Red Flag Warning 2, NWS Riverton, WY

000 
WWUS85 KRIW 012352
RFWRIW

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE RIVERTON WY
552 PM MDT TUE SEP 1 2009


WYZ283-020100-
/O.EXP.KRIW.FW.W.0002.000000T0000Z-090902T0000Z/
UPPER WIND RIVER BASIN / WIND RIVER BASIN-
552 PM MDT TUE SEP 1 2009

...RED FLAG WARNING WILL EXPIRE AT 6 PM MDT THIS EVENING...

THE RED FLAG WARNING WILL EXPIRE AT 6 PM MDT THIS EVENING. 

THIS INCLUDES THE FOLLOWING FIRE WEATHER ZONES...
IN WYOMING...283

THE WIND SPEEDS WILL DECREASE TO 10 TO 15 MPH BY 7 PM AND THE
RELATIVE HUMIDITY WILL INCREASE AS WELL. THUS THE RED FLAG WARNING
WILL BE ALLOWED TO EXPIRE AT 6 PM.

$$

WYZ280-020100-
/O.EXP.KRIW.FW.W.0002.000000T0000Z-090902T0000Z/
NATRONA COUNTY / CASPER BLM-
552 PM MDT TUE SEP 1 2009

...RED FLAG WARNING WILL EXPIRE AT 6 PM MDT THIS EVENING...

THE RED FLAG WARNING WILL EXPIRE AT 6 PM MDT THIS EVENING. 

THIS INCLUDES THE FOLLOWING FIRE WEATHER ZONES...
IN WYOMING...280

THE WIND SPEEDS WILL DECREASE TO 10 TO 15 MPH BY 7 PM AND THE
RELATIVE HUMIDITY WILL INCREASE AS WELL. THUS THE RED FLAG WARNING
WILL BE ALLOWED TO EXPIRE AT 6 PM.

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
320 AM MDT TUE SEP 1 2009

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
CLOSED...NEARLY CUT OFF...UPPER LOW SPINNING JUST NORTH OF
LIVINGSTON MT EARLY THIS MORNING. THIS FEATURE FARTHER NORTH THAN
PREVIOUSLY PROGGED. THE LOW HAS ENTRAINED GOOD DEAL OF DRY AIR
FROM THE NORTHERN GREAT BASIN AND HAS BEGUN THE FILLING/WEAKENING
PROCESS. DECREASED PRECIPITATION CHANCES SOMEWHAT FOR MOST AREAS
WITH THE BEST LIFT AND INSTABILITY REMAINING NORTH...NEAR THE
CENTER OF THE LOW...OF WYOMING TODAY. UPPER LEVEL HEIGHTS RISE
RAPIDLY THIS AFTERNOON OVER EASTERN IDAHO IN THE WAKE OF THE
CLOSED LOW...AHEAD OF A SEASONABLY STRONG CLOSED LOW APPROACHING
THE PACIFIC NORTHWEST. SURFACE AND NEAR SURFACE NORTHERLY FLOW
EAST OF THE DIVIDE WILL BRING A WEAK COLD FRONT/WIND SHIFT TO THE
BIG HORN BASIN DURING THE MORNING AND THROUGH THE WIND RIVER BASIN
AND NATRONA COUNTY DURING THE AFTERNOON. THE SURFACE CONVERGENCE
ALONG THE FRONT MAY INDUCE A THUNDERSTORM OR TWO DURING THE LATE
AFTERNOON...SO KEPT ISOLATED THUNDERSTORMS IN THE FORECAST AS A
RESULT. SIMILAR SCENARIO EXPECTED EAST OF THE DIVIDE ON
WEDNESDAY...BUT WITH WARMING TEMPS AT H5 AND A LITTLE LESS MID-
LEVEL MOISTURE TO WORK WITH...ONLY EXPECTING ISOLATED HIGH BASED
AFTERNOON THUNDERSTORMS IN THE CENTRAL AND NORTHERN MOUNTAINS.
MAINLY HIGH LEVEL MONSOON MOISTURE ASSOCIATED WITH CATEGORY 4
HURRICANE JIMENA...MOVING NORTHWARD ALONG BAJA CALIFORNIA...EXPECTED
TO MOVE UP THROUGH THE WESTERN GREAT BASIN WEDNESDAY AND INTO
WESTERN WYOMING THURSDAY. LATEST GFS INDICATING THE MOISTURE WILL
REMAIN ABOVE H5..WITH LITTLE INCREASE IN PWAT VALUES.

.LONG TERM...FRIDAY THROUGH TUESDAY

A TROUGH CURRENTLY OVER THE BERING STRAIT WILL BE THE MAIN PLAYER
OVER THE NORTHERN ROCKIES DURING THE EXTENDED...ESPECIALLY DURING
THE LATTER HALF OF LABOR DAY WEEKEND INTO NEXT WEEK. MEDIUM RANGE MODELS
HAVE BEEN VERY INCONSISTENT WITH THE TIMING AND STRENGTH OF THIS
TROUGH MOVING THROUGH THE ROCKIES. THEREFORE...CONFIDENCE IS
LOWER THAN NORMAL FOR THE EXTENDED...BUT MEDIUM RANGE MODELS ARE
IN GENERAL AGREEMENT THAT A TROUGH WILL AFFECT THE REGION EARLY
NEXT WEEK. AHEAD OF THE THIS TROUGH...A RIDGE OVER THE AREA ON
FRIDAY WILL GRADUALLY WEAKEN AND SHIFT EAST OF THE AREA BY
SATURDAY. FRIDAY SHOULD BE THE WARMEST DAY OF THE EXTENDED BEFORE
A SLIGHT COOLING TREND IS EXPECTED SATURDAY AND SUNDAY...BEFORE
POSSIBLY MORE SUBSTANTIAL COOLING TAKES PLACE MONDAY/TUESDAY
BEHIND THE MAIN COLD FRONT...ASSOCIATED WITH THE TROUGH. A
SHORTWAVE TROUGH MOVING THROUGH THE MEAN TROUGH IS EXPECTED TO
PUSH THROUGH THE PACIFIC NORTHWEST AND NORTHERN INTERMOUNTAIN WEST
LATE SATURDAY/SATURDAY NIGHT. THIS COULD HELP ENHANCE CONVECTION
OUT WEST DURING THIS TIMEFRAME. SUNDAY THROUGH TUESDAY...POPS HAVE
BEEN BROAD BRUSHED WITH SLIGHT IN THE LOWER ELEVATIONS AND CHANCE
POPS IN THE HIGHER TERRAIN...DUE TO THE CURRENT UNCERTAINTIES IN
THE DETAILS WITH THIS TROUGH.

&&

.AVIATION...
VFR CONDITIONS WILL OCCUR TODAY THROUGH 06Z WED. ISOLATED SHOWERS
WILL OCCUR IN FAR NORTHERN WY THROUGH 18Z. ADDITIONAL SHOWERS AND
ISOLATED THUNDERSTORMS WILL OCCUR AFTER 18Z IN NORTHERN WY. THIS
ACTIVITY WILL DECREASE AFTER 01Z WED WITH A FEW LINGERING SHOWERS
OVER NORTHERN WY UNTIL 06Z. WIND SPEEDS WILL INCREASE TO 10 TO 20
KNOTS OVER MANY AREAS AFTER 18Z TODAY...THEN DIMINISH AFTER 01Z WED.

&&

.FIRE WEATHER...
AN UPPER LEVEL STORM SYSTEM OVER EASTERN MONTANA WILL CONTINUE TO
PRODUCE SCATTERED THUNDERSTORMS OVER THE NORTHERN MOUNTAINS THIS
AFTERNOON AND EARLY EVENING. ISOLATED AFTERNOON THUNDERSTORMS ARE
EXPECTED ELSEWHERE IN THE DISTRICT TODAY. MODERATE WEST WIND WILL
RETURN TO SOUTHWEST AND SOUTH- CENTRAL WYOMING ALONG WITH DRY
CONDITIONS. A WEAK PACIFIC TROUGH WILL BRING INCREASING HIGH
CLOUDS TO THIS AREA DURING THE AFTERNOON...LIMITING INSTABILITY
AND THE POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS
LASTING MORE THAN AN HOUR OR SO. LIGHT WIND ALONG WITH
ISOLATED...MAINLY MOUNTAIN...AFTERNOON THUNDERSTORMS IS EXPECTED
ALL AREAS WEDNESDAY.

&&

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

&&

SHORT TERM...CHURCH
LONG TERM...WM
AVIATION...AR
FIRE WEATHER...CHURCH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
500 AM MDT TUE SEP 1 2009

WYZ001>020-022>030-021100-
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 TUE SEP 1 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING.

.DAY ONE...TODAY AND TONIGHT

ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
ARE EXPECTED...MAINLY OVER NORTHERN WYOMING TODAY. THE STRONGER
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING BRIEF HEAVY RAIN...SMALL
HAIL...AND WIND GUSTS TO 40 MPH.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT RAINFALL AMOUNTS OF ONE QUARTER
INCH OR GREATER...HAIL LARGER THAN PEA SIZE AND WIND GUSTS EXCEEDING
40 MPH. THANK YOU.

TEAM RIVERTON