Additional low and mid-level moisture moved into the state of Utah on July 14th through 16th. Organized thunderstorms formed across much of the state, producing gusty winds, large hail, and widespread flash flooding.
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 SLC wrote it up.
Additional low and mid-level moisture moved into the state of Utah on July 14th through 16th. Organized thunderstorms formed across much of the state, producing gusty winds, large hail, and widespread flash flooding.
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 Salt Lake City, UT wrote its last area forecast discussion before the first event at Jul 14, 9:00 AM MST, 5 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1000 AM MDT SAT JUL 14 2012
.SYNOPSIS...AN UPPER LEVEL TROUGH OVER THE WEST COAST STATES WILL
LIFT NORTHEAST INTO AND ACROSS THE GREAT BASIN THIS WEEKEND. THIS
TROUGH COMBINED WITH THE VERY MOIST AIRMASS OVER THE BASIN WILL
PRODUCE WIDESPREAD PRECIPITATION THE NEXT COUPLE OF DAYS.
&&
.DISCUSSION...DEEP MOISTURE IN PLACE ACROSS THE FORECAST AREA THIS
MORNING...WITH PWS RUNNING WELL OVER TWO STANDARD DEVIATIONS ABOVE
AVERAGE IN ALL LOCATIONS. VORT MAX OVER EASTERN NEVADA IS ACTING AS THE
FOCUS FOR SHOWERS OVER WESTERN AND SOUTHERN UTAH THIS
MORNING...WITH LIGHTER SHOWERS BEING OBSERVED OVER CENTRAL UTAH.
HOWEVER...ABUNDANT CLOUD COVER IS LIMITING THE DEVELOPMENT OF
THUNDERSTORMS. THE CLOUD COVER AND THE COOLER AIRMAS WILL KEEP
TEMPERATURES DOWN TODAY...WITH MAXES RUNNING AROUND 10F BELOW
SEASONAL NORMS.
SECOND VORT MAX OVER ARIZONA IS PROGGED TO PUSH INTO THE STATE
THIS AFTERNOON...PROVIDING A FOCUS FOR AFTERNOON CONVECTION. THIS
FEATURE HAS GOOD JET SUPPORT WITH IT AND WILL BE COMING DURING
BETTER DAYTIME HEATING. CLOUD COVER MAY STILL BE A NEGATIVE FACTOR
BUT CONDITIONS ARE OTHERWISE GOOD FOR WIDESPREAD CONVECTIVE
DEVELOPMENT. WITH SUCH A MOIST AIRMASS...HEAVY RAIN IS POSSIBLE
WITH ANY STORMS THAT DEVELOP. FLASH FLOOD WATCH FOR SOUTHERN AND
CENTRAL UTAH COVERS THIS THREAT WELL.
MONSOONAL MOISTURE REMAINS IN PLACE THROUGH AT LEAST EARLY NEXT
WEEK. DYNAMIC FORCING MAY NOT BE AS GOOD TOMORROW WITH NO WELL
DEFINED VORT MAXIMA IMPACTING THE AREA. HOWEVER...WITH LESS CLOUD
COVER DAYTIME HEATING WILL BE MORE OF A FACTOR.
NO UPDATES EXPECTED TO THE FORECAST THIS MORNING.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL
THROUGH THE AFTERNOON. SOUTHERLY WINDS ARE EXPECTED TO
PREVAIL...BUT DEVELOPING SHOWERS AND THUNDERSTORMS WILL RESULT IN
PERIODS OF GUSTY AND/OR ERRATIC WINDS...PARTICULARLY THIS
AFTERNOON. THERE IS A 30 PERCENT CHANCE THAT THE TERMINAL WILL SEE
BRIEF MVFR CONDITIONS IN HEAVIER SHOWERS. THERE IS A 40 PERCENT
CHANCE THAT A THUNDERSTORM WILL DIRECTLY IMPACT THE TERMINAL THIS AFTERNOON.
&&
.FIRE WEATHER...DEEP MONSOONAL MOISTURE REMAINS IN PLACE ACROSS THE
FIRE DISTRICT THIS MORNING. HUMIDITIES WILL REMAIN HIGH ALLOWING
CONDITIONS TO BECOME INCREASINGLY RIPE FOR SHOWER AND THUNDERSTORM
DEVELOPMENT DURING THE DAY. SHOWERS AND THUNDERSTORMS WILL BECOME
NUMEROUS BY THE AFTERNOON WITH WIDESPREAD WETTING RAIN POTENTIAL
INTO THE EARLY EVENING. LIGHTNING ACTIVITY LEVELS ARE EXPECTED TO BE A
BIT HIGHER TODAY WITH DEEPER INSTABILITY IN PLACE PROVIDING
ANOTHER DAY FOR HEIGHTENED POTENTIAL OF NEW STARTS AREAWIDE.
THE NUMEROUS SHOWERS/STORMS WILL HOLD INTO THIS EVENING BEFORE
COVERAGE WANES WITH LOSS OF HEATING. HUMIDITY LEVELS WILL REMAIN
ELEVATED INTO SUNDAY ALLOWING YET ANOTHER ACTIVE PRECIPITATION DAY
THOUGHT AREAL COVERAGE OF WETTING RAINS SHOULD BEGIN TO DECLINE AT
THAT TIME AS SLIGHTLY DRIER AIR BEGINS TO WORK IN FROM THE WEST.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR
UTZ004-008-010-012>016-019>021-517-518.
WY...NONE.
&&
TRAPHAGAN
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SALT LAKE CITY UT 605 AM MDT SAT JUL 14 2012 UTZ001>016-019>021-517-518-WYZ021-151300- CACHE VALLEY/UTAH PORTION-NORTHERN WASATCH FRONT- SALT LAKE AND TOOELE VALLEYS-SOUTHERN WASATCH FRONT- GREAT SALT LAKE DESERT AND MOUNTAINS-WASATCH MOUNTAIN VALLEYS- WASATCH MOUNTAINS I-80 NORTH-WASATCH MOUNTAINS SOUTH OF I-80- WESTERN UINTA MOUNTAINS-WASATCH PLATEAU/BOOK CLIFFS- WESTERN UINTA BASIN-CASTLE COUNTRY-SAN RAFAEL SWELL- SANPETE/SEVIER VALLEYS-WEST CENTRAL UTAH-SOUTHWEST UTAH- UTAHS DIXIE AND ZION NATIONAL PARK-SOUTH CENTRAL UTAH- GLEN CANYON RECREATION AREA/LAKE POWELL-CENTRAL MOUNTAINS- SOUTHERN MOUNTAINS-SOUTHWEST WYOMING- 605 AM MDT SAT JUL 14 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS OF UTAH AND SOUTHWEST WYOMING. .DAY ONE...TODAY AND TONIGHT THE VERY MOIST AIR MASS CURRENTLY OVER THE REGION WILL SPAWN NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH TONIGHT. THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL TO ACCOMPANY THE STRONGER SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. THIS HEAVY RAINFALL COULD PRODUCE FLASH FLOODING...ESPECIALLY IN AREAS PRONE TO FLOODING SUCH AS SLOT CANYONS...SLICK ROCK COUNTRY...AND WHERE LARGE BURN SCARS EXIST FROM RECENT WILDFIRE ACTIVITY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE LATTER HALF OF THE WEEKEND WILL REMAIN WET...WITH SHOWERS AND THUNDERSTORMS EXPECTED AGAIN ON SUNDAY. THE POTENTIAL FOR HEAVY RAINFALL WILL EXIST ON SUNDAY...WITH RECENT BURN SCARS AND SLOT CANYONS ONCE AGAIN THE FOCUS FOR ANY FLASH FLOODING THREAT. DRIER AIR WILL BEGIN TO WORK INTO UTAH FROM THE WEST EARLY IN THE UPCOMING WEEK. RESIDUAL MOISTURE WILL PRODUCE AFTERNOON/EVENING SHOWER SAND STORMS OVER MAINLY THE HIGHER TERRAIN MONDAY...WITH SUBSTANTIALLY LESS ACTIVITY FOR TUESDAY. THE DRIER AIR SHOULD BE FIRMLY ESTABLISHED BY WEDNESDAY...RESULTING IN LITTLE THREAT FOR SHOWERS EVEN OVER THE HIGHER TERRAIN. TEMPERATURES WHICH WILL GENERALLY BE BELOW NORMAL LATE IN THE WEEKEND WILL SHOW A GRADUAL WARMING TREND THROUGH MIDWEEK. READINGS WILL LIKELY EQUAL OR EXCEED THE MID-JULY NORMS BY THE END OF THE WEEK. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE) FOR INFORMATION ON POTENTIAL TRAVEL IMPACTS VISIT... HTTP://WWW.UDOTTRAFFIC.UTAH.GOV/ROADWEATHERFORECAST.ASPX
The Cedar City radar (KICX), 46 km away, was scanning. The volume nearest the first event began at 16:02 UTC.
11 flash flood, 3 thunderstorm wind, 1 hail. Local standard time, as filed.
Multiple slot canyons in Zion National Park experienced flash flooding.
An ash flow was reported after heavy rain fell over the Wood Hollow burn scar. Parts of Wood Hollow Road were washed out due to this flash flood.
Major flash flooding occurred in St. George, Utah, as heavy rain fell over the area for nearly an hour. The rain overwhelmed many of the storm drains across the city, with manhole covers popping up in a few locations, including Main Street. Water rose as high as three or four feet on some streets, and several drivers were stranded in their cars with water up to their windows. A few small landslides were reported, and mud and debris flowed onto some streets. Approximately 100 homes and a few businesses experienced at least minor damage.
The Beaver Dam Wash experienced a flash flood, with flow in the wash increasing from zero to 1244 cfs.
Flash flooding occurred along Sulphur Creek in Capitol Reef National Park, impacting a section of State Route 24.
Numerous drainages within Zion National Park experienced flash flooding, most notably La Verkin Creek and Spry Canyon.
Flash flooding was reported in Buckskin Gulch and surrounding drainages.
A thunderstorm dropped enough hail on Hurricane, Utah to cover the ground, with an estimated maximum hail size of 1 inch in diameter.
Moderate sized tree branches were downed by thunderstorm winds in La Verkin, Utah.
A sensor in Nephi, Utah recorded a maximum wind gust of 60 mph.
A sensor near Point of the Mountain, named Portable RWIS #2, recorded a maximum wind gust of 58 mph. In addition, damage was reported in the Spanish Fork area, with multiple trees and power lines blown over.
The Fort Pearce Wash experienced a large flash flood, with flows in the wash increasing from zero to 8049 cfs.
Flash flooding was reported in some drainages near Hurricane, Utah.
Flash flooding was reported along the Paria River, including where the river meets State Route 89.
A large flash flood occurred on Wahweap Creek and was observed as it passed through Big Water. The high water from Wahweap Creek cut off the Smokey Mountain Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2012Every state in 2012This day in weather historyWarnings in Utah, 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: 403701, 405464, 405465, 405467, 405468, 405486, 405491, 403698, 403699, 403697, 403696, 405473, 405492, 405493, 405461.