Strong thunderstorms developed across Utah on May 28 through May 30, with some of these storms producing tornadoes and severe wind gusts.
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 developed across Utah on May 28 through May 30, with some of these storms producing tornadoes and severe wind gusts.
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 May 28, 7:50 AM MST, 4 hours 20 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 850 AM MDT Mon May 28 2018 .SYNOPSIS...The upper level low pressure system centered across the Great Basin will slowly weaken as it moves east away from the area through tonight. High pressure will return midweek, followed by the next Pacific trough late in the week. && .DISCUSSION... Antecedent Conditions... Extreme Drought is occurring from Provo south to Cedar City and to the southeast. Severe Drought is occurring surrounding the Extreme Drought, in areas south of Ogden and Duchesne to the Arizona border. Drought conditions scale down to Abnormally Dry along the Idaho and Wyoming border. Big Picture... During the past 5 days, the patter across the Pacific has amplified. Water Vapor Satellite shows an expansive and deep closed low over west central Utah. 400-250 MDCARS wind observations show a 60-80kt jet around the aforementioned closed low, with a 80-105kt westerly subtropical jet from southern California into New Mexico. Local Observations and Trends... 12Z KSLC RAOB shows some warming aloft has weakened lapse rates a bit, with mid level flow remaining weak. Precipitable Water values range from 0.20"-0.40" mountains to 0.55"-0.80" western valleys. This represents an increase of 0.10"-0.25" in Precipitable Water during the past 24 hours. A 1008mb surface cyclone is located in western Colorado, with a cold front stretching from about the southwest tip of Utah to Boulder Summit to Roosevelt. A 1016mb surface anticyclone is located across east central Nevada, which has combined with the low to our east to support a 7mb northwesterly pressure gradient across the state. 24 hour trends: Generally 5-15F cooler across Utah. Dewpoint Depression have generally decreased (moistened) 5-15F across the state. Forecast... Going forecast in good shape with only a few tweaks. Moderately strong instability today with the cold pool aloft. Lapse rates have weakened a little as noted earlier, compared to yesterday. Several vorticity lobes continue to rotate around the closed low. The strongest of which is across west central Utah this morning, pivoting across southwest Utah early this afternoon and south central and southeast Utah late this afternoon and evening. A second area of positive vorticity advection will be across far northern Utah from the southeast. Terrain circulations will also support convective development. Storm motion will easterly across southwest Wyoming, northeasterly northern and west central Utah, northwesterly southwest Utah and southwesterly south central and eastern Utah. Storms should propagate 5-15kts (slower today) except southern Utah where they will propagate 15-25kts. Copious lightning and small hail are expected with the strongest updrafts, as equilibrium temperatures are between -40C and -45C. Storms across the north will be in a low LCL environment with 3-5kft of warm cloud layer, which would support locally heavy rainfall. LCL is substantially higher southern and eastern valleys, where dry microbursts could support locally gusty winds. && .PREVIOUS DISCUSSION... The upper low currently centered along the Utah/Nevada border will gradually weaken as it moves off to the east-northeast into the central Rockies tonight. High pressure aloft will replace the exiting upper low midweek. For today anticipating a fairly rapid increase in convection again this afternoon. The ambient air mass will remain moist, especially across northern/western Utah where PWAT values will remain near or above 0.75". Convection should get an early start this morning due in part to limited cloud cover allowing for good surface heating over central/northern Utah, and across far western Utah near the center of the upper low. Vorticity lobes rotating around the low center will bring organization to the convection in the eastern flank of the low beginning late this morning and continue through early this evening. Generally light flow aloft will allow for stronger convection to produce heavy rains this afternoon through early evening. High pressure aloft will following the exiting upper low on Tuesday. Residual moisture and good differential heating will spawn terrain-based convection which should peak around mid- afternoon Tuesday. Increasing dynamic subsidence and a gradual decrease in moisture with the arrival of the upper ridge will bring an end to most if not all convection by early Tuesday evening. Limited terrain-based convection may form again Wednesday afternoon as weak flow aloft will not quite scour out any remaining moisture over the forecast area. Temperatures today will remain near or slightly below seasonal averages owing to cloud cover and precip. Temperatures will turn modestly warmer Tuesday, then jump midweek as increasing near 700mb temps and winds set up on Wednesday. Southerly winds are expected to pick up Thursday ahead of the next Pacific storm system. The global models remain in pretty good agreement with this system with the GFS ensemble the deepest and the EC reverting back to being the weakest and fastest as it wants to lift the trough northeast after reaching its strongest point along the California coast late Wednesday night. With the brunt of the trough lifting north of the CWA across Idaho, only expecting slight chance of showers across the extreme northwest Thursday and as far south as the central Wasatch Mountains Thursday night. Temperatures will be 5-10 degrees above normal Thursday with locally windy conditions. The associated cold front will move across the north Thursday night creating those aforementioned showers. Temperatures will cool Friday by about 10 degrees in the north with little change across the south. Temperatures will rebound Saturday, but another brush by disturbance will notch the temperatures down some by Sunday across the north. A reinforcing cold front will arrive Monday but once again the brunt of this storm system will be over Idaho, so expect it to be dry across the CWA with only some slightly cooler temperatures. && .AVIATION... VFR conditions are expected throughout the day at the SLC terminal. Cigs will generally be around 6000-7000 feet AGL with showers and thunderstorms developing in the vicinity of the terminal. Southeast winds are expected to shift to the northwest between 17Z and 19Z but there is a 20 percent chance that nearby showers will result in some erratic winds. && .FIRE WEATHER... ERC values at RAWS sites are trending higher areawide, and range from the 80th to 89th percentile southeast valleys, 50th to 69th percentile southwest Utah and eastern valleys, and below the 50th percentile further north and west. Today will be the last day that a spring storm system will dominate the weather across Utah. A cold front crosses southern and eastern Utah this afternoon. A warming and drying trend is forecast Tuesday through Thursday. Thursday gusty southerly winds develop across the state ahead of the next cold front which crosses the state Thursday night and Friday. Isolated to scattered showers and thunderstorms may occur across the north Friday, with a short lived cooling and moistening trend. Critical Fire weather conditions are possible Wednesday across western Utah and Thursday across much of the state. The chance of showers and scattered thunderstorms thin each day through mid week. The chance of wetting rain averages out to be 10-20% valleys and 40-60% mountains today. By Tuesday the chance of wetting rain lowers to 0-10% valleys and 15-35% mountains. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && PUBLIC...10/Conger/Struthwolf AVIATION...Traphagan FIRE WEATHER...10 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 542 AM MDT Mon May 28 2018 UTZ001>016-019>021-517-518-WYZ021-291200- 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- 542 AM MDT Mon May 28 2018 This Hazardous Weather Outlook is for the western two thirds of Utah and southwest Wyoming. .DAY ONE...Today and Tonight The upper level low pressure system over Utah will bring another round of showers and thunderstorms to mainly northern and western Utah, along with southwest Wyoming. The shower and thunderstorm activity will peak this afternoon through early this evening. Locally heavy rainfall is possible with the stronger showers and storms. Lingering showers and isolated thunderstorms will be confined to far northern Utah and southwest Wyoming late tonight. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday High pressure will return to the outlook area by Tuesday. Residual moisture will fueled additional showers and thunderstorms over and near the higher terrain both Tuesday and Wednesday afternoons. Temperatures will warm each day, with readings ending up above normal across the entire outlook area by Wednesday. The next storm system to impact the area will move into the Great Basin from the eastern Pacific late in the week. This feature will move through the outlook area fairly quickly and will generate some shower and thunderstorm activity late Thursday through Friday morning. Breezy and warm conditions will return for the weekend. .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
The Salt Lake City radar (KMTX), 167 km away, was scanning. The volume nearest the first event began at 19:10 UTC.
5 thunderstorm wind, 2 tornado. Local standard time, as filed.
A brief, weak tornado touchdown was reported and photographed by multiple individuals at Strawberry Reservoir. No damage was observed. Time, exact location, and path width are all estimated.
A brief tornado touchdown was observed and photographed near Snowville. No damage was reported. Time, exact location, and path width are all estimated.
The Salt Flats sensor in the U.S. Army Dugway Proving Ground mesonet recorded a peak wind gust of 58 mph.
The Target R sensor in the U.S. Army Dugway Proving Ground mesonet recorded a maximum wind gust of 60 mph.
A 58 mph wind gust was recorded at the Camel Back Mountain sensor in the U.S. Army Dugway Proving Ground mesonet.
The SR-201 at I-80 sensor recorded a maximum wind gust of 59 mph.
A strong microburst, with estimated wind speeds of 50-65 mph, caused primarily tree damage in Centerville. Damage was also reported to trampolines in the area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2018Every state in 2018This day in weather historyThe tornado archive for Utah, 2018Warnings in Utah, May 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: 759730, 759732, 759714, 759715, 759716, 759717, 759728.