Alert archive / Wyoming / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 25, NWS Riverton, WY

July 1, 1998Washakie County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jul 1, 1998, 6:03 PM MDT for Washakie County, Wyoming. It was in force for 32 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 1, 1998, 6:03 PM MDT (00:03 UTC)
Expired: Jul 1, 1998, 6:35 PM MDT
In force: 32 min
Issued by: NWS Riverton, WY
Area: Whole counties

County Washakie County, WY

What was reported inside it

Time	Report	Where	Remark
Jul 1, 6:05 PM MDT	Hail 1.5	Ten Sleep, WY

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Riverton, WY (KRIW), launched 00:00Z, 0.1 hours before the alert went out and 109 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: 228 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 3425 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 71 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 1, 1:00 PM MDT, 5 hours 3 minutes earlier.

Area forecast discussion, Jul 1, 1:00 PM MDT, 5 hours 3 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
100 PM MDT WED JUL 1 1998

MOIST/UNSTBL AMS ACRS MUCH OF CWFA ERLY THIS AFTN...WITH LTST ADAP
SHWG LI'S < -4 FM NW TO SE WY...AND SFC DEW POINTS RANGING FROM THE
MID 40S TO MID 50S. RADAR/SATL IMAGERY/LTG DETECTION SHWS TSTMS
ALREADY UNDERWAY OVR NW WY...AND THESE SHUD CONT...INTENSIFY...AND
SPREAD E/SE ACRS NRN/CNTRL PTNS RIW CWFA THIS AFTN/EVE. WILL MNTN SCT
TSTMS NRN/CNTRL ZNS THRU EVE HRS WITH PSBL HAIL/STG WNDS. WATR VPR
IMAGERY SHWS VRY DRY AIR INTO SW WY THIS AFTN...SO NIL POPS THERE
TNGT. MOS MINS APPR RSNBL.    DN

In the hours before

Special weather statement, Jul 1, 1:21 PM MDT, 4 hours 42 minutes before

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Special weather statement, Jul 1, 1:21 PM MDT, 4 hours 42 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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Special weather statement, Jul 1, 5:25 PM MDT, 38 minutes before

WYZ027-028-020025-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
525 PM MDT WED JUL 1 1998

...STRONG THUNDERSTORMS WERE MOVING THROUGH EAST JOHNSON COUNTY...

STRONG THUNDERSTORMS WERE STILL MOVING NORTHEAST OF KAYCEE IN SOUTHEAST
JOHNSON COUNTY. THESE THUNDERSTORMS HAVE HAIL...STRONG WINDS AND
DANGEROUS CLOUD TO GROUND LIGHTNING. PERSONS SHOULD SEEK SHELTER UNTIL
THEY PASS THROUGH THEIR AREA. THESE THUNDERSTORMS WILL CONTINUE TO MOVE
NORTHEAST AT 20 MPH INTO NORTHWEST CAMPBELL COUNTY THROUGH 6 PM.

WCJIN-WYNE

CLARK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 1, 7:27 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	38 min
Jul 1, 9:47 PM MDT	Flash Flood Warning	RIW	Johnson	118 min
Jul 2, 3:33 PM MDT	Severe Thunderstorm Warning	RIW	Park	32 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1998 Every severe thunderstorm warning in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.