Thunderstorms dropped between 1 to 2 inches of rainfall over portions of Mesa County during the early evening hours of July 22nd.
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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.
Thunderstorms dropped between 1 to 2 inches of rainfall over portions of Mesa County during the early evening hours of July 22nd.
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 22, 1:50 PM MST, 2 hours 58 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 250 PM MDT SUN JUL 22 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 248 PM MDT SUN JUL 22 2012 RIDGE OVER THE GREAT PLAINS AND TROUGH OVER THE WEST COAST CONTNUE TO ALLOW A MOIST SOUTHERLY FETCH OVER THE FORECAST AREA THROUGH THE SHORT TERM PERIOD. A BIT MORE CLOUD COVER THIS MORNING HAS DELAYED ONSET OF CONVECTION BUT AS CONDITIONS ARE STARTING TO CLEAR OUT EARLY THIS AFTERNOON ACTIVITY HAS PULSED UP IN THE LAST HOUR. RUC13 AND WV ARE SHOWING TWO POTENTIAL TRIGGERS IN THIS FLOW THIS AFTERNOON. ONE IS OVER CENTRAL ARIZONA WHICH IS EXPECTED TO MOVE EAST ACROSS THE FOUR CORNERS REGION BY LATE THIS AFTERNOON. THE OTHER IS OVER SOUTHWESTERN COLORADO EARLY THIS AFTERNOON AND IS EXPECTED TO MOVE SLOWLY NORTHEAST THIS AFTERNOON. THE MAIN THREAT ONCE AGAIN WILL BE HEAVY RAIN WITH SOME ISOLATED FLASH FLOODING POSSIBLE...ALONG WITH FREQUENT CLOUD TO RAIN LIGHTNING. SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE AFTER MIDNIGHT. BY MONDAY...PACIFIC NORTHWEST TROUGH WILL MOVE SLOWLY EAST...OTHERWISE NOT MUCH CHANGE IN WEATHER PATTERN WITH ABUNDANT MOISTURE IN PLACE...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS AFTERNOON AND EVENING THUNDERSTORMS WITH THE POTENTIAL FOR HEAVY RAIN. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 248 PM MDT SUN JUL 22 2012 UPPER CLOSED LOW OVER SRN ALBERTA WILL DRIFT SLOWLY EWRD TUESDAY... FLATTENING THE RIDGE OF HIGH PRESSURE THAT HAS BEEN OVER OUR REGION. THIS WILL ALSO USHER IN A WIND SHIFT TO THE NORTHWEST. SOME DYNAMIC INSTABILITY WILL HELP TO GENERATE ANOTHER AFTERNOON OF WIDESPREAD CONVECTION TUESDAY AFTERNOON. HOWEVER SIGNIFICANT DRYING ALOFT IS SEEN FROM THE NORTHWEST TUESDAY NIGHT AND WEDNESDAY. THIS WILL RESULT IN A NOTABLE DOWNTURN IN CONVECTION WEDNESDAY OVER MOST OF THE CWA...EXCEPT NEAR AND ALONG THE CONTINENTAL DIVIDE WHERE A LITTLE DEEPER MOISTURE WILL RESIDE. SHEAR PROFILE ALSO LOOKS LIKE IT MAY BECOME A LITTLE MORE FAVORABLE FOR STRONGER STORM DEVELOPMENT IN THAT AREA. HIGH PRESSURE WILL START TO REBUILD OVER THE SRN GRT BASIN THURSDAY HELPING HELPING TO SUPPRESS CONVECTION...BUT LOW LEVEL MOISTURE SHOULD STILL BE IN PLACE FOR AT LEAST ISOLATED STORM DEVELOPMENT. THE NEXT UPSTREAM TROF IN THE GULF OF ALASKA WILL APPROACH OUR PACIFIC COAST FRIDAY WHICH WILL PUSH THE ABOVE MENTIONED HIGH PRESSURE CELL EASTWARD...WHICH WILL THEN ALLOW A SOUTHWESTERLY FLOW TO REDEVELOP. ACCOMPANYING THIS FLOW WILL BE ANOTHER SURGE OF SUB-TROPICAL MOISTURE. THIS WILL BRING INCREASING CHANCES OF SHOWER AND THUNDERSTORM DEVELOPMENT FRIDAY AFTERNOON THROUGH THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 248 PM MDT SUN JUL 22 2012 DIURNAL HEATING COMBINING WITH ABUNDANT SOUTHERLY FETCH OF MOISTURE IS GENERATING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WHICH WILL CONTINUE INTO THE EVENING HOURS ACROSS MUCH OF THE FORECAST AREA. EXPECT SCATTERED TO NUMEROUS THUNDERSTORM COVERAGE BY LATE THIS AFTERNOON WHICH WILL RESULT IN FREQUENT MOUNTAIN OBSCURATIONS AND GUSTY OUTFLOW WINDS FROM 30 TO 40 MPH. REGIONAL AIRPORTS IN CLOSE PROXIMITY TO HIGHER TERRAIN WILL SEE THE BEST CHANCE OF THUNDERSTORM ACTIVITY FROM 22Z TO 03Z. THESE STORMS WILL BRING BRIEF MVFR CIGS AND/OR VSBY IN HEAVY RAIN. SHOWER ACTIVITY WIL DECREASE 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 SUN JUL 22 2012 COZ001>014-017>023-UTZ022>025-027>029-231200- 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 SUN JUL 22 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 ARE POSSIBLE WITH THE STRONGEST STORMS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY MONSOON MOISTURE WILL CONTINUE TO SWEEP OVER THE REGION EARLY THIS WEEK. THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAIN. THUNDERSTORM COVERAGE WILL DECREASE WEDNESDAY AND THURSDAY DURING A BRIEF BREAK FROM MONSOONAL FLOW WITH STORMS LARGELY CONFINED TO THE MOUNTAINS OF WESTERN COLORADO. HOWEVER... THE MONSOON BECOMES REESTABLISHED FRIDAY AND WILL CONTINUE INTO THE WEEKEND. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED TODAY OR TONIGHT...HOWEVER SPOTTERS ARE ENCOURAGED TO RELAY RAINFALL AMOUNTS OR ANY OBSERVED FLOODING TO THE GRAND JUNCTION FORECAST OFFICE.
The national radar mosaic for the moment the first event began.
1 heavy rain. Local standard time, as filed.
Thunderstorms produced 1.3 inches of rain within 40 minutes near Powderhorn Ski Resort. Gusts up to 40 mph and some pea-sized hail also fell with these storms. The storm total precipitation at this location was 1.80 inches. no significant flooding was reported.
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: 479519.