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 Jul 11, 2:00 PM MST, 7 hours 30 minutes earlier.
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 300 PM MDT WED JUL 11 2001 COLORADO AND THE ROCKY MOUNTAIN WEST REMAINS DIRECTLY CONNECTED TO THE ITCZ FOR ANOTHER DAY. THIS CONVEYOR BELT OF MOISTURE EXTENDS FROM 10DEG N LAT NORTHWARD ACROSS MEXICO AND UP TO MONTANA. WATER VAPOR LOOP CURRENTLY SHOWING AN ABSENCE OF SIGNIFICANT DYNAMIC LIFT...UNLIKE YESTERDAYS MORE PRONOUNCED CYCLONIC SPIN MOVING NORTH OUT OF NEW MEX. ETA ANALYSIS DOES RECOGNIZE A WEAK VORT CENTER WHICH MATCHES PRETTY WELL WITH SOME SLIGHT H2O VAPOR BRIGHTENING THIS MORNING OVR THE SAN JUANS WITH ANOTHER ONE ABOUT 200 MILES BEHIND IT. THIS FIRST AREA MAY BE THE KICKER DE JOUR FOR THE BOU CWA. THERE ALSO APPEARS TO BE A WEAK STATIONARY BOUNDARY ALONG THE FRONT RANGE AS SEEN IN THE MSAS PRESSURE AND MOISTURE FIELDS. THIS WILL NEED TO BE WATCHED TO SEE IF CONVECTION FORMS ON A BOUNDARY AWAY FROM THE URBAN CORRIDOR LIKE MONDAY OR IF CONVECTION INITIATES ALONG THE FOOTHILLS LIKE YESTERDAY. THETA-E RIDGE IS ORIENTED FROM SOUTHEAST TO NORTHWEST OVR WASH AND NRN WELD COUNTIES. THE DEN MORNING SOUNDING IS A LITTLE WETTER THAN YESTERDAYS...HOWEVER SOMEWHAT CONCERNED ABOUT THE WEAK CAP BETWEEN 580MB-550MB. THIS MAY NOT MEAN MUCH FOR LOCATIONS IN AND NEAR THE FOOTHILLS...BUT MAY SUPRESS CONVECTION UNTIL LATER IN THE EVE ON THE PLAINS. MESO-ETA FCST SOUNDINGS ON THE PLAINS CONTAIN 1900-2400 J/KG OF ENERGY WHICH IS LESS THAN THE DENVER POTENTIAL. WITH ANY REASONING...WITH HEALTHY AMOUNTS OF SFC MOISTURE...SEE NO REASON TO GO LESS THAN SCT COVERAGE FOR CWA AND A FLASH FLOOD WATCH MAY BE NEEDED AGAIN. THROUGH TIME...MDLS START TO SLOWLY RETROGRADE THE UPPER HIGH TO THE WEST. FOR THURSDAY AND FRIDAY...DECENT MID AND UPPER LVL MOISTURE FROM THE TROPICS IS STILL UPON THE STATE. MESO-ETA STILL SHOWS AN UNSTABLE SOUNDING WITH HIGH POSITIVE ENERGY AND SOUTHEASTERLY SFC FLOW TO HOLD SFC DEW POINTS UP EACH DAY. SEE NOTHING IN THE THURS-FRI PD TO SCOUR THE SFC DRY. AGAIN DYNAMICS NEARLY IMPOSSIBLE TO DETECT...BUT AVN AND ETA SWINGS A SERIES OF VORT CENTERS AROUND UPPER RIDGE WHICH COULD BE FROM BURNT OUT ORGANIZED CONVECTION COMING OUT OF MEX. SCT COVERAGE SHD AGAIN BE THE RULE. EXTENDED PD SATURDAY THROUGH WEDNESDAY...PREDICTED CENTER OF UPPER HIGH RESTS OVR NEW MEX BY SATURDAY AS DRYER PACIFC AIR MOVES OVER THE GREAT BASIN. AVN CONTINUES TO HOLD HIGHER RHS IN THE LOWER LVLS OF THE EAST. RIDGE WEAKENS AND ELONGATES FOR SUNDAY AND MONDAY BUT REBUILDS OVER THE SOUTHERN HALF OF THE STATE TUESDAY AND WEDNESDAY. WOULD EXPECT SUBSIDENCE TO HAVE GREATEST EFFECT ON THUNDERSTORM DEVELOPMENT AND COVERAGE FOR TUESDAY AND WEDNESDAY AND WILL TRIM POPS ACCORDINGLY. TEMP GUIDANCE HOLDS TEMPS WITHIN SEASONAL NORMS. FREDIN .DEN...NONE.
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
0725 PM MDT WED JUL 11 2001
...PRELIMINARY STORM REPORT FOR JULY 11 2001...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0320 PM 10 E KIOWA CO 1.00 INCH HAIL
07/11/01 ELBERT
0645 PM KEENSBURG CO 0.75 INCH HAIL
07/11/01 WELD
RAYCOZ042-044>051-120215- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER COLORADO 759 PM MDT WED JUL 11 2001 ...SEVERE THUNDERSTORM WATCH FOR PORTIONS OF NORTHEAST COLORADO HAS EXPIRED... SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER NORTHEAST COLORADO THIS EVENING HOWEVER THE THREAT OF WIDESPREAD SEVERE WEATHER HAS DIMINISHED SO THE SEVERE THUNDERSTORM WATCH WILL BE ALLOWED TO EXPIRE. RPK
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
0808 PM MDT WED JUL 11 2001
...PRELIMINARY STORM REPORT FOR JULY 11 2001...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0320 PM 10 E KIOWA CO 1.00 INCH HAIL
07/11/01 ELBERT
0553 PM 5 SE BOULDER CO 0.75 INCH HAIL
07/11/01 BOULDER
0645 PM KEENSBURG CO 0.75 INCH HAIL
07/11/01 WELD
0715 PM LONGMONT CO 0.75 INCH HAIL
07/11/01 BOULDER
RAYThe national radar mosaic for the moment the first event began.
1 flash flood. Local standard time, as filed.
Heavy rain caused flash flooding in the vicinity of Nunn. The floodwaters made several streets and intersections impassable.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2001Every state in 2001This day in weather historyWarnings in Colorado, July 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: 5272370.