Hail in Wyoming, August 28, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
255 PM MDT WED AUG 28 2002

FIRST PERIOD FORECAST MORE COMPLICATED TODAY THAN IN RECENT DAYS
WITH DYNAMICS MORE SUBTLE.  VERTICAL MODEL CROSS SECTIONS INDICATE
ONLY WEAK UPWARD MOTION OVERNIGHT...HINTING AT MINIMAL ACTIVITY.
HOWEVER...AFTERNOON CONVECTION OVER WEST AND NORTHWEST MOUNTAINS
WERE PROGGED BY ALL MODELS...WITH MESOETA SHOWING BEST PLACEMENT.
SPEED MAX SHOWING UP ON WATER VAPOR IMAGERY EXTRAPOLATES TO CENTRAL
AND NORTHEAST WY BY MID EVENING...SUPPORTING MESOETA SOLUTION OF
THUNDERSTORMS ZEROING IN ON OWL CREEKS AND SOUTHERN BIG HORNS.  WITH
SURFACE UPSLOPE FLOW WEAK BUT PERSISITENT...COULD GET A FEW STORMS
THAT BACKBUILD ALONG SOME OF THE MOUNTAINS AND DUMP VERY HEAVY
RAIN...HOPEFULLY NOT IN SOUTHERN JOHNSON COUNTY WHERE THEY ARE STILL
CLEANING UP FROM FLASH FLOOD TUESDAY MORNING.  THIS WILL NEED TO BE
CLOSELY WATCHED BY EVENING/MID SHIFTS.

FARTHER OUT...BETTER OVERALL DYNAMICS FOR MORE WIDESPREAD CONVECTION
TOMORROW AFTERNOON AND EVENING BEFORE TROF TO WEST FILLS IN AND WE
DRY OUT FOR FRIDAY.

.RIW...NONE.

JBS

WYZ005-008-009-011>015-026>028-291200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
122 PM MDT WED AUG 28 2002

...POTENTIAL FOR HAIL AND ISOLATED HEAVY RAINS FROM THUNDERSTORMS
THIS AFTERNOON AND EVENING...

THE GREATEST THREAT OF SIGNIFICANT SEVERE WEATHER EXTENDS FROM
WESTERN FREMONT COUNTY NORTHEAST ACROSS HOT SPRINGS...WASHAKIE...AND
JOHNSON COUNTIES.

WINDS GUSTING TO 60 MPH AND HAIL UP TO AN INCH IN DIAMETER COULD
OCCUR WITH THE STRONGER STORMS. ADDITIONALLY...ISOLATED STORMS COULD
PRODUCE VERY HEAVY RAIN.

THE STRONGEST STORMS ARE EXPECTED TO DEVELOP OVER THE WEST END
OF THE WIND RIVER MOUNTAINS BY LATE AFTERNOON...THEN MOVE
NORTHEAST TOWARD THE OWL CREEKS AND SOUTHERN BIG HORN MOUNTAINS BY
LATE EVENING.  WHILE MOST LOCATIONS WILL RECEIVE RAINFALL OF LESS
THAN ONE HALF INCH...ISOLATED LOCATIONS ALONG THE EAST SLOPES
OF THE BIG HORN MOUNTAINS COULD RECEIVE OVER AN INCH AS EASTERLY LOW
LEVEL WINDS PROVIDE PERSISTENT UPSLOPE CONDITIONS THROUGH THE
EVENING AND NIGHTTIME HOURS.

OTHER STORMS ARE FORECAST FROM AROUND JACKSON TO CODY. MOST OF THE
THUNDERSTORMS WILL MOVE TO THE NORTH AROUND 25 MPH.

WCJIN-WYNE-WYNW
SULLIVAN