Flash Flood Warning 6, NWS Riverton, WY

000 
WGUS75 KRIW 120247
FFSRIW

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
847 PM MDT THU SEP 11 2008

WYC023-120256-
/O.CAN.KRIW.FF.W.0006.000000T0000Z-080912T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LINCOLN WY-
847 PM MDT THU SEP 11 2008

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN
LINCOLN COUNTY...

THE FLOODING HAS SUBSIDED IN OPAL AND ADDITIONAL FLOODING IS NOT 
EXPECTED. THEREFORE THE WARNING HAS BEEN CANCELLED.

REPORT FLOODING TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT
1-800-211-1448.

LAT...LON 4202 11026 4189 11006 4162 11028 4171 11050

$$

MURRELL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
337 PM MDT THU SEP 11 2008

.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
THE COLD STORM SYSTEM OVER WYOMING WILL DRIFT EAST
THROUGH THE AREA TONIGHT WITH SOME SHOWERS AND THUNDERSTORMS LINGERING
ACROSS THE SOUTH AND EAST.  THE SHOWERS WILL DECREASE IN THE MORNING
WITH CLEARING ACROSS THE WEST AND NORTH SPREADING SOUTH AND EAST THROUGH
THE DAY.  TEMPERATURES WILL BE SLIGHTLY WARMER BUT REMAIN BELOW NORMAL
FRIDAY.  HUMIDITY WILL DECREASE BUT STILL REMAIN ABOVE NORMAL.  SATURDAY
WILL BE WARMER AND GENERALLY DRYER WITH ISOLATED SHOWERS DEVELOPING IN
THE AFTERNOON ACROSS THE NORTH. MODELS IN GOOD AGREEMENT WITH
EXITING LOW AND DEVELOPING NORTHWEST FLOW. MODELS HAVING PROBLEMS
DEVELOPING PRECIPITATION WHICH USUALLY OCCURS IN THE NORTHWEST
FLOW ALTHOUGH THE MID LEVEL MOISTURE FIELDS INCREASE AND FRANTICNESSS
IS INDICATED. HAVE ISOLATED PRECIPITATION SATURDAY AFTERNOON AND EVENING
AT THIS TIME BUT THIS WILL LIKELY NEED TO BE INCREASED AND EXPECT MODELS
TO PICK UP ON IT OVER THE NEXT 24 HOURS. TEMPERATURES ON FRIDAY
NIGHT AND SATURDAY MORNING MY BE COOLER THAN FORECAST AT THIS TIME BUT
LOOKS LIKE FREEZING TEMPERATURES WILL REMAIN OVER THE MOUNTAINS
AND IN THE WESTERN VALLEYS WITH THE CENTRAL AND EASTERN LOWER ELEVATIONS
AVOIDING A KILLING FREEZE. THIS WILL NEED TO BE CLOSELY MONITORED
FOR POTENTIAL FREEZE WARNINGS.

.LONG TERM...SUNDAY THROUGH THURSDAY
ECMWF WAS GENERALLY FOLLOWED TONIGHT BUT MORE CHANGES WILL BE NEEDED
IF TRENDS CONTINUE ANOTHER NIGHT. OVERALL ECMWF IS SHOWING A LARGE
RIDGE OVER THE WEST TO START THE MEDIUM RANGE PERIOD. THIS UPPER
HIGH IS PROGRESSIVE AND IS FORECAST TO SHIFT OVERHEAD LATE MONDAY
AND THEN OFF TO THE EAST ON TUESDAY. A TROUGH OFF THE CALIFORNIA
COAST IS THEN EXPECTED TO COMBINE WITH THE SLY FLOW ON THE BACKSIDE
UP THIS UPPER HIGH TO BRING SOME MONSOONAL MOISTURE NED BY MIDWEEK.
ECMWF HINTS THAT WE MAY SEE ISOLATED STORMS OFF THE UINTAS AS EARLY
AS LATE TUESDAY BUT IVE HELD OFF INTRODUCING STORMS DOWN THERE
UNTIL WEDNESDAY. IN FACT THE IDEA OF ISOLATED STORMS ACROSS MOST OF
THE SW AND WCNTRL MTNS STILL LOOKS GOOD. KEPT THIS SAME IDEA INTO
THURSDAY BUT THE NEW ECMWF SHOWS A MUCH STRONGER TROUGH DIGGING INTO
THE PACNW ON THURSDAY WITH A LEAD SHORTWAVE MOVING INTO NW WYOMING.
IF THE EURO IS RIGHT ON THIS TIMING AND STRENGTH WE WILL NEED TO
INTRODUCE MORE POPS ACROSS NOT ONLY THE REST OF THE WEST BUT EVEN
EAST OF THE DIVIDE IN THURSDAY.

&&

.AVIATION...
LOW CLOUDS WILL GRADUALLY ERODE OVER MUCH OF THE AREA OVERNIGHT AS
THE UPPER LOW MOVES SOUTH INTO UTAH.  SWEETWATER COUNTY WILL LIKELY
REMAIN SOCKED IN OVERNIGHT INTO THE LATE MORNING HOURS.  SHOWERS AND
THUNDERSTORMS WILL BE ENCOUNTERED OVER THIS AREA AS WELL...AND MORE
ISOLATED ACTIVITY OVER THE REMAINDER OF THE SOUTHWEST AND NATRONA
COUNTY.  OTHERWISE IMPROVEMENT WILL BE SEEN FRIDAY.

&&

.FIRE WEATHER...
THE COLD STORM SYSTEM OVER WYOMING WILL DRIFT EAST THROUGH THE
AREA TONIGHT WITH SOME SHOWERS AND THUNDERSTORMS LINGERING ACROSS
THE SOUTH AND EAST. THE SHOWERS WILL DECREASE IN THE MORNING WITH
CLEARING ACROSS THE WEST AND NORTH SPREADING SOUTH AND EAST
THROUGH THE DAY. TEMPERATURES WILL BE SLIGHTLY WARMER BUT REMAIN
BELOW NORMAL FRIDAY. HUMIDITY WILL DECREASE BUT STILL REMAIN ABOVE
NORMAL. SATURDAY WILL BE WARMER AND GENERALLY DRYER WITH ISOLATED
SHOWERS DEVELOPING IN THE AFTERNOON ACROSS THE NORTH.

&&

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

SHORT TERM...C.BAKER
LONG TERM...SKRBAC
AVIATION...TWB
FIRE WEATHER...C.BAKER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
500 AM MDT THU SEP 11 2008

WYZ001>020-022>030-121100-
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-
500 AM MDT THU SEP 11 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING.

.DAY ONE...TODAY AND TONIGHT

ONE TO TWO INCHES OF SNOWFALL IS EXPECTED ABOVE 7500 FEET ACROSS
THE BIG HORN MOUNTAINS THIS MORNING. ONE TO THREE INCHES OF SNOWFALL
IS EXPECTED ABOVE 7500 FEET ACROSS THE WIND RIVER AND THE ABSAROKA
MOUNTAINS TODAY ALONG WITH ANOTHER INCH EXPECTED ACROSS THE WIND
RIVER MOUNTAINS TONIGHT. GRANITE AND POWDER RIVER PASSES WILL
LIKELY BECOME SLICK AND SNOW COVERED EARLY THIS MORNING. SOUTH
PASS...TOGWOTEE PASS AS WELL AS THE CHIEF JOSEPH HIGHWAY WILL
LIKELY BECOME SLICK AND SNOW COVERED AT TIMES TODAY AND THIS
EVENING.

THERE IS A GOOD CHANCE OF THUNDERSTORMS THIS AFTERNOON THAT WILL
LIKELY PRODUCE SMALL HAIL ACROSS SWEETWATER COUNTY...THE UPPER
GREEN RIVER BASIN AS WELL AS SOUTHERN LINCOLN COUNTY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS AS WELL AS
HAIL SIZES. THANK YOU.

TEAM RIVERTON