Heavy snow fell in and near the foothills of Larimer and Boulder Counties. 5 inches at Glen Haven, 8 inches, 8 miles west of Fort Collins and 5 inches at Horsetooth Inlet Bay.
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 BOU wrote it up.
Heavy snow fell in and near the foothills of Larimer and Boulder Counties. Snowfall totals included: 10.5 inches at Eldorado Springs, 10 inches near Estes Park and Masonville, 9 inches at Rist Canyon, 8.5 inches at Glen Haven, 8 inches, 8 miles west of Fort Collins and 5 inches at Horsetooth Inlet Bay.
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 Nov 21, 3:15 PM MST, 5 hours 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 315 PM MST FRI NOV 21 2003 .SHORT TERM...UPPER LEVEL TROUGH WORKING ITS WAY INTO THE GREAT BASIN...ALREADY SEEING SIGNS OF BANDED PRECIPITATION WORKING ITS WAY ACROSS NORTHERN ZONES. WATER VAPOR LOOPS SUGGEST JET STREAK MOVING ACROSS THESE ZONES...WHICH EXPLAINS THE INCREASE IN SPEEDS AT 300 MB IN THE PLATTEVILLE PROFILER. SHORT TERM MODELS SHOW NO BREAK IN SNOWFALL THROUGH SATURDAY. SO...BASED ON WHAT HAS RECENTLY TRANSPIRED...WILL NEED TO UPGRADE THE WATCH FOR THE MOUNTAIN AND FOOTHILL ZONES 30..32..33 AND 35 TO A WARNING...MOVING UP THE TIMING. DIV-Q FIELDS SHOW ADEQUATE QG LIFT ACROSS THE MOUNTAINS TONIGHT. WILL ISSUE ADVISORY FOR SNOW FOR 34...36 AND 37...DESPITE UNFAVORABLE OROGRAPHICS. SNOW TO CONTINUE THROUGH THE DAY SATURDAY AS TROUGH EXPECTED TO MOVE OVER AREA. CROSS SECTIONS SHOW INCREASE IN LAPSE RATES BY AFTERNOON...MAY SEE SOME THUNDER AS TROUGH AXIS MOVES OVERHEAD. WARNINGS AND ADVISORIES TO CONTINUE THROUGH DAY. WILL UP SOME OF THE SNOW AMOUNTS...MAINLY BASED ON POTENTIAL FOR CONVECTION. AS FOR THE PLAINS...RADAR SHOWING BANDED PRECIPITATION ACROSS ZONE 38...MAINLY NEAR WYOMING BORDER. EXPECT COVERAGE TO INCREASE OVERNIGHT AS TROUGH MOVES CLOSER TO AREA. WILL UPGRADE TO A WARNING...THOUGH BEST POTENTIAL FOR SNOW LATE TONIGHT. ELSEWHERE...SNOW SHOULD BEGIN AFTER MIDNIGHT. WILL KEEP THE CURRENT POPS AS IS. ON SATURDAY...UPSLOPE PROGGED TO INCREASE AS DYNAMICS ALOFT MOVE OVER...SO SNOW TO INCREASE IN COVERAGE AS DAY PROGRESSES. MODELS KEEP BEST SNOW ACCUMULATIONS IN BANDED AREA ACROSS NORTHERN ZONES. AM CONCERNED WITH SURFACE WIND BY 18Z SATURDAY...WHEN SURFACE LOW EXPECTED TO WIND UP AND MOVE ACROSS KANSAS. MODELS SHOW SUSTAINED 20 KTS. WILL ISSUE ADVISORY FOR SNOW AND BLOWING SNOW... BUT MAINLY FOR THE WIND WITH POTENTIAL FOR BLOWING AND DRIFTING SNOW. TEMPERATURES TO BE ABOUT 15-20 DEGREES COLDER SATURDAY THAT TODAY AS NEXT COLD SURGE OVERTAKES AREA. ETA GUIDANCE MORE IN LINE WITH MIDDLE .LONG TERM...UPR TROUGH WILL CONTINUE TO TRACK ACROSS THE CWFA SATURDAY NIGHT INTO SUNDAY. DECREASING QG ASCENT SATURDAY NIGHT WITH SUBSIDENCE DVLPG SUNDAY AS TROF AXIS SHIFTS TO THE EAST. MESOETA SOUNDINGS INDICATE UPSLOPE TO H7 AT 00Z BUT THIS TRANSITIONS TO NWLY OVERNIGHT AFTER 03Z SUNDAY. ALTHOUGH THE SNOW WILL BE WINDING SNOW THE WIND WILL CONTINUE...ESPECIALLY ACROSS THE EASTERN PLAINS. FOR THIS REASON WILL MAINTAIN HIGHLIGHTS THROUGH SATURDAY NIGHT FOR SNOW AND BLOWING SNOW. DRY BUT VERY COLD ON SUNDAY WITH ARCTIC AMS IN PLACE. SUNDAY NIGHT LOOKS TO BE VERY COLD WITH CLEARING SKIES AND EXTENSIVE SNOW COVER EXPECTED. WARMUP WILL OCCUR ON MONDAY AS FLOW BECOME MORE ZONAL AND SHORT WAVE 500 MB RIDGE MOVES OVER THE STATE. SOME MOISTURE WILL INCREASE WEST OF THE DIVIDE AS NEXT PACIFIC SYSTEM MOVES INTO THE MOUNTAINS OF COLORADO MONDAY NIGHT INTO TUESDAY. WILL MAINTAIN POPS IN THE MOUNTAINS THROUGH WENDESDAY BUT KEEP THE REMAINDER OF THE CWFA DRY FOR NOW. && .BOU WATCHES/WARNINGS/ADVISORIES...WINTER STORM WARNING NRN MOUNTAINS AND NRN FOOTHILLS ZNS 30>33..35..38 TNT THRU SAT NITE. .WINTER WEATHER ADVISORY FOR SATURDAY AND SATURDAY NIGHT FOR THE REMAINDER OF THE NORTHERN MOUNTAINS...FRONT RANGE FOOTHILLS AND ADJACENT PLAINS...ZNS 34..36..37..39>51. D-L/COOPER
COZ030>051-221300- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1050 AM MST FRI NOV 21 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT A COLD STORM SYSTEM FROM THE PACIFIC NORTHWEST WILL BEGIN TO INFLUENCE THE WEATHER THIS AFTERNOON. ISOLATED SNOW SHOWERS WILL DEVELOP OVER THE MOUNTAINS...MAINLY NORTH OF INTERSTATE 70. THE SNOW WILL INCREASE LATE TONIGHT...WITH 1 TO 3 INCHES OF SNOW ACCUMULATION POSSIBLE IN THE NORTHERN MOUNTAINS AND FOOTHILLS. TEMPERATURES WILL BE MUCH COOLER TODAY WITH HIGH TEMPERATURES IN THE 40S. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SNOW WILL DEVELOP AND BECOME WIDESPREAD OVER THE MOUNTAINS AND EASTERN COLORADO SATURDAY AFTERNOON AND NIGHT. THE SNOW IS EXPECTED TO BE HEAVIEST ACROSS THE NORTHERN MOUNTAINS AND NORTHERN FRONT RANGE FOOTHILLS...WHERE TOTAL ACCUMULATIONS OF 6 TO 12 INCHES ARE POSSIBLE. ELSEWHERE...ACCUMULATIONS OF 2 TO 5 INCHES ARE POSSIBLE WITH THE HEAVIEST AMOUNTS EXPECTED NEAR THE FOOTHILLS AND IN THE PLAINS...ALONG AND NORTH OF THE I-76 CORRIDOR. VERY COLD TEMPERATURES IN THE TEENS AND 20S CAN BE EXPECTED. GUSTY NORTHERLY WINDS 20 TO 30 MPH ARE EXPECTED TO DEVELOP ACROSS THE NORTHEAST PLAINS OF COLORADO SATURDAY AFTERNOON AND SATURDAY NIGHT CAUSING AREAS OF BLOW AND DRIFTING SNOW. BE PREPARED FOR WINTER DRIVING CONDITIONS AS ROADS WILL BECOME ICY AND SNOWPACKED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. D-L/FMC
The national radar mosaic for the moment the first event began.
2 winter storm. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2003Every state in 2003This day in weather historyWarnings in Colorado, November 2003
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: 5331590, 5331591.