A landspout tornado was observed in Eastern Box Elder County.
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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.
A landspout tornado was observed in Eastern Box Elder County.
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 27, 2:18 PM MST, 2 hours 32 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 318 PM MDT Sun Aug 27 2023 .SYNOPSIS...High pressure will bring a drying trend heading into the upcoming week. A dry cold front will cross northern Utah Tuesday night. The next surge of monsoon moisture will arrive Thursday, and remain across the region into Labor Day weekend. && .SHORT TERM (THROUGH 12Z TUESDAY)...High pressure over area is building westward today while a weak disturbance crosses Idaho. The transition to a more westerly flow aloft is helping to spread drier air into the area. Latest PWAT analysis shows a pocket of 0.8-0.9 inches over northern Utah while drier air (~0.5 inches PWAT) is spreading into west-central Utah. The lingering moisture pocket across northern Utah, coupled with some instability and weak forcing attributed to the disturbance over Idaho, will maintain isolated to scattered showers and thunderstorms mainly from near the UT/ID border through the Uinta Mountains into this evening. Drier air will continue to spread into Utah tomorrow, with little in the way of convection expected. What does develop should be limited to the higher terrain of northeastern Utah. Temperatures will continue to trend warmer with afternoon maxes from near normal to around 4-8F above normal. An upstream storm system (currently near 135W off the PacNW coast) will start to eject inland tomorrow night. This will start to nudge the high pressure back eastward while bringing some stronger southwest flow into the Great Basin. .LONG TERM (After 12Z/6AM Tuesday)...The long-term period is broadly characterized by two regimes: 1) Hot and dry to start, followed by 2) another monsoon push for Thursday and beyond. A weak cold front Tuesday evening will bring a slight decrease in temperatures to northern areas but will otherwise be unimpactful. Tuesday will be the hottest day of the long-term, with temperatures around 5-10 degrees above normal. Increased southwesterly flow will produce gusts to around 30mph across western valleys ahead of the incoming trough and associated weak cold front. This cold front is likely to arrive Tuesday evening and overnight as it pushes across northern Utah, bringing highs back to near-normal on Wednesday. The trough will continue to move northeastward into the Northern Plains, which will allow high pressure to build to our southeast across NM and another longwave trough to develop along the west coast. Thus, the familiar monsoonal pattern returns, with a moisture push arriving from the south on Thursday. Scattered showers and thunderstorms will likely be limited to southern and central Utah on Thursday, moving across the entire area by Friday. Thus, expect an increased flash flood risk late in the work week, with a chance for dry microbursts along the initial northward push. While there is still decent uncertainty in the extent of the moisture, the ensemble means for the PW values are sitting at roughly 0.9" across northern Utah and 1.2" across southern Utah (climatological ~90th percentile). Uncertainty in the forecast really increases on Day 7 (Sunday), with model disagreement in the progression of the west coast trough. Roughly 70% of ensemble members favor continued elevated moisture with the trough moving inland, while the other 30% favor a weakening trough and drier air mass pushing in. && .AVIATION...KSLC...VFR conditions are forecast through tomorrow with merely high based clouds present. Diurnal wind shifts are forecast at light speeds with the next shift out of the southeast expected at 03z. .REST OF UTAH AND SOUTHWEST WYOMING...Scattered thunderstorms and rain showers are forecast through early this evening across portions of northern Utah and southwest Wyoming, with the highest likelihood for impacts at LGU and EVW terminals. Gusty and erratic winds are possible in and near thunderstorms along with lowered VIS in heavier rain which may briefly lead to MVFR conditions. Ceilings are expected to remain mid to high based. Southern Utah terminals are forecast to remain at VFR conditions through tomorrow. && .FIRE WEATHER...High pressure shifting westward today is resulting in a drier westerly flow aloft while a weak disturbance continues to graze northern Utah. Isolated to widely scattered showers and thunderstorms will continue into this evening across portions of northern Utah in association with this weak disturbance. Once this passes, the airmass will become more stable with drier air continuing to spread into the area. A corresponding decrease in showers and thunderstorms can be expected through Wednesday, along with a decrease in relative humidities. Otherwise, another storm system grazing northern Utah on Tuesday will push a dry cold front into northern utah Tuesday night. Ahead of this front, breezy southwest winds can be expected across much of the area on Tuesday and across southern and eastern Utah on Wednesday. Thereafter, moisture looks to make a return to the area Thursday into the weekend. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && Cheng/Cunningham/NDeSmet For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity
Special Weather Statement
National Weather Service Salt Lake City UT
356 PM MDT Sun Aug 27 2023
UTZ101-272245-
Great Salt Lake Desert and Mountains UT-
356 PM MDT Sun Aug 27 2023
...A strong thunderstorm will impact portions of northern Box Elder
County through 445 PM MDT...
At 355 PM MDT, Doppler radar was tracking a strong thunderstorm 9
miles north of Park Valley, or 25 miles south of Malta, moving east
at 20 mph.
HAZARD...Wind gusts of 50 to 55 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Curlew Junction.
This includes Utah Route 30 between mile markers 68 and 76.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4188 11300 4187 11336 4199 11340 4200 11305
4199 11304
TIME...MOT...LOC 2155Z 255DEG 20KT 4195 11328
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH
JWThe national radar mosaic for the moment the first event began.
1 strong wind. Local standard time, as filed.
LANDSPOUT. Location: 41.89, -112.50. Multiple photos were shared with media of a landspout tornado east of Snowville. Time and location were estimated from radar. No damage was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2023Every state in 2023This day in weather historyWarnings in Utah, August 2023
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: 1163351.