Severe Thunderstorm Warning 15, NWS Riverton, WY

Issued

Jul 21, 2002, 3:44 PM MDT (21:44 UTC)

Expired

Jul 21, 2002, 4:30 PM MDT

In force

46 min

Issued by

NWS Riverton, WY

Area

Whole counties

County Hot Springs County, WY

The Riverton/Lander radar (KRIW), 73 km from the middle of the area, began a volume at 21:45 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.

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.

695 
WUUS55 KRIW 212144
SVRRIW
WYC017-212230-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
340 PM MDT SUN JUL 21 2002

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN HOT SPRINGS COUNTY IN CENTRAL WYOMING

* UNTIL 430 PM MDT

* AT 340 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A SEVERE THUNDERSTORM OVER WESTERN HOT SPRINGS COUNTY...OR ABOUT   
  15 MILES WEST OF GRASS CREEK...MOVING SOUTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE...BE OVER RURAL NORTHWESTERN AND   
  CENTRAL HOT SPRINGS COUNTY IN CENTRAL WYOMING FROM 340 PM MDT
  TO 430 PM MDT

THE SEVERE THUNDERSTORM IS CAPABLE OF PRODUCING...
 HAIL UP TO 1.5 INCHES IN DIAMETER.
 WINDS UP TO 60 MILES AN HOUR.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WINDS IN EXCESS OF 55 MPH...LARGE HAIL...AND DEADLY
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN RIVERTON.

$$

LAT...LON 4401 10883 4392 10893 4392 10912 4366 10879
          4395 10844

CUNNINGHAM

WCJIN-WYNW

NWS Riverton, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 2:40 PM MDT, 1 hour 4 minutes earlier.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
240 PM MDT SUN JUL 21 2002

COLD FRONT MOVING SOUTHWARD ACROSS NORTHERN WYOMING THIS AFTERNOON
WITH ISOLATED CONVECTION FIRING ALONG IT FROM OWL CREEK MOUNTAINS
SOUTHEAST TO NORTHERN NATRONA.  FEW STORMS NORTH OF BOUNDARY ALSO
BUT OVERALL CAP IS STRONGER.  BEST CONVECTION THIS EVENING SHOULD
BE IN VICINITY OF FRONT AS IT WORKS IT WAY INTO THE WIND RIVER BASIN
AND NATRONA COUNTY BUT AVAILABLE INSTABILITY IS LIMITED. WILL
GENERALLY GO ISOLATED ACROSS THE CENTRAL AND NORTH BUT COVERAGE COULD
BE HIGHER IN VICINITY OF FRONT. ON MONDAY...UPSLOPE FLOW ALONG THE
LEE OF THE WIND RIVERS AND ABSAROKAS SHOULD AID IN WIDELY SCATTERED
TO POSSIBLY SCATTERED CONVECTION IN THIS AREA. MSO-ETA CAPES OF 1000
TO 1200 J/KG WITH LIFTED INDICES OF -2 TO -4 WITH SMALL CIN SHOULD
PROVIDE FOR A FEW BIG CELLS (AS LONG AS ITS NOT TOO COOL TOMORROW).
COOLER SURFACE AND H7 TEMPERATURES EAST OF THE BIG HORNS SHOULD
INHIBIT CONVECTION UP THERE. THEN ON MONDAY NIGHT THE EASTERN EDGE OF
THE DEFORMATION AXIS FROM CALIFORNIA/OFFSHORE UPPER LOW...BRUSHES
WESTERN WYOMING WITH A LITTLE MOISTURE AND POTENTIAL WEAK LIFT. WILL
INDICATE SOME ISOLATED SHOWERS OR THUNDERSTORMS IN THE FAR WEST FOR
MONDAY NIGHT. THE AVN THEN SPREADS THIS LIMITED MOISTURE ACROSS THE
STATE ON TUESDAY (SOME FROM THE SOUTH) FOR SOME HIGH BASED ISOLATED
CONVECTION. AS THE UPPER HIGH REBUILDS NEAR THE 4-CORNERS...THE AVN
INDICATES MORE MONSOONAL MOISTURE RETURNING BRIEFLY WEDNESDAY AND
ACROSS THE EAST ON THURSDAY (BUT MAINLY IN THE MID LEVELS). THE
NORTHERN STREAM TROUGH THEN BRUSHES THE NORTHERN ZONES LATE THURSDAY
AND FRIDAY PUSHING A WEAK FRONT SOUTHWARD. WILL INDICATE SOME
THUNDERSTORMS CHANCES DURING THIS PERIOD IN THE FAR NORTH. FOLLOWING
THE MRF (AVN) BEYOND THIS INDICATES THE POSSIBILITY OF MORE MONSOONAL
MOISTURE LATE IN THE WEEKEND BUT ITS A TOUGH CALL BETWEEN THE DRIER
WESTERLY FLOW LURKING NEARBY. THE EUROPEAN SHOWS MORE OF A TROUGH IN
THE FLOW OVER THE NORTHWEST WITH LITTLE HINT OF MONSOONAL MOISTURE.
FOR NOW...WILL STICK WITH IDEA OF SOME MONSOONAL RETURNING AGAIN LATE
IN THE WEEKEND BUT ITS CERTAINLY SUBJECT TO CHANGE.

.RIW...NONE.

SKRBAC

Severe Thunderstorm Warnings in Wyoming, 2002Every severe thunderstorm warning in 2002

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; radar from the NEXRAD Level II archive.