More strong thunderstorms developed between August 18 and August 20, with the strongest thunderstorms moving across the southern portions of Utah. Multiple locations received significant flash flooding from the heavy rainfall.
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.
More strong thunderstorms developed between August 18 and August 20, with the strongest thunderstorms moving across the southern portions of Utah. Multiple locations received significant flash flooding from the heavy rainfall.
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 Aug 18, 2:44 PM MST, 1 hour 16 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 344 PM MDT MON AUG 18 2014 .SYNOPSIS...A WEAK WAVE OVER WESTERN ARIZONA COMBINED WITH INCREASED SOUTHWESTERLY FLOW ALOFT WILL CONTINUE TO SPREAD DEEP MOISTURE SOUTH TO NORTH ACROSS THE AREA OVER THE NEXT 24 HOURS. A GRADUAL DRYING TREND IS EXPECTED FOR THE LATTER HALF OF THE WEEK. && .DISCUSSION...THE MID LEVEL RIDGE ACROSS THE DESERT SOUTHWEST HAS SHIFTED EAST TODAY AS A CLOSED LOW OVER NORCAL CONTINUES TO GRADUALLY TRACK SOUTH DOWN THE PACIFIC COAST. INCREASED SOUTHWESTERLY FLOW ALOFT AND RIDGE SHIFT HAVE OPENED THE DOOR FOR MONSOONAL MOISTURE TO BEGIN SPREADING NORTH BACK INTO THE AREA. DEWPOINTS ACROSS THE FAR SOUTH HAVE TAKEN A NOTED JUMP TODAY...CURRENTLY LOW 50S AT KSGU. THE COLUMN HAS MOISTENED SIGNIFICANTLY ACROSS THE SOUTHWEST AS WELL WITH PWAT JUMPING FROM ROUGHLY .60 INCHES TO 1.3 INCHES IN AND AROUND DIXIE. A RETURN FLOW WAVE CURRENTLY OVER NORTHWESTERN ARIZONA HAS SPARKED CONVECTION SOUTH OF THE BORDER OVER THE LAST FEW HOURS...WITH SOME ORGANIZATION OF STORMS NOTED DUE TO SHORT WAVE INFLUENCE. THIS ACTIVITY WILL CONTINUE TO SPREAD NORTH INTO AND AROUND DIXIE/ZION NP OVER THE NEXT FEW HOURS AND LOCALIZED HEAVY RAIN IS A POTENTIAL. SPC MESO-ANALYSIS CURRENTLY INDICATING UP TO 2000 J/KG IN THAT AREA...WITH NORMALIZED CAPE VALUES OF .20 SIGNIFYING QUITE A MEATY INSTABILITY PROFILE. ALONG WITH HEAVY RAIN SOME HAIL/WIND WILL BE POSSIBLE WITH THESE STORMS AND CAN NOT RULE OUT A SEVERE STORM. HRRR HAS BEEN STATING SIMILAR COVERAGE FOR MANY RUNS AND EXPECT ACTIVITY WILL REACH AS FAR NORTH AS I-70 BY LATE EVE. COMBINATION OF CONVECTIVE BLOW OFF FROM THE SOUTH AND A NET INCREASE OF UPPER LEVEL MOISTURE CURRENTLY OVER CENTRAL NEVADA WILL BEGIN TO SPREAD SIGNIFICANT CLOUD COVER TO MOST ALL AREAS LATER TONIGHT. MODELS CONTINUE TO INDICATE THE RETURN WAVE ENERGY WILL TRACK INTO CENTRAL UTAH BY TOMORROW MORNING SPREADING SHOWERS AND FEW STORMS AS FAR NORTH AS I-80 BY TOMORROW MORNING. ALL AREAS BY THE AFTERNOON. BY THAT TIME PWAT SHOULD EXCEED AN INCH MOST ALL AREAS AND COMBINED WITH WEAK DYNAMIC LIFT AT LEAST A DECENT CHANCE OF SHOWERS/STORMS. AREAS THAT DO RECEIVE SOME SOLAR INPUT...NAMELY FAR NORTHERN AND EASTERN AREAS ON THE LEADING EDGE OF THE SHORT WAVE...WILL LIKELY HAVE THE GREATEST THREAT OF HEAVY RAIN TOMORROW...WITH THOSE SOUTH AND WEST OF THE ENERGY BECOMING AT LEAST SOMEWHAT SUBSIDENT BY LATE MORNING. HAVE HELD OFF OF A FLASH FLOOD WATCH DUE TO TIMING OF WAVE AND LIKELIHOOD OF SUBSIDENCE/CLOUD COVER IN WAKE OF IT BUT WILL NEED TO CONTINUE MONITORING TRENDS TONIGHT. BY LATE EVENING ALL ENERGY LOOKS TO TRACK OFF TO THE NORTHEAST AND BULK OF ACTIVITY LOOKS TO TRACK WITH IT. GLOBAL MODELS IN SLIGHTLY BETTER AGREEMENT REGARDING TRACK AND EVOLUTION OF THE NORCAL CLOSED LOW AND PATTERN CHANGE TOWARDS DEVELOPMENT OF A LONGWAVE TROUGH ACROSS THE PACNW/NORTHERN ROCKIES MID/LATE WEEK. THE GFS REMAINS MORE PROGRESSIVE WITH THE FORMER OPENING IT UP THROUGH THE STATE THURSDAY...WHILE THE ECMWF REMAINS SLIGHTLY SLOWER PASSING BULK OF THE ENERGY THROUGH THE 4-CORNERS. INFLUENCE OF THE LONG WAVE/NORTHERN BRANCH ENERGY SHOULD FOCUS ON THE FAR NORTH THE MOST AND HAVE TRENDED POPS UP MIDWEEK ALONG THE UT/ID BORDER. THOUGH THE AIRMASS WILL BE TRENDING TO DRY MODELS DO NOT INDICATE SIGNIFICANT FLOW TO SCOUR LOWER LEVEL MOISTURE IN PLACE UNTIL POSSIBLY THE WEEKEND. THIS SAID...CONFIDENCE IN DETAILS OUTSIDE OF THE LARGER SCALE FEATURES REMAINS LIMITED AT BEST MID TO LATE WEEK AS MODEL TO MODEL CONSISTENCY HAS BEEN LESS THAN IDEAL AS OF LATE. && .AVIATION...NORTH TO NORTHWEST WINDS WILL SHIFT TO THE SOUTHEAST AT THE SLC TERMINAL BETWEEN 02-04Z THIS EVENING. THERE IS LITTLE CHANCE OF CONVECTION IMPACTING THE AIRPORT THIS AFTERNOON AND EVENING. && .FIRE WEATHER...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS SOUTHERN UTAH THIS AFTERNOON AND EVENING AS MOISTURE MOVES INTO UTAH FROM ARIZONA. INITIALLY...THERE IS THE THREAT FOR DRY LIGHTNING...BUT MOISTURE WILL INCREASE QUICKLY...AND BY EARLY EVENING MOST STORMS WILL BE ACCOMPANIED BY WETTING RAIN. STORMS WILL CONTINUE OVERNIGHT...WITH AREAL COVERAGE INCREASING NORTHWARD OVERNIGHT. BY TOMORROW AFTERNOON...THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS EXISTS STATEWIDE. STORM ACTIVITY WILL DECREASE TUESDAY EVENING...WITH THE POTENTIAL FOR STORM DEVELOPMENT OVER THE HIGHER TERRAIN WEDNESDAY AND THURSDAY. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...NONE. WY...NONE. && MERRILL/KRUSE/HOSENFELD 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 608 AM MDT MON AUG 18 2014 UTZ001>016-019>021-517-518-WYZ021-191200- 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- 608 AM MDT MON AUG 18 2014 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS OF UTAH AND SOUTHWEST WYOMING. .DAY ONE...TODAY AND TONIGHT MONSOON MOISTURE WILL MOVE NORTH INTO SOUTHERN UTAH TODAY AND THEN SPREAD NORTH THROUGH THE REMAINDER OF THE OUTLOOK AREA TONIGHT. THIS WILL BRING SHOWERS AND THUNDERSTORMS TO THE STATE... BEGINNING IN SOUTHERN UTAH THIS AFTERNOON AND THEN STATEWIDE TONIGHT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A MOIST AIRMASS WILL REMAIN ACROSS THE OUTLOOK TUESDAY BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING HEAVY RAIN AND LOCALIZED FLASH FLOODING. DRIER AIR IS THEN EXPECTED TO BEGIN MOVING BACK INTO THE REGION ON WEDNESDAY. .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 ROAD TRAVEL IMPACTS VISIT... HTTP://WWW.UDOTTRAFFIC.UTAH.GOV/ROADWEATHERFORECAST.ASPX
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
144 PM MDT MON AUG 18 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0142 PM FLASH FLOOD 7 SE TORREY 38.23N 111.33W
08/14/2014 WAYNE UT PARK/FOREST SRVC
0142 PM FLASH FLOOD 7 SE TORREY 38.23N 111.33W
08/14/2014 WAYNE UT 911 CALL CENTER
FLASH FLOODING IN BURRO,COTTONWOOD, AND PLEASANT CREEK
DRAINAGES IN CAPITOL REEF NATIONAL PARK.
&&
BMCINERNEYPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
145 PM MDT MON AUG 18 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0302 PM FLASH FLOOD 8 SE TORREY 38.22N 111.31W
08/15/2014 WAYNE UT PARK/FOREST SRVC
FLASH FLOOD IN SHEETS GULCH IN CAPITOL REEF NATIONAL
PARK.
&&
BMCINERNEYSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
331 PM MDT MON AUG 18 2014
UTZ019-020-518-182215-
SOUTH CENTRAL UTAH UT-UTAH'S DIXIE AND ZION NATIONAL PARK UT-
SOUTHERN UTAH MOUNTAINS UT-
331 PM MDT MON AUG 18 2014
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN WASHINGTON COUNTY
UNTIL 415 PM MDT...
AT 330 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 11 MILES SOUTH OF HURRICANE...OR 16 MILES EAST OF
ST GEORGE...MOVING NORTHEAST AT 15 MPH.
PENNY TO NICKEL SIZE HAIL AND WINDS OF 40 TO 55 MPH WILL BE POSSIBLE.
LOCATIONS IMPACTED INCLUDE...
ST GEORGE...ST. GEORGE...WASHINGTON...HURRICANE...SANTA CLARA...LA
VERKIN...IVINS...HILDALE...TOQUERVILLE...LEEDS...VIRGIN...
SPRINGDALE...ROCKVILLE AND BLOOMINGTON.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF THREATENING WEATHER APPROACHES...TAKE SHELTER IN A STURDY
BUILDING.
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
&&
LAT...LON 3700 11368 3724 11365 3719 11359 3719 11353
3723 11351 3720 11347 3729 11337 3730 11328
3728 11327 3730 11325 3725 11322 3725 11317
3717 11298 3700 11302
TIME...MOT...LOC 2130Z 210DEG 15KT 3700 11330
CRKThe Cedar City radar (KICX), 78 km away, was scanning. The volume nearest the first event began at 22:59 UTC.
6 flash flood, 1 flood. Local standard time, as filed.
Heavy rain caused flash flooding in Washington City, including road flooding along Main Street. At least 6 homes were damaged by flood waters, and flooding also occurred in a grocery store.
Members of the public reported flash flooding in Red Canyon.
Flash flooding occurred along the Fort Pearce Wash, with recorded flows rising from zero to 7,692 cfs in a very short period of time. This was the 3rd highest recorded flow since 1985. Due to mitigation efforts following previous floods, no damage was reported from these flows.
Flash flooding was reported in several drainages in Zion National Park, with the worst flooding in Birch Hollow, Heaps Canyon, and Pine Creek.
Heavy rain during the early morning hours of August 20 led to flooding in West Jordan and Murray, with approximately 25 houses reporting some degree of flood damage. This flooding was most common in driveways, garages, and basements, with some homes receiving significant damage.
The Forest Service reported flash flooding in Red Canyon and Butch Cassidy Wash.
Isolated street and house flooding was reported in Panguitch, with flooding also reported in nearby dry washes.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2014Every state in 2014This day in weather historyWarnings in Utah, August 2014
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: 541427, 541417, 541399, 541418, 541412, 541414, 541420.