Alert archive / Wyoming / Winter Storm Warnings in 2019

Winter Storm Warning 8, NWS Riverton, WY

May 27, 20198 counties in Wyoming

NWS Riverton, WY issued this winter storm warning at May 27, 2019, 3:57 AM MDT for 8 counties in Wyoming. It took effect at May 27, 2019, 6:00 PM MDT. It was in force for 19 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 27, 2019, 3:57 AM MDT (09:57 UTC)
In effect from: May 27, 2019, 6:00 PM MDT
Expired: May 28, 2019, 1:13 PM MDT
In force: 19 hr
Issued by: NWS Riverton, WY

Counties Big Horn County, WY, Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Natrona County, WY, Park County, WY, Sublette County, WY, Washakie County, WY

The radar

The Riverton/Lander radar (KRIW), 72 km from the middle of the area, began a volume at 09:59 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

Riverton, WY (KRIW), launched 00:00Z, 10.0 hours before the alert went out and 70 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 259 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 2520 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 168 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this winter storm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Riverton, WY wrote its last area forecast discussion before this winter storm warning went out at May 26, 10:32 PM MDT, 5 hours 25 minutes earlier.

Area forecast discussion, May 26, 10:32 PM MDT, 5 hours 25 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, May 27, 3:22 AM MDT, 35 minutes before

Hazardous Weather Outlook
National Weather Service Riverton WY
322 AM MDT Mon May 27 2019

WYZ001>020-022>030-280930-
Yellowstone National Park-Absaroka Mountains-Cody Foothills-
North Big Horn Basin-Southwest Big Horn Basin-
Southeast Big Horn Basin-Owl Creek and Bridger Mountains-
Bighorn Mountains West-Bighorn Mountains Southeast-
Northeast Johnson County-Southeast Johnson County-
Teton and Gros Ventre Mountains-Jackson Hole-
Wind River Mountains West-Wind River Mountains East-
Upper Wind River Basin-Wind River Basin-Lander Foothills-
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-Casper Mountain-Star Valley-
Salt River and Wyoming Ranges-Upper Green River Basin Foothills-
Upper Green River Basin-South Lincoln County-
Rock Springs and Green River-Flaming Gorge-East Sweetwater County-
322 AM MDT Mon May 27 2019

...Flood Watch from Noon Today through Tuesday afternoon for
Johnson and Natrona Counties...

...Winter Storm Warning from 6 PM this evening to Noon Tuesday
for the Absaroka, Wind River and Bighorn Mountains...

This Hazardous Weather Outlook is for Western and Central
Wyoming.

.DAY ONE...Today and Tonight.

Rain likely with high elevation snow. Snow levels will lower to
near 8000 feet across central Wyoming tonight with heavy, wet
snow developing in the mountains. Rain could be heavy at times
across central Wyoming. Rainfall amounts of 1 to 2.5 inches are
possible across central Wyoming, with the heaviest amounts
expected across Johnson and Natrona Counties.

Please see Winter Storm Warnings and Flood Watches for the latest
information.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Tuesday...Areas of moderate to heavy rain continuing across the
lower elevations of central Wyoming with heavy wet snow in the
mountains. Precipitation tapering off north to south Tuesday
night.

Thursday through Sunday...Isolated to scattered afternoon and
evening thunderstorms.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

In the hours before

Special weather statement, May 26, 10:13 PM MDT, 5 hours 44 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>

Special weather statement, May 26, 10:42 PM MDT, 5 hours 15 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>

Special weather statement, May 27, 12:32 AM MDT, 3 hours 25 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>

The office that day

Everything else NWS Riverton, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 26, 7:06 PM MDT	Special Weather Statement	RIW	Park	39 min
May 26, 10:13 PM MDT	Special Weather Statement	RIW	Hot Springs	32 min
May 27, 12:32 AM MDT	Special Weather Statement	RIW	Hot Springs	43 min
May 27, 11:58 AM MDT	Areal Flood Advisory	RIW	Hot Springs	3 hr

Nearby

Winter Storm Warnings in Wyoming, 2019 Every winter storm warning in 2019

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.