Thunderstorms moving across western Colorado produced areas of heavy rainfall, with flooding being reported in Mesa County. Outflow winds from these storms also produced damage in Pitkin County.
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.
Thunderstorms moving across western Colorado produced areas of heavy rainfall, with flooding being reported in Mesa County. Outflow winds from these storms also produced damage in Pitkin 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 Jul 21, 1:52 PM MST, 1 hour 9 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 252 PM MDT SAT JUL 21 2012 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 247 PM MDT SAT JUL 21 2012 MOIST SUBTROPICAL FLOW WITH CONTINUE THROUGH THE WEEKEND. ATMOSPHERE CONTINUES TO BE QUITE MOIST AS SHOWN BY THE GJT SOUNDING AND MODEL SOLUTIONS. WATER VAPOR AND RUC13 PICKING UP A SHORT WAVE MOVING NORTHWEST ACROSS UTAH THIS AFTERNOON WHICH WILL KEEP BEST FORCING FROM THIS WAVE WEST OF THE CWA. HOWEVER...AS DIURNAL HEATING INCREASES THIS AFTERNOON EXPECT CONVECTION TO INCREASE INTO THE EVENING HOURS. IN ADDITION...RUC13 AND NAM12 ALSO SHOW INDICATIONS OF ANOTHER SHORT WAVE WHICH WILL MOVE NORTH ACROSS SOUTHWESTERN COLORADO THIS EVENING AND PRODUCE ADDITIONAL LIFT FOR THIS MOIST AND UNSTABLE AIRMASS. SHOWERS AND THUNDERSTORM ACTIVITY WILL DECREASE OVERNIGHT...BUT WOULD NOT RULE OUT SOME ADDITIONAL ACTIVITY DURING THE EARLY MORNING HOURS. MODELS SHOW MORE OF THE SAME FOR SUNDAY AS MOIST UNSTABLE SOUTHERLY FETCH CONTINUES OVER THE FORECAST AREA WITH ANOTHER ROUND OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...DECREASING OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 247 PM MDT SAT JUL 21 2012 A COUPLE OF MINOR CHANGES SEEN DURING THIS PERIOD...OTHERWISE VERY LITTLE DIFFERENCE SEEN IN THE SENSIBLE WX PATTERN. HIGH PRESSURE OVER THE PLAINS CONTINUES TO BE A FAVORABLE POSITION TO BRING A STEADY STREAM OF MONSOONAL MOISTURE INTO THE SWRN U.S. INCLUDING ERN UT AND WRN CO. IN THE MEANTIME A CLOSED UPPER LOW OVER THE PACIFIC NW MOVES EWRD INTO SRN ALBERTA BY TUESDAY AFTERNOON. THIS FLATTENS THE RIDGE SOME AND RESULTS IN THE UPPER LEVEL WINDS TRANSITIONING FROM SWRLY TO NWRLY BY TUES AFTERNOON. BUT LIKE STATED ABOVE LITTLE IF ANY IMPACT IS SEEN ON OUR SENSIBLE WX PATTERN. THIS HAS BEEN HIGHLIGHTED BY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM FORMATION FOCUSED OVER THE HIGHER TERRAIN. A SLIGHT DOWNTURN IN CONVECTION IS SEEN WED/THU AS A DRIER NORTHWESTERLY FLOW INVADES THE REGION. HOWEVER IT IS QUICKLY FOLLOWED BY THE NEXT SURGE OF SUBTROPICAL MOISTURE WHICH SHOULD OCCUR FRIDAY AND SATURDAY AS THE FLOW SWITCHES BACK TO THE SOUTHWEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1039 AM MDT SAT JUL 21 2012 SHOWERS AND THUNDERSTORMS ARE A BIT SLOWER TO FIRE THIS MORNING THAN YESTERDAY WITH VFR CONDITIONS DOMINATING ACROSS THE REGION. THE EXCEPTION IS OVER NORTHEASTERN UTAH WHERE SOME LIGHT SHOWERS ARE LINGERING LATE THIS MORNING. AS DAYTIME HEATING INCREASES EARLY THIS AFTERNOON...EXPECT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WITH A FEW CELLS APPEARING OVER HIGHER TERRAIN AS EARLY AS 18Z. BY MID-AFTERNOON...SCATTERED TO NUMEROUS THUNDERSTORM COVERAGE OVER THE HIGHER TERRAIN WILL RESULT IN FREQUENT MOUNTAIN OBSCURATIONS AND GUSTY OUTFLOW WINDS FROM 30 TO 40 MPH. REGIONAL AIRPORTS WHICH ARE IN CLOSE PROXIMITY TO HIGHER TERRAIN FACE THE BEST CHANCE OF THUNDERSTORMS FROM 22Z TO 03Z. SHOWERS AND THUNDERSTORMS WILL DECREASE...BUT NOT FULLY DIMINISH OVERNIGHT. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM...MPM LONG TERM...MC AVIATION...TGJT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 545 AM MDT SAT JUL 21 2012 COZ001>014-017>023-UTZ022>025-027>029-221200- 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 SAT JUL 21 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING. STORMS WILL FAVOR THE MOUNTAINS...BUT WILL DRIFT OVER THE VALLEYS LATE THIS AFTERNOON AND INTO THE EVENING. GUSTY WINDS FROM 30 TO 40 MPH...HEAVY RAIN...AND SMALL HAIL IS POSSIBLE WITH THE STRONGEST STORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY MONSOON MOISTURE WILL CONTINUE TO SWEEP OVER THE REGION DURING THE REMAINDER OF THE WEEKEND AND INTO THE COMING WEEK. THIS WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE AREA WITH LOCALLY HEAVY RAINFALL AGAIN POSSIBLE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 207 PM MDT SAT JUL 21 2012 COZ017-018-020-212100- NORTHWESTERN SAN JUAN MOUNTAINS CO-PARADOX VALLEY/LITTLE DOLORES RIVER CO-UNCOMPAHGRE PLATEAU/DALLAS DIVIDE CO- 207 PM MDT SAT JUL 21 2012 ...SIGNIFICANT WEATHER ADVISORY FOR WESTERN OURAY...EASTERN SAN MIGUEL AND SOUTHERN MONTROSE COUNTIES UNTIL 300 PM MDT... AT 204 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR SAWPIT...OR 32 MILES SOUTH OF MONTROSE... MOVING NORTHWEST AT 10 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING. LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE... SAWPIT... NORWOOD... FALL CREEK... PLACERVILLE... THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. 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 3809 10837 3830 10808 3805 10777 3788 10793 MDA
The Grand Junction radar (KGJX), 40 km away, was scanning. The volume nearest the first event began at 22:00 UTC.
1 flash flood, 1 thunderstorm wind. Local standard time, as filed.
Thunderstorms with heavy rainfall produced flooding in Unaweep Canyon closing Highway 141 between mile markers 140 and 141 due to water over the roadway.
Severe thunderstorm wind gusts downed a tree at Avalanche Road near Redstone, blocking both lanes of Highway 133.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2012Every state in 2012This day in weather historyWarnings in Colorado, July 2012
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: 482128, 479518.