Numerous strong to severe thunderstorms moved through western Colorado on the afternoon of July 14th, producing areas of very heavy rainfall and wind gusts over 60 mph.
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.
Numerous strong to severe thunderstorms moved through western Colorado on the afternoon of July 14th, producing areas of very heavy rainfall and wind gusts over 60 mph.
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 14, 9:39 AM MST, 4 hours 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 1039 AM MDT SAT JUL 14 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 352 AM MDT SAT JUL 14 2012 MONSOON MOISTURE WILL CONTINUE SURGING NORTH ACROSS THE FORECAST AREA TODAY WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS EXPECTED. MORNING CONVECTION WILL BE DISSIPATING AFTER SUNRISE...BUT WILL RE-FIRE BY MIDDAY AS CONDITIONS DESTABILIZE ONCE AGAIN. ATTM...NO MAJOR TRIGGER IN OUR AREA TO KICK OFF WIDESPREAD HEAVY RAIN AND SFC HEATING WILL BE KNOCKED BACK A BIT BY EXTENSIVE CLOUD SHIELD TODAY. AS A RESULT...WILL NOT BE ISSUING ANY FLASH FLOOD WATCHES EVEN WITH PRECIPITABLE WATER VALUES EXCEEDING ONE INCH. STILL WILL BE SOMETHING TO MONITOR AS THE DAY PROGRESSES...SHOULD THE CLOUD SHIELD ERODE SUFFICIENTLY AND ALLOW DEEPER CONVECTION TO DEVELOP. STILL EXPECT DECENT COVERAGE OF SHOWERS AND HAVE BOOSTED POPS INTO THE LIKELY CATEGORY FOR MUCH OF THE AREA THIS AFTERNOON. HAVE ALSO SLICED TEMPS BACK A NOTCH WITH DENSER CLOUD COVER AND HIGHER SFC MOISTURE IN PLACE. TONIGHT AND SUNDAY...WITH THE MONSOONAL PLUME DIRECTLY OVERHEAD...SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE SLOW TO DISSIPATE. IN ADDITION TO THE MOISTURE PLUME...A BROAD TROUGH THAT COVERS MUCH OF THE WRN CONUS WILL INCREASE SHEAR. THIS SPEED SHEAR WILL BE IN THE 20-30 KNOT RANGE WITH THE AXIS FROM SE UTAH TO NW COLORADO. THIS WOULD BE FAVORABLE FOR SOME ORGANIZED STRONG PULSE STORMS AND MULTICELLS...EXCEPT IT WILL BE OUT OF PHASE WITH THE DIURNAL CYCLE. AT ANY RATE...SCATTERED SHOWERS MAY PERSIST THROUGH THE NIGHT. SPEED SHEAR WEAKENS A NOTCH BY SUNDAY AFTERNOON...BUT STRONGER THAN NORMAL PULSE STORMS HAVE THE POTENTIAL TO BE GOOD HEAVY RAINERS. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 352 AM MDT SAT JUL 14 2012 AIR MASS REMAINS MOIST SUNDAY NIGHT AND EXPECT SHOWERS WITH EMBEDDED STORMS TO LIVE BEYOND MIDNIGHT. THE AXIS OF THE DEEPEST MOIST LAYER SHIFTS EAST AND WILL BE POSITIONED OVER THE WESTERN SLOPE ON MONDAY AFTERNOON...THEREFORE THE BEST OR STRONGEST CONVECTIVE ACTIVITY WILL BE OVER THE ERN HALF OF THE FORECAST AREA WITH LESS ACTION OVER ERN UTAH. THIS TREND CONTINUES INTO TUESDAY AS THE PACIFIC NORTHWEST TROUGH ATTEMPTS TO MOVE INLAND. CURRENT MODEL DATA INDICATE THAT SOME DRIER AIR REACHES WRN COLORADO. NOT DRY ENOUGH TO SHUT DOWN CONVECTIVE STORMS...BUT REDUCE CAPE VALUES WITH MOST STORMS CONFINED TO THE CENTRAL AND SOUTHERN HIGH COUNTRY. DRYING TREND CONTINUES FROM WEDNESDAY THROUGH THE END OF THE WEEK WITH MOISTURE PLUME SHUNTED EAST. THIS WILL KEEP THE BEST CHANCE OF DIURNALLY DRIVEN CONVECTION OVER THE SAN JUANS AND ALONG THE DIVIDE. TEMPERATURES WILL BE CLIMBING ONCE AGAIN AS THE ATMOSPHERE DRIES OUT WITH READINGS RETURNING TO ABOVE NORMAL BY THE END OF THE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1033 AM MDT SAT JUL 14 2012 STILL EXPECT MONSOON MOISTURE TO CONTINUE SURGING NORTHWARD UNABATED OVER THE REGION THROUGH SUNDAY. SEVERAL EMBEDDED DISTURBANCES WITHIN THE SOUTHERLY FLOW WILL CONTINUE TO GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION. DURING THE PERIOD FROM 18Z TODAY TO ROUGHLY 03Z SUNDAY...DAYTIME HEATING COMBINED WITH INCREASED MONSOON MOISTURE WILL GENERATE STRONGER STORMS CAPABLE OF RESULTING IN MVFR CIGS/VSBY AND EVEN LOCALIZED IFR CONDITIONS IN HEAVY RAINFALL. WIND GUSTS TO 40 MPH ARE POSSIBLE IN THE VICINITY OF STRONGER CELLS. MOUNTAINS WILL BE FREQUENTLY OBSCURED AND AIRPORTS IN THE SOUTHERN AND CENTRAL VALLEYS WILL HAVE A GOOD CHANCE OF EXPERIENCING BRIEF PERIODS OF MVFR CIGS AND/OR VSBY IN HEAVY RAIN. CONDITIONS ARE EXPECTED TO IMPROVE BEYOND 03Z SUNDAY WITH SHOWERS BECOMING MORE SCATTERED IN NATURE. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM...JDC/PF LONG TERM...PF/JDC AVIATION...TGJT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 510 AM MDT SAT JUL 14 2012 COZ001>014-017>023-UTZ022>025-027>029-151200- 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- 510 AM MDT SAT JUL 14 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF EASTERN UTAH AND WESTERN COLORADO THROUGH TONIGHT. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE...ESPECIALLY ACROSS SOUTHEAST UTAH AND SOUTHWEST COLORADO. SMALL HAIL AND WINDS GUSTING TO OVER 40 MPH WILL ALSO BE POSSIBLE WITH THE STRONGEST STORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. LOCALLY HEAVY RAIN...SMALL HAIL...AND FREQUENT CLOUD TO GROUND LIGHTNING STRIKES WILL OCCUR WITH THE STRONGEST STORMS. MUD DEBRIS FLOWS AND SUDDEN INCREASES IN WATER IN SMALL CREEKS AND STREAMS WILL BE POSSIBLE THROUGH THIS WEEKEND. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
222 PM MDT SAT JUL 14 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0212 PM TSTM WND GST 15 NW MOAB 38.73N 109.74W
07/14/2012 M60 MPH GRAND UT ASOS
WIND GUST MEASURED AT CANYONLANDS AIRPORT
&&
EVENT NUMBER GJT1200444
DCThe Grand Junction radar (KGJX), 67 km away, was scanning. The volume nearest the first event began at 21:07 UTC.
3 heavy rain, 1 thunderstorm wind. Local standard time, as filed.
Thunderstorm outflow winds gusted to 68 mph from the southwest producing areas of blowing dust and tree damage.
Heavy rainfall of 0.43 inches in less than a half of an hour was reported along Highway 82 south of Glenwood Springs.
Heavy rainfall 5 miles west of Glenwood Springs produced mudslides which closed one lane of west bound Interstate 70.
Heavy rainfall in excess of one inch fell during the early evening hours in Ouray.
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: 479479, 479483, 479487, 479488.