Severe thunderstorms were observed across primarily northern Utah from August 5 through August 7, with significant wind damage on multiple days.
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.
Severe thunderstorms were observed across primarily northern Utah from August 5 through August 7, with significant wind damage on multiple days.
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 5, 3:29 PM MST, 51 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 429 PM MDT WED AUG 5 2015 .SYNOPSIS...A WEAK UPPER LEVEL DISTURBANCE WILL CROSS NORTHERN UTAH THIS EVENING. A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE REGION ON THURSDAY. AN UPPER LOW WILL BRING AN INCREASE IN MONSOON MOISTURE AS IT LIFTS ACROSS THE GREAT BASIN FRIDAY AND SATURDAY. && .SHORT TERM (THRU 12Z SATURDAY)...A FAIRLY VIGOROUS SHORT WAVE TROF IS ENTERING NWRN UT AT THIS TIME AND WILL CROSS NRN UT THRU THIS EVE. SCATTERED CONVECTION HAS FORMED OVER THE FAR NW WITH AND WILL SPREAD ACROSS THE FAR NRN CWA AS THIS FEATURE MOVES EAST WITH THE SRN EXTENT OF THE THREAT OF SHOWERS DOWN TO ABOUT SALT LAKE COUNTY. THERE IS A TAP OF TROPICAL MOISTURE AT MID AND UPPER LEVELS FEEDING INTO THIS SHORT WAVE FROM THE WEAKENING TROPICAL STORM GUILLERMO OUT NEAR HAWAII. THIS HAS SUPPLIED AN ASSIST TO THIS WAVE AND ISOLATED STRONG STORMS HAVE DEVELOPED AND WILL CONTINUE TO BE POSSIBLE INTO EARLY EVE. THIS WAVE MOVES EAST OF THE CWA AFTER 06Z TONIGHT TAKING THE CONVECTION WITH IT. SHORT WAVE RIDGING BUILDS OVER THE CWA THU WITH THE AXIS OVER EASTERN UT AS A CLOSED LOW APPROACHES THE CA COAST. THIS TAPS TROPICAL MOISTURE FROM OLD MEXICO THAT STARTS TO SPREAD INTO SWRN UT BY 00Z FRI AND ACROSS THE CWA OVER THE NEXT 24 HOURS. THIS MOISTURE WILL LIKELY BRING WIDESPREAD PRECIP TO THE AREA AND HAVE RAISED POPS INTO THE LIKELY CATEGORY FOR MOST AREAS FRIDAY AFTERNOON AND EVENING. THE CLOSED LOW LIFTS INTO THE WESTERN GREAT BASIN ON FRI AND STARTS TO OPEN UP. IT THEN SHIFTS EAST FRIDAY NIGHT AND DRIER AIR STARTS TO SPREAD IN FROM THE SOUTHWEST. .LONG TERM (AFTER 12Z SATURDAY)...A WEAKENING TROUGH WILL CONTINUE TO LIFT NORTHEASTWARD ACROSS NORTHEAST NEVADA INTO SOUTHERN IDAHO THROUGH THE DAY SATURDAY. A SIGNIFICANT DEEP MOISTURE SURGE AHEAD OF THIS WAVE WILL PROVIDE SUFFICIENT MOISTURE FOR ONGOING PRECIPITATION SATURDAY MORNING ACROSS PORTIONS OF NORTHERN AND CENTRAL UTAH. AS A DRY SLOT CONTINUES TO PROGRESS NORTH AND EAST...EXPECT PRECIPITATION TO GRADUALLY END FROM SOUTHWEST TO NORTHEAST BY EVENING. THE WAVE WILL LIFT AWAY FROM THE AREA BY LATER SATURDAY...ENDING THE PRECIPITATION ACROSS THE REGION. IN THE WAKE OF THIS WAVE...HIGH PRESSURE WILL BUILD ACROSS THE AREA...BRINGING A PERIOD OF WARM AND DRY CONDITIONS TO THE STATE. AS A FAIRLY POTENT UPPER LEVEL SYSTEM APPROACHES THE PACIFIC NORTHWEST...MOISTURE WILL BEGIN TO SURGE NORTHWARD AGAIN...INTO PORTIONS OF SOUTHERN UTAH BY TUESDAY. GLOBAL MODELS HAVE BEEN FAIRLY CONSISTENT WITH THE EVOLUTION OF THIS MOISTURE SURGE. && .AVIATION...GUSTY SOUTHERLY WINDS WILL CONTINUE AT KSLC UNTIL THE ARRIVAL OF A COLD FRONT BETWEEN 23-00Z THEN SWITCH TO NORTHWEST. THE NORTHWEST WINDS WILL BE GUSTY FOR A COUPLE OF HOURS BEHIND THE FRONT. && .FIRE WEATHER...GUSTY SOUTHWESTERLY WINDS WILL CONTINUE INTO THIS EVENING ACROSS MUCH OF THE AREA AHEAD OF A COLD FRONT. THE GUSTY WINDS AND LOW RH VALUES WILL KEEP FIRE WEATHER CONDITIONS CRITICAL OVER FAR SOUTHERN UTAH THIS AFTERNOON INTO EARLY THIS EVENING AND HAVE KEPT THE RED FLAG WARNING IN EFFECT FOR THIS. THE FRONT WILL CROSS NORTHERN UTAH THIS EVENING WITH SCATTERED SHOWERS AND THUNDERSTORMS AND GUSTY SHIFTING WINDS. HIGH PRESSURE WILL BRIEFLY STRENGTHEN THURSDAY...BEFORE MONSOON MOISTURE SURGES NORTHWARD ACROSS THE AREA LATE THURSDAY NIGHT THROUGH FRIDAY. WETTING RAINS WILL BE LIKELY ACROSS MUCH OF THE AREA FRIDAY INTO FRIDAY NIGHT WITH THIS MOISTURE BEFORE DRIER AIR SPREADS BACK TO THE REGION FROM THE SOUTHWEST BEGINNING SATURDAY. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR UTZ497-498. WY...NONE. && WILENSKY/KRUSE 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 855 AM MDT WED AUG 5 2015 UTZ001>016-019>021-517-518-WYZ021-061200- 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- 855 AM MDT WED AUG 5 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS OF UTAH AND SOUTHWEST WYOMING. .DAY ONE...TODAY AND TONIGHT HAZARDOUS FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS FAR SOUTHWEST AND SOUTH CENTRAL UTAH THROUGH EARLY THIS EVENING. ISOLATED TO SCATTERED THUNDERSTORMS CAN BE EXPECTED THIS AFTERNOON AND EARLY EVENING ACROSS NORTHERN UTAH. STRONG GUSTY WINDS WILL BE POSSIBLE WITH THE STORMS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE THURSDAY NIGHT THROUGH FRIDAY NIGHT STATEWIDE. SOME OF THESE THUNDERSTORMS MAY BE STRONG FRIDAY AFTERNOON AND EVENING WITH GUSTY WINDS AND SMALL HAIL. IN ADDITION...ANY THUNDERSTORMS DURING THIS PERIOD WILL HAVE THE POTENTIAL FOR HEAVY RAINFALL AND ISOLATED FLASH FLOODING. .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
The Salt Lake City radar (KMTX), 61 km away, was scanning. The volume nearest the first event began at 23:18 UTC.
16 thunderstorm wind, 1 hail. Local standard time, as filed.
Quarter to ping pong ball sized hail was observed and video taped along Interstate 84 north of Bothwell.
Strong thunderstorm winds destroyed a wooden barn in Bothwell.
The White Reef RAWS recorded a peak wind gust of 60 mph.
The Wendover AWOS recorded a peak gust of 79 mph.
The North Salt Flats sensor in the Dugway Proving Ground mesonet recorded a maximum wind gust of 68 mph.
The West Salt Flats sensor in the Dugway Proving Ground mesonet recorded a peak wind gust of 61 mph.
The West of Wildcat Mountain sensor in the Dugway Proving Ground mesonet recorded a wind gust of 69 mph.
The Lower Cedar Mountain sensor in the Dugway Proving Ground mesonet recorded a maximum wind gust of 59 mph.
A 64 mph wind gust was recorded at the Camel Back Mountain sensor in the Dugway Proving Ground mesonet.
The Portable RWIS 5 sensor, located northeast of Lakeside along Interstate 80, recorded a maximum wind gust of 64 mph.
Peak wind gusts from the line of thunderstorms in Box Elder County included 76 mph at Lakeside Mountain, 66 mph at the Utah Test and Training Range Oasis Compound, and 60 mph at Hat Island.
A 76 mph wind gust was recorded at the Lake Point at Interstate 80 sensor.
Peak recorded wind gusts as the line of thunderstorms moved through Salt Lake County included 65 mph at the Great Salt Lake Marina, 64 mph at Parley's Canyon, and 63 mph at the Salt Lake City International Airport. In addition, the strong winds hit the finish line of the Tour of Utah bike race, where many had gathered for a medal ceremony. A large metal structure was knocked over by the winds, and two people were injured.
Peak recorded wind gusts in Davis County included 65 mph in Farmington and 61 mph at the Centerville UDOT sensor.
Maximum recorded wind gusts in Weber County included 62 mph at the Great Salt Lake Minerals sensor and 61 mph at Ogden Peak.
The SR-65 at Big Mountain Pass sensor recorded a peak wind gust of 80 mph.
Several large trees were knocked down by thunderstorm winds near Henefer.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2015Every state in 2015This day in weather historyWarnings in Utah, August 2015
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: 600650, 600651, 600652, 600659, 600661, 600663, 600664, 600665, 600666, 600667, 600658, 600668, 600654, 600655, 600656, 600657, 600653.