOME DOWNSLOPING INFLUENCE OVER CENTRAL AREAS.
AS BETTER FORCING CONTINUES TO BUILD IN AND THE DEPTH OF THE
ARCTIC INCREASES OVERNIGHT SHOULD SEE SNOWFALL FILL IN OVER THE
NEXT FEW HOURS. REST OF THE FORECAST IS ON TRACK AND NO
ADJUSTMENTS TO SNOW AMOUNTS IS ANTICIPATED. CHAMBERS
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MODELS STILL SHOWING THE ARCTIC AIR TO BE ERODED OUT OF THE
FORECAST AREA BY WEDNESDAY WITH THE COOLEST AIR STILL BEING
ACROSS THE FAR NORTHEAST PORTIONS OF THE FORECAST AREA. AS THE
PREVIOUS SHIFT MENTIONED...WILL NEED TO WATCH FOR COLD AIR
DRAINAGE DOWN THE CLARKS FORK RIVER VALLEY AND INTO SOUTHWEST
YELLOWSTONE COUNTY AS THIS MAY HINDER TEMPERATURES FROM WARMING
AS QUICKLY AS GUIDANCE IS SUGGESTING. IN ANY CASE...DOWNSLOPE
FLOW RESULTING IN WARMER TEMPERATURES IS EXPECTED FOR WEDNESDAY
AND THURSDAY WITH DRY CONDITIONS OR JUST A SLIGHT SNOW SHOWER
CHANCE FOR THE PLAINS. HIGHER CHANCE POPS WILL REMAIN FOR THE
SOUTHWEST MOUNTAINS AS A MOIST WESTERLY FLOW ALOFT WILL PERSIST
BOTH DAYS.
ANOTHER UPPER LEVEL DISTURBANCE DIVES SOUTHEAST OUT OF CANADA
LATE THURSDAY INTO EARLY FRIDAY BRINGING A BETTER CHANCE FOR
LIGHT SNOW OR SNOW SHOWERS THURSDAY NIGHT AND FRIDAY. MODELS ARE
KEEPING HIGH PRESSURE RIDGING OVER THE PACIFIC NORTHWEST THROUGH
THIS PERIOD. THIS WILL BRING A COLDER NORTHWEST FLOW ALOFT ACROSS
THE FORECAST AREA FRIDAY INTO NEXT WEEKEND. GIVEN THE UNSTABLE
NORTHWEST FLOW ALOFT...WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE
POPS FOR THE PLAINS WITH HIGHER CHANCES OVER THE MOUNTAINS. HAVE
ALSO CONTINUED THE PREVIOUS SHIFTS THINKING OF COOLING
TEMPERATURES A FEW MORE DEGREES EACH DAY. HOOLEY
&&
.AVIATION...
ARCTIC COLD WILL CONTINUE THROUGH THE DAY MONDAY WHILE A MOIST
PACIFIC FLOW ALOFT WILL MOVE OVER THE COLD AIR. THIS WILL RESULT
IN PERIODS OF SNOW...SOMETIMES HEAVY...ACROSS THE ENTIRE FORECAST
AREA. THE SNOWFALL IS EXPECTED TO INTENSIFY LATE THIS EVENING
THROUGH MONDAY MORNING. EXPECT MVFR TO IFR CONDITIONS TO PREVAIL
THROUGHOUT THE REMAINDER OF TODAY AND THROUGHOUT THE OVERNIGHT
HOURS INTO MONDAY. HEAVY SNOW IS LIKELY ACROSS THE
BEARTOOTH/ABSAROKA MOUNTAINS. EXPECT OBSCURATIONS TO ALL
MOUNTAINS IN OUR FORECAST AREA THROUGH THE NIGHT. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 911/003 907/027 022/040 026/042 024/035 024/039 024/030
+7/S 30/B 00/B 12/J 11/B 10/B 12/J
LVM 908/011 009/035 027/040 027/040 023/038 027/039 025/030
+7/S 21/N 11/N 12/J 11/B 11/N 12/J
HDN 911/000 911/024 009/038 016/043 016/036 017/040 014/030
+7/S 30/B 01/B 12/J 21/B 10/B 11/B
MLS 917/903 917/018 007/034 015/036 016/032 015/036 016/028
96/S 30/B 00/B 12/J 21/B 11/U 11/B
4BQ 914/000 914/023 006/037 015/040 018/034 013/039 014/029
97/S 30/B 00/B 12/J 21/B 11/U 11/U
BHK 918/903 919/015 003/032 014/034 015/028 009/034 010/024
76/S 20/B 00/B 12/J 31/B 11/U 11/U
SHR 909/009 908/029 010/040 015/041 015/034 013/040 012/031
+7/S 40/B 00/B 12/J 21/B 10/B 01/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 PM MST MONDAY FOR
ZONES 28>42-56>58-63>66.
WINTER STORM WARNING IN EFFECT UNTIL 5 PM MST MONDAY FOR ZONE
67.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 PM MST MONDAY FOR
ZONE 99.
&&
WEATHER.GOV/BILLINGSHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BILLINGS MT 333 PM MST SUN DEC 13 2009 MTZ028>042-056>058-063>068-WYZ098-099-142245- SOUTHERN WHEATLAND-MUSSELSHELL-TREASURE-NORTHERN ROSEBUD-CUSTER- FALLON-NORTHERN STILLWATER-YELLOWSTONE-POWDER RIVER-CARTER- SOUTHERN BIG HORN-EASTERN CARBON-NORTHERN PARK- NORTHERN SWEET GRASS-GOLDEN VALLEY-RED LODGE FOOTHILLS- NORTHERN BIG HORN-SOUTHERN ROSEBUD-JUDITH GAP-PARADISE VALLEY- LIVINGSTON AREA-BEARTOOTH FOOTHILLS-ABSAROKA/BEARTOOTH MOUNTAINS- CRAZY MOUNTAINS-NORTHEAST BIG HORN MOUNTAINS-SHERIDAN FOOTHILLS- 333 PM MST SUN DEC 13 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...SOUTH CENTRAL MONTANA...SOUTHEAST MONTANA AND NORTH CENTRAL WYOMING. .DAY ONE...TONIGHT AREAS OF LIGHT SNOW WILL CONTINUE THROUGH THE NIGHT. THE SNOW MAY BECOME HEAVY AT TIMES LATE TONIGHT. TWO TO THREE INCHES OF ACCUMULATIONS WILL BE POSSIBLE ACROSS THE PLAINS WITH FOUR TO SIX INCHES LIKELY OVER THE BEARTOOTH/ABSAROKA MOUNTAINS. IN ADDITION...WIND CHILLS FROM 10 TO 30 BELOW ZERO WILL BE COMMON WITH THE COLDEST READINGS FROM BILLINGS EASTWARD TO MILES CITY AND BAKER. HAZARDOUS TRAVEL CONDITIONS DUE TO SLICK AND SNOWPACKED ROADS AS WELL AS LIMITED VISIBILITIES WILL BE LIKELY OVERNIGHT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SNOWFALL WILL CONTINUE INTO MONDAY BEFORE DECREASING LATE IN THE AFTERNOON. THE MONDAY MORNING COMMUTE MAY SEE SNOWPACKED ROADS AND BITTER COLD WIND CHILLS FROM 10 TO 30 BELOW ZERO. TWO TO FOUR INCHES OF TOTAL ACCUMULATION CAN BE EXPECTED BY MONDAY EVENING WITH LOCALLY HEAVIER AMOUNTS POSSIBLE. THE WEST FACING MOUNTAIN SLOPES AROUND COOKE CITY MAY SEE OVER A FOOT OF TOTAL SNOWFALL WHILE LESS AMOUNTS ARE EXPECTED ON EAST FACING SLOPES ABOVE RED LODGE. PEOPLE SHOULD ALLOW FOR EXTRA TIME DURING THE MONDAY MORNING COMMUTE. A WARMING TREND WILL BEGIN ON TUESDAY AS THE ARCTIC AIR BEGINS ITS RETREAT TO THE EAST. ABOVE NORMAL TEMPERATURES AND MELTING SNOW ARE EXPECTED WEDNESDAY AND THURSDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. HOOLEY
The national radar mosaic for the moment the first event began.
2 winter storm. Local standard time, as filed.
Whitetail and Fisher Creek Snotels reported 13 inches and 25 inches of snow respectively.
Nye received 6 inches of snow while Absaroke received 10 inches of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2009Every state in 2009This day in weather historyWarnings in Montana, December 2009
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: 203390, 203391.