High pressure over eastern Colorado and a stationary upper trough over the Pacific allowed monsoonal moisture to continue streaming into the area. Slow moving thunderstorms produced heavy rain which caused minor flooding and debris flows in Ouray County.
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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 episode as NWS GJT wrote it up.
High pressure over eastern Colorado and a stationary upper trough over the Pacific allowed monsoonal moisture to continue streaming into the area. Slow moving thunderstorms produced heavy rain which caused minor flooding and debris flows in Ouray County.
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 Grand Junction, CO wrote its last area forecast discussion before the first event at Sep 4, 1:36 PM MST, 3 hours 9 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 236 PM MDT WED SEP 4 2013 .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 235 PM MDT WED SEP 4 2013 STRONG HIGH PRESSURE OVER THE CENTRAL ROCKIES AND MIDWEST WITH STRONG LOW PRESSURE OFF THE WEST COAST WILL CONTINUE RATHER STAGNANT CONDITION THE NEXT DAY AND A HALF. MOISTURE WILL CONTINUE TO RECYCLE WITHIN THE HIGH BUT THERE ARE NO DYNAMIC FEATURES TO FOCUS CONVECTIVE DEVELOPMENT. WINDS ALOFT WILL REMAIN LIGHT SO NO VERTICAL SHEAR WILL BE PRESENT. THIS LEADS A CONTINUATION OF DIURNAL TERRAIN LOCKED SHOWERS AND THUNDERSTORMS. OUTFLOWS FROM THESE WILL HELP SOME STORMS TO DRIFT OFF THE RIDGES AND OVER THE VALLEYS. MAX AND MIN TEMPS WILL REMAIN 5-10 DEGREES ABOVE NORMAL. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 235 PM MDT WED SEP 4 2013 UPPER LOW OVER THE PACIFIC NORTHWEST FRIDAY SLOWLY TRACKS TO THE EAST THIS PERIOD...CROSSING THE NORTHERN ROCKIES SUNDAY AND THEN LIFTING ACROSS THE UPPER GREAT LAKES AS AN OPEN TROUGH ABOUT TUESDAY. CONCURRENTLY...THE UPPER HIGH GETS PUSHED EAST AND FLATTENS BEFORE REBOUNDING OVER THE ROCKIES WEDNESDAY BEHIND THE LOW/TROUGH. SOME DIFFERENCES IN THE EASTWARD SPEED OF THE LOW BECOME MORE NOTICEABLE EARLY NEXT WEEK...BUT OVERALL MODELS APPEAR IN REASONABLE AGREEMENT. THE FORECAST CHALLENGE WILL BE THE EXTENT OF ANY IMPACT FROM THE LOW PASSING TO OUR NORTH. MODELS CONTINUE TO SUGGEST A WEAK COOL FRONT REACHING NE UT/NW CO SUNDAY NIGHT OR MONDAY...BUT ITS SOUTHWARD PROGRESS REMAINS DEBATABLE. 12Z MEX GUIDANCE SHOWS ABOUT 5 DEGREES OF COOLING BETWEEN SUNDAY AND TUESDAY INDICATING A RETURN TO MORE NORMAL TEMPS MONDAY-WEDNESDAY. AS THE LOW PASSES TO OUR NORTH SUNDAY-MONDAY...IT MAY ALSO DRAW UP SOME MOISTURE AHEAD AND SOUTH OF THE FRONTAL BOUNDARY FOR PERHAPS AN UPTICK IN PRECIPITATION CHANCES EARLY NEXT WEEK. UNTIL THE DETAILS GET SORTED OUT...WILL FOLLOW THE CONSENSUS FORECAST WHICH BASICALLY CONTINUES THE DIURNAL PATTERN OF MAINLY AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EACH DAY WITH A GRADUAL COOLING TO MORE NORMAL LEVELS EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 235 PM MDT WED SEP 4 2013 VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES TONIGHT THROUGH THU EVENING. SHOWERS AND THUNDERSTORMS WILL BE PREDOMINANTLY OVER THE HIGHER ELEVATIONS...SO THERE SHOULD BE LOCALIZED MOUNTAINTOP OBSCURATIONS UNTIL ABOUT 03Z. OUTFLOWS FROM THE OROGRAPHIC THUNDERSTORMS MAY HELP A FEW STORMS TO MIGRATE OVER THE VALLEYS AND AFFECT AREA AIRPORTS. AS A RESULT...TAF SITES...KASE...KEGE...AND KRIL HAVE ABOUT A 15% CHANCE OF MVFR VSBYS IN MODERATE SHOWERS UNTIL 03Z. SIMILAR ACTIVITY WILL DEVELOP AFTER 18Z THU. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM...CC LONG TERM...JAD AVIATION...CC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 545 AM MDT WED SEP 4 2013 COZ001>014-017>023-UTZ022>025-027>029-051145- LOWER YAMPA RIVER BASIN-CENTRAL YAMPA RIVER BASIN- ROAN AND TAVAPUTS PLATEAUS-ELKHEAD AND PARK MOUNTAINS- UPPER YAMPA RIVER BASIN-GRAND VALLEY-DEBEQUE TO SILT CORRIDOR- CENTRAL COLORADO RIVER BASIN-GRAND AND BATTLEMENT MESAS- GORE AND ELK MOUNTAINS/CENTRAL MOUNTAIN VALLEYS- CENTRAL GUNNISON AND UNCOMPAHGRE RIVER BASIN- WEST ELK AND SAWATCH MOUNTAINS-FLATTOPS- UPPER GUNNISON RIVER VALLEY-UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE- NORTHWEST SAN JUAN MOUNTAINS-SOUTHWEST SAN JUAN MOUNTAINS- PARADOX VALLEY/LOWER DOLORES RIVER- FOUR CORNERS/UPPER DOLORES RIVER-ANIMAS RIVER BASIN- SAN JUAN RIVER BASIN-SOUTHEAST UTAH-EASTERN UINTA MOUNTAINS- EASTERN UINTA BASIN-TAVAPUTS PLATEAU-ARCHES/GRAND FLAT- LA SAL AND ABAJO MOUNTAINS-CANYONLANDS/NATURAL BRIDGES- 545 AM MDT WED SEP 4 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ONCE AGAIN THIS AFTERNOON AND EVENING...PRIMARILY OVER THE HIGHER TERRAIN. BRIEF HEAVY RAIN WILL BE POSSIBLE WHICH MAY RESULT IN LOCALIZED RUNOFF PROBLEMS...ESPECIALLY IN STEEP TERRAIN AND OVER BURN SCARS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY EXPECT SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGHOUT THE PERIOD FAVORING HIGHER TERRAIN. A PERSISTENT INFLUX OF MONSOON MOISTURE POSES THE THREAT OF LOCALIZED RUNOFF PROBLEMS EACH DAY INTO EARLY NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The national radar mosaic for the moment the first event began.
1 heavy rain, 1 debris flow. Local standard time, as filed.
A storm spotter in the town of Ouray received 0.7 inches of rain within one hour. The heavy rainfall caused minor street flooding.
Heavy rainfall caused mud and debris flows in Senator Gulch past Angle Creek.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2013Every state in 2013This day in weather historyWarnings in Colorado, September 2013
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: 517453, 517455.