Alert archive / Wyoming / Special Weather Statements in 2018

Special Weather Statement, NWS Riverton, WY

July 29, 2018Natrona County, Wyoming

NWS Riverton, WY issued this special weather statement at Jul 29, 2018, 1:25 PM MDT for Natrona County, Wyoming. It was in force for 50 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
Jul 29, 2018, 1:25 PM MDT (19:25 UTC)
Expired
Jul 29, 2018, 2:15 PM MDT
In force
50 min
Issued by
NWS Riverton, WY

County Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 139 km from the middle of the area, began a volume at 19:28 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 12:00Z, 7.4 hours before the alert went out and 133 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, Riverton, WY at 12:00Z on 2018-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 498 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2018-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 square meters per square second.1939587897117Sfc1 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
498 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
1073 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
415 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

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 Riverton, WY wrote its last area forecast discussion before this special weather statement went out at Jul 29, 11:21 AM MDT, 2 hours 4 minutes earlier.

Area forecast discussion, Jul 29, 11:21 AM MDT, 2 hours 4 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.
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Hazardous weather outlook, Jul 29, 2:03 AM MDT, 11 hours 22 minutes before
Hazardous Weather Outlook
National Weather Service Riverton WY
203 AM MDT Sun Jul 29 2018

WYZ001>020-022>030-301100-
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-
203 AM MDT Sun Jul 29 2018

A Red Flag Warning is in effect for Sweetwater, Uinta, and Southern
Lincoln Counties today.

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and Tonight

Scattered thunderstorms, especially along and east of the
Continental Divide. Some of these storms will likely produce small
hail, locally heavy rainfall, frequent lightning, and strong gusty
winds. There will be a few strong thunderstorms and even isolated
severe thunderstorms are possible.

Low relative humidity, very warm temperatures, and dry thunderstorms
producing strong wind gusts in southwest Wyoming will create erratic
fire behavior today.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Tuesday through Thursday...Isolated afternoon and evening
thunderstorms, mainly over and near the northwest mountains.

Thursday and Friday...Warm and dry conditions with gusty west wind
will elevated fire weather conditions across southern Wyoming during
the afternoon and early evening.

.SPOTTER INFORMATION STATEMENT...

Spotters urged to report wind gusts past 45 mph, hail size, and
rainfall amounts. Thank you.

In the hours before

Special weather statement, Jul 29, 12:53 PM MDT, 32 minutes before
Special Weather Statement
National Weather Service Riverton WY
1253 PM MDT SUN JUL 29 2018

WYZ007-017-291930-
Owl Creek and Bridger Mountains-Wind River Basin-
1253 PM MDT SUN JUL 29 2018

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL FREMONT COUNTY UNTIL 130
PM MDT...

At 1253 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles north of Pavillion, moving south at 25 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

This strong thunderstorm will be near...
  Pavillion around 110 PM MDT.
  Kinnear and Ocean Lake around 130 PM MDT.

Other locations impacted by this storm include Midvale and Pavillion
Natural Gas Processing Plant.

LAT...LON 4349 10889 4353 10859 4321 10818 4305 10881
TIME...MOT...LOC 1853Z 338DEG 20KT 4336 10868

Hattings
Special weather statement, Jul 29, 1:25 PM MDT, 0 minutes before
Special Weather Statement
National Weather Service Riverton WY
125 PM MDT SUN JUL 29 2018

WYZ020-292015-
Natrona County Lower Elevations-
125 PM MDT SUN JUL 29 2018

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL NATRONA COUNTY UNTIL 215
PM MDT...

At 125 PM MDT, Doppler radar was tracking a strong thunderstorm over
Goldeneye Reservoir, or 25 miles northwest of Casper, moving
southeast at 25 mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

This strong thunderstorm will be near...
  Emigrant Gap and Natrona County Airport around 200 PM MDT.

Other locations impacted by this storm include Natrona and Casper
Natrona County Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

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 4308 10699 4319 10675 4289 10636 4271 10675
TIME...MOT...LOC 1925Z 326DEG 25KT 4303 10675

Hattings

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 6:09 PM MDTSpecial Weather StatementRIW36 min
Jul 28, 6:16 PM MDTSevere Thunderstorm WarningRIWNatrona33 min
Jul 28, 6:29 PM MDTSpecial Weather StatementRIWSheridan31 min
Jul 28, 6:42 PM MDTSpecial Weather StatementRIWBig Horn33 min
Jul 28, 7:00 PM MDTSpecial Weather StatementRIWPark30 min
Jul 28, 7:13 PM MDTSpecial Weather StatementRIW32 min
Jul 28, 7:14 PM MDTSpecial Weather StatementRIWTeton31 min
Jul 28, 7:16 PM MDTSpecial Weather StatementRIW29 min
Jul 28, 7:49 PM MDTSpecial Weather StatementRIW26 min
Jul 28, 8:10 PM MDTSpecial Weather StatementRIWTeton35 min
Jul 28, 8:23 PM MDTSpecial Weather StatementRIWPark37 min
Jul 28, 9:08 PM MDTSevere Thunderstorm WarningRIWJohnson37 min
Jul 29, 12:53 PM MDTSpecial Weather StatementRIWFremont37 min
Jul 29, 1:34 PM MDTSpecial Weather StatementRIWFremont41 min
Jul 29, 1:57 PM MDTSpecial Weather StatementRIWJohnson48 min
Jul 29, 2:02 PM MDTSpecial Weather StatementRIWNatrona43 min
Jul 29, 2:21 PM MDTSpecial Weather StatementRIW39 min
Jul 29, 2:34 PM MDTSpecial Weather StatementRIWJohnson41 min
Jul 29, 2:35 PM MDTSpecial Weather StatementRIWJohnson40 min
Jul 29, 2:54 PM MDTSpecial Weather StatementRIW36 min
Jul 29, 3:25 PM MDTSpecial Weather StatementRIW50 min
Jul 29, 3:31 PM MDTSpecial Weather StatementRIWFremont44 min
Jul 29, 3:35 PM MDTSpecial Weather StatementRIW25 min
Jul 29, 3:38 PM MDTSpecial Weather StatementRIWNatrona37 min
Jul 29, 3:42 PM MDTSevere Thunderstorm WarningRIWFremont, Sweetwater28 min
Jul 29, 3:58 PM MDTSpecial Weather StatementRIWFremont32 min
Jul 29, 4:04 PM MDTSpecial Weather StatementRIWHot Springs26 min
Jul 29, 4:11 PM MDTSpecial Weather StatementRIW34 min
Jul 29, 4:30 PM MDTSpecial Weather StatementRIW30 min
Jul 29, 4:43 PM MDTSpecial Weather StatementRIWHot Springs32 min
Jul 29, 4:44 PM MDTSpecial Weather StatementRIWHot Springs31 min
Jul 29, 5:05 PM MDTSpecial Weather StatementRIWHot Springs25 min
Jul 29, 5:15 PM MDTSevere Thunderstorm WarningRIWFremont45 min
Jul 29, 5:22 PM MDTSpecial Weather StatementRIW23 min
Jul 29, 5:35 PM MDTSpecial Weather StatementRIWNatrona40 min
Jul 29, 5:50 PM MDTSpecial Weather StatementRIWHot Springs25 min

Nearby

Special Weather Statements in Wyoming, 2018Every special weather statement in 2018

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.