A monsoonal push of moisture initiated heavy rain producing thunderstorms across southeast Utah during the morning and afternoon hours on September 9th. Runoff from these storms produced flash flooding in and near Canyonlands National Park.
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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.
A monsoonal push of moisture initiated heavy rain producing thunderstorms across southeast Utah during the morning and afternoon hours on September 9th. Runoff from these storms produced flash flooding in and near Canyonlands National Park.
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 Sep 9, 8:43 AM MST, 37 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 943 AM MDT MON SEP 9 2013 .UPDATE... ISSUED AT 943 AM MDT MON SEP 9 2013 PLENTY OF MUCH NEEDED RAIN BEING REPORTED ACROSS THE CWA THIS MORNING WITH REPORTS ALONG THE TAVAPUTS/ROAN PLATEAUS READING FROM .7 INCHES TO .85 INCHES OVER THE LAST 24 HOURS WITH AROUND .5 INCHES FOR REMAINING AREAS NORTH OF I-70. BUMPED UP POPS TO FOLLOW AREA OF HEAVIER SHOWERS THIS MORNING AND ALSO DROPPED HIGH TEMPS A FEW DEGREES AS CLOUDS WILL KEEP HEATING DOWN. ATTM...STEADY STREAM OF MOISTURE LOOKS LIKE CLOUDS DOWN SOUTH WILL STAY PUT KEEPING CONVECTION TO A MINIMUM. HAVING SAID THAT...WATER VAPOR IMAGERY DOES SHOW A TONGUE OF DRY AIR TRYING TO MAKE ITS WAY INTO 4 CORNERS REGION...WHETHER IT MAKES IT OR NOT WILL DETERMINE THE INTENSITY AND COVERAGE FOR PRECIP IN THAT AREA. FLOOD WATCH CONTINUES. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 252 AM MDT MON SEP 9 2013 WET START TO THE NEW WORK WEEK IN STORE FOR ALL OF EASTERN UTAH AND WESTERN COLORADO AS DEEP SUB-TROPICAL MOISTURE CONTINUES TO DRIVE NORTHEAST THROUGH THE REGION. EVENING SOUNDINGS INDICATED PRECIPITABLE WATER VALUES RUNNING CLOSE TO 200 PERCENT OF NORMAL FOR THIS TIME OF YEAR. CURRENT FLASH FLOOD WATCH FOR SOUTHEAST AND EAST CENTRAL UTAH AND PORTIONS OF SOUTHWEST COLORADO WILL BE CONTINUED AS STORMS FIRE ALONG SHEAR AXIS ALIGNED FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST AREA. CLOUD COVER AND MUCH COOLER SFC TEMPERATURES WILL RESULT IN MORE STRATIFORM TYPE COVERAGE OF SHOWERS TODAY...ALTHOUGH ANY THINNING OR BREAKS IN CLOUD COVER WILL ALLOW DEEPER POCKETS OF CONVECTION TO DEVELOP. THIS APPEARS MOST LIKELY TO OCCUR ACROSS PORTIONS OF SOUTHEAST UTAH ALONG THE WESTERN EDGE OF THE DEEP SUB-TROPICAL PLUME. THIS IN NO WAY RULES OUT POTENTIAL FOR HEAVY RAIN ELSEWHERE ACROSS THE FORECAST AREA...BUT POTENTIAL FOR FLASH FLOODING EVENTS SHOULD BE HIGHEST IN OUR SLOT CANYON COUNTRY. SO NO EXPANSION OF THE WATCH IS PLANNED AT THE MOMENT. TEMPERATURES WILL BE RUNNING ANOTHER 5 TO 10 DEGREES COOLER VERSUS READINGS SEEN YESTERDAY AFTERNOON...WITH 70S FOR MOST VALLEY LOCATIONS AND 60S FOR THE MOUNTAINS. DEEP MOISTURE REMAINS IN PLACE TONIGHT AND TUESDAY. A DRIER AIR MASS WORKS INTO EXTREME NE UTAH...MAINLY NORTH OF THE UINTA MTNS...TONIGHT BUT MOISTURE RE-INVADES EVEN THERE ON TUESDAY. STORM MOTION REMAINS TO THE NORTH AT 15-20KTS SOUTH TO 10KTS NORTH...SO STORM TRAINING IS THE MAIN THREAT FOR RUNOFF OR MUDSLIDE PROBLEMS. A LOW DIURNAL SPREAD IS EXPECTED UNDER RAIN-COOLED AND CLOUDY SKIES WITH AFTERNOON HIGHS WELL BELOW NORMAL. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 252 AM MDT MON SEP 9 2013 THE VERTICALLY STACKED UPPER TROUGH REMAINS OVER THE GREAT BASIN CENTERED NEAR LAS VEGAS THROUGH WEDNESDAY NIGHT. SPOKES OF ENERGY ARE STILL PROGGED TO ROTATE NORTH THROUGH EASTERN UTAH AND FAR WESTERN COLORADO PROVIDING ENHANCEMENT. MOISTURE BEGINS TO DIMINISH SOMEWHAT ON TUESDAY BUT PRECIPITABLE WATER VALUES REMAIN NEAR ONE INCH AND WELL ABOVE NORMAL. CLOUDY SKIES WILL KEEP TEMPERATURES COOL AND LIMIT INSTABILITY. STILL ANY CONVECTIVE CELL WILL HAVE HEAVY RAINFALL POTENTIAL. SOUTH-FACING SLOPES REMAIN THE MOST VULNERABLE. CUTOFF LOW UNDERNEATH BROAD WESTERN RIDGE WILL SIT OVER THE GREAT BASIN THROUGH FRIDAY...BEFORE LIFTING ENE ACROSS WYOMING THIS WEEKEND. AS THE LOW PUSHES INTO WYOMING...HEIGHTS REBOUND ACROSS THE GREAT BASIN WITH GENERAL NW COMPONENT DEVELOPING ACROSS OUR FORECAST AREA. THIS WILL DRIVE DRIER CONDITIONS INTO THE REGION...ESPECIALLY FOR OUR SOUTHERN ZONES...ALTHOUGH SCATTERED DIURNAL CONVECTION WILL BE HANGING ON ACROSS THE NORTHERN ZONES. PATTERN IS TRYING TO BECOME A BIT MORE PROGRESSIVE LATE IN THE PERIOD AS THE WESTERLIES DIP SOUTH WITH OUR DEEPER SRLY FLOW BECOMING MORE AND MORE LIMITED INTO EARLY NEXT WEEK...PER THE GFS. HOWEVER...THE ECMWF REMAINS VERY BULLISH ON THE MONSOONAL FEED RIGHT ON INTO THE WEEKEND AND BASED ON RECENT HISTORY...WILL LEAN THAT DIRECTION ALTHOUGH DROP POPS BACK A BIT. TEMPERATURES WILL BE HOLDING AT TO SLIGHTLY BELOW SEASONAL NORMS THROUGH THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 252 AM MDT MON SEP 9 2013 WIDESPREAD -SHRA WITH LOCAL VIS BLO 3SM +SHRA BR DURING THE NEXT 24 HOURS. AREAS OF IFR CIGS/VIS AT MOUNTAIN TAF SITES AND AIRFIELDS. MOUNTAIN TOPS WILL BE FREQUENTLY OBSCURED. ISOLATED THUNDERSTORMS NORTH IF I-70 WITH SCATTERED THUNDERSTORMS SOUTH...WITH ANY THUNDERSTORMS HAVING THE POTENTIAL OF PRODUCING HEAVY RAIN SHOWERS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...FLASH FLOOD WATCH THROUGH THIS EVENING FOR COZ020-021. UT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR UTZ022-025-027>029. && UPDATE...TGR SHORT TERM...JDC/JOE LONG TERM...JOE/JDC AVIATION...JDC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 455 AM MDT MON SEP 9 2013 COZ001>014-017>023-UTZ022>025-027>029-101200- 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- 455 AM MDT MON SEP 9 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS EASTERN UTAH AND WESTERN COLORADO THROUGH TONIGHT. HEAVY RAIN WILL BE POSSIBLE...ESPECIALLY ACROSS SOUTHEAST UTAH AND THE LOWER VALLEYS OF EXTREME SOUTHWEST COLORADO...WHERE A FLASH FLOOD WATCH WILL BE IN EFFECT THROUGH THIS EVENING. THE POTENTIAL EXISTS FOR FLASH FLOODING IN THESE AREAS...ESPECIALLY IN NARROW SLOT CANYONS...NEAR STEEP TERRAIN AND OVER BURN SCARS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY EXPECT SHOWERS AND THUNDERSTORMS THROUGHOUT THE PERIOD FAVORING HIGHER TERRAIN. A PERSISTENT INFLUX OF MONSOON MOISTURE POSES THE THREAT OF LOCALIZED RUNOFF PROBLEMS EACH DAY THROUGH MIDWEEK. SOME DRYING CAN BE EXPECTED FRIDAY...ALTHOUGH ANOTHER SURGE OF MOISTURE APPEARS POISED TO BACK THROUGH THE REGION OVER THE WEEKEND. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
544 AM MDT MON SEP 09 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0521 AM HEAVY RAIN ROOSEVELT 40.30N 109.97W
09/09/2013 M0.97 INCH UINTAH UT BROADCAST MEDIA
OVERNIGHT RAINFALL
&&
EVENT NUMBER GJT1301473
DCThe Grand Junction radar (KGJX), 170 km away, was scanning. The volume nearest the first event began at 16:19 UTC.
2 flash flood. Local standard time, as filed.
Runoff water rushed through several normally dry washes in the western portion of Canyonlands National Park. Elephant Hill Road and many secondary roads where washed out and became impassable.
Water up to a foot deep flowed over Highway 191 near Church Rock due to runoff from heavy rainfall.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2013Every state in 2013This day in weather historyWarnings in Utah, September 2013
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: 528758, 528762.