A weak snowpack following recent heavy snowfall resulted in about 170 reported avalanches in the western San Juan Mountains of southwest Colorado. S.
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 GJT wrote it up.
A weak snowpack following recent heavy snowfall resulted in about 170 reported avalanches in the western San Juan Mountains of southwest Colorado. Some of the avalanches ran across U.S. highway 550 in the Red Mountain Pass 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 Grand Junction, CO wrote its last area forecast discussion before the first event at Feb 20, 2:30 PM MST, 9 hours 30 minutes earlier.
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
230 PM MST WED FEB 20 2002
STEADY MOUNTAIN SNOW THAT HAS OCCURRED OVER THE NORTHWESTERN
MOUNTAINS HAS TAPERED OFF.. BUT EXPECT SNOW INTENSITY TO INCREASE
FOR A FEW HOURS THROUGH THE EVENING AS INSTABILITY REACHES ITS PEAK
AROUND SUNSET. STRONG MOIST NORTHWEST FLOW WILL FAVOR WEST AND
NORTHWEST FACING AREAS.. INCLUDING THE NORTHWESTERN SAN JUAN
MOUNTAINS. SHORT WAVE AXIS OVER SOUTHWEST IDAHO RAPIDLY DROPS
SOUTHEASTWARD OVERNIGHT ACROSS WESTERN COLORADO. AIR MASS STABILIZES
QUICKLY ONCE SHORT WAVE REACHES THE AREA.. AND THIS WILL BRING A
RAPID END TO THE MOUNTAIN SNOW. WILL CONTINUE WITH THE CURRENT
HIGHLIGHTS INTO THE EVENING HOURS.
BUILDING RIDGE OVER THE WEST COAST MOVES INLAND THURSDAY. MOST
VALLEY AREAS WILL CLEAR OUT FRIDAY MORNING.. BUT WILL LINGER UNDER
SUBSIDENCE INVERSION OVER THE MOUNTAINS. WARM ADVECTIVE MID LEVEL
CLOUD DECK WILL MOVE ACROSS THE NORTHERN ZONES ADJACENT TO WYOMING
THURSDAY EVENING AND NIGHT. NO WEATHER EXPECTED FROM THESE CLOUDS AS
JET WILL HAVE RETREATED NORTHWARD AND THE AIR MASS WILL BE STABLE.
THESE CLOUDS MARK THE ONSET OF WARMING TREND.. AND EXPECT
TEMPERATURES TO RECOVER AROUND 5F VALLEYS AND 10F MOUNTAINS ON
FRIDAY.
A STRONG POLAR VORTEX MOVING EASTWARD ALONG THE CANADIAN BORDER
BREAKS DOWN THE RIDGE LATE ON FRIDAY. A SURFACE COLD FRONT MOVES
ACROSS THE AREA ON SATURDAY BRINGING MORE MOUNTAIN SNOW.. ESPECIALLY
ACROSS THE NORTHERN MOUNTAINS. FRISBIE
EXTENDED (SUN-WED)...REGION IN MOIST NW FLOW BEHIND S/W TROUGH SUN
AND MON. THIS WILL LIKELY RESULT IN PERIODIC SNOW FOR THE NORTHERN
AND CENTRAL MOUNTAINS. A COOLER AIRMASS WILL SETTLE ACROSS THE CWFA
SUNDAY...WITH BELOW NORMAL TEMPS. HAVE DROPPED MIN/MAX TEMPS IN
THE FCST SUN-MON. EARLY NEXT WEEK...LATEST MRF RUN (00Z/20) IS MORE
PROGRESSIVE AND LESS AMPLIFIED WITH WAVES DIVING SOUTH FROM CANADA.
HOWEVER...LATEST AVN RUN (12Z/20) SHOWS A MORE AMPLIFIED S/W OVER
MONTANA AT 12Z/MON...WHICH IS IN BETWEEN THE PREVIOUS 2 MRF RUNS.
THUS...BELIEVE BEST THREAT OF PRECIP WILL EXIST TUES...WITH THE AREA
REMAINING IN A RELATIVELY MOIST WESTERLY FLOW INTO WED. DJN.83
.GJT...WINTER STORM WARNINGS THROUGH THIS EVENING CO NORTHWESTERN
MOUNTAINS (ZONES 4/10/13)
SNOW AND BLOWING SNOW ADVISORY THROUGH TONIGHT CO WEST
CENTRAL MOUNTAINS (CO ZONES 9/12/18)
SNOW ADVISORY UNTIL 9 PM STEAMBOAT SPRINGS VICINITY (CO ZONE
5).The national radar mosaic for the moment the first event began.
2 avalanche. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2002Every state in 2002This day in weather historyWarnings in Colorado, February 2002
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: 5282128, 5282129.