A potent spring snowstorm brought heavy snow to the portions of the northern mountains and Front Range Foothills. 5 inches near Georgetown; with 9 inches at Loveland 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 potent spring snowstorm brought heavy snow to the portions of the northern mountains and Front Range Foothills. Storm totals included: 16.5 inches near Blackhawk; 16 inches at Nederland; 15.5 inches at Coal Creek Canyon and 4.6 miles northeast of Ward; 15 inches near Allenspark; 14 inches, 3 miles south-southwest of Estes Park; 13.5 inches near Aspen Springs; 12.5 inches, 5 miles northwest of Idaho Springs; 12 inches at Echo Mountain Ski Area; 11 inches at Arapahoe Basin and Winter Park Ski Areas; 10.5 inches near Georgetown; with 9 inches at Loveland 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 Apr 13, 2:10 AM MST, 11 hours 59 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 310 AM MDT WED APR 13 2011 .SHORT TERM...AN UPPER LEVEL TROUGH WILL DIG INTO THE GREAT BASIN BY LATE AFTN WITH SWLY FLOW ALOFT. CROSS-SECTIONS SHOW LIMITED MOISTURE PRETTY MUCH THRU LATE AFTN HOWEVER WITH LAPSE RATES IN THE 7-8 C/KM RANGE COULD SEE A SLIGHT CHC OF CONVECTION IN THE MTNS AND FOOTHILL AREAS AFTER 21Z. EAST OF THE MTNS SFC HIGH PRESSURE WILL BUILD ACROSS THE CNTRL PLAINS INTO NERN CO THRU THE DAY WITH MAINLY ENE LOW LEVEL FLOW. SOUNDINGS SHOW A RATHER STABLE AIRMASS OVER THE PLAINS SO WILL NOT MENTION ANY PCPN EXCEPT NR THE FOOTHILLS WHERE I WILL LEAVE IN A SLIGHT CHC OF LATE AFTN SHOWERS. HIGHS THIS AFTN OVER NERN CO LOOK TO BE IN THE 55-60 DEGREE RANGE BASED ON LATEST 850-700 MB TEMPS. FOR TONIGHT THE UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL MOVE INTO COLORADO WITH DECENT MID LVL QG ASCENT. LOW LEVEL FLOW WILL BECOME MORE SELY BY THIS EVENING WITH INCREASING MOISTURE SO SHOULD SEE PCPN INCREASE IN THE MTNS AND FOOTHILLS WHICH SHOULD MOVE ACROSS THE FRONT RANGE URBAN CORRIDOR THIS EVENING AND THE PLAINS AFTER MIDNGHT. AM A LITTLE CONCERNED WITH THE SELY WINDS WHICH MAY FOCUS BEST CHC OF PCPN FM BOULDER NORTH TO THE WYOMING BORDER WITH NOT AS MUCH PCPN FM DENVER SOUTH ACROSS THE PALMER DIVIDE. ANOTHER CONCERN IS SNOW AMOUNTS IN THE MTNS ON EAST FACING SLOPES AND POSSIBLY THE FOOTHILLS DUE TO ENHANCED SELY FLOW AND POTENTIAL CONVECTION WHICH MAY LEAD TO HEAVY SNOWFALL IN SOME AREAS. AM NOT CONFIDENT ENOUGH TO ISSUE A WINTER STORM WARNING FOR THE MTNS SO WILL GO WITH A SNOW ADVISORY. IN THE FOOTHILLS THE SNOW LEVEL SHOULD DROP TO AROUND 7500 FT BY MIDNIGHT SO COULD SEE SOME DECENT AMOUNTS SO NEXT SHIFT MAY HAVE TO PONDER AN ADVISORY. AT LOWER ELEVATIONS COULD SEE A RAIN/SNOW MIXTURE LATE TONIGHT ALONG THE WY-CO BORDER AND POSSIBLY OVER THE PALMER BUT WILL NOT MENTION ANY ACCUMULATIONS. .LONG TERM...ON THURSDAY...THE UPPER TROF OVER NCENTRL CO AT 12Z WILL STRENGTHEN AS IT CLOSES UP OVER CENTRAL KANSAS BY 00Z FRIDAY. THE STRONGEST QG ASCENT WILL BE OVER ERN CO PRIOR TO 18Z...THEN THE QG ASCENT WILL GRADUALLY WEAKEN IN THE AFTN AS THE TROF SHIFTS TO THE EAST. STRONG WINDS WILL DEVELOP IN THE AFTERNOON AS THE FLOW ALF INCREASES AND THE SFC PRESSURE GRADIENT STRENGTHENS. SNOW SHOWERS WILL CONTINUE IN THE MTNS THROUGH 18Z THEN GRADUALLY DCRS IN THE AFTN. ALTHO THE SNOW WILL DCRS...STRONG GUSTY WINDS WILL ALLOW FOR AREAS OF BLOWING SNOW OVER THE HIGHER MOUNTAIN PASSES. THURSDAY NIGHT...PCPN ACROSS MUCH OF THE CWFA WILL DIMINISH AS WITH INCRG STABILITY/QG DESCENT. ON FRIDAY...AN SHORT WAVE RIDGE WILL BE OVER NERN CO. THE AMS WILL BE DRIER AND WARMER...BUT A STRONG NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR GUSTY WINDS TO CONTINUE. FIRE DANGER HOWEVER SHOULD BE LOW IN SPITE OF THE STRONG WINDS IF THE PCPN WEDNESDAY NIGHT AND THURSDAY PANS OUT. THE FLOW ALOFT WILL BECOME MORE ZONAL OVER THE WEEKEND. PACIFIC MOISTURE EMBEDDED IN THE FLOW SHOULD ALLOW FOR AT LEAST A SLIGHT CHC OF SNOW IN THE HIGH COUNTRY. AFTN HEATING MAY ALLOW FOR A SLIGHT CHC OF RAIN SHOWERS ACROSS THE NERN PLAINS AS WELL. THE MDLS MOVE THE NEXT TROF ACROSS THE MONTANA ON MONDAY. THE COLD FRONT ASSOCIATED WITH THIS PASSING SYSTEM MAY MOVE INTO THE CWFA MONDAY NIGHT INTO TUESDAY. THIS MAY RESULT IN ADDITIONAL PCPN FOR NORTHEAST COLORADO MONDAY NIGHT. && .AVIATION...NOT SURE ABOUT LOW CLOUDS AND FOG EARLY THIS MORNING AS BOTH THE NAM AND HRRR SHOW MOST OF IT REMAINING NR THE CO-WY BORDER AND NOT MOVING SOUTHWARD. CURRENT SATELLITE TRENDS WOULD SEE TO BACK THIS SCENARIO SO FAR THUS WILL BACK OFF ON LIFR CONDITIONS IN NEXT TAF. I SUPPOSE ITS STILL POSSIBLE MVFR CONDITIONS COULD DEVELOP FOR A FEW HOURS IN THE 12Z-15Z TIMEFRAME. FOR THIS AFTN EXEPCT VFR CONDITIONS WITH ENE WINDS. COULD SEE AN ISOLD -SHRA AFTER 21Z BUT BEST CHANCES FOR RAIN SHOULD BE AFT 00Z WITH MVFR CONDITONS DEVELOPING IN THE 01Z-04Z TIMEFRAME AND CONTINUING OVERNIGHT. IF HEAVIER RAINFALL OCCURS COULD SEE BRIEF LIFR CONDITIONS FM 04Z-08Z. MEANWHILE SOUNDINGS SHOW PCPN SHOULD STAY AS ALL RAIN TONIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES...WINTER WEATHER ADVISORY TONIGHT THRU 15Z THURSDAY FOR MTN ZNS 31..33 AND 34. && RPK/FMC
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE DENVER CO ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO 1043 AM MDT WED APR 13 2011 COZ030>051-141300- 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- 1043 AM MDT WED APR 13 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL COLORADO...EAST CENTRAL COLORADO...NORTH CENTRAL COLORADO AND NORTHEAST COLORADO. .DAY ONE...TODAY AND TONIGHT A STORM SYSTEM WILL MOVE INTO THE REGION TONIGHT AND PRODUCE SNOW IN THE MOUNTAINS WITH ACCUMULATIONS OF 4 TO 10 INCHES BY THURSDAY MORNING. RAIN WILL DEVELOP IN THE FOOTHILLS THIS EVENING AND CHANGE TO SNOW BY MIDNIGHT WITH 3 TO 8 INCHES OF ACCUMULATION ABOVE 7000 FEET. OVER NORTHEAST COLORADO RAIN WILL DEVELOP NEAR THE FOOTHILLS THIS EVENING AND THEN SPREAD ACROSS THE PLAINS OVERNIGHT. SOME SNOW MAY MIX IN WITH THE RAIN NEAR THE COLORADO...WYOMING BORDER AND OVER THE PALMER DIVIDE WITH ACCUMULATIONS OF AN INCH POSSIBLE. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY A STRONG UPPER LEVEL DISTURBANCE WILL EXIT COLORADO BY THURSDAY AFTERNOON. LIGHT SNOW WILL PERSIST ON THE MOUNTAINS ON THURSDAY WITH MAINLY RAIN SHOWERS OVER LOWER ELEVATIONS. GUSTY NORTHWEST WINDS WILL DEVELOP ON THURSDAY AND FRIDAY WITH GUSTS UP TO 50 MPH OVER THE FAR EASTERN PLAINS AND OVER THE HIGHER MOUNTAIN PASSES AND FOOTHILLS. DRIER AND WARMER CONDITIONS WILL RETURN ON FRIDAY. OVER THE WEEKEND...MOISTURE WILL INCREASE AGAIN OVER THE MOUNTAINS WITH A CHANCE OF SNOW DEVELOPING. ANOTHER STORM SYSTEM COULD BRING ADDITIONAL PRECIPITATION TO NORTHEAST COLORADO BY EARLY NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.
The national radar mosaic for the moment the first event began.
2 winter storm, 2 winter weather. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2011Every state in 2011This day in weather historyWarnings in Colorado, April 2011
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: 302958, 302959, 302965, 302968.