Persistent subtropical moisture within a light southerly flow aloft over the region resulted in thunderstorms that produced heavy rainfall in many areas of western Colorado.
Every event with a place to put it. 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 episode as NWS GJT wrote it up.
Persistent subtropical moisture within a light southerly flow aloft over the region resulted in thunderstorms that produced heavy rainfall in many areas of western Colorado.
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 Jul 19, 1:52 PM MST, 1 hour 48 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 252 PM MDT TUE JUL 19 2011 .SHORT TERM...TONIGHT THROUGH FRIDAY... MOST THUNDERSTORM ACTIVITY HAS STARTED OVER THE SOUTHERN MTNS BUT WILL SPREAD NORTHWARD WITH FURTHER AFTERNOON HEATING. THE TROPICAL DISTURBANCE HAS LOST SOME COHESION BUT IS STILL PROVIDING SOME BROAD UPPER SUPPORT MAINLY FOR THE NORTHERN HALF OF THE FORECAST AREA THIS AFTERNOON AND EARLY EVENING. MOST STORMS ARE MOVING TO THE NE AT 10-15 MPH BUT A FEW ARE REBUILDING ON THEIR SOUTH FLANKS FOR MUCH SLOWER STORM MOTION. VERY HEAVY RAINFALL HAS ALREADY FALLEN IN THE DARK CANYON WILDERNESS TO THE SOUTHERN PORTION OF CANYONLANDS NP THIS AFTERNOON...IN THE TAVAPUTS AND ALSO IN THE MOUNTAINS ABOVE CARBONDALE. WE EXPECT TO BE ISSUING FURTHER FLASH FLOOD PRODUCTS THROUGH THE AFTERNOON. THIS EVENING THE TROPICAL DISTURBANCE EXITS NE AND THE WESTERN TROUGH PASSES TO OUR NORTH USHERING IN A SUBSIDENT AND DRIER AIRMASS. THIS IS EXPECTED TO SHUT DOWN MOST CONVECTION. THE DRYING TREND CONTINUES INTO WEDNESDAY AND THURSDAY MAINLY ACROSS THE NORTHERN HALF OF THE FORECAST AREA. WEAK DISTURBANCES IN SW FLOW ALOFT PASS ACROSS THE NORTH BOTH AFTERNOONS SO CANNOT RULE OUT SOME CONVECTION. BUT SCATTERED STORMS WILL FAVOR THE SOUTHERN MTNS. WITH LESS CLOUD COVER DIURNAL SPREAD WILL INCREASE. NOCTURNAL CONVECTION IS NOT EXPECTED WEDNESDAY OR THURSDAY NIGHT. FRIDAY...THE UPPER LEVEL RIDGE CENTERED OVER MISSOURI NUDGES SOUTHWESTWARD. MONSOONAL MOISTURE BEGINS TO SURGE INTO THE SOUTHERN FORECAST AREA AGAIN AND HAVE RAISED POPS FOR THIS PERIOD. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY... THE PERSISTENT TROF OVER THE NORTHWEST STATES WILL BREAK FREE AND MOVE ACROSS THE NORTHERN PLAINS TO THE GREAT LAKES OVER THE WEEKEND PERIOD. THIS WILL FLATTEN THE NORTHERN PORTION OF THIS HOT RIDGE AND ALLOW IT TO BULGE BACK WESTWARD TOWARD THE 4 CORNERS REGION. THE MOISTURE PLUME AND SOURCE OF SCATTERED THUNDERSTORM ACTIVITY LOOKS TO REMAIN ANCHORED MAINLY OVER THE SAN JUANS INTO THE HIGH PLAINS THROUGH THE WEEKEND AND HAVE CONTINUED THE TREND OF AFTERNOON CONVECTION IN THE HIGHER TERRAIN OF OUR SOUTHERN AND FAR WESTERN CWA...AS DRIER REMAIN IN PLACE ACROSS THE NORTHERN AND WESTERN PORTIONS. GFS AND BULK OF ENSEMBLE FORECASTS IN FAIR AGREEMENT EARLY NEXT IN BRINGING YET ANOTHER TROF TO THE WEST COAST...RETURNING THE PATTERN TO ONE FAVORING THE MOISTURE PLUME TO BECOME RE-ESTABLISHED ACROSS THE GJT CWA. AS SUCH EXPECT AN UPTICK IN AFTERNOON AND EVENING CONVECTION MONDAY INTO TUESDAY AS PRECIPITABLE WATER VALUES AGAIN INCREASE BACK TOWARD THE 1 INCH MARK. TEMPERATURES SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL OVER THE WEEKEND DROPPING SLIGHTLY TOWARD THE FIRST HALF OF NEXT WEEK AS THE ADDITIONAL MOISTURE AND CLOUD COVER COMES INTO PLAY. && .AVIATION... SCATTERED TO WIDESPREAD THUNDERSTORMS WILL CONTINUE THIS EVENING ACROSS THE FORECAST AREA...AFFECTING ALL THE TAF SITES. MVFR CONDITIONS CAN BE EXPECTED NEAR THESE STORMS WITH ISOLATED IFR CONDITIONS POSSIBLE WITH THE STRONGER CELLS. BY MIDNIGHT THUNDERSTORM COVERAGE WILL BECOME ISOLATED. VFR CONDITIONS WILL DOMINATE EXCEPT FOR ISOLATED MVFR CONDITIONS IN THE VICINITY OF STORMS. SCATTERED SHOWERS AND STORMS WILL REGENERATE ON WEDNESDAY MAINLY ALONG AND SOUTH OF I-70. STORMS WILL PRODUCE MVFR/ISOLD IFR CIGS AND VSBYS WEDNESDAY AFTERNOON. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM......JOE LONG TERM.......DP AVIATION........JOE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 431 AM MDT TUE JUL 19 2011 COZ001>014-017>023-UTZ022>025-027>029-201130- ANIMAS RIVER BASIN-ARCHES/GRAND FLAT-CANYONLANDS/NATURAL BRIDGES- CENTRAL COLORADO RIVER BASIN- CENTRAL GUNNISON AND UNCOMPAHGRE RIVER BASIN- CENTRAL YAMPA RIVER BASIN-DEBEQUE TO SILT CORRIDOR- EASTERN UINTA BASIN-EASTERN UINTA MOUNTAINS- ELKHEAD AND PARK MOUNTAINS-FLAT TOPS- FOUR CORNERS/UPPER DOLORES RIVER- GORE AND ELK MOUNTAINS/CENTRAL MOUNTAINS-GRAND AND BATTLEMENT MESAS- GRAND VALLEY-LA SAL AND ABAJO MOUNTAINS-LOWER YAMPA RIVER BASIN- NORTHWEST SAN JUAN MOUNTAINS-PARADOX VALLEY/LOWER DOLORES RIVER- ROAN AND TAVAPUTS PLATEAUS-SAN JUAN RIVER BASIN-SOUTHEAST UTAH- SOUTHWEST SAN JUAN MOUNTAINS-TAVAPUTS PLATEAU- UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE-UPPER GUNNISON RIVER VALLEY- UPPER YAMPA RIVER BASIN-WEST ELK AND SAWATCH MOUNTAINS- 431 AM MDT TUE JUL 19 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT... MONSOONAL MOISTURE WILL CONTINUE ACROSS THE FORECAST AREA. EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO INCREASE DURING THE DAY AND CONTINUE INTO THE EVENING. LOCALLY HEAVY RAIN IS POSSIBLE WITH THESE STORMS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY... OUR MONSOONAL SURGE WILL BEGIN TO WANE BY MIDWEEK AS A DRIER SOUTHWESTERLY FLOW ALOFT BECOMES ESTABLISHED. THIS PATTERN IS EXPECTED TO CONTINUE INTO EARLY NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
151 PM MDT TUE JUL 19 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0149 PM FLASH FLOOD CANYONLANDS NP 38.40N 109.88W
07/19/2011 SAN JUAN UT PARK/FOREST SRVC
FLASH FLOODING OCCURRING WITH WATER FLOWING THROUGH
DAVIS AND LAVENDER CANYON IN THE NEEDLES DISTRICT. THESE
CANYONS DRAIN INTO INDIAN CREEK.
&&
EVENT NUMBER GJT1100510
MALEKSASPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 313 PM MDT TUE JUL 19 2011 COZ001>003-192200- CENTRAL YAMPA RIVER BASIN CO-LOWER YAMPA RIVER BASIN CO-ROAN AND TAVAPUTS PLATEAUS CO- 313 PM MDT TUE JUL 19 2011 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL RIO BLANCO AND EXTREME SOUTHERN MOFFAT COUNTIES UNTIL 400 PM MDT... AT 311 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8 MILES SOUTHEAST OF RANGELY...OR 53 MILES SOUTHEAST OF NAPLES...MOVING NORTHEAST AT 20 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN. TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED ROADWAY. LAT...LON 4027 10845 4001 10824 3989 10870 4011 10880
The Grand Junction radar (KGJX), 125 km away, was scanning. The volume nearest the first event began at 22:40 UTC.
3 flash flood. Local standard time, as filed.
Flash flooding deposited 6 to 12 inches of mud and debris on Highway 145.
Flash flood waters up to a foot deep deposited mud and rocks onto Highway 64 which was closed until crews cleared the road of debris.
Flash floods deposited mud and other debris up to 2 feet deep on a quarter mile section of the much used Rio Grande Trail. Additionally, the Stein Trail which leads to the Aspen Airport Business Center was also was hit with flood waters that left a significant amount of mud and debris on the road. The Aspen-Pitkin County Airport also incurred flowing water up to a half foot deep across the facility.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2011Every state in 2011This day in weather historyWarnings in Colorado, July 2011
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: 331545, 331549, 331581.