Heavy Snow in Colorado, December 21 to 22, 2001

Name: Heavy Snow in Colorado, December 21 to 22, 2001
Start: 2001-12-21T12:00
End: 2001-12-22T04:00
Location: Colorado

December 21 to 22, 2001 · NWS GJT · 6 events in 6 counties and zones

An upper level low pressure system produced 6 to 12 inches of new snow over most mountain areas of western Colorado. The highest amount reported was 18 inches near Rabbit Ears Pass.

Where it happened

Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 6

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.

What happened

The episode as NWS GJT wrote it up.

An upper level low pressure system produced 6 to 12 inches of new snow over most mountain areas of western Colorado. The highest amount reported was 18 inches near Rabbit Ears Pass.

What forecasters said that day

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 Grand Junction, CO wrote its last area forecast discussion before the first event at Dec 21, 3:03 AM MST, 8 hours 57 minutes earlier.

Area forecast discussion, Dec 21, 3:03 AM MST, 8 hours 57 minutes before

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
303 AM MST FRI DEC 21 2001

BAROCLINIC ZONE WITH MID TO HIGH LEVEL CLOUD HAVE BEEN STREAMING OVER
WESTERN COLORADO THIS MORNING. PREFRONTAL WINDS OR ENHANCED DRAINAGE
WINDS HAVE OCCURRED AT SOME HIGHER VALLEY LOCATIONS.. LIKE ASPEN..
TELLURIDE.. AND CORTEZ THAT HAVE PREVENTED TEMPERATURES FROM FALLING
BELOW FREEZING.  THIS IS INDICATIVE OF THE WARM AIR MASS IN PLACE..
EXCEPT WHERE SHALLOW BUT STRONG INVERSIONS PERSISTS SUCH AS THE UINTA
BASIN.

DRASTIC CHANGES OCCURS TODAY AS CLOSED UPPER LOW OVER CENTRAL
CALIFORNIA AND ASSOCIATED TROUGH AXIS SHIFTS EASTWARD DURING THE
DAY.  SATELLITE PICTURES SHOW EXTENSIVE AREA OF CLEARING BEHIND
BAROCLINIC CLOUD ACROSS UTAH.  BUT EXPECT THIS AREA TO FILL IN WITH
CLOUD BY MIDDAY WITH MID LEVEL COLD ADVECTION UNDERWAY.  WITH A WARM
AIR MASS SITUATED OVER THE HIGHER TERRAIN.. LAPSE RATES WILL BE NEAR
8C/KM DURING THE EARLY AFTERNOON FOR RAPID CUMULI DEVELOPMENT WITH
MOUNTAIN SNOW SHOWERS INCREASING DURING THE AFTERNOON HOURS.  AIR
MASS DESTABILIZATION SHOULD HELP MIX SOME VALLEYS (LIKE VERNAL) TO
SEE MUCH WARMER CONDITIONS.. BUT THE HIGHER MOUNTAIN LOCATIONS WILL
BEGIN THEIR COOLING TREND.

THE FORECAST CONCERN THIS MORNING CONCERNS THE WINTER STORM WATCH
THAT WAS HOISTED THURSDAY AFTERNOON.  THIS SYSTEM LACKS SEVERAL
FEATURES TO JUSTIFY UPGRADING TO A WARNING.. LACK OF MOISTURE WITH
SPECIFIC HUMIDITY BRIEFLY REACHING 2.5 G/KG THIS AFTERNOON.  SURFACE
FRONT LAGS WELL BEHIND UPPER LEVEL FRONT.. GRADIENT FLOW WILL BE
RELATIVELY WEAK ONCE TROUGH AXIS PASSES SINCE THERE/S NO JET ALOFT.
ENERGY FROM ALBERTA SHORT WAVE DIVING INTO THE NORTHERN PLAINS MAY
BRIEFLY ENHANCE NORTHWEST GRADIENT FLOW SATURDAY MORNING.. BUT THIS
WILL BE BRIEF.  OROGRAPHIC SNOW MODEL GENERATES AROUND 4 TO 8
INCHES.. AND THIS LOOKS REASONABLE WITH MODEL QPF. WITH THESE
REASONS.. WILL JUST ISSUE A SNOW ADVISORY THIS AFTERNOON THROUGH
SATURDAY MORNING FOR THE NORTHWESTERN MOUNTAINS. WARMING ALOFT AND
SUBSIDENCE DURING SATURDAY WILL DECREASE SNOW SHOWER ACTIVITY
THROUGH THE DAY.

EXTENDED...(SUN-THU): UPPER LOW WILL CONTINUE TO KEEP A BROAD TROUGH
OVER THE CENTRAL PORTION OF THE U.S. AS RIDGE BUILDS ALONG THE WEST
COAST. SOME MODEL DISCREPANCIES EXIST ON SUNDAY CONCERNING A WAVE
PUSHING SOUTHEASTWARD FROM THE PACIFIC NORTHWEST. THE AVN AND MRF
PORTRAY IT DIGGING INTO THE SOUTHWEST PORTIONS OF THE CWA...WHILE
THE ETA SHOWS THE FEATURE WEAKER AND MORE TO OUR NORTHWEST.
REGARDLESS, WILL BUMP UP CLOUD COVER IN THE SUNDAY ZONES...
ESPECIALLY SOUTHWEST.

NORTHWEST FLOW WILL PERSIST THROUGH THE PERIOD WITH ANOTHER SHORTWAVE
ARRIVING LATE TUESDAY AND AFFECTING THE CWFA THROUGH WEDNESDAY.
NORTHERN MOUNTAINS WILL HAVE POPS THROUGH THE PERIOD. TEMPERATURES
WILL BOTTOM OUT ON TUESDAY MORNING WITH THE ARRIVAL OF A MODIFIED
ARCTIC AIR MASS...THEN A SLIGHT WARM-UP AFTER CHRISTMAS.

PF/BA

EMERGENCY MANAGERS IN COUNTIES THAT CONTAIN THE CENTRAL AND NORTHERN
COLORADO MOUNTAINS SHOULD MAINTAIN A HEIGHTENED WEATHER AWARENESS
FOR WINTRY CONDITIONS THIS AFTERNOON THROUGH SATURDAY MORNING. THE
REMAINDER OF WESTERN COLORADO AND EASTERN UTAH EMERGENCY MANAGERS
SHOULD MAINTAIN A NORMAL LEVEL OF WEATHER AWARENESS TODAY.

.GJT...SNOW ADVISORY THIS AFTERNOON UNTIL 12 PM SATURDAY FOR CO ZONE
          04 09 10 13.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

6 heavy snow. Local standard time, as filed.

Heavy Snow, Elkhead and Park Mountains

When: December 21, 12:00 PM MST to December 22, 4:00 AM MST
Where: Elkhead and Park Mountains forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 40.552, -107.599 (the zone’s center; the record gives no point)

Heavy Snow, Gore and Elk Mountains/Central Mountain Valleys

When: December 21, 12:00 PM MST to December 22, 4:00 AM MST
Where: Gore and Elk Mountains/Central Mountain Valleys forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 39.481, -107.172 (the zone’s center; the record gives no point)

Heavy Snow, West Elk and Sawatch Mountains

When: December 21, 12:00 PM MST to December 22, 4:00 AM MST
Where: West Elk and Sawatch Mountains forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 38.643, -107.721 (the zone’s center; the record gives no point)

Heavy Snow, Northwestern San Juan Mountains

When: December 21, 12:00 PM MST to December 22, 4:00 AM MST
Where: Northwestern San Juan Mountains forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 38.210, -107.755 (the zone’s center; the record gives no point)

Heavy Snow, Grand and Battlement Mesas

When: December 21, 12:00 PM MST to December 22, 4:00 AM MST
Where: Grand and Battlement Mesas forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 39.159, -108.078 (the zone’s center; the record gives no point)

Heavy Snow, Flattop Mountains

When: December 21, 12:00 PM MST to December 22, 4:00 AM MST
Where: Flattop Mountains forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 40.062, -107.603 (the zone’s center; the record gives no point)

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Colorado in 2001 Every state in 2001 This day in weather history Warnings in Colorado, December 2001

Sources

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: 5276127, 5276128, 5276129, 5276130, 5276131, 5276132.