5 flash flood, as filed by the National Weather Service.
Every event with a place to put it; 5 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 18, 12:50 PM MST, 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 150 PM MDT WED AUG 18 2004 .SHORT TERM DISCUSSION...HVY RAIN EVENT QUICKLY BEGINNING ACRS THE DISTRICT THIS AFTN. STG NELY FLOW HAS ALREADY DVLPD AS SFC CDFNT HAS BEEN SVRL HRS AHD OF THIS MRNGS MDL GDNC. NELY SFC WNDS ARE UP TO 15 KTS AT NMRS SITES ACRS THE PLAINS THIS AFTN WHILE PLATTEVILLE PROFILER INDG NELY WNDS OF 20 KTS UP TO 600 MB. DESPITE THE UPSLOPE FLOW...CONVECTIVE TEMPS WERE REALIZED AN HOUR AGO...UNDOUBTEDLY AIDED BY THE HEAD START FM THE WARM OVERNIGHT TEMPS. NMRS HVY RAIN SHOWERS AND TSTMS HV DVLPD...RADAR ESTIMATES OVER 2 INCHES OF RAIN NR PINGREE PARK IN LARIMER COUNTY DURING THE LAST HR OR SO. GIVEN ALL THIS...HAVE MOVED UP THE FLASH FLOOD WATCH TO INCLUDE THIS AFTERNOON. PCPN SHOULD CONTINUE INTO THE OVERNIGHT HR WITH DEEP AND STG NELY FLOW ACRS THE FNT RANGE BEFORE AREA OF RAIN TAPERS OFF AND SINKS SOUTH OUT OF THE AREA. STORM TOTAL PCPN THRU 12Z THURS MRNG IS NEARLY 4 INCHES OVER THE FOOTHILLS...WHICH UNFORTUNATELY MAY BE REALIZED IN A FEW PLACES GIVEN THE VERY WK STORM MOTION. FLASH FLOOD WATCH WILL CONTINUE OVERNIGHT NEEDLESS TO SAY. TMRW...STG AND DP ELY FLOW WL CONT THRU MOST OF THE DAY. MUCH OF THE PLAINS WL RMN SOCKED IN WITH STRATUS AND THUS NUMERICAL GDNC TEMPS ARE ONLY IN THE LWR TO MID 60S. SOME SCT SHWRS WL DVLP IN THE HIR TRRN...BUT MOST WL NOT SURVIVE LONG IN THE STBL ATM ACRS THE PLAINS. OVERALL...A VERY COOL AND DAMP DAY XPCTD THURS. .LONG TERM DISCUSSION...THE UPPER TROF WILL BE EXITING TO THE EAST OF COLORADO THURSDAY EVENING AS A WEAK TO MODERATE NORTHWESTERLY FLOW ALOFT DEVELOPS. INTERACTIVE SOUNDINGS FOR LATE THURSDAY AFTERNOON STILL SHOW SUFFICIENT CAPE WITH PW VALUES AROUND .90 INCHES...FOR SCT THUNDERSTORMS ALONG THE FRONT RANGE. FURTHER E IT MAY JUST BE SHOWERS AS PLENTY OF MSTR WILL BE PRESENT IN THE EVENING BUT THERE WILL BE LITTLE IF ANY CAPE. MAIN DRYING ALOFT WILL OCCUR ON FRIDAY AS ANY REMNANTS OF THE UPPER TROF ARE WELL TO THE EAST. IN SPITE OF DRYING ON FRIDAY...DRIER AIR WILL GIVE WAY TO MORE HEATING SO WILL MAINTAIN A CHANCE OF THUNDERSTORMS...EXPECIALLY ALONG THE FRONT RANGE. A WEAK FRONT IS PROGGED TO SLIP INTO THE NORTHEAST PLAINS FRIDAY NIGHT. THIS MAY HELP TO MAINTAIN SOME LOW LEVEL MSTR OVER THE NORTHEAST PLAINS FOR SATURDAY. IN ADDITION A WEAK UPPER LEVEL TROF EMBEDDED IN THE FLOW IS PROGGED TO SLIP ACROSS NRN CO SATURDAY AFTN. AS A RESULT...THERE LOOKS TO BE ENUF FVBL INGREDIENTS FOR A CONTINUED CHANCE OF THUNDERSTORMS ON SATURDAY ALONG THE FRONT RANGE. FOR SUNDAY THROUGH WEDNESDAY...FLOW ALOFT BECOMES WEST SOUTHWESTERLY AS AN ANOTHER TROF MOVES INTO THE WRN U.S. DRIER AS WELL BUT SEE NO REASON TO NIX SLGT CHANCE IN THE ZONES AT THIS TIME. WILL MAINTAIN TEMPERATURE AT OR SLIGHTLY ABV SEASONAL NORMALS. && .BOU...WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH THIS AFTERNOON THROUGH TONIGHT FOR FRONT RANGE FOOTHILLS AND URBAN CORRIDOR... CO ZNS 035-036-038>041. && 046/COOPER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1049 AM MDT WED AUG 18 2004 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- 1049 AM MDT WED AUG 18 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT A WET AND SLOW MOVING STORM SYSTEM WILL APPROACH THE AREA TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING THIS AFTERNOON WILL BECOME MORE WIDESPREAD LATER THIS AFTERNOON AS A COLD FRONT DROPS INTO THE NORTHEAST PLAINS. STRONG UPSLOPE FLOW WILL DEVELOP THIS EVENING WHICH SHOULD CAUSE PRECIPITATION TO BECOME MODERATE TO HEAVY IN THE FOOTHILLS AND ADJACENT AREAS OF THE PLAINS. THE WIDESPREAD PRECIPITATION WILL PERSIST OVERNIGHT RESULTING IN UP TO THREE INCHES OF RAIN IN THE FOOTHILLS. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR TONIGHT FOR THE FOOTHILLS AND URBAN CORRIDOR. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY COOLER TEMPERATURES ALONG WITH SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED THURSDAY AND FRIDAY. SLIGHTLY DRIER AND WARMER CONDITIONS WILL RETURN TO THE REGION SATURDAY THROUGH TUESDAY AS AN UPPER LEVEL RIDGE SLOWLY MOVES OVER THE STATE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. 046/COOPER
The Cheyenne radar (KCYS), 77 km away, was scanning. The volume nearest the first event began at 20:27 UTC.
5 flash flood. Local standard time, as filed.
Heavy rain caused flash flooding which forced the closure of several roads north of Glen Haven. Flash flooding was also reported in Miller Fork.
Heavy rain caused Trail Creek to jump its banks. As a result, the ensuing flash floods washed out several county roads and private driveways along the creek.
Heavy rain caused flash flooding across much of Denver. A rain gage at City Park registered 4.37 inches of rainfall in the deluge. Several roads in and around the city had to be closed due to floodwaters, stranding vehicles. The fire department conducted at least 15 water rescues. One driver, nearly drowned, when he made a wrong turn into a retaining pond. Four men who witnessed the accident, were able to save the man before his car became completely submerged. Considerable street flooding was reported in the vicinity of the old Stapleton Airport. Standing water over 6 inches deep were reported near I-70 and Quebec, I-225 south of I-70, and I-25 near 6th Ave. Floodwaters reached 8 feet deep in some low lying areas as sewers became clogged and the storm runoff pipes were unable to handle the heavy flow of water.
Heavy rain caused additional flash flooding south of Denver. Floodwaters forced the closure of Stonegate Parkway near Jordan Road and Lincoln Avenue. Flooding was also reported on Meridion Blvd., near I-25.
Several intersections in Centenniel and southern Aurora were impassable due to floodwaters. Two feet of water covered portions of the roadway near Park Meadows Mall. One person had to be rescued near the intersection of Arapahoe Road and Liverpool.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2004Every state in 2004This day in weather historyWarnings in Colorado, August 2004
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: 5420251, 5420252, 5420253, 5420254, 5420255.