Snowmelt brought enhanced flows, with avalanches, flooding and debris flows.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Snowmelt brought enhanced flows, with avalanches, flooding and debris flows.
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 Apr 10, 2:48 AM MST, 6 hours 12 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 348 AM MDT Mon Apr 10 2023 .SYNOPSIS...High pressure will remain the dominant weather feature over the area through Tuesday, bringing dry and warm conditions. A cold front will make its way across the area late Wednesday through Thursday before high pressure returns for the upcoming weekend. && .SHORT TERM (Through 12Z Wednesday)...High pressure is centered over Utah and southwest Wyoming this morning, resulting in dry and stable conditions with light winds. Seeing a few high clouds drifting over northwest Utah, but skies are otherwise clear. The warming trend in temperatures will continue today as the ridge continues to build, resulting in maxes averaging 10F or more above seasonal normals for most locations. By Tuesday, the ridge axis will have shifted east in response to a storm system approaching the Pacific Northwest coast. The resultant increase in southwest flow will allow for further warming, with some locations, including the Salt Lake Valley, seeing highs in excess of 15F above seasonal normals. .LONG TERM (After 12Z Wednesday)...The long term period will consist of an exiting ridge of high pressure on Wednesday. This will be followed by a trough entering the region on Wednesday bringing unsettled weather Thursday and Friday. Another ridge builds in over the weekend. A trough across the PNW will be migrating into the Great Basin on Wednesday. Southwesterly flow will increase ahead of this trough. This will lead to gusty southwesterly winds primarily across the southern and eastern halves of Utah as well as SW Wyoming. Peak gusts across the terrain are forecast to be near 50 mph. Once the trough pushes through flow will gradually transition to northwesterly and this will cool down temperatures across northern Utah closer to average as well as dampen the wind gusts. Temperatures across southern Utah will still remain 5-10 degrees above average on Wednesday as the airmass slowly moves south. A weak jet aloft will help to initiate showers across far northern Utah mountains Wednesday afternoon, but the best forcing comes when the cold front pushes through northern Utah early Thursday. Given the lack in synoptic lift QPF values will be minimal. 50th percentile QPF values are generally <0.1" across northern valleys and <0.2" across northern mountains with little to no precipitation in this percentile across central and southern Utah. Temperatures behind the cold front will drop close to 10 degrees below normal across northern Utah with temperatures moderating back to near normal for southern Utah. Mountains have <50% chance at seeing snow totals of more than a couple of inches. Northern valleys have ~30% chance of rain briefly turning to snow behind the front on Thursday morning, but there is <10% chance of receiving >1". Precipitation quickly pushes east by Thursday afternoon. Another shortwave brings ~30% chance of some diurnally-driven showers, mainly to the mountains on Friday afternoon. A ridge of high pressure builds back into the area over the weekend with temperatures slowly climbing 5-10 degrees above normal by Sunday and Monday with dry and clear skies. && .AVIATION...KSLC...VFR conditions will persist for the KSLC terminal under the influence of high pressure. Expect clear skies and light and diurnally driven winds. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions and clear skies will prevail for most terminals across the area as high pressure is in place. The only exception is KLGU where intermittent fog will produce MVFR/IFR conditions through sunrise. Otherwise, winds will be light and variable across the northern half of the area with gusty southerly winds during the day across sou && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && SHORT TERM...Traphagan LONG TERM/AVIATION...Mahan For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity
The national radar mosaic for the moment the first event began.
2 flood, 1 avalanche, 1 debris flow. Local standard time, as filed.
Continued warmth and snowmelt produced a number of large wet avalanches on state Route 210 (Little Cottonwood Canyon Road), including White Pine Chutes 1-4 which ran over the road prolonging closures.
State Route 66 between Morgan and East Canyon Reservoir began flooding on the 12th, resulting in closure. It was opened the next day.
A new development on Orchard Ridge Lane in Kaysville experienced drainage issues, which resulted in significant flooding opening up a sinkhole. Entire driveways collapsed into the sinkhole along with dumpsters and construction debris.
The eastbound lanes of Interstate 80 were closed in Parleys Canyon for around two hours in the morning near the Emigration Canyon exit due to a mudslide. The slide led to two single-vehicle crashes. One person received minor injuries in one of the crashes.
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, April 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: 1096144, 1096143, 1096136, 1096141.