A strong Pacific cold front moving across Colorado produced up to 11 inches of late season snow. More than 8 inches of snow fell in the Mosquito and eastern Sawatch Ranges, and on Pikes Peak.
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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 PUB wrote it up.
A strong Pacific cold front moving across Colorado produced up to 11 inches of late season snow. More than 8 inches of snow fell in the Mosquito and eastern Sawatch Ranges, and on Pikes Peak.
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 Pueblo, CO wrote its last area forecast discussion before the first event at May 10, 2:40 PM MST, 6 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 340 PM MDT TUE MAY 10 2011 .SHORT TERM... (TONIGHT AND WEDNESDAY) ...HAZARDOUS FIRE WEATHER CONDITIONS INTO THIS EVENING... AN UPPER LEVEL STORM SYSTEM WILL MOVE FROM ARIZONA INTO SOUTH CENTRAL COLORADO WEDNESDAY MORNING...AND WILL COMBINE WITH A SOUTHWARD MOVING COLD FRONT TO BRING SHOWER ACTIVITY TO THE MOUNTAINS AND ADJACENT PLAINS THROUGH WEDNESDAY. SOME HIGHER ELEVATIONS WILL RECEIVE SUBSTANTIAL SNOWS AS THE UPPER LEVEL STORM MOVES ACROSS THE AREA...ESPECIALLY OVER THE EASTERN MOUNTAINS. EXPECT SNOW TO BEGIN ACCUMULATING ACROSS THE HIGHER ELEVATIONS BY WEDNESDAY MORNING WITH MOST OF THE SNOW FALLING DURING THE DAY WEDNESDAY. SNOW LEVELS WILL BE RELATIVELY HIGH INITIALLY...BUT WILL LOWER DURING THE EVENT AS THE COLDER AIR MOVES IN. THE PLAINS SHOULD REMAIN DRY EXCEPT RIGHT ALONG THE LEE SLOPES OF THE MOUNTAINS WHERE SHOWERS WILL BE LIKELY. AS THE FRONT MOVES THROUGH NORTHERN EL PASO COUNTY OVERNIGHT...STRONG NORTHERLY WINDS WILL DEVELOP DOWNSLOPE FLOW SOUTH OF THE PALMER DIVIDE. THIS WILL LIMIT PRECIPITATION AMOUNTS IN THE CITY OF COLORADO SPRINGS...AND SOUTH TO NEAR PUEBLO DURING THE TIME THAT THE GREATEST CHANCE OF SNOW IS EXPECTED. WEDNESDAY...STRONG NORTHEAST WINDS WILL CONTINUE ACROSS THE PALMER DIVIDE THROUGH MOST OF THE DAY...LIMITING PRECIPITATION TO THE SOUTH. SUBSTANTIAL SNOWS ARE EXPECTED TO CONTINUE THROUGH AT LEAST MID AFTERNOON ACROSS THE MOUNTAINS. AS THE SURFACE A LOW PRESSURE CENTER WILL DEVELOP AND MOVES THROUGH SOUTHEASTERN COLORADO DURING THE DAY...STRONG SOUTHERLY WINDS ARE EXPECTED TO DEVELOP ACROSS THE EXTREME EASTERN COUNTIES AHEAD OF THIS LOW. WITH STRONG WINDS AND A COLD FRONT STALLING TO THE SOUTH OF HIGHWAY 50...A FEW VERY STRONG THUNDERSTORMS MAY DEVELOP AND PRODUCE SEVERE WEATHER FROM LATE MORNING INTO EARLY EVENING OVER THE FAR EASTERN COUNTIES. -JKH .LONG TERM... (WEDNESDAY NIGHT THROUGH TUESDAY) WRAPPED UP SYSTEM LIFTS SLOWLY TO THE NORTHEAST INTO THE CENTRAL PLAINS STATES BY THURS MORNING. STILL SOME DISCREPANCIES ON TIMING AND TRACK...WITH ECMWF AND NAM SLOWER THAN THE GFS. ECMWF IS ALSO A TAD FARTHER NORTH WITH THE TRACK OF THE SYSTEM. SHOULD STILL BE SEEING SOME FAIRLY WIDESPREAD SHOWERS/ISOLATED EMBEDDED THUNDERSTORMS...ESP ACROSS NORTHERN PORTIONS OF THE SOUTHEAST PLAINS...WHERE AXIS OF BEST ISENTROPIC LIFT WILL BE SITUATED ALONG NW QUAD OF UPPER LOW. PRECIPITATION WILL FALL AS SNOW ACROSS NORTHERN EL PASO COUNTY...WHERE ANOTHER COUPLE INCHES OF WILL BE POSSIBLE ON GRASSY SURFACES WED EVENING. AS FOR SEVERE THUNDERSTORM POTENTIAL...THE SFC LOW WILL HAVE SHIFTED INTO WESTERN KS BY 00Z...AND CONSEQUENTLY AXIS OF BEST INSTABILITY/THUNDERSTORMS WILL TRANSITION FROM PORTIONS OF SE CO...INTO WEST CENTRAL/NW KS. HOWEVER...18Z RUN HAS TRENDED SLOWER WITH THE NORTHEAST PROGRESSION OF THE SFC LOW...SO ITS POSSIBLE THERE WILL STILL BE SOME ISOLATED LOW TOPPED SUPERCELLS ACROSS EAST CENTRAL CO (PARTICULARLY KIOWA COUNTY) EARLY WED EVENING...ESP IF SYSTEM SLOWS DOWN ANY FURTHER. HOWEVER...EVENT SHOULD BE QUICKLY TRANSITIONING TOWARDS A MORE WIDESPREAD SHOWERY EVENT BY EARLY EVENING UNDER THE TROWAL. AFTER 06Z...WESTERLY MID LVL FLOW WILL HELP SHUT DOWN PRECIPITATION FOR THE SE MTS AND MOST OF THE I-25 CORRIDOR. SOME AREAS COULD COME CLOSE TO THE FREEZING MARK WED NIGHT...ESPECIALLY ALONG THE PALMER DIVIDE...BUT WITH PERSISTENT CLOUD COVER AND SOME MIXING DUE TO THE NORTH TO NORTHWEST WINDS...DON'T THINK THE DURATION WILL BE LONG ENOUGH TO WARRANT ANY FREEZE HIGHLIGHTS. COOLER AND UNSETTLED CONDITIONS WILL PERSIST INTO THURS...WITH SOME LINGERING SHOWERS ALONG THE FAR EASTERN PLAINS...DEPENDING ON HOW QUICKLY SYSTEM EXITS TO THE EAST. HAVE MAINTAINED SOME LOW ISOLATED POPS DURING THE AFTERNOON FOR THE EASTERN MTS AS WELL...WHERE SOME RESIDUAL MOISTURE/NE UPSLOPE FLOW MAY HELP TRIGGER SOME ISOLATED -SHRA. THESE SHOULD DIMINISH QUICKLY AFTER SUNSET. A DRYING AND WARMING TREND SETS IN FOR FRIDAY THROUGH THE WEEKEND. GFS LATCHES ON TO UPPER LOW FROM CANADA AND TRIES TO DUMBBELL IT BACK WESTWARD THROUGH THE CENTRAL PLAINS ON SAT...WHICH SENDS A REINFORCING COLD FRONT INTO THE AREA BY SAT AFTN. THIS WOULD SUGGEST ANOTHER UPSWING IN PRECIPITATION FOR SATURDAY/SAT NIGHT WITH ANOTHER COOL DOWN. ECMWF SEEMS MORE REASONABLE IN KEEPING THE FRONT FARTHER NORTH. COOLED OFF MAX TEMPS A COUPLE DEGREES FOR SAT...BUT DIDN/T GO AS COOL AS LATEST GFS SUGGESTS. THE NEXT UPPER TROF DROPS INTO THE GREAT BASIN NEXT TUESDAY. INCREASING SOUTHERLY FLOW MAY HELP BRING THE DRYLINE BACK WESTWARD BY THE MIDDLE OF NEXT WEEK...WITH MORE ACTIVE PATTERN FOR THUNDERSTORMS POSSIBLE FOR THE SOUTHEAST PLAINS. -KT && .AVIATION... VFR CONDITIONS AT ALL TERMINAL THROUGH THIS EVENING. A COLD FRONT IS FORECAST TO DROP SOUTH ACROSS THE PLAINS OVERNIGHT WITH A NORTHERLY WIND SHIFT EXPECTED AT KCOS AROUND 04Z/WED AND 08Z/WED AT KPUB. WINDS ARE FORECAST TO BE GUSTY BEHIND THE FRONT. SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE OVER THE HIGHER TERRAIN OVERNIGHT WITH IFR CONDITIONS EXPECTED TO DEVELOP AROUND KALS DURING THE MORNING. SHOWERS ARE EXPECTED VICINITY KCOS AND KALS AFTER 06Z/WED. && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ224-226>237. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM MDT WEDNESDAY FOR COZ059-061>063-066-068-072-074>076-078-079-081. WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 3 PM MDT WEDNESDAY FOR COZ058-060-073-080-082. && 51/31
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE PUEBLO CO 1056 AM MDT TUE MAY 10 2011 COZ058>089-093>099-111300- WESTERN MOSQUITO RANGE/EAST LAKE COUNTY ABOVE 11000 FT- LEADVILLE VICINITY/LAKE COUNTY BELOW 11000 FT- EASTERN SAWATCH MOUNTAINS ABOVE 11000 FT- WESTERN CHAFFEE COUNTY BETWEEN 9000 AND 11000 FT- CENTRAL CHAFFEE COUNTY BELOW 9000 FT- WESTERN MOSQUITO RANGE/EAST CHAFFEE COUNTY ABOVE 9000 FT- SAGUACHE COUNTY WEST OF CONTINENTAL DIVIDE BELOW 10000 FT- SAGUACHE COUNTY EAST OF CONTINENTAL DIVIDE BELOW 10000 FT- LA GARITA MOUNTAINS ABOVE 10000 FT- UPPER RIO GRANDE VALLEY/EASTERN SAN JUAN MOUNTAINS BELOW 10000 FT- EASTERN SAN JUAN MOUNTAINS ABOVE 10000 FT- DEL NORTE VICINITY/NORTHERN SAN LUIS VALLEY BELOW 8500 FT- ALAMOSA VICINITY/CENTRAL SAN LUIS VALLEY BELOW 8500 FT- SOUTHERN SAN LUIS VALLEY- NORTHERN SANGRE DE CRISTO MOUNTAINS BETWEEN 8500 AND 11000 FT- NORTHERN SANGRE DE CRISTO MOUNTAINS ABOVE 11000 FEET- SOUTHERN SANGRE DE CRISTO MOUNTAINS BETWEEN 7500 AND 11000 FT- SOUTHERN SANGRE DE CRISTO MOUNTAINS ABOVE 11000 FT- NORTHWESTERN FREMONT COUNTY ABOVE 8500 FT- WESTERN/CENTRAL FREMONT COUNTY BELOW 8500 FT- WET MOUNTAIN VALLEY BELOW 8500 FEET- WET MOUNTAINS BETWEEN 6300 AND 10000 FT- WET MOUNTAINS ABOVE 10000 FT- TELLER COUNTY/RAMPART RANGE ABOVE 7500 FT/PIKES PEAK BETWEEN 7500 AND 11000 FT-PIKES PEAK ABOVE 11000 FT- CANON CITY VICINITY/EASTERN FREMONT COUNTY- NORTHERN EL PASO COUNTY/MONUMENT RIDGE/RAMPART RANGE BELOW 7500 FT- COLORADO SPRINGS VICINITY/SOUTHERN EL PASO COUNTY/RAMPART RANGE BELOW 7400 FT-PUEBLO AND VICINITY/PUEBLO COUNTY BELOW 6300 FT- WALSENBURG VICINITY/UPPER HUERFANO RIVER BASIN BELOW 7500 FT- TRINIDAD VICINITY/WESTERN LAS ANIMAS COUNTY BELOW 7500 FT- CROWLEY COUNTY-LA JUNTA VICINITY/OTERO COUNTY- EASTERN LAS ANIMAS COUNTY-WESTERN KIOWA COUNTY- EASTERN KIOWA COUNTY-LAS ANIMAS VICINITY/BENT COUNTY- LAMAR VICINITY/PROWERS COUNTY-SPRINGFIELD VICINITY/BACA COUNTY- 1056 AM MDT TUE MAY 10 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL...EAST CENTRAL...SOUTH CENTRAL AND SOUTHEAST COLORADO. .DAY ONE...THIS AFTERNOON AND TONIGHT DANGEROUS FIRE WEATHER CONDITIONS ARE EXPECTED TO DEVELOP ACROSS THE SAN LUIS VALLEY AND THE EASTERN PLAINS. WIDESPREAD WIND GUSTS OF 30 MPH WILL COMBINE WITH LOW HUMIDITY VALUES AND DRY FUELS TO PRODUCE HAZARDOUS FIRE WEATHER CONDITIONS. SHOWERS AND EMBEDDED THUNDERSTORMS WILL BE POSSIBLE OVER THE CENTRAL MOUNTAINS THROUGH THIS EVENING. THE MAIN THREATS FROM THESE THUNDERSTORMS WILL BE LIGHTNING AND PEA SIZE HAIL. SNOW IS EXPECTED TO INCREASE ALONG THE CONTINENTAL DIVIDE AFTER MIDNIGHT AND BECOME MODERATE TO HEAVY BY TOMORROW MORNING..ESPECIALLY OVER THE CENTRAL AND EASTERN MOUNTAINS. SEVERAL INCHES OF SNOW ACCUMULATION ARE EXPECTED IN THE HIGHER ELEVATIONS BY TOMORROW MORNING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SNOW...HEAVY AT TIMES...WILL LIKELY BE FALLING ACROSS MOST OF NOT ALL OF THE MOUNTAINS WEDNESDAY MORNING. SNOW WILL ALSO LIKELY FALL AT ELEVATIONS DOWN TO 6000 FEET...BUT WILL START TO ACCUMULATE AT ELEVATIONS ABOVE 7000 FEET. THE HEAVIEST SNOW WEDNESDAY MORNING SHOULD FALL ACROSS THE NORTHERN SANGRE DE CRISTO MOUNTAINS...THE HIGHER ELEVATIONS OF THE WET MOUNTAINS...ALL OF THE CENTRAL MOUNTAINS...THE UPPER ARKANSAS RIVER VALLEY ABOVE 8000 FEET...AND THE HIGHER ELEVATIONS OF PIKES PEAK. THE HIGHER ELEVATIONS OF NORTHERN EL PASO COUNTY WILL ALSO LIKELY SEE SNOW WEDNESDAY MORNING...HOWEVER NEARLY ALL ACCUMULATIONS WILL OCCUR ON GRASSY SURFACES. IF THE SNOW IS HEAVY...IT MAY CAUSE ROADWAYS TO BECOME SLUSHY. SEVERE THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY WEDNESDAY ACROSS THE FAR EASTERN PLAINS. COUNTIES WHICH WILL HAVE THE HIGHEST PROBABILITY OF SEVERE STORMS WILL BE KIOWA...BENT AND PROWERS COUNTIES. DUE TO VERY FAVORABLE LOW LEVEL SHEAR...A TORNADO OR TWO WILL BE POSSIBLE. CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE ACROSS ALL OF THE REGION LATE TONIGHT THROUGH TOMORROW. SMALL HAIL UP TO 1/2 INCH IN DIAMETER WILL BE POSSIBLE WITH THE STRONGER STORMS. .SPOTTER INFORMATION STATEMENT... WEATHER CONDITIONS THAT MEET CRITERIA FOR SPOTTERS WILL BE POSSIBLE THIS AFTERNOON INTO THIS EVENING OVER THE HIGHER TERRAIN. 51/31
The national radar mosaic for the moment the first event began.
3 winter storm. 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, May 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: 316702, 316703, 316704.