An ice jam formed on the Beaverhead River in Twin Bridges causing localized flooding in portions of the town.
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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 TFX wrote it up.
An ice jam formed on the Beaverhead River in Twin Bridges causing localized flooding in portions of the town.
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 Great Falls, MT wrote its last area forecast discussion before the first event at Jan 4, 3:59 AM MST, 1 minute earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 359 AM MST TUE JAN 4 2011 .DISCUSSION... TODAY THROUGH THURSDAY...MID-HIGH LEVEL CLOUDS WILL CONTINUE TO MOVE OVERHEAD AS SHORTWAVE ENERGY MOVES THROUGH THE REGION THIS MORNING. THERE WILL BE SOME CLEARING THIS AFTERNOON BEFORE OUR NEXT STRONGER SHORTWAVE ARRIVES WEDNESDAY AND TEMPERATURES WILL CONTINUE TO CLIMB TO AROUND SEASONAL AVERAGES. WINDS WILL REMAIN GUSTY ALONG THE ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS BOTH TODAY AND WEDNESDAY WITH GUSTS UP TO 50 MPH POSSIBLE. LOCALIZED HIGHER WIND GUSTS THROUGH FAVORED MOUNTAIN PASSES AND CANYONS MAY STILL BE POSSIBLE. DEBATED A HIGH WIND WATCH OR WARNING...HOWEVER HELD OFF AS WIND DIRECTION REMAINS MORE NORTHWESTERLY AND PARALLEL TO THE CONTINENTAL DIVIDE. WITH MOISTURE TO CONTINUING TO MOVE OVER A WEAKENING UPPER-LEVEL RIDGE WILL KEEP CONTINUED CHANCES OF SNOW ALONG THE CONTINENTAL DIVIDE AND HAVE THUS INCREASED POPS FOR THIS AREA. ON WEDNESDAY...A STRONGER SHORTWAVE WILL INCREASE PRECIPITATION CHANCES ACROSS A WIDER AREA WITH LIKELY POPS IN THE MOUNTAINS AND SLIGHT CHANCE TO CHANCE POPS OVER THE SOUTHWEST MONTANA VALLEYS AND PARTS OF CENTRAL MONTANA. THIS WAVE WILL ALLOW THE UPPER-LEVEL RIDGE THAT HAS REMAINED OVER THE PACIFIC NORTHWEST TO BREAK DOWN AND BECOME MORE ZONAL WEDNESDAY NIGHT. MODELS SUGGEST SOME WEAK WARM AIR ADVECTION WEDNESDAY NIGHT AND THURSDAY ALLOWING TEMPERATURES TO CONTINUING RISING WITH CONTINUED PRECIP CHANCES. AS TEMPERATURES INCREASE...PRECIPITATION TYPE IN THE PLAINS AND VALLEYS BECOMES A LITTLE MORE TRICKY WITH RAIN AND SNOW POSSIBLE OVER THE NORTH-CENTRAL PLAINS ON WEDNESDAY. LIGHT SNOW IS EXPECTED OVER SOUTHWEST MONTANA WITH LITTLE SNOW ACCUMULATION EXPECTED AS QPF AMOUNTS STAY FAIRLY LIGHT. THERE AREA ALSO HINTS OF SOME VERY LIGHT FREEZING RAIN OR DRIZZLE THURSDAY MORNING OVER THE NORTH-CENTRAL PLAINS AND EVEN THE SOUTHWEST VALLEYS AS TEMPS RISE. SOUNDINGS INDICATE A DECENT LEVEL OF DRIER AIR TOWARDS THE SURFACE WITH DECENT MOISTURE ALOFT SO SOME PRECIP MAY EVAPORATE BEFORE REACHING THE GROUND SO HAVE LOW CONFIDENCE THAT THERE WILL ACTUALLY BE FREEZING PRECIPITATION BUT KEPT SLIGHT CHANCES FOR THURSDAY MORNING. HIGHS ON WEDNESDAY AND THURSDAY WILL BE ABOVE SEASONAL AVERAGES. MLS THURSDAY NIGHT THROUGH TUESDAY...THE PERIOD WILL BEGIN WITH AN UPPER LEVEL HIGH PRESSURE RIDGE IN PLACE OVER THE WESTERN US. A SHORTWAVE WILL MOVE ACROSS THE TOP OF THIS RIDGE AND MOVE INTO ALBERTA THURSDAY NIGHT. THIS WILL KEEP A STRONG SURFACE PRESSURE GRADIENT ACROSS THE LEE OF THE ROCKIES AND STRONG...GUSTY WINDS WILL LAST INTO FRIDAY AFTERNOON. DOWNSLOPE SHOULD KEEP THE CHANCE OF PRECIP LOW ALTHOUGH FORECASTED SOUNDINGS SHOW THE POSSIBILITY OF THIS PRECIP FALLING AS FREEZING RAIN. A LOW PRESSURE TROF WILL BE MOVING OVER THE WEST COAST FRIDAY AND MOISTURE AHEAD OF THIS SYSTEM WILL BE OVER THE ROCKIES DURING THE DAY. MOISTURE WILL INCREASE ACROSS THE ZONES FRIDAY NIGHT AS THE LOW PRESSURE TROF MOVES ACROSS THE PACIFIC NORTHWEST. WIDESPREAD SNOW WILL DEVELOP BUT ACCUMULATIONS IN MOST AREAS AT THIS POINT WILL GENERALLY BE LOW. THE WESTERN MOUNTAINS...HOWEVER...COULD BEGIN TO SEE SIGNIFICANT ACCUMULATIONS. AN ARCTIC COLD FRONT WILL MOVE ACROSS THE BORDER LATE FRIDAY NIGHT AND EARLY SATURDAY MORNING...THE ECMWF IS PERHAPS 6 HOURS FASTER THAN THE GFS WHICH BRINGS THE FRONT THROUGH GTF BETWEEN 12Z-18Z SAT. MAX TEMPS ACROSS THE NORTHERN AND CENTRAL ZONES WILL OCCUR EARLY BEFORE THE FRONTAL PASSAGE. SNOW AND STRONG...GUSTY WINDS WILL MOVE SOUTH ALONG WITH THE FRONT AND MOVE INTO SOUTHWEST MONTANA BY LATE AFTERNOON. TEMPERATURES ACROSS THE ZONES WILL BE FALLING DURING SATURDAY AND COLD TEMPERATURES WILL HAVE SPREAD ACROSS THE ZONES BY SUNDAY. THE VERY MOIST CONDITIONS...COLD TEMPS...AND STRONG UPSLOPE FLOW WILL LIKELY CAUSE WINTER STORM CONDITIONS ACROSS THE CWA. ALONG WITH THE HEAVY SNOWFALL...STRONG WINDS WILL CAUSE WIDESPREAD AREAS OF BLOWING AND DRIFTING SNOW WITH POSSIBLE WHITEOUT CONDITIONS. WINDS AND UPSLOPE FLOW WILL WEAKEN BY SUNDAY AND SNOW SHOULD DIMINISH AS THE COLD...DRY AIRMASS MOVES OVER THE ZONES. UNSETTLED NORTHWEST FLOW WILL BE IN PLACE AGAIN BY MONDAY AND...ALTHOUGH HIGH PRESSURE WILL BE BUILDING...SNOW SHOWERS WILL CONTINUE ACROSS THE CWA. ZELZER && .AVIATION... UPDATED 0545Z. NORTHWEST FLOW ALOFT CONTINUES OVER THE AREA. SURFACE WINDS HAVE DECREASED A LITTLE DURING THE EVENING HOURS BUT WILL BECOME GUSTY AGAIN ON TUESDAY. MID AND HIGH CLOUDS WILL INCREASE AS THEY MOVE ACROSS THE AREA OVERNIGHT. VFR CONDITIONS PREVAIL. && .HYDROLOGY... ICE JAM CONDITIONS ARE OCCURRING ON THE GALLATIN RIVER NEAR LOGAN...PRODUCING MINOR FLOODING. THE RIVER IS OUT OF ITS BANKS BUT NO ROADS OR STRUCTURES ARE THREATENED AT THIS TIME. FURTHER WATER RISES ARE POSSIBLE. NATIONAL WEATHER SERVICE AND LOCAL OFFICIALS WILL CONTINUE TO CLOSELY MONITOR THIS SITUATION. && .PRELIMINARY POINT TEMPS/POPS... GTF 32 26 38 29 / 10 10 20 20 CTB 29 22 35 26 / 10 10 20 10 HLN 26 19 35 21 / 10 10 20 20 BZN 25 10 31 14 / 10 10 20 20 WEY 15 6 19 10 / 30 40 50 30 DLN 23 13 31 19 / 10 10 40 20 HVR 24 13 34 16 / 10 10 10 10 LWT 30 20 35 25 / 10 10 20 20 && .TFX WATCHES/WARNINGS/ADVISORIES... AIR STAGNATION ADVISORY UNTIL 6 PM MST THIS EVENING FOR THE HELENA VALLEY INCLUDING THE CITY OF HELENA. && WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 712 PM MST MON JAN 3 2011 MTZ055-050215- GALLATIN- 712 PM MST MON JAN 3 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...TONIGHT A FLOOD WARNING IS IN EFFECT UNTIL FURTHER NOTICE FOR THE GALLATIN RIVER NEAR LOGAN DUE TO AN ICE JAM. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN ARCTIC COLD FRONT WITH ABUNDANT PACIFIC MOISTURE IS EXPECTED TO BRING WIDESPREAD SNOW AND BITTERLY COLD TEMPERATURES TO THE REGION LATER IN THE WEEK. TEMPERATURES WILL DROP 35 TO 45 DEGREES BELOW AVERAGE. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ014-050215- CENTRAL AND SOUTHERN LEWIS AND CLARK- 712 PM MST MON JAN 3 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...TONIGHT AN AIR STAGNATION ADVISORY IS IN EFFECT FOR THE HELENA VALLEY. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN AIR STAGNATION ADVISORY REMAINS IN EFFECT FOR THE HELENA VALLEY UNTIL 6 PM MST TUESDAY. AN ARCTIC COLD FRONT WITH ABUNDANT PACIFIC MOISTURE IS EXPECTED TO BRING WIDESPREAD SNOW AND BITTERLY COLD TEMPERATURES TO THE REGION LATER IN THE WEEK. TEMPERATURES WILL DROP 35 TO 45 DEGREES BELOW AVERAGE. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ008>013-015-044>054-050215- BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL- CASCADE-CHOUTEAU-MADISON-TOOLE-LIBERTY-EASTERN PONDERA-BLAINE- SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS- JEFFERSON-BROADWATER-MEAGHER- 712 PM MST MON JAN 3 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TONIGHT THE PROBABILITY IS LOW FOR WIDESPREAD HAZARDOUS WEATHER. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN ARCTIC COLD FRONT WITH ABUNDANT PACIFIC MOISTURE IS EXPECTED TO BRING WIDESPREAD SNOW AND BITTERLY COLD TEMPERATURES TO THE REGION LATER IN THE WEEK. TEMPERATURES WILL DROP 35 TO 45 DEGREES BELOW AVERAGE. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
Ice jamming was occurring along the Beaverhead River in Twin Bridges affecting private residential areas on Bridge street as well as Jessen Park. During the event, Jessen Park was closed due to flooding and several private residences and the high school were affected.
Ice jamming was occurring along the Beaverhead River in Twin Bridges affecting private residential areas on Bridge street as well as Jessen Park. During the event, Jessen Park was closed due to flooding and several private residences and the high school were affected.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2011Every state in 2011This day in weather historyWarnings in Montana, January 2011
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: 368895, 368896.