6 hail, 4 thunderstorm wind, 2 lightning, 1 tornado, as filed by the National Weather Service.
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 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 Aug 1, 1:55 PM MST, 1 hour 35 minutes earlier.
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 255 PM MDT WED AUG 01 2001 PERSISTENT UPR LVL RDG WL BE DOMINATING NERN AND N-CENTRAL CO WX FOR THE NEXT SEVERAL DAYS. FOR THE NEXT DAY OR SO...PLUME OF MID AND UPR LVL MSTR WL BE CROSSING THE AREA TO MAINTAIN THE CHANCE OF AFTN AND EVENING SHOWERS. AT THIS TIME...SHOWER ACTIVITY OVR MTNS HAS BE MOVG ALONG WHILE WEAK UPSLP FLOW CONTS ACRS THE PLAINS. ACARS SNDGS SHOWED SOME MID LVL CAPPING OF THE AMS TIL ABT 20Z...BUT LATEST DATA SHOWS ABT 600 J/KG CAPE AND LTL CONVECTIVE INHIBITION. TUTT LOW IS PRESENTLY QUITE ORGANIZED OVR WRN NM...BUT MODELS INDICATE THAT IT WL LOSE ITS IDENTITY ON THUR AS IT ROTATES NWD ARND THE UPR RDG. RH FIELDS CONT HINTING AT A CONTINUATION OF MONSOONAL MSTR ALOFT. AS LONG AS THIS CONTS...WL HAVE TO CONT MENTIONING AFTN AND EVENING SHOWERS IN THE FCST. OVR THE WEEKEND AND INTO NEXT WEEK...THE MRF SHOWS THE CENTER OF THE UPR LVL RIDGE BLDG NWWD AND SETTING UP OVR SWRN WY. HGTS ALSO RISE TO NEAR 600 DM. THIS SHIFT IN THE UPR AIR PATTERN COULD DECREASE THE CHANCES OF SHOWERS...BUT DIFFERENCES ARE NOT WORTH M7ENTIONING AT THIS POINT. TEMPS ARE GOING TO CONT ABV SEASONAL VALUES...AND CURRNT FCST HAS THESE FEATURES COVERED. KDRBY .DEN...NONE
COZ030>051-312000- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1035 AM MDT WED AUG 01 2001 THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES ADAMS ARAPAHOE BOULDER CLEAR CREEK DENVER DOUGLAS ELBERT GILPIN GRAND JACKSON JEFFERSON LARIMER LINCOLN LOGAN MORGAN PARK PHILLIPS SEDGWICK SUMMIT WASHINGTON WELD SYNOPSIS: MOISTURE LEVELS WILL CONTINUE TO INCREASE THROUGH THIS EVENING AS THE PLUME OF MONSOONAL MOISTURE STREAMS INTO COLORADO FROM NEW MEXICO AND ARIZONA. A SURGE OF HIGH PRESSURE OVER WYOMING AND AN ASSOCIATED WEAK FRONT ACROSS FAR NORTHEAST COLORADO WILL CONTINUE TO SLOWLY SLIP SOUTHWARD THROUGH NORTHEAST COLORADO THIS AFTERNOON. THIS WILL INCREASE THE NORTHEASTERLY UPSLOPE FLOW AND BRING MORE MOISTURE TO THE REGION. THE ATMOSPHERE IS RATHER STABLE THIS MORNING DUE TO THE INITIAL CLOUD COVER OVER THE MOUNTAINS AND URBAN CORRIDOR AND THE WEAK FRONTAL SYSTEM TO THE NORTH. HOWEVER...THERE DOES APPEAR TO BE SOME CLEARING WORKING IN FROM THE SOUTH. THUNDERSTORM DEVELOPMENT WILL BE LATER TODAY DUE TO THE INITIAL INSTABILITY...BUT WILL BEGIN TO FIRE OVER HIGHER TERRAIN IN THE SOUTHERN FOOTHILLS AND EXTENDING OUT OVER THE PALMER DIVIDE BY EARLY AFTERNOON...THEN ACROSS THE URBAN CORRIDOR AFTER 3 PM. THE ATMOSPHERE IS EVEN MORE STABLE ACROSS THE FAR NORTHEAST PLAINS...AND STORMS THERE MAY NOT DEVELOP UNTIL THE EVENING HOURS. THE MAIN THREAT TODAY WILL BE HEAVY RAIN WITH THUNDERSTORMS AND POSSIBLE MINOR FLOODING IN URBAN AREAS AND SMALL STREAMS. RAINFALL AMOUNTS OF UP TO 2 INCHES PER HOUR IS POSSIBLE WITH THE STRONGER STORMS. AN ISOLATED SEVERE STORM CAN NOT BE RULED OUT AS THE SHEAR PROFILE AND INSTABILITY WILL STILL BE SUFFICIENT THROUGH THE EARLY EVENING HOURS...ESPECIALLY ACROSS THE PALMER DIVIDE AND STRETCHING INTO WASHINGTON COUNTY AND THE FAR NORTHEAST PLAINS. HAIL UP TO ONE INCH IN DIAMETER MAY OCCUR WITH THE STRONGER STORMS. OVERALL...SPOTTER ACTIVATION IS NOT ANTICIPATED WITH THE MAIN THREAT OF HEAVY RAIN. HOWEVER...HEAVY RAIN REPORTS AND HAIL OCCURENCES FURTHER EAST WILL BE APPRECIATED. ENTREKIN NSWE
The Denver radar (KFTG), 64 km away, was scanning. The volume nearest the first event began at 23:35 UTC.
6 hail, 4 thunderstorm wind, 2 lightning, 1 tornado. Local standard time, as filed.
Lightning coupled with strong thunderstorm winds knocked out power to approximately 10,000 Excel Energy customers.
A 34-year-old man on the South Platte River bike path received minor injuries when lightning struck a nearby tree.
A small tornado touched down but did no damage.
Intense thunderstorm winds to 70 mph snapped tree limbs 8 inches in diameter.
Damaging thunderstorm winds to 80 mph blew over an 8-foot by 10-foot shed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2001Every state in 2001This day in weather historyThe tornado archive for Colorado, 2001Warnings in Colorado, August 2001
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: 5264995, 5264994, 5264983, 5264984, 5264985, 5264986, 5264987, 5264988, 5264989, 5264990, 5264991, 5264992, 5264993.