Heavy rain producing thunderstorms occurred over eastern Utah and caused flooding in portions of Grand County and northwest San Juan County.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Heavy rain producing thunderstorms occurred over eastern Utah and caused flooding in portions of Grand County and northwest San Juan 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 Aug 5, 3:10 AM MST, 9 hours 3 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 410 AM MDT SUN AUG 5 2007 .SHORT TERM...TODAY THROUGH MONDAY NIGHT... DAY TO DAY CHANGES CONTINUE TO BE SUBTLE WITH THE OVERALL PATTERN STAYING THE SAME FOR THE NEXT TWO DAYS. MONSOONAL MOISTURE CONTINUES TO STREAM INTO ERN UTAH AND WRN COLORADO WITH THE DEEPEST LAYERED MOISTURE GOING INTO SWRN COLORADO. THIS IS EVIDENT AT 09Z WITH SHOWERS FROM NEW MEXICO MOVING INTO MESA VERDE NATIONAL PARK AND DURANGO AREA. SOMEWHAT DRIER OVER THE NORTHWEST PORTION OF OUR FORECAST AREA...AND LAST EVENINGS 00Z SOUNDING SHOWED THIS AS PRECIPITABLE WATER CONTENT DROPPED BELOW ONE INCH. ONE THING TO NOTE IS THE DRIER AIR THAT HAS SPREAD WESTWARD ACROSS NEW MEXICO... ALMOST TO THE ERN ARIZONA BORDER. MOST OF THIS DRYING IS IN THE MID TO UPPER LEVELS AS GOES SOUNDER IMAGES SHOWS HIGH PRECIPITABLE WATER ACROSS NEW MEXICO. EVEN SO...SOME OF THIS DRYING ALOFT WILL ADVECT INTO SW COLORADO AND CONVECTION MAY NOT BE QUITE AS DEEP AS IT HAS BEEN FOR THE PAST FEW DAYS. A FEW HEAVY RAINERS WILL STILL OCCUR... BUT PERHAPS A BIT SUBDUED. ANOTHER NEGATIVE FACTOR FOR DEEP CONVECTION...SW COLORADO WILL BE BEHIND A PASSING IMPULSE DURING THE PEAK HEATING HOURS (CURRENTLY MOVING NORTHWARD FROM ERN ARIZONA AND CROSSES SW COLORADO THIS MORNING). ON MONDAY...PACIFIC COAST TROUGH ATTEMPTS TO MOVE INLAND. THIS TROUGH DOES NOT GET VERY FAR...BUT ENOUGH TO INCREASE WIND SHEAR ACROSS NE UTAH AND EXTREME NW COLORADO. THE SLIGHT INCREASE IN GRADIENT FLOW WILL TAP INTO MOISTURE FROM THE SUBTROPICAL WAVE NEAR THE BAJA GULF. PIECES OF ENERGY FROM THIS WAVE WILL STREAM TOWARD THE FORECAST AREA. WITH THE INCREASED WIND SHEAR...CONVECTION MAY BE ENHANCED OVER NW COLORADO AND POP GRIDS SHOW A HIGHER THUNDERSTORM THREAT. .LONG TERM...TUESDAY THROUGH SATURDAY... THE BASIC PATTERN REMAINS THE SAME FOR MUCH OF THE WEEK. HIGH PRESSURE REMAINS CENTERED OVER TX AND THE WESTERN GULF OF MEXICO...WITH A TROUGH ALONG THE WEST COAST. THIS SETUP KEEPS THE MONSOON MOISTURE PLUME OVER THE FOUR CORNERS. CONVECTION EACH DAY WILL BE ENHANCED BY PASSING VORT MAXES ROTATING AROUND THE HIGH WHICH MODELS HAVE HAD A VERY HARD TIME ACCURATELY PROJECTING EVEN 24 HOURS OUT. THE TREND FROM WED THROUGH SAT SHOWS SLOW DRYING AS THE TROUGH DRAWS DRIER AIR INTO THE AREA...ESPECIALLY OVER NE UT AND NW CO. THE HIGH CENTER ALSO IS PROJECTED TO RETROGRADE NW TO KANSAS WHICH CUTS OFF THE MONSOON FLOW SOMEWHAT AND FORCING IT WEST OVER AZ AND BAJA CA BY FRIDAY. && .AVIATION... CONVECTIVE SHOWERS CONTINUE TO POSE THE GREATEST HAZARD TO AVIATORS. ALTHOUGH VFR CONDITIONS WILL DOMINATE...SOME AREAS WILL HAVE BRIEF PERIODS OF MVFR CEILINGS AND VISIBILITY FROM HEAVY SHOWERS. SHOWERS AND LOW CEILINGS WILL OBSCURE MOUNTAINOUS TERRAIN. THE BEST THREAT OF HEAVY SHOWERS WILL BE OVER SOUTHEAST UTAH AND SOUTHWEST COLORADO. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. SHORT TERM...PF LONG TERM...CJC AVIATION...PF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 600 AM MDT SUN AUG 5 2007 COZ001>014-017>023-UTZ022>025-027>029-061200- 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- 600 AM MDT SUN AUG 5 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT EXPECT SCATTERED SHOWERS AND THUNDERSTORMS...MORE NUMEROUS OVER THE WESTERN COLORADO MOUNTAINS...TODAY AND THIS EVENING. A FEW OF THESE STORMS WILL CONTINUE PAST MIDNIGHT. A FEW STORMS WILL PRODUCE HEAVY RAIN THAT WILL CAUSE ARROYOS AND SMALL STREAMS TO QUICKLY FILL OR RUN HIGH WITH FAST FLOWING WATER. THE STRONGER STORMS WILL PRODUCE FREQUENT CLOUD TO GROUND LIGHTNING AND SMALL HAIL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP EACH AFTERNOON AND EVENING THROUGH TUESDAY. SOME STORMS WILL BE SLOW MOVERS AND PRODUCE BRIEF HEAVY RAIN AND SMALL HAIL. URBAN OR SMALL STREAM FLOODING WILL BE POSSIBLE. WEDNESDAY THROUGH SATURDAY...CONDITIONS WILL BECOME SLIGHTLY DRIER EACH DAY...WITH THUNDERSTORM DEVELOPMENT DECREASING FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THIS AFTERNOON OR TONIGHT. HOWEVER...REPORTS RELAYED TO THE NATIONAL WEATHER SERVICE OF HEAVY RAIN...HAIL...AND ANY WEATHER RELATED DAMAGE WOULD BE GREATLY APPRECIATED.
The Grand Junction radar (KGJX), 114 km away, was scanning. The volume nearest the first event began at 19:14 UTC.
2 heavy rain, 1 debris flow, 1 flash flood. Local standard time, as filed.
Heavy rain caused street flooding in Castle Valley. Pea-size hail was mixed with the rain. Rainfall reports ranged from 1.63 to 2.90 inches in Castle Valley. At one location, 2.30 inches of rain fell within 45 minutes.
Heavy rainfall caused a boulder the size of a garage to dislodge and crash onto White Rim Road in Taylor Canyon near the Green River. A lot of mud washed over the road as well.
Heavy rain caused extensive water and mud to flow over the Shafer and Pot Ash Trails in the northeast section of Canyonlands National Park.
Runoff from heavy rain caused water and mud to flow across Highway 191 near the entrance to Arches National Park.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2007Every state in 2007This day in weather historyWarnings in Utah, August 2007
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: 56717, 56711, 56684, 56697.