Thunderstorms produced very heavy rain and continuous lightning over Summit County. 17 inches of rain at local weather station, most of the rain fell in less than 3 hours.
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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.
Thunderstorms produced very heavy rain and continuous lightning over Summit County. The historic rainstorm in the town of Breckenridge produced 3.17 inches of rain at local weather station, most of the rain fell in less than 3 hours. A cooperative observer with the National Weather Service also recorded 3.59 inches of rainfall in east Breckenridge. The highest recorded 24-hr rainfall prior to this event occurred in the early 1890s when 2.6 inches was observed. Nearly 3,900 cloud to ground lightning strikes were also recorded during the 3-hr span. The steeple of the Father Dyer Church in Breckenridge sustained a direct hit from one of those strikes, damaging the historic structure.
The heavy rainfall produced a large landslide a few miles above Dillon where a section of treeline collapsed. Large amounts of sediment partially covered a section of Straight Creek, which is the main water supply to thousands in the area. In addition, mudslides closed a portion of State Highway 9 north of Dillon, and Airport Road in Breckenridge. Extensive flooding also forced the closure of Breckenridge Golf Course for several days.
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 Jul 18, 2:00 PM MST, 5 hours 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 300 PM MDT MON JUL 18 2011 .SHORT TERM...AS LIKE YESTERDAY...CONVECTION CONTINUES TO DEVELOP OVER THE MOUNTAINS AND FOOTHILLS WITH STEERING FLOW TO THE NNE. THE HIGH PRESSURE IS STILL CENTERED OVER THE CENTRAL PLAINS WITH MUCH OF THE EASTERN PLAINS OF COLORADO STILL CAPPED UNDER THE BIG HIGH. INTEGRATED PRECIPITABLE WATER TRENDS FROM GPS HAVE INCREASED OVER THE FRONT RANGE WITH PW READINGS JUST OVER AN INCH. MOST OF THE STORMS SHOULD REMAIN OVER THE FOOTHILLS...BUT THEY ARE CLOSE ENOUGH THAT AN OUTFLOW BOUNDARY COULD KICK UP AN ISOLATED STORM OVER WESTERN PORTIONS OVER THE URBAN CORRIDOR. FOR TUESDAY...THE HIGH WILL SHIFT EASTWARD AS THE UPPER TROF NOW OFF THE NRN CALIFORNIA COAST MOVES INLAND. THIS WILL ALLOW THE STORMS TO MOVE OFF THE FOOTHILLS AND ACROSS PORTIONS OF THE NORTHEAST PLAINS BY LATER TUESDAY AFTERNOON. THE STEERING FLOW WILL BE NORTHEAST AND ALLOW BETTER PROPAGATION OVER THE PLAINS. HAVE ADDED POPS TO THE GRIDS TO THE PLAINS ADJACENT FOR TUESDAY. HAVE ALSO LOWERED TEMPS A FEW DEGREES. MOS GUIDANCE CONTINUES TO BE TOO WARM IN MOST LOCALES. .LONG TERM...SOUTHWEST FLOW ALOFT WILL CONTINUE OVER THE STATE TUESDAY NIGHT AS THE UPPER RIDGE STAYS OVER THE MISSISSIPPI VALLEY. SHOULD CONTINUE SEEING SCATTERED THUNDERSTORMS OVER THE PLAINS TUESDAY EVENING WITH A FEW ISOLATED STORMS LASTING PAST MIDNIGHT OVER THE FAR EASTERN PLAINS. A WEAK DISTURBANCE ALOFT WILL PUSH A WEAK FRONT ACROSS NORTHEASTERN COLORADO WEDNESDAY. AN INCREASE IN MOISTURE WILL BE MOVING IN THE SOUTHWEST FLOW ALOFT FROM THE CURRENT TROPICAL STORM DORA WEDNESDAY AND THURSDAY...INCREASING PRECIPITABLE WATER VALUES. THIS DISTURBANCE AND ASSOCIATED FRONT WILL COMBINE WITH THE INCREASED MOISTURE TO BRING AT LEAST SCATTERED CONVECTIVE ACTIVITY TO NORTHEASTERN COLORADO WEDNESDAY AND THURSDAY. INCREASED POPS BOTH DAYS TO REFLECT THIS PATTERN. BOTH DAYS WILL SEE TEMPERATURES COOL BACK TOWARD AVERAGE...IN THE UPPER 80S TO LOWER 90S FOR THE PLAINS AND IN THE 70S AND LOW 80S FOR THE MOUNTAINS. THE THREAT WILL REMAIN TO BE LOCALLY HEAVY RAINFALL AS FREEZING LEVELS STAY QUITE HIGH WITH THE RIDGE NEARBY. DID NOT CHANGE THE FORECAST PAST THURSDAY...WITH 10-20 PERCENT POPS DURING THE AFTERNOONS AND EVENINGS THROUGH THE WEEKEND AND TEMPERATURES WARMER THAN AVERAGE AS THE UPPER RIDGE BEGINS TO MOVE BACK WEST AND OVER THE REGION. AS THE MOIST MONSOONAL FLOW CONTINUES OVER THE STATE...THE MAIN THREAT FROM SHOWERS IS GOING TO BE LOCALLY HEAVY RAINFALL. && .AVIATION...STILL NOT EXCITED ABOUT ANY STORMS OVER THE LOCAL TERMINALS THROUGH THIS EVENING. HOWEVER GIVEN THE PROXIMITY OF STORMS IN THE FOOTHILLS...THEY COULD KICK OUT A BOUNDARY WHICH COULD IGNITE STORMS OVER WESTERN PORTIONS...INCLUDING BJC. WILL MAINTAIN THE VCTS AT BJC BUT KEEP APA/DEN DRY. EXPECT AN INCREASE IN STORM COVERAGE ON TUESDAY AS STEERING FLOW TURNS SW TO NE AND MORE MOISTURE OVER THE URBAN CORRIDOR. HAVE ALREADY INTRODUCED A POP30 FOR KDEN LATER TUESDAY AFTN. && .HYDROLOGY...SCATTERED THUNDERSTORMS WITH SOME TRAINING OF ECHOES WILL KEEP A SMALL THREAT FOR FLASH FLOODING OVER THE EAST SLOPES THIS AFTERNOON AND EVENING IF STORMS CONTINUE TO FLOW OVER THE SAME AREAS. THE THREAT FOR FLASH FLOODING OVER THE FOOTHILL BURN SCARS IS ALSO LOW TODAY WITH MOST OF THE STORMS STAYING JUST WEST OF THE BURN AREAS. HOWEVER...A SLOW MOVING STORM CAN NOT BE RULED OUT FOR THE BURN AREAS. SOUTH PLATTE RIVER CONTINUES TO RUN HIGH OVER NORTHEAST COLORADO WITH FLOOD ADVISORIES CONTINUING FROM BALZAC TO JULESBURG FOR THE NEXT SEVERAL DAYS. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && ENTREKIN/KRIEDERMAN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1019 AM MDT MON JUL 18 2011 COZ030>051-191200- 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- 1019 AM MDT MON JUL 18 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL AGAIN FORM OVER THE FOOTHILLS AND MOUNTAINS THIS AFTERNOON AND EVENING. BRIEF HEAVY RAIN AND SMALL HAIL WILL ACCOMPANY THE THUNDERSTORMS. IF THUNDERSTORMS TRAIN OVER THE SAME AREA FLASH FLOODING WILL POSSIBLE. THE AIRMASS WILL BE TOO STABLE FOR THUNDERSTORMS OVER THE NORTHEAST PLAINS THROUGH TONIGHT. TEMPERATURES OVER THE EASTERN PLAINS WILL RANGE FROM THE MID 90S TO LOW 100S. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY WARMER TO MUCH WARMER THAN AVERAGE TEMPERATURES WILL CONTINUE THROUGH NEXT WEEKEND AS A STRONG RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE CENTRAL PART OF THE UNITED STATES. WILL BEGIN TO SEE SOME OF THE THUNDERSTORMS OVER THE HIGHER TERRAIN SPREAD OVER THE PLAINS TUESDAY....THEN MUCH MORE ON WEDNESDAY AS A WEATHER DISTURBANCE PUSHES A COOL FRONT DOWN THE PLAINS. PERIODS OF HEAVY RAINFALL WILL BE THE MAIN CONCERN THROUGH THE WEEK...AND COULD LEAD TO LOCALIZED FLOODING. WILL CONTINUE TO MONITOR THE FIRE BURN AREAS FOR ANY STRONGER STORMS THAT MAY MOVE OVERHEAD WITH THE HEAVY RAINFALL POSSIBILITY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. ENTREKIN/KRIEDERMAN
The Denver radar (KFTG), 132 km away, was scanning. The volume nearest the first event began at 02:31 UTC.
1 flash flood, 1 heavy rain, 1 lightning. Local standard time, as filed.
Severe thunderstorms caused flash flooding in Summit County around Breckenridge. Extensive flooding damaged the Breckenridge Golf Course. In addition, Airport Road was closed.
A mudslide partially closed a section of State Highway 9.
Lightning struck a church.
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, July 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: 338822, 338828, 338826.