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, 2:10 PM MST, 3 hours 50 minutes earlier.
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 310 PM MDT SAT AUG 2 2003 SHORT TERM DISCUSSION: THIS AFTN APPRS TO BE A CASE OF NE CO LYING ON THE WRONG SIDE OF THE THERMAL RIDGE ALOFT. ALL LTNG STRIKES UP TO THIS POINT IN THE AFTN HAVE OCCURRED ON THE WRN SIDE OF THE NEG TILTED 600 MB THERMAL RIDGE DEPICTED BY THE MESO-ETA. WITH WINDS ALOFT OUT OF THE NW...THERE MUST BE JUST ENOUGH WARM ADVECTION ALOFT TO KEEP A MID-LVL CAP IN PLACE. MTN AREAS HAVE SEEN A FEW WEAK SHOWERS THIS AFTN...AND ONE CELL IS CURRENTLY ON THE CO/WY BORDER BETWEEN KCYS AND FORT COLLINS. SATELLITE PICTURES DO NOT SHOW ANY SHORT WAVE DROPPING DOWN THE BACKSIDE OF THE RIDGE...SO I DONT EXPECT ANYTHING MORE THAN ISOLD COVERAGE THIS EVENING. FOR THE MOST PART THE PLAINS WL REMAIN TOO CAPPED TO SUSTAIN ANY CONVECTION. FOR TMRW...THE UPR RIDGE REMAINS OVR THE REGION...BUT MSTR FROM THIS AFTNS SHOWERS OVR ERN OREGON AND ID SHOULD COME BACK OVER CO AS IT REMAINS ENTRAINED IN THE NWLY FLOW ALOFT. LOW LVL MSTR FIELDS FROM THE ETA ALSO SHOW INCRSG MSTR FM THE SE...LEFT OVR FM LAST NITES MCS OVR THE SRN PLAINS. SYNOPTIC PATTERN WL BE SIMILAR TO THE PAST FEW DAYS...SO IDEA OF AFTN SHOWERS DVLPG OVR MTNS AND THEN SPREADING TO THE PLAINS LOOKS VALID AGAIN. WITH MSTR PRESENT AT BOTH LOW AND MID LVLS...THE CHANCE FOR LCLY HVY RAINS COULD RETURN. WL NEED TO WAIT TIL TMRW MRNG TO ASSESS HOW SLOW MOVING THE THUNDERSTORMS WL BE. KDRBY LONG TERM DISCUSSION: MODELS CONTINUE TO SHOW MID AND HIGH LEVEL MOISTURE ROTATING OVER THE RIDGE SUNDAY NIGHT. SHOULD BE A CLOUDY ENVIRONMENT WITHOUT A LOT OF SHEAR...DEEP STORMS BUT NOT A LOT OF CAPE...SO HEAVY RAIN IS PROBABLY THE MAIN THREAT. MARGINAL ENOUGH TO NOT GO CRAZY WITH RAIN FORECAST AT THIS POINT. MON LOOKS LIKE A BIT OF A DOWN DAY AS THERE IS DRYING BEHIND THE SHORT WAVE AND WARMING ALOFT STARTING TO COME IN FROM THE WEST. LESS CLOUD COVER SHOULD ALLOW TEMPERATURES TO REBOUND FROM THE MORNING COOLING AND GENERATE LATE DAY CONVECTION. FOR TUE THROUGH SAT...A GENERALLY WARM DRY PERIOD AS THE RIDGE CENTER WILL BE NEAR US. AT MIDWEEK WARM TEMPERATURES ALOFT SHOULD NEARLY QUELL THE CONVECTION...THOUGH THERE WILL LIKELY BE A GRADUAL INCREASE IN MOISTURE AGAIN. OPERATIONAL MRF HAS BEEN CONSISTENTLY LOWERING HEIGHTS ON THE WEST SIDE OF THE RIDGE MORE THAN ITS ENSEMBLE AND OTHER MODELS...SO I WILL DELAY THE TREND TOWARD LESS HEAT AND MORE MOISTURE AT THE END OF THE WEEK. GIMMESTAD .DEN...NONE.
COZ030>051-031200- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1115 AM MDT SAT AUG 02 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT A FEW SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS NORTHEAST COLORADO THIS AFTERNOON AND EVENING. SCATTERED THUNDERSTORMS WILL FIRST DEVELOP OVER THE MOUNTAINS AND FOOTHILLS BY 1 PM AND THEN SPREAD SOUTHEASTWARD ACROSS THE PLAINS THROUGH THE AFTERNOON AND EVENING. INSTABILITY AND WIND SHEAR IN THE ATMOSPHERE WILL BE STRONG ENOUGH TO SUPPORT THE DEVELOPMENT OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. THE HIGHEST THREAT OF SEVERE WEATHER IS ALONG AND EAST OF THE INTERSTATE 25 CORRIDOR. THE AFTERNOON AND EVENING THUNDERSTORMS WILL ALSO BE CAPABLE OF PRODUCING AN INCH OF RAIN IN 20 TO 30 MINUTES. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY ABUNDANT MOISTURE WILL LINGER OVER THE AREA SUNDAY AND THERE WILL BE A GOOD CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS...PARTICULARLY OVER THE HIGH COUNTRY. AS AN UPPER HIGH PRESSURE RIDGE APPROACHES OUR VICINITY...THE FLOW ALOFT WILL WEAKEN AND THE STORMS WHICH DEVELOP SUNDAY WILL BE SLOW MOVING AND CAPABLE OF PRODUCING HEAVY RAIN. FLOODING MAY BE A CONCERN IF THE STORMS MOVE ACROSS THE BURN AREAS. WIND SHEAR...HOWEVER...WILL BE LESS THAN SATURDAY AND THERE WILL BE LESS OF A THREAT OF SEVERE WEATHER. MONDAY AND BEYOND...THE ATMOSPHERE WILL BEGIN TO DRY OUT SOMEWHAT AS HIGH PRESSURE MOVES DIRECTLY OVER COLORADO. HOWEVER...THE FLOW ALOFT WILL BE VERY WEAK AND SOME MOISTURE WILL BE TRAPPED UNDER THE HIGH PRESSURE RIDGE. THUS...THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS EACH DAY WITH TEMPERATURES NEAR SEASONAL NORMALS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED ON THE PLAINS AFTER 3 PM. DANKERS/GIMMESTAD
The Denver radar (KFTG), 61 km away, was scanning. The volume nearest the first event began at 01:02 UTC.
1 flash flood. Local standard time, as filed.
Heavy rain producing thunderstorms triggered flash flooding at the confluence of Westcreek and Trail Creek in the Hayman burn area. Significant erosion was observed along the Trail Creek drainage. Vegetation along the drainage was flattened with mud and silt.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2003Every state in 2003This day in weather historyWarnings in Colorado, August 2003
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: 5374665.