A storm system brought additional snowfall to the North Central Mountains of Colorado. Storm totals included 8 inches at Loveland Ski Area; with 6 inches at Dillon, Elliot Ridge SNOTEL, Hoosier Pass and Keystone Ski Area.
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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.
A storm system brought additional snowfall to the North Central Mountains of Colorado. Storm totals included 8 inches at Loveland Ski Area; with 6 inches at Dillon, Elliot Ridge SNOTEL, Hoosier Pass and Keystone Ski 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 Denver/Boulder, CO wrote its last area forecast discussion before the first event at Dec 24, 10:11 AM MST, 3 hours 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER/BOULDER CO 1011 AM MST MON DEC 24 2012 .UPDATE... && .SHORT TERM...MOUNTAIN WEB CAMS SUGGESTING SOME LIGHT SNOW ACROSS THE HIGHER PEAKS ALONG THE CONTINENTAL DIVIDE AS WELL AS OVER RABBIT EARS PASS. LATEST SNOTEL DATA INDICATING PERHAPS AN INCH OF SNOW HAD FALLEN OVER THE HIGHER PEAKS ON THE WEST SIDE OF ROCKY MOUNTAIN PARK IN THE LAST HOUR. RADAR BEGINNING TO SHOW SOME ECHOES OVER NORTHEAST LARIMER AND NORTHWEST WELD COUNTIES...BUT RECENT SURFACE OBS IN THAT AREA NOT INDICATING PRECIP. AS TROUGH BEGINS TO MOVE ACROSS STATE THIS AFTERNOON...SHOULD SEE MOISTURE AND LIFT INCREASE WITH SNOW DEVELOPING ACROSS MOUNTAINS. ACROSS PLAINS...SHOULD TAKE SOME TIME FOR THE LOWER LAYERS TO SATURATE ENOUGH FOR PRECIP TO OCCUR. CURRENT FORECAST OF SNOW DEVELOPING AND INCREASING ACROSS MOUNTAINS THIS MORNING...SPREADING ONTO PLAINS DURING THE AFTERNOON STILL SEEMS ON TRACK. MAY NEED TO INCLUDE SOME POPS FOR ZONE 38 A BIT EARLIER AND INCREASE POPS FOR ZONE 35 GIVEN THE RADAR TRENDS. CURRENT ADVISORIES STILL LOOK GOOD. AMOUNTS STILL LOOKING A BIT SHY OF ADVISORY CRITERIA ACROSS THE REMAINDER OF THE PLAINS...THOUGH MAY BE CLOSE FOR THE URBAN CORRIDOR. WILL ADDRESS THIS LATER. .AVIATION...CURRENT TAF TRENDS STILL LOOKING ON TRACK WITH WINDS BECOMING MORE NORTHWEST BY THE AFTERNOON...THEN EASTERLY DURING THE AFTERNOON. SNOW SHOULD DEVELOP AROUND 00Z WITH IFR/LIFR CONDITIONS BY 05Z...CONTINUING THROUGH ABOUT 15Z. CONDITIONS TO IMPROVE AFTER 15Z. STILL THINKING TOTAL SNOW ACCUMULATIONS OF 3 TO 5 INCHES...WITH THE HIGHER AMOUNTS AT APA AND BJC. WINDS TO BE LIGHT ENOUGH SO BLOWING SNOW SHOULD NOT BE AN ISSUE. && .PREV DISCUSSION... /ISSUED 445 AM MST MON DEC 24 2012/ SHORT TERM...CURRENT WATER VAPOR LOOP SHOWS SHORT WAVE TROUGH MOVING ACROSS NEVADA AT THIS TIME...AS WELL AS LARGE SCALE UPPER LEVEL DIVERGENCE ACROSS THE CENTRAL ROCKIES. PRECIPITATION ECHOES WERE INCREASING ACROSS WESTERN COLORADO AND WYOMING AS Q-G LIFT/ UPPER LEVEL DIVERGENCE INCREASE. OVERALL FORECAST WITH SNOW INCREASING IN THE MOUNTAINS DURING THE DAY AND OVERSPREADING THE PLAINS THIS EVENING LOOKS GOOD. IF ANYTHING...THERE HAS BEEN A SLIGHT SLOWING IN THE SPEED AS UPPER TROUGH IS DIGGING WELL AT THIS HOUR. Q-G VERTICAL MOTION INCREASES THROUGH THE DAY WHICH WILL RESULT IN A THICKENING MID LEVEL CLOUD DECK AND VIRGA ACROSS THE PLAINS THIS AFTERNOON. THE LOW LEVELS ARE RATHER DRY...BUT BY EVENING THE AIRMASS WILL EVENTUALLY SATURATE WITH PERSISTENT AND MODERATE Q-G LIFT. THE Q-G LIFT SHOULD REACT NICELY WITH THE NEUTRAL STABILITY PROFILE IN THE MID LEVELS FOR BETTER PRECIPITATION PRODUCTION. THE 00Z MODEL RUNS WERE MORE AGGRESSIVE WITH PRECIPITATION AND THUS SNOW AMOUNTS...WHICH THEREFORE LOOKS REASONABLE. 06Z RUN OF THE NAM SEEMS UNRELIABLE WITH WESTERLY FLOW PUSHING OFF THE FRONT RANGE AND DISCARDED. A CONSENSUS APPROACH FROM LATEST SREF PLUMES AND 00Z GFS...CANADIAN...AND ECMWF ALL SUPPORT THE INCREASE IN SNOW FORECAST BY AN INCH OR TWO IN MOST LOCATIONS. THIS PUSHES US INTO ADVISORY CRITERIA FOR THE FOOTHILLS AND PALMER DIVIDE AND NEARLY THAT ACROSS THE FRONT RANGE I-25 CORRIDOR. WE WOULD LIKE TO GET THE LATEST 12Z SOUNDING/MODEL DATA AND SEE HOW EFFICIENTLLY AIRMASS SATURATES TODAY...BUT WE MAY NEED TO ADD AN ADVISORY FOR I-25 CORRIDOR ONTO PORTIONS OF THE PLAINS FOR TONIGHT INTO CHRISTMAS MORNING. MOUNTAIN SNOW AMOUNTS AND ADVISORIES LOOK GOOD...BUT WE DID MOVE UP THE START TIME OF THE ADVISORY IN ZONE 31 GIVEN CURRENT RADAR TRENDS. LONG TERM...THE ONGOING SNOW EVENT WILL BE WINDING DOWN ACROSS THE FORECAST AREA THROUGH TUESDAY MORNING. AREAS FROM THE MOUNTAINS TO THE PLAINS MAY PICK UP AN ADDITIONAL INCH OF ACCUMULATION AFTER SUNRISE...BUT WITH THE COLD TEMPERATURES IN PLACE...THE LAST OF THE SNOW IS EXPECTED TO BE QUITE LOW DENSITY. MODELS SHOW THE RELATIVE HUMIDITY LEVELS DRYING OUT ACROSS THE FORECAST AREA AS AN UPPER LEVEL RIDGE POPS UP OVER THE STATE THROUGH WEDNESDAY MORNING. MODEL SOUNDINGS ALSO SHOW STRONG DRYING FROM 18Z TUESDAY MORNING THROUGH WEDNESDAY MORNING WHEN HIGH LEVEL MOISTURE BEGINS INCREASING AGAIN. THE DRYING ACROSS THE STATE WILL BE SHORT-LIVED THOUGH AS EACH OF THE MODELS SHOW THE NEXT UPPER TROUGH MOVING INTO THE GREAT BASIN BY 12Z WEDNESDAY MORNING. MOUNTAIN AREAS SHOULD BEGIN PICKING UP SOME MORE LIGHT SNOW BY WEDNESDAY EVENING. ONE PIECE OF THIS UPPER TROUGH IS FORECAST TO MOVE OUT OVER NORTHEAST COLORADO ON THURSDAY...BUT TROUGHINESS IS EXPECTED TO REMAIN OVER THE NORTHERN ROCKIES AND GREAT BASIN THROUGH FRIDAY...ACCORDING TO THE GFS AND ECMWF. THIS SHOULD LEAD TO CONTINUED UNSETTLED AND SHOWERY WEATHER OVER THE MOUNTAINS. THIS WEAKLY ORGANIZED UPPER TROUGH SHOULD CLEAR OUT OF THE STATE BY SATURDAY WITH DRY WEATHER SPREADING ACROSS THE FORECAST AREA THROUGH THE WEEKEND. TEMPERATURES ON THE PLAINS AND IN THE MOUNTAINS WILL GENERALLY BE COOLER THAN NORMAL FOR THE BULK OF THE FORECAST PERIOD. SOME MODERATION WILL OCCUR OVER THE WEEKEND. AVIATION...DENVER CYCLONE WIND PATTERN IN PLACE WILL GIVE POTENTIAL FOR WEST/NORTHWEST SURFACE WINDS AS FAR EAST AS KDEN THIS MORNING. THEN WINDS SHOULD EVENTUALLY TRANSITION BACK TO EASTERLY THIS AFTERNOON WITH POTENTIAL FOR GUSTS TO 20 KTS. SNOW WILL LIKELY DEVELOP BETWEEN 00Z AND 03Z WITH IFR/LIFR CONDITIONS DEVELOPING THROUGH 05Z AND THEN PERSISTING THROUGH ABOUT 15Z. CONDITIONS WILL IMPROVE TO VFR 15Z-19Z TUESDAY. TOTAL SNOW AMOUNTS SHOULD RANGE FROM 3-5 INCHES MOST FRONT RANGE AIRPORTS...WITH MAINLY A DRY FLUFFY SNOWFALL. WINDS LIGHT ENOUGH SO BLOWING SNOW SHOULD NOT BE A PROBLEM. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 AM MST TUESDAY FOR COZ031. WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM MST TUESDAY FOR COZ035-036-041. WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM MST TUESDAY FOR COZ033-034. && SHORT TERM...D-L LONG TERM....DANKERS AVIATION...D-L
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER/BOULDER CO 1105 AM MST MON DEC 24 2012 COZ030>051-251815- 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- 1105 AM MST MON DEC 24 2012 ...WHITE CHRISTMAS WITH COLD TEMPERATURES ON TAP... ...WINTER WEATHER ADVISORY FOR MOUNTAINS...FOOTHILLS AND PALMER DIVIDE... THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT SNOW WILL CONTINUE TO DEVELOP ACROSS THE MOUNTAINS DURING THE DAY AND THEN SPREAD EASTWARD OVER THE PLAINS BY THIS EVENING. THIS WILL BE A WIDESPREAD SNOW EVENT ACROSS THE CENTRAL ROCKIES AND CENTRAL HIGH PLAINS...SO ANYONE WITH TRAVEL PLANS SHOULD BE PREPARED FOR WINTER DRIVING CONDITIONS AND SLOW TRAVEL. A STORM SYSTEM LOCATED OVER IDAHO AND NEVADA WILL PUSH QUICKLY SOUTHEAST ACROSS COLORADO TONIGHT. AT THE SAME TIME...A COLD FRONT WILL DROP SOUTHWARD ACROSS THE HIGH PLAINS RESULTING IN THE WIDESPREAD SNOWFALL ACROSS THE REGION. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY SNOW WILL END FROM WEST TO EAST ON TUESDAY. TOTAL SNOWFALL AMOUNTS OF 2 TO 5 INCHES ARE EXPECTED ON THE PLAINS WITH UP TO 8 INCHES IN THE FOOTHILLS AND UP TO 12 INCHES IN THE HIGHER MOUNTAINS. SNOW COVERED ROADS SHOULD BE EXPECTED CHRISTMAS MORNING. TEMPERATURES WILL REMAIN COLD THE REST OF THE WEEK. ANOTHER WEATHER DISTURBANCE WILL MOVE OVER THE STATE ON THURSDAY OR FRIDAY BRINGING A CHANCE OF LIGHT SNOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT BUT REPORTS OF SNOWFALL WILL BE APPRECIATED. LESZCYNSKI/GIMMESTAD
The national radar mosaic for the moment the first event began.
3 winter weather. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2012Every state in 2012This day in weather historyWarnings in Colorado, December 2012
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: 426811, 426812, 426813.