Alert archive / Utah / Winter Weather Advisories in 2021
Winter Weather Advisory 17, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this winter weather advisory at Oct 7, 2021, 3:09 PM MDT for Duchesne County, Summit County, Wasatch County, Utah. It took effect at Oct 8, 2021, 6:00 AM MDT. It was in force for 36 hr.
The area
The counties it named.
The facts
- Issued
- Oct 7, 2021, 3:09 PM MDT (21:09 UTC)
- In effect from
- Oct 8, 2021, 6:00 AM MDT
- Expired
- Oct 9, 2021, 6:00 PM MDT
- In force
- 36 hr
- Issued by
- NWS Salt Lake City, UT
Counties Duchesne County, UT, Summit County, UT, Wasatch County, UT
The radar
The Salt Lake City radar (KMTX), 159 km from the middle of the area, began a volume at 21:08 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Salt Lake City I, UT (KSLC), launched 12:00Z, 9.2 hours before the alert went out and 94 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 40 J/kg
- Mixed-layer CIN
- -97 J/kg
- Mixed-layer LCL
- 1145 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 48 m²/s²
- 0-3 km storm-relative helicity
- 148 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
What forecasters said that day
The local office's own words before this winter weather advisory went out, 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 this winter weather advisory went out at Oct 7, 12:11 PM MDT, 2 hours 58 minutes earlier.
Area forecast discussion, Oct 7, 12:11 PM MDT, 2 hours 58 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>Hazardous weather outlook, Oct 7, 6:02 AM MDT, 9 hours 7 minutes before
Hazardous Weather Outlook National Weather Service Salt Lake City UT 602 AM MDT Thu Oct 7 2021 UTZ101>131-WYZ021-081215- 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- 602 AM MDT Thu Oct 7 2021 This Hazardous Weather Outlook is for the western two thirds of Utah and southwest Wyoming. .DAY ONE...Today and Tonight Showers and isolated thunderstorms are expected this afternoon and evening across northern and central Utah. These storms will be most numerous along the higher terrain this afternoon and early evening, then across areas north of I-80 through the evening. Gusty winds, occasional lightning, and brief heavy rainfall can be expected with the strongest storms. .DAYS TWO THROUGH SEVEN...Friday through Wednesday The next storm system will impact much of the outlook area Friday through Saturday. Showers and thunderstorms are expected Friday afternoon through Friday evening. Locally heavy rainfall could result in isolated incidents of flash flooding within slot canyons, small streams, and normally dry washes across southern Utah, as well as near recent burn scars. Much cooler air will arrive Friday night lowering snow levels to near 7500 feet Saturday. Accumulating snow can be expected across northern Utah above 8000 feet during the day Saturday. A colder storm system will impact the outlook area during the first half of next week, bringing the potential for significant mountain snowfall, as well as lowering snow levels to the benches, and resulting in freezing overnight temperatures across most valleys excluding the St George area beginning Monday night. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. 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 office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 7, 2:45 PM MDT | Flood Watch | SLC | Box Elder, Cache, Davis, Iron, Kane, Morgan and 5 more | 33 hr |
Nearby
Winter Weather Advisories in Utah, 2021Every winter weather advisory in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.