A dry microburst brought isolated severe winds in the West Desert.
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The episode as NWS SLC wrote it up.
A dry microburst brought isolated severe winds in the West Desert.
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 1, 2:58 PM MST, 1 hour 17 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 358 PM MDT Sat May 1 2021 .SYNOPSIS...Dry and mild southwesterly flow will prevail for much of today. A dry cold front will push through the area late this afternoon through this evening, with the parent storm system following Sunday into Monday. Unsettled weather will continue into the middle of next week. && .SHORT TERM (Through 12Z Tuesday)...A very spring-like day here across the Intermountain West this afternoon...with temperatures averaging 10 to 20 degrees above normal. Afternoon satellite analysis indicates a fairly robust vort max near the Boise area with resulting strong convection. A recent wind gust to 65 mph was reported northeast of Boise. Meanwhile, a speed max is crossing the West, with upper level diffluence aiding in the development of weak convection across mainly northern and eastern Utah. Afternoon mesoanalysis indicates SBCAPE values near 500-1000 J/kg across northern Utah though significant convection inhibition is in place. RAP forecasts do gradually erode this instability. Dewpoint depressions remain on the order of 40 to 50 degrees across much of northern Utah. Deep layer shear is not lacking...unsurprisingly...with values near 40 to 50 kts across northern Utah. Given a very dry sub-cloud environment, expect the main threat from any convection will be gusty and erratic microburst winds. Looking at a variety of CAMS this afternoon, several develop reality modest convection but nearly every run keeps this convection to the north of the Idaho/Utah border. This would correlate well with satellite analysis of the current location of the best forcing and location of the vort max combined with the convective inhibition currently stretched across northern Utah. Those enjoying the beautiful day at Bear Lake should keep an eye on the weather. The associated cold front will cross northern Utah this evening, stalling across portions of southwest to northeast Utah tonight. With the main trough dropping into Utah Sunday, the front will again shift southeastward Sunday afternoon. This front will serve as a focus for convection through the day Sunday...though by nature of this system, expected mainly weak, unorganized convection. The biggest impact for most will be a marked decrease in temperatures from Saturday...with temperatures near to slightly below normal across much of the state (dropping around 10-20 degrees from Saturday's highs). Attention will then transition to wrap around precipitation associated with the slowly evolving trough over the Great Basin. This will bring a period of mountain snow to portions of northern Utah Sunday morning into Monday morning. Expect the Wasatch to see a few inches of snow above about 8000 feet or so. The high Uintas may see 5 to 10 inches with locally higher amounts. Those planning recreational activities across the northern mountains...especially above 8000 feet should be prepared for winter conditions Sunday morning through early Monday. .LONG TERM (After 12Z Tuesday)...A shortwave will graze southwest Wyoming and northeast Utah Tuesday. Most GEFS and EPS members indicate little or no rainfall from the Cache Valley east through Uinta County. Slightly better chances for rain and snow are expected in the Uinta Mountains in the afternoon, although little rain or snow accumulation is expected. A Pacific ridge will move inland Tuesday night into Wednesday, further contributing to drying things out through the middle of the week. Upstream of that, a stronger trough than the one at the start of the week will act to further amplify the ridge. Ensembles have a range of solutions with how the trough moves inland, but there is good confidence with how the ridge will move through the region. By Wednesday, the ridge is expected to be centered from California, northward into western Canada. Locally, northwest flow will remain in place, but a temperature increase of roughly 5-10F with much less cloud cover in southwest Wyoming and northeast Utah is likely. The ridge axis is expected to move through the Great Basin Thursday, which will coincide with the warmest temperatures of the week of around 15-20F warmer than average. Placement of the aforementioned trough results in model differences late in the week into the weekend. GEFS, EPS, and CMCE members are close to split on the trough diminishing to the north or digging far enough south to bring more impact to the CWA. That leads to low confidence on precipitation chances around that time. What is more likely is a cool down, even if it doesn't fully move into the CWA late in the week or into the weekend with gusty southwest flow ahead of it. && .AVIATION...KSLC...VFR conditions are expected across the KSLC terminal through the valid TAF period under a thinning cloud deck. Winds have shifted to a northerly flow and should persist through the valid TAF period. Winds may become breezy between 20-06z with isolated wind gusts up to 24 knots possible. Rest of Utah and southwest Wyoming...VFR conditions will be maintained across the region with a decrease in the mid to upper level cloud deck. There is a 20% chance for isolated convection to develop around the KENV terminal after 23z. Elsewhere, gusty southwesterly winds are expected to continue into the evening and impact the KCDC, KBCE, and KEVW terminals. Gusts in the 20-30kt range are likely at those terminals through 03z. Some LLWS conditions are possible at the KSGU terminal between 06-08z. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && Kruse/Wilson/Woodward 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 333 PM MDT Sat May 1 2021 UTZ101>131-WYZ021-021300- Great Salt Lake Desert and Mountains-Tooele and Rush Valleys- Eastern Box Elder County-Northern Wasatch Front-Salt Lake Valley- Utah Valley-Cache Valley/Utah Portion-Wasatch Back- Bear Lake and Bear River Valley-Wasatch Mountains I-80 North- Wasatch Mountains South of I-80-Western Uinta Mountains- Wasatch Plateau/Book Cliffs-Western Uinta Basin- Western Millard and Juab Counties-Eastern Juab/Millard Counties- Central Mountains-Sanpete Valley-Sevier Valley-Castle Country- San Rafael Swell-Southwest Utah-Lower Washington County- Zion National Park-Southern Mountains-Upper Sevier River Valleys- Bryce Canyon Country-South Central Utah- Capitol Reef National Park and Vicinity-Western Canyonlands- Glen Canyon Recreation Area/Lake Powell-Southwest Wyoming- 333 PM MDT Sat May 1 2021 This Hazardous Weather Outlook is for portions of central Utah... northern Utah...southern Utah...southwest Utah and southwest Wyoming. .DAY ONE...This Afternoon and Tonight Gusty and erratic winds are possible near high based showers and thunderstorms across portions of northern Utah through the evening. .DAYS TWO THROUGH SEVEN...Sunday through Friday High elevation snow is expected Sunday morning into Monday across mainly northern Utah. Occasional winter driving conditions can be expected on high elevation routes especially during the evening and overnight hours. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. 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), 133 km away, was scanning. The volume nearest the first event began at 23:15 UTC.
1 thunderstorm wind. Local standard time, as filed.
A peak wind gust of 64 mph was recorded by the Horizonal Grid sensor.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2021Every state in 2021This day in weather historyWarnings in Utah, May 2021
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: 962613.