Severe Thunderstorm Warning 9, NWS Riverton, WY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
323 AM MDT SUN JUN 2 2002

A DECENT AMOUNT OF LOW TO MID CLOUDS IN THE FAR WEST...WITH A
SMATTERING OF MAINLY MID AND HIGH ELSEWHERE.  UPPER TROF NOW IN THE
INTERMOUNTAIN REGION WITH NICE SHORTWAVE AT THE BASE MOVING INTO
SOUTHERN NEVADA.  THIS APPEARS TO HEADED FOR WESTERN WYOMING FOR
THIS AFTERNOON...WITH PRIMARILY NVA FARTHER EAST.  BUT MOST OF THE
AREA WILL BE RATHER UNSTABLE ONCE AGAIN WITH BEST CHANCE FOR STRONG
TO SEVERE STORMS APPARENTLY FROM THE BIG HORNS INTO EAST JOHNSON
COUNTY AND SOUTH THROUGH CASPER.  THIS IS AREA PROGGED TO BE THE
MOST UNSTABLE...WITH NICE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE PAIRING...AND THETA-E RIDGING.  700MB TROF ALSO OVER THE
AREA TODAY TO ADD TO THE MIX.  SPC DOES HAVE SLIGHT RISK AREA JUST
POKING INTO EAST JOHNSON COUNTY FOR TODAY.  THUS LOOKS LIKE ANOTHER
ROUND FAIRLY SIMILAR TO YESTERDAY.  SURFACE COLD FRONT STILL
EXPECTED TO MOVE THROUGH THE AREA THIS EVENING IN THE NORTH AND
TONIGHT FARTHER SOUTH.  BEHIND THE FRONT WIND VEERS TO NORTHEAST AND
REMAINS SO MONDAY FROM BUFFALO AND CASPER OVER THROUGH RIVERTON AND
LANDER.  SO EXPECTING CONVECTION TONIGHT TO GIVE WAY TO STRATIFORM
RAIN IN THOSE SPOTS MONDAY.  MONDAY NIGHT SURFACE HIGH PRESSURE
BECOMES FIRMLY ESTABLISHED WHILST THE UPPER TROF AXIS MOVES EAST OF
THE AREA BY TUESDAY MORNING.  SO WILL GO WITH DECREASING CLOUDS MOST
AREAS MONDAY NIGHT...AND PARTLY TO MOSTLY SUNNY TUESDAY WITH SOME
INSTABILITY SHOWERS OVER THE MOUNTAINS A POSSIBILITY.
BACK TO THE SHORTER TERM - HIGHER ELEVATIONS IN THE NORTHWEST
MOUNTAINS LIKELY TO SEE SOME LIGHT SNOW ACCUMULATION TONIGHT AND
MONDAY AS TEMPERATURES DROP.  700MB TEMEPRATURES DIP TO -1 TO -3
TONIGHT AND MONDAY THERE.  MUCH COOLER ALL AROUND MONDAY...
ESPECIALLY UPSLOPE AREAS WHERE LITTLE OR NO SUN IS EXPECTED AND
LIGHT RAIN MAY OCCUR.  RIDGING IS EXPECTED BEGINNING TUESDAY AND
LASTING THROUGH EARLY FRIDAY...WHEN NEXT TROF/FRONT APPROACHES.  SO
A MAINLY DRY PERIOD EXPECTED TUESDAY THROUGH EARLY FRIDAY.

WILL FOREGO ANY FIRE WEATHER HIGHLIGHTS AS COOLER AND MORE MOIST
AIRMASS EXPECTED...ALONG WITH LESSER PREVAILING WIND SPEEDS.

.RIW...NONE.

WYZ004-005-008-009-015-026>028-022100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
1046 AM MDT SUN JUN 2 2002

THE SEVERE WEATHER POTENTIAL ACROSS NORTH CENTRAL AND EAST CENTRAL
WYOMING THROUGH THIS EVENING.

SPOTTER ACTIVATION MAY BE NECESSARY.

DISCUSSION...THE ATMOSPHERE WILL BECOME UNSTABLE THIS AFTERNOON IN
EAST CENTRAL AND NORTH CENTRAL WYOMING.  THE AIRMASS WILL BE MOIST
AND WITH AFTERNOON HEATING SCATTERED THUNDERSTORMS WILL FORM. ALSO A
WEATHER SYSTEM WILL MOVE ACROSS THE REGION AND THIS MAY AID IN
THUNDERSTORM DEVELOPMENT.  A FEW OF THESE STORMS MAY BECOME STRONG
TO SEVERE...WITH LARGE HAIL AND DAMAGING WIND THE MAIN THREATS.

THIS OUTLOOK IS FOR THE FOLLOWING COUNTIES IN CENTRAL WYOMING.

JOHNSON...NATRONA...BIG HORN...HOT SPRINGS...WASHAKIE

WCJIN-WYNW-WYNE

AR