Severe Thunderstorm Warning 4, NWS Riverton, WY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
113 PM MDT MON MAY 22 2006

.SHORT TERM...TONIGHT THROUGH THURSDAY
INSTABILITY INCREASING ACROSS OUR SRN ZONES WHERE BREAK IN CLOUDS
HAS ALLOWED FOR DECENT HEATING. FEW STRONG STORMS ALREADY ROAMING
ABOUT THE SOUTHWEST...ESPECIALLY SWEETWATER COUNTY. THREAT OF
ISOLATED SEVERE THUNDERSTORMS CONTINUES THROUGH THE EVENING HOURS.
MAIN THREAT WILL BE WIND GUSTS OVER 60 MPH BUT A COUPLE STORMS
COULD PRODUCE PENNY SIZE HAIL. SOME HEAVY RAIN IS ALSO A DISTINCT
POSSIBILITY. EXPECT CONVECTION TO GRADUALLY INCREASE THE REMAINDER
OF THE AFTERNOON AND THEN BECOME MORE ORGANIZED THIS EVENING AS
NEGATIVELY TILTED TROUGH APPROACHES. EXPECT RATHER WIDESPREAD
CONVECTION OVER THE SOUTHWEST...SWING INTO OUR SERN ZONES DURING
THE COURSE OF THE EVENING. WILL KEEP MENTION OF STRONG WINDS...SMALL
HAIL AND HEAVY RAIN IN MOST OF OUR SRN ZONES THIS EVENING. PER THE
PARALLEL NAM...THIS SYSTEM MAY CLOSE OFF AGAIN OVER WRN SD ON
TUESDAY AND KEEP THE THREAT OF SHOWERS AND THUNDERSTORMS GOING OVER
OUR NERN ZONES THROUGH THE DAY. FLAT RIDGE THEN BUILDS IN FOR
WEDNESDAY AND THURSDAY WITH WARMING TEMPERATURES AGAIN AFTER
TUESDAYS DECENT COOLDOWN. USED SOME WRF WINDS AGAIN FOR THE SHORT
TERM AND THIS GIVES SOME AREAS IN AND NEAR THE MOUNTAINS SOME VERY
WINDY CONDITIONS...BUT THIS LOOKS GOOD.

LONG TERM...THURSDAY NIGHT THROUGH MONDAY
SOUTHWEST FLOW INCREASE THURSDAY WELL AHEAD OF THE NEXT UPPER LOW.
MOISTURE INCREASES AS WELL SO SHOWERS AND THUNDERSTORMS THAT
DEVELOP SHOULD PRODUCE SOME DECENT MOISTURE...PRIMARILY IN THE WEST
AND NORTH.  SOUTHWEST WINDS INCREASE IN THE TYPICAL SPOTS WITH LEE
TROUGH DEVELOPING.  CLOSED SURFACE LOW WINDS UP OVER SE MONTANA
BY FRIDAY MORNING...WITH A FRONTAL SURGE INTO THE NORTH.  UPPER LOW
APPROACHES FRIDAY WITH FLOW BACKING TO THE SSW...WITH DRYSLOT OVER
ALL BUT WESTERN WYOMING THROUGH SATURDAY MORNING.  THE SURFACE LOW
LIFTS NORTHEAST INTO NORTH DAKOTA...ALLOWING THE SOUTHWEST WINDS TO
MIX BACK IN.  ANOTHER LEE TROUGH FORMS FRIDAY EVENING...WITH
ANOTHER SURGE FRIDAY NIGHT...MAKING IT INTO THE CENTRAL
ZONES.  MOISTURE INCREASES AS THE UPPER LOW MOVES INTO THE NORTHWEST
STATES ON SATURDAY.  THIS MERITS MENTION OF POPS EVERYWHERE...THOUGH
WITH FRONT ALONG THE MONTANA BORDER...HAVE POPS ACROSS THE NORTH
SATURDAY AND SUNDAY.  THE UPPER LOW SWINGS THROUGH MONDAY BRINGING IN
MUCH COOLER AND POTENTIALLY WETTER WEATHER.  THE ATMOSPHERE
STABILIZES FROM WEST TO EAST WITH THE PASSAGE OF THE TROUGH...THOUGH
HAVE LEFT THUNDER MENTION DUE TO DYNAMICS MOVING THROUGH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

SHORT TERM...SKRBAC
LONG TERM...TWB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
759 AM MDT MON MAY 22 2006

WYZ001>020-022>030-231300-
ABSAROKA MOUNTAINS-BIGHORN MOUNTAINS SOUTHEAST-
BIGHORN MOUNTAINS WEST-CASPER MOUNTAIN-CODY FOOTHILLS-
EAST SWEETWATER COUNTY-FLAMING GORGE-
GREEN MOUNTAINS AND RATTLESNAKE RANGE-JACKSON HOLE-LANDER FOOTHILLS-
NATRONA COUNTY LOWER ELEVATIONS-NORTH BIG HORN BASIN-
NORTHEAST JOHNSON COUNTY-OWL CREEK AND BRIDGER MOUNTAINS-
ROCK SPRINGS AND GREEN RIVER-SALT RIVER AND WYOMING RANGES-
SOUTH LINCOLN COUNTY-SOUTHEAST BIG HORN BASIN-
SOUTHEAST JOHNSON COUNTY-SOUTHWEST BIG HORN BASIN-STAR VALLEY-
TETON AND GROS VENTRE MOUNTAINS-UPPER GREEN RIVER BASIN-
UPPER GREEN RIVER BASIN FOOTHILLS-UPPER WIND RIVER BASIN-
WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST-
YELLOWSTONE NATIONAL PARK-
759 AM MDT MON MAY 22 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING.

.DAY ONE...TODAY AND TONIGHT

A STRONG STORM SYSTEM WILL MOVE ACROSS THE SOUTHERN GREAT BASIN
TODAY AND THEN TRACK NORTHEAST ACROSS WYOMING LATE TONIGHT. MOISTURE
WILL STREAM NORTH ACROSS UTAH...COLORADO...AND WYOMING TODAY AHEAD OF
THIS SYSTEM. STRONG THUNDERSTORMS...AND POSSIBLY A FEW SEVERE
THUNDERSTORMS...WILL DEVELOP AROUND MIDDAY IN THIS REGION OF HIGHER
MOISTURE. THE MAIN THREAT IN ASSOCIATION WITH THESE STORMS WILL BE
GUSTY WIND...ALTHOUGH BRIEF HEAVY RAIN AND SMALL HAIL WILL BE LIKELY.
SWEETWATER...LINCOLN...AND SUBLETTE COUNTIES ARE EXPECTED TO BE THE
MOST AT RISK FROM THE THREAT OF THESE HAZARDS. SCATTERED SHOWERS
AND THUNDERSTORMS WILL OCCUR ACROSS THE REMAINDER OF THE AREA
BEGINNING EARLY THIS AFTERNOON. PLEASE STAY TUNED FOR FURTHER
STATEMENTS FROM THE NATIONAL WEATHER SERVICE IN RIVERTON AS
THUNDERSTORMS IMPACT THE REGION TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION...ESPECIALLY ACROSS SOUTHWEST WYOMING...MAY BE
NEEDED THIS AFTERNOON AND EVENING. SPOTTERS ARE ENCOURAGED TO CALL
THE RIVERTON NATIONAL WEATHER SERVICE WITH REPORTS OF STRONG WIND
GUSTS...HAIL OF ANY SIZE...AND HEAVY RAINFALL.

TRIW