Strong winds developed over the higher ridges of the North-Central Mountains, as an upper level jetstream passed overhead. Peak wind gusts included: 96 mph atop Berthoud Pass, 93 mph atop Loveland Pass and 89 mph atop Niwot Ridge.
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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 BOU wrote it up.
Strong winds developed over the higher ridges of the North-Central Mountains, as an upper level jetstream passed overhead. Peak wind gusts included: 96 mph atop Berthoud Pass, 93 mph atop Loveland Pass and 89 mph atop Niwot Ridge.
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 Denver/Boulder, CO wrote its last area forecast discussion before the first event at Jan 11, 2:10 PM MST, 13 hours 22 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 210 PM MST SUN JAN 11 2009 .SHORT TERM...CLOUDS DCRG THIS AFTN FOLLOWING THE PASSAGE OF A WEAK DISTURBANCE THAT PASSES TO THE NORTH AND EAST OF CO. IN THE MTNS ...WL CONTINUE WITH A CHC OF SNOW IN THE MTNS. THERE WILL BE SOME MID LVL SUBSIDENCE THIS EVNG AS THE SHORT WAVE EXITS THE REGION. SPATIAL CROSS-SECTIONS KEEP MSTR FAIRLY SHALLOW THROUGH 06Z...THEN THE MSTR STARTS TO DEEPEN AHD OF THE NEXT STORM SYSTEM. MOUNTAIN TOP WINDS WILL REMAIN W-WNLY. MAY AGAIN HAVE GUSTY WINDS IN AND NEAR THE FOOTHILLS TNGT...AHD OF THE NEXT SYSTEM. WL KEEP SOME GUSTS IN THE 50-60 MPH RANGE THROUGH THIS EVENING. WIND SHUD DCRS AFTER MIDNIGHT AS THEY BECOME MORE NLY BY 12Z...AHD OF AN APPROACHING COLD FRONT. ON MONDAY...THE COLD FRONT IS PROGGED TO MOVE INTO THE DENVER AREA AROUND 15Z...WITH A BRIEF PERIOD OF UPSLOPE. WL INCREASE THE POPS ALONG THE FRONT RANGE BUT KEEP IT IN THE CHC CATEGORY. SO FAR THE UPSLOPE LOOKS TO BRIEF AND THE LOWER LEVELS MSTR TOO DRY FOR MUCH SNOWFALL. ZONES 36 AND 41 MAY GET AN INCH. AS FOR THE MTNS...A PERSISTENT WNWLY FLOW WL ALLOW FOR LGT SNOW TO CONTINUE IN THOSE AREAS. THE NAM12 INDICATES WEAK QG ASCENT AOA 700 MB IS PROGGED TO OCCUR FM 09Z TO 15Z. THE GFS IS NOT AS OPTIMISTIC. SNOW MDL INDICATES AMOUNTS IN THE 2-4 INCH RANGE. WEAK QG ASCENT PRESENT SO WL STICK WITH THESE VALUES. .LONG TERM...MEAN UPPER LEVEL FLOW TURNS NORTH-NORTHEASTERLY OVER COLORADO BY EARLY MONDAY EVENING WITH MAX SPEEDS AROUND 150KTS UP AT 300MBS OVER THE NERN CORNER OF THE STATE. OVERNIGHT THE CORE OF IS POWERFUL JET TRANSLATES EASTWARD OVER KANSAS/NEBRASKA AS THE STRONG UPPER LEVEL RIDGE OFF THE WEST COAST MAKES VERY SLOW HEADWAY ONSHORE. MODELS AND MODEL ENSEMBLE MEMBERS FOR THE MOST PART SHOW THE MEAN UPPER RIDGE AXIS REMAINING OVER THE WEST COAST REGION THE ENTIRE WEEK. OVER NORTHEAST COLORADO ON TUESDAY...WIND SPEEDS ABOVE 500MBS WEAKEN AS THEY BACK AROUND TO A NORTHWESTERLY COMPONENT DURING THE DAY. CONCURRENTLY...TEMPS AT 500MBS OVER THE COLORADO FRONT RANGE WARM 6C DURING THE 24HR PERIOD ENDING 00Z/WED. MEANWHILE MODEL WINDS WITHIN THE 700-600MB LAYER...GO WEST-NORTHWESTERLY OVER THE FRONT RANGE ON TUESDAY...WITH GFS-BASED CROSS SECTIONS SHOWING +60KT WINDS LOWERING TO AROUND 600MB BY LATE AFTERNOON. NAM-BASED CROSS SECTIONS NOT AS STRONG WITH WIND SPEEDS AS THEY INDICATE ONLY 25-35 KT WLY WINDS WORKING DOWN THE EAST SLOPE OF THE FRONT RANGE IN THE AFTERNOON. AND YET BOTH MODELS INDICATE FALLING SFC PRESSURES AT THE BASE OF THE FRONT RANGE DURING THE DAY WITH A TIGHT GJT-DEN PRES GRADIENT BY AFTERNOON. FURTHERMORE SANGSTER WIND MODEL BASED ON THE NAM...GFS AND SREF INDICATES WIND GUSTS IN THE WATCH CATEGORY FROM BASICALLY 12Z/TUE TO 09Z/WED. ANOTHER ONE OF THOSE TOUGH CALLS. FOR NOW...WILL HOLD OFF MENTIONING ANY STRONG/HIGH WINDS OVER AND/OR NEAR THE FRONT RANGE ON TUESDAY. BUT WILL MAKE SURE WESTERLY WINDS ARE IN THE FCST WITH POSSIBLE GUSTS TO AROUND 30MPH IN THIS AREA. THEREFORE WITH DOWNSLOPE FLOW IN PLACE...LOOKING FOR A DRY AND WARMER DAY TUESDAY WITH FCSTD 700MB TEMP OVER DENVER NEAR 0C BY 00Z/WED. BROUGHT DOWN DRY ADIABATICALLY THAT WOULD GIVE US A HIGH AT DENVER IN THE UPPER 50S. ALTHOUGH THE LATEST MOS TEMP GUIDANCE WAS ONLY INDICATING A HIGH AROUND 50. UNDERSTANDABLY...FARTHER EAST OF THE FRONT RANGE WHERE DOWNSLOPE WARMING LESS OF A FACTOR...TEMPS WILL BE COOLER. UP ALONG THE FRONT RANGE CHINOOK BREEZES SHOULD PUSH THE MERCURY WELL INTO THE 50S. COULD SEE SIMILAR TEMPS HIGHER AREAS ON THE PALMER DIVIDE. WEDNESDAY AND BEYOND...WINDS DIE DOWN CONSIDERABLY EAST OF THE FRONT RANGE TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE LOCAL PRESSURE GRADIENT EASIES AND VERTICAL WIND FIELD DECOUPLES. ALL THIS IN ADVANCE OF A CLIPPER SYSTEM RACING SOUTHEASTWARD OUT OF ALBERTA DOWN THE BACKSIDE OF THE WEST COAST RIDGE. MODELS SHOW A COLD FRONT ASSOCIATED WITH A MID-LEVEL SHORTWAVE SWEEPING THRU NERN COLORADO WEDNESDAY NIGHT WITH BNDRY LAYER WINDS TURNING EASTERLY BY THURSDAY MORNING. FCST SOUNDINGS AND CROSS SECTIONS INDICATE ONLY LIMITED LOW/MID-LEVEL MOISTURE WITH THIS SYSTEM. PROBABLY ENOUGH TO INCREASE CLOUD COVER ON THE PLAINS AND TO PRODUCE A FEW LIGHT SNOW SHOWERS OVER THE NERN CORNER OF THE STATE DURING THE LATE NIGHT-EARLY MORNING HRS ON THURSDAY. THEREAFTER...THE LIFT PRODUCED BY THE PASSING JET AND FRONTAL SYSTEM SHIFTS SOUTH AND EAST OF THE STATE AS GEOPOTENTIAL HEIGHTS RISE ACROSS THE GREAT BASIN. BY FRIDAY SHOULD SEE TEMPS ABOVE NORMAL AREAWIDE WITH PLENTY OF SUNSHINE. THROUGHOUT THIS PERIOD...MTNS...ESPLY WEST OF THE CONTINENTAL DIVIDE WILL CONTINUE TO HAVE AT LEAST A SLIGHT CHANCE OF OROGRAPHIC SNOWFALL. ANY ACCUMULATIONS WILL BE MINIMAL AND MAINLY CONFINED TO THE HIGHEST ELEVATIONS MONDAY NIGHT AND TUESDAY MORNING. LASTLY...COULD SEE ANOTHER ALBERTA CLIPPER SYSTEM DROPPING SOUTH OVER THE FCST AREA DURING THE WEEKEND. WILL LEAVE THAT ONE ALONE FOR NOW AS THE MODELS OFTEN DO FUNNY THINGS THAT FAR OUT. && .AVIATION...VFR CONDITIONS WL CONTINUE THROUGH 12Z MONDAY. SURFACE WINDS WILL PRIMARILY BY SSWLY THROUGH THAT TIME FRONT. A COLD FRONT IS EXPECTED TO MOVE INTO THE DENVER AREA BY 14Z WITH E-NELY UPSLOPE SFC WNDS. IT DOES LOOK FOR FAVORABLE FOR THE POTENTIAL FOR LGT SNOW AFTER 16Z. MVFR CONDITIONS WL DVLP BY THAT TIME. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. COOPER/GIMMESTAD
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1054 AM MST SUN JAN 11 2009 COZ030>051-121300- JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000 FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/ NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/ SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/ EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES- NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS COUNTY- 1054 AM MST SUN JAN 11 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED LIGHT SNOW SHOWERS WILL OCCUR IN THE MOUNTAINS TODAY AND TONIGHT WITH ACCUMULATIONS OF AN INCH OR TWO POSSIBLE. OVER THE PLAINS IT WILL BE DRY WITH SEASONAL TEMPERATURES. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY LIGHT SNOW WILL BE LIKELY IN THE MOUNTAINS TOGETHER WITH A CHANCE OF SNOW IN THE HIGH VALLEYS ON MONDAY AND MONDAY NIGHT. ONLY MINIMAL SNOW ACCUMULATIONS ARE ANTICIPATED. THERE WILL ALSO BE A SLIGHT CHANCE OF SNOW ON THE PLAINS AND IN THE FOOTHILLS ON MONDAY WITH WEAK UPSLOPE FLOW. SNOW ACCUMULATION IS NOT EXPECTED IN THESE AREAS. THE HIGH COUNTRY...PARTICULARLY AREAS WEST OF THE CONTINENTAL DIVIDE...WILL CONTINUE TO HAVE AT LEAST A SLIGHT CHANCE OF SNOW FOR THE REMAINDER OF THE WEEK. WHILE THE HIGH PLAINS SHOULD CONTINUE DRY WITH THE NEXT DIP IN TEMPERATURES ON THURSDAY FOLLOWING THE PASSAGE OF A COLD FRONT WEDNESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. COOPER/BAKER
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2009Every state in 2009This day in weather historyWarnings in Colorado, January 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: 149819.