Strong thunderstorms continued to produce flash flooding over central and southern Utah in mid-July. Some thunderstorms also produced some gusty winds over northwest Utah during the evening of July 16.
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.
Strong thunderstorms continued to produce flash flooding over central and southern Utah in mid-July. Some thunderstorms also produced some gusty winds over northwest Utah during the evening of July 16.
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, 9:01 AM MST, 4 hours 59 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 1001 AM MDT Sat Jul 14 2018 .SYNOPSIS...Deep moisture will much of the area outside of the far north through today. A drier airmass from the northwest will spread into much of the area beginning Sunday. && .DISCUSSION...Morning water vapor and H5 analysis place the upper ridge axis along the Utah/Colorado border, with the return flow continuing to advect deep moisture north into the area along the western periphery of the mid level circulation. Note an upper short wave currently over east-central Nevada lifting north- northeast, further driving elevated PWAT back north into northern Utah over the last several hours. Only gradual moistening is occurring across the north per surface dew point analysis, with the bulk of the moisture advection remaining above H7. Very deep moisture remains across central/southern Utah where dewpoints range from the mid 50s to low 60s, and PWAT hovers between 1.2-1.5 inches per SPC mesoanalysis. The primary update this morning was to increase PoPs and lower temps across the north/west in advance of the approaching short wave. Dynamic lift in advance of this feature (noted in cooling cloud tops in IR) has induced scattered showers north of Juab County, and prolific mid level cloud cover across all of the north. Continued northeast-east translation of this short wave will only induce further activity through the day, but convective potential will be somewhat hampered by meager mid level lapse rates and suppressed heating. Focus of the shift will once again revolve around diurnal convective development and locally heavy rain potential across central/southern Utah. Veering flow (to near westerly) associated with the passing wave will aid downstream propagation of terrain based cells across central portions (increased flash flood potential for Capitol Reef), while light flow across the south coupled with primed low levels should once again promote down- drainage propagation of terrain based cells (initially) along developing outflow boundaries, continuing well into the evening. Previous discussion below... .PREVIOUS DISCUSSION...In the wake of the passing wave the models have been consistent in spreading subsidence and much drier air into the area Sunday. This will likely limit any convective threat to the far south with only isolated coverage. This drier air will remain in place into the day Monday, again resulting in little if any convective threat during the day. By Monday evening a shortwave trough which is forecast to brush by northern Utah is expected to spread convection out of Nevada and into northwest Utah. Have introduced slight chance PoPs across northwestern Utah for this time period. Additional convection influenced by the passing trough, particularly across the northwest, could continue into early Tuesday, before the trough axis passes east of the area by Tuesday afternoon. After this initial bit of forcing, the larger impact may be that the trough ushers in a drier airmass to northern Utah behind the wave, potentially confining showers and thunderstorms to the southern portions of the forecast area Tuesday and Wednesday afternoons. The shifting upper level high looks to pass overhead on Wednesday, and then center itself east of the area for Thursday onward. This pattern could allow a significant return of moisture to Utah from the south on Thursday and Friday, with showers once again possible area-wide. Have generally increased POPs across the area Thursday through Saturday, with temperatures dropping off a little bit heading into the weekend after a very warm Wednesday and Thursday. && .AVIATION....Showers will be in the vicinity of the terminal through the late morning/early afternoon. Despite these showers expect ceilings to generally stay above 7k ft and VFR conditions to prevail through the day. Light southerly winds (at times variable this AM due to showers) are expected to shift to northerly around 17-18Z. && .FIRE WEATHER...Ample moisture remains in place across central and southern Utah this morning, and should allow for another round of showers and thunderstorms capable of producing heavy rainfall. A weak weather system passing through the north will help temporarily pull some of this moisture into the north as well, allowing for a chance of showers and thunderstorms through this evening. High pressure will follow on Sunday allowing for a drying trend, which will likely continue into the upcoming week. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && DISCUSSION/AVIATION...Merrill/Carr PREVIOUS DISCUSSION...Seaman/Schoening For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity For frequently asked questions about the Area Forecast Discussion visit... http://weather.gov/saltlakecity/general/afd_faqs.php
Hazardous Weather Outlook National Weather Service Salt Lake City UT 643 AM MDT Sat Jul 14 2018 UTZ001>016-019>021-517-518-WYZ021-151200- 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- 643 AM MDT Sat Jul 14 2018 This Hazardous Weather Outlook is for the western two thirds of Utah and southwest Wyoming. .DAY ONE...Today and Tonight Showers and thunderstorms will be possible across the outlook area through this evening. A threat of locally heavy rainfall and isolated flash flooding exists across central and southern Utah. .DAYS TWO THROUGH SEVEN...Sunday through Friday High pressure will bring a drying trend across the area Sunday into Monday. This high will strengthen by midweek bringing hot temperatures to the region. .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 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
131 PM MDT SAT JUL 14 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0915 PM FLASH FLOOD WASHINGTON 37.13N 113.49W
07/13/2018 WASHINGTON UT EMERGENCY MNGR
FLASH FLOODING IN THE NORTHEASTERN PART OF WASHINGTON
CITY DAMAGED APPROXIMATELY SIX HOMES.
&&
MTThe Cedar City radar (KICX), 67 km away, was scanning. The volume nearest the first event began at 21:00 UTC.
18 flash flood, 3 thunderstorm wind. Local standard time, as filed.
Heavy rain resulted in flash flooding in the city of Kanab. The water made several city roads impassable, and they were temporarily closed.
Heavy rain caused flash flooding that damaged fields and homes in Richfield, including 260 acres of a 320 acre property used for farming and growing sod.
Heavy rain produced flash flooding in Twentyfive Mile Wash and Harris Wash.
Heavy rain caused widespread flash flooding at Zion National Park. Some park visitors were temporarily stranded on the Riverside Walk hiking trail due to the water.
Heavy rain produced a flash flood in the vicinity of Marysvale that temporarily closed Interstate 70.
Heavy rain caused a flash flood on the Paria River near the Paria Townsite.
Heavy rain produced flash flooding in Hildale.
Heavy rain produced a flash flood in Wahweap Creek.
Heavy rain produced a large flash flood in Johnson Canyon.
Heavy rain produced flash flooding in the city of Kanab. Water was reported to have been rushing over roads at the mouth of Kanab Creek in town.
Heavy rain caused a debris flow on the Trail Mountain Fire burn scar.
The Durand Road wind sensor on the U.S. Army Dugway Proving Ground measured a peak wind gust of 58 mph.
The Gunnison Island wind sensor reported a peak wind gust of 58 mph.
The Baccus/SR111 UDOT sensor measured a peak wind gust of 58 mph.
Heavy rain resulted in flash flooding along the Paria River, with the Paria River gage near Kanab rising to 1390 cfs due to the rain.
Heavy rain produced flash flooding that temporarily closed Interstate 15 near the town of Leeds. Flash flooding was also reported in Leeds and Washington City.
Heavy rain caused widespread flash flooding in the town of Marysvale. At least five homes were damaged, a gas line was broken, and mud covered many roadways in the area. The flood waters temporarily forced the closure of U.S. Highway 89 through the center of town.
Heavy rain resulted in flash flooding near Panguitch that temporarily closed U.S. Highway 89 in both directions.
Flash flooding occurred in the city of Kanab due to heavy rain. Local law enforcement reported that sandbagging was necessary in and around town.
Heavy rain caused flash flooding in the city of Hildale, as well as nearby Short Creek.
Heavy rain produced flash flooding along Wahweap Creek.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2018Every state in 2018This day in weather historyWarnings in Utah, July 2018
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: 771693, 771789, 771694, 771695, 771762, 771696, 771700, 771699, 771701, 771702, 771704, 771763, 771765, 771766, 771754, 771758, 771761, 771753, 771756, 771759, 771760.