Alert archive / Wyoming / Special Weather Statements in 2021

Special Weather Statement, NWS Cheyenne, WY

June 24, 2021Niobrara County, Wyoming

NWS Cheyenne, WY issued this special weather statement at Jun 24, 2021, 4:56 PM MDT for Niobrara County, Wyoming. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 24, 2021, 4:56 PM MDT (22:56 UTC)
Expired
Jun 24, 2021, 5:30 PM MDT
In force
34 min
Issued by
NWS Cheyenne, WY

County Niobrara County, WY

The radar

The Rapid City radar (KUDX), 201 km from the middle of the area, began a volume at 22:58 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

Rapid City, SD (KUNR), launched 12:00Z, 10.9 hours before the alert went out and 194 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-pSkew-T log-p diagram, Rapid City, SD at 12:00Z on 2021-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2021-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -60 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
8 J/kg
Mixed-layer CIN
-490 J/kg
Mixed-layer LCL
1569 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-60 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

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

NWS Cheyenne, WY wrote its last area forecast discussion before this special weather statement went out at Jun 24, 2:21 PM MDT, 2 hours 35 minutes earlier.

Area forecast discussion, Jun 24, 2:21 PM MDT, 2 hours 35 minutes before
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<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.
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Hazardous weather outlook, Jun 24, 5:15 AM MDT, 11 hours 41 minutes before
Hazardous Weather Outlook
National Weather Service Cheyenne WY
515 AM MDT Thu Jun 24 2021

NEZ002-003-019>021-054-055-095-096-WYZ101>103-106>108-116>119-
251115-
Dawes County-Box Butte County-Scotts Bluff County-Banner County-
Morrill County-Kimball County-Cheyenne County-
Northern Sioux County-Southern Sioux County-
Converse County Lower Elevations-Niobrara County-
North Laramie Range-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-South Laramie Range-
South Laramie Range Foothills-Central Laramie County-
East Laramie County-
515 AM MDT Thu Jun 24 2021

This hazardous weather outlook is for portions of panhandle
Nebraska...east central Wyoming and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Showers and thunderstorms are expected to develop along and east
of the Laramie Range by early to mid afternoon, becoming numerous
in coverage during the late afternoon and evening. A few strong to
severe storms are possible. The main hazards will be strong wind
gusts up to 60 MPH and hail up to the size of quarters.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Numerous showers and storms are expected again on Friday.

.Spotter information statement...

Spotter activation is not anticipated. However, spotters are
encouraged to report significant weather to the National Weather
Service in Cheyenne.

WYZ104-105-109>113-115-251115-
Ferris/Seminoe/Shirley Mountains-Shirley Basin-
Central Carbon County-North Snowy Range Foothills-
Southwest Carbon County-Sierra Madre Range-
Upper North Platte River Basin-Laramie Valley-
515 AM MDT Thu Jun 24 2021

This hazardous weather outlook is for portions of south central
Wyoming and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Showers and thunderstorms are expected to develop by early to mid
afternoon, likely continuing through the evening. Some storms may
produce strong wind gusts up to 60 MPH.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Numerous showers and storms are expected again on Friday.

.Spotter information statement...

Spotter activation is not anticipated. However, spotters are
encouraged to report significant weather to the National Weather
Service in Cheyenne.

WYZ114-251115-
Snowy Range-
515 AM MDT Thu Jun 24 2021

This hazardous weather outlook is for portions of south central
Wyoming.

.DAY ONE...TODAY AND TONIGHT

Multiple rounds of showers and thunderstorms are expected in the
vicinity of the Snowy Range today and tonight. Some storms could
produce locally heavy rainfall, resulting in a conditional threat
for flash flooding and debris flows over the Mullen Burn Scar.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Numerous showers and storms are expected again on Friday.

.Spotter information statement...

Spotter activation is not anticipated. However, spotters are
encouraged to report significant weather to the National Weather
Service in Cheyenne.

In the hours before

Special weather statement, Jun 24, 2:56 PM MDT, 2 hours before
Special Weather Statement
National Weather Service Cheyenne WY
256 PM MDT Thu Jun 24 2021

WYZ103-105-242130-
Shirley Basin WY-North Laramie Range WY-
256 PM MDT Thu Jun 24 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL ALBANY COUNTY UNTIL
330 PM MDT...

At 255 PM MDT, Doppler radar was tracking a thunderstorm 12 miles
west of Garrett, or 44 miles west of Wheatland. This storm was
nearly stationary.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas of north central
Albany County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 4196 10578 4204 10590 4219 10577 4206 10560
TIME...MOT...LOC 2055Z 227DEG 2KT 4205 10582

Brothers
Special weather statement, Jun 24, 3:33 PM MDT, 1 hour 23 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
333 PM MDT Thu Jun 24 2021

WYZ116-117-242200-
South Laramie Range WY-South Laramie Range Foothills WY-
333 PM MDT Thu Jun 24 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN ALBANY AND
SOUTHWESTERN LARAMIE COUNTIES UNTIL 400 PM MDT...

At 333 PM MDT, Doppler radar was tracking a strong thunderstorm near
Crystal Lake Campground, or 19 miles west of Cheyenne, moving
northeast at 10 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Crystal Lake Campground and Buford.

This includes Interstate 80 in Wyoming between mile markers 334 and
352.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4102 10520 4106 10537 4113 10534 4119 10500
      4102 10496
TIME...MOT...LOC 2133Z 245DEG 9KT 4108 10515

Brothers
Special weather statement, Jun 24, 4:56 PM MDT, 0 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
456 PM MDT Thu Jun 24 2021

WYZ101-102-242330-
Converse County Lower Elevations WY-Niobrara County WY-
456 PM MDT Thu Jun 24 2021

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL NIOBRARA AND
NORTHEASTERN CONVERSE COUNTIES UNTIL 530 PM MDT...

At 455 PM MDT, Doppler radar was tracking a strong thunderstorm 12
miles north of Manning Ranch, or 36 miles northeast of Douglas,
moving northeast at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas of west central
Niobrara and northeastern Converse Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4309 10500 4314 10506 4325 10509 4333 10487
      4320 10469 4308 10490
TIME...MOT...LOC 2255Z 234DEG 21KT 4317 10493

Mokry

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 24, 12:40 PM MDTAreal Flood AdvisoryCYSCarbon65 min
Jun 24, 2:56 PM MDTSpecial Weather StatementCYSAlbany34 min
Jun 24, 3:33 PM MDTSpecial Weather StatementCYSLaramie27 min

Nearby

Special Weather Statements in Wyoming, 2021Every special weather statement 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.