4 hail, 2 tornado, 1 flash flood, as filed by the National Weather Service.
Every event with a place to put it; 1 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 2, 1:40 PM MST, 35 minutes earlier.
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
240 PM MDT THU AUG 2 2001
CURRENT VISIBLE SATELLITE SHOWS CONVECTION HAS BROKEN OUT OVER THE
FOOTHILLS AND ALONG THE CONVERGENCE ZONE FROM DOUGLAS THROUGH
EASTERN ADAMS COUNTIES. RAINFALL HAS BEEN INTENSE WITH SOME
STORMS...AND EXPECT A CONTINUATION OF THAT THROUGH THE EVENING WITH
PRECIPITABLE WATER VALUES OF 1.0 TO 1.25 INCHES...AND STORM MOTION
5 KTS OR LESS. WILL KEEP FLASH FLOOD WATCH UNTIL 10 PM. LAPS
ANALYSIS SHOWS SOME CIN IN AREAS NORTH OF INTERSTATE 76...AND RADAR
BACKS THIS UP WITH STORMS MOVING INTO THAT AREA COLLAPSING. WILL
THEREFORE KEEP HIGHEST POPS IN MOUNTAINS AND PLAINS SOUTH OF I-76
TONIGHT...BUT CANT RULE OUT STORMS LATER THIS AFTERNOON AND EVENING
IN AREAS FARTHER NORTH AS OUTFLOW BOUNDARIES INTERACT WITH PRIMED
AIRMASS.
LOOKS LIKE MORE OF THE SAME FOR FRIDAY ESPECIALLY IN/NEAR MOUNTAINS
WHERE CONVECTIVE TEMPS WILL BE REACHED. LOCALLY HEAVY RAIN WILL
AGAIN BE A THREAT WITH PRECIPITABLE WATER OVER AN INCH AND SLOW
STORM MOVEMENT. MODELS ALSO HINT AT SOME SORT OF ANOTHER UPPER
LEVEL DISTURBANCE APPROACHING THE AREA LATE IN THE DAY...AND THIS
MAY BE REALIZED IF WAVE OVER SOUTHERN ARIZONA MOVES SLOWLY NORTHWARD.
RIDGE RETROGRADES AND BUILDS OVER NORTHERN COLORADO AND SOUTHERN
WYOMING FROM LATE SATURDAY THROUGH THE EXTENDED WITH 500 MB HEIGHTS
INCREASING TO 600 DM. HOWEVER...FLOW UNDER THE RIDGE SHOULD BE VERY
WEAK SO MOISTURE SHOULD NOT BE SCOURED OUT. HOWEVER...WITH WARM
UPPER LEVEL TEMPS AND HINTS OF WEAK LEE TROFING...WILL DROP BACK TO
A SLIGHT CHANCE OF LATE AFTERNOON AND EVENIN,G STORMS OVER THE
PLAINS.
BARJENBRUCH
.DEN...FLASH FLOOD WATCH FOR THE FRONT RANGE FOOTHILLS AND PLAINS
UNTIL 10 PM MDT...ZONES 35>36..38>51.COZ030>051-022000- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1100 AM MDT THU AUG 2 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: A WEAK SOUTHWESTERLY FLOW ALOFT WILL BE OVER THE REGION THIS AFTERNOON AND TONIGHT. A WEAK UPPER LEVEL DISTURBANCE LOCATED OVER WESTERN NEW MEXICO IS EXPECTED TO MAKE ITS WAY INTO COLORADO BY THIS EVENING. LOW LEVEL MOISTURE COUPLED WITH AFTERNOON HEATING WILL ALLOW FOR THE AIRMASS TO BECOME INCREASINGLY UNSTABLE TODAY. THE MAIN FOCUS FOR THUNDERSTORMS WOULD APPEAR TO BE ALONG FRONT RANGE FOOTHILLS. SCATTERED THUNDERSTORMS WILL DEVELOP IN THE MOUNTAINS AND FRONT RANGE FOOTHILLS AFTER 1 PM. THE STORMS WILL MOVE SLOWLY INTO THE URBAN CORRIDOR AFTER 4 PM...EVENTUALLY SPREADING INTO THE NORTHEASTERN PLAINS AFTER 6 PM. DUE TO THE SLOW MOVEMENT OF THE STORMS...VERY HEAVY RAIN...1.5 TO 2.5 INCHES IN LESS THAN AN HOUR MAY OCCUR. FLASH FLOODING MAY DEVELOP WITH THE STORMS THAT BECOME STATIONARY OR TRAIN OVER THE SAME AREA. A FLASH FLOOD WATCH MAY BE NECESSARY FOR LATE THIS AFTERNOON AND EVENING ALONG THE FRONT RANGE FOOTHILLS AND URBAN CORRIDOR. A FEW STORMS COULD BECOME SEVERE IN THE PLAINS THIS EVENING... PRODUCING LARGE HAIL AND DAMAGING WINDS. SPOTTER ACTIVATION IS NOT ANTICIPATED...HOWEVER RAINFALL REPORTS WOULD BE GREATLY APPRECIATED. COOPER
COZ030>051-022100- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 110 PM MDT THU AUG 2 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: A WEAK SOUTHWESTERLY FLOW ALOFT WILL BE OVER THE REGION. IN ADDITION...A WEAK UPPER LEVEL DISTURBANCE LOCATED OVER NORTHWEST NEW MEXICO IS EXPECTED TO MAKE ITS WAY INTO COLORADO BY THIS EVENING. LOW LEVEL MOISTURE COUPLED WITH AFTERNOON HEATING WILL ALLOW FOR THE AIRMASS TO BECOME INCREASINGLY UNSTABLE THIS AFTERNOON AND EVENING. THE MAIN FOCUS FOR THUNDERSTORMS WOULD APPEAR TO BE ALONG FRONT RANGE FOOTHILLS. ANOTHER CONVERGENCE LINE EXTENDED FROM AROUND HOYT IN SOUTHWEST MORGAN COUNTY TO NEAR CASTLE ROCK. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP IN THESE AREAS INITIALLY...THEN GRADUALLY SPREAD NORTH AND EAST. DUE TO THE SLOW MOVEMENT OF THE STORMS...VERY HEAVY RAIN...2 TO 3 INCHES IN LESS THAN AN HOUR MAY OCCUR. FLASH FLOODING MAY DEVELOP WITH THE STORMS THAT BECOME STATIONARY OR TRAIN OVER THE SAME AREA. AS A RESULT...A FLASH FLOOD WATCH WATCH HAS BEEN ISSUED FOR THE FRONT RANGE FOOTHILLS...URBAN CORRIDOR AND NORTHEASTERN PLAINS THROUGH 10 PM. A FEW STORMS COULD BECOME SEVERE IN THE PLAINS THIS EVENING...MAINLY ALONG THE BOUNDARY MENTIONED EARLIER. THE STORMS COULD PRODUCE WIND GUSTS TO 60 MPH...HAIL UP TO AN INCH IN DIAMETER AND MAYBE EVEN A< SMALL TORNADO. SPOTTER ACTIVATION IS NOT ANTICIPATED...HOWEVER RAINFALL REPORTS WOULD BE GREATLY APPRECIATED. COOPER
The national radar mosaic for the moment the first event began.
4 hail, 2 tornado, 1 flash flood. Local standard time, as filed.
Severe thunderstorms producing heavy rain and hail either washed out or damaged several county roads in the Watkins and Bennett areas.
A small tornado touched down but did no damage.
A small tornado touched down but did no damage.
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: 5265002, 5264996, 5264997, 5264998, 5264999, 5265000, 5265001.