Area Forecast Discussion
Issued by NWS Riverton, WY

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000
FXUS65 KRIW 180959
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
359 AM MDT FRI JUL 18 2014

.SHORT TERM...FRIDAY THROUGH SUNDAY NIGHT

ONCE AGAIN THE FICKLE WYOMING WEATHER DECIDED TO THUMB ITS NOSE AT
WEATHER FORECASTERS TODAY AS THE SHORTWAVE THAT MOVED THROUGH
YESTERDAY MOVED THUNDERSTORMS FURTHER SOUTH THAN EXPECTED. MOST
HAVE WEAKENED TO SHOWERS AS OF EARLY THIS MORNING AND SHOULD BE
GONE BY DAYBREAK. HOWEVER...ANOTHER SHORTWAVE WILL APPROACH THIS
AFTERNOON. THIS SEEMS SIMILAR TO YESTERDAY SO WE KEPT THE POPS
ISOLATED. HOWEVER...WE DID ALLOW FOR ISOLATED LATE DAY CONVECTION
IN MANY AREAS. AGAIN...A VAST MAJORITY OF THE DAY SHOULD BE RAIN
FREE FOR MOST AREAS. THERE WILL BE A BIT MORE WIND EAST OF THE
DIVIDE AND MANY PARTS OF THE COUNTRY WOULD CALL IT BREEZY...BUT IN
WYOMING WE CALL IT FRIDAY. WITH THICKNESSES CONTINUING TO RISE
TEMPERATURES WILL CONTINUE TO RISE WITH MANY BASIN LOCATIONS
SEEING HIGH TEMPERATURES RISE INTO THE 90S. ANY CONVECTION SHOULD
END BY MIDNIGHT TONIGHT.

BY SATURDAY...THE RIDGE WILL BE EVEN STRONGER OVER THE AREA WITH
EVEN HIGHER HEIGHTS. THE NAM SHOWS PRECIPITABLE WATER VALUES
DROPPING TO UNDER 0.50 INCHES ACROSS MOST OF THE STATE. AS A RESULT
ALL THE MODELS HAVE TRENDED DRIER FOR THIS DAY SO WE HAVE MAINTAINED
THE DRY FORECAST A VAST MAJORITY OF THE COUNTY WARNING AREA. THE
EXCEPTION IS ACROSS SOUTHERN SWEETWATER COUNTY WHERE A BIT OF
MONSOONAL MOISTURE CREEPING NORTH MY BRING AN ISOLATED THUNDERSTORM.
OTHERWISE EXPECT ANOTHER WARM TO HOT DAY WITH HIGHS IN THE 90S IN
MOST LOWER ELEVATIONS AND BREEZY CONDITIONS ACROSS THE USUAL FAVORED
AREAS.

AS FOR SUNDAY...MOISTURE MOVING FROM THE SOUTH OF WYOMING WILL MAKE
A TRANSITION FROM BRIGHT AND SUNNY SPELLS IN THE MORNING TO MORE
CLOUDY INTERVALS IN THE AFTERNOON AND EVENING. PERIODS OF
SHOWERS...SOME HEAVY AND THUNDERY WILL SPREAD FROM THE SOUTH IN THE
AFTERNOON AND EVENING MAY DEVELOP WITH THE RISK OF GUSTY WINDS AND
HAIL. SHOWERS...SOME THUNDERY MAY PERSIST SUNDAY NIGHT WITH SOME
CLEAR INTERVALS POSSIBLE LATE. ACROSS THE NORTH AND EAST OF THE
COUNTY WARNING AREA...IT WILL BE HOT WITH GOOD SUNNY SPELLS FOLLOWED
BY MORE SUNNY AND CLOUDY INTERVALS AND ONLY ISOLATED SHOWERS.

NOW FOR THOSE OF YOU CONFUSED...I WILL NOW REVERT BACK FROM THE
BRITISH VERSION TO AMERICAN ENGLISH. BY SUNDAY DEEPER MONSOONAL
MOISTURE WILL MOVE NORTHWARD FROM UTAH AND COLORADO ACCOMPANIED BY
AN ASSOCIATED SHORTWAVE. THE DAY SHOULD START DRY BEFORE DEEPER
MOISTURE MOVES NORTHWARD INTO THE STATE. SHOWERS AND THUNDERSTORMS
WILL BREAK OUT IN THE SOUTH AND SPREAD NORTH AND EAST ACROSS MUCH OF
THE SOUTHWESTERN HALF OF THE COUNTY WARNING AREA THROUGH THE
EVENING. THE CHANCE OF CONVECTION WILL LINGER INTO THE NIGHTTIME AS
WELL...MAINLY ACROSS THE WESTERN HALF OF THE AREA. TEMPERATURES WILL
REMAIN ABOVE NORMAL WITH HIGHS IN THE 90S ONCE AGAIN ACROSS THE
LOWER ELEVATIONS.

.LONG TERM...MONDAY THROUGH FRIDAY

UPPER LOW FROM BAJA CALIFORNIA CONTINUES TO SHEAR NE ACROSS WYOMING
ON MONDAY WITH THE BEST MOISTURE AND INSTABILITY ACROSS THE NORTH
HALF OF THE STATE IN THE AFTERNOON/EVENING.  ISOLATED TO SCATTERED
THUNDERSTORMS WILL BLOSSOM ACROSS MAINLY THE NORTH IN THE AFTERNOON
WITH THIS ACTIVITY MOVING OUT INTO THE NORTHERN HIGH PLAINS THROUGH
THE EVENING.  DRIER...WARM AND BREEZY CONDITIONS ARE EXPECTED ACROSS
SOUTHERN WYOMING MONDAY AFTERNOON WITH CONTINUED ELEVATED FIRE
DANGER...WITH LIGHTNING ACTIVITY ON SUNDAY/SUNDAY NIGHT POTENTIALLY
IGNITING NEW FIRES.

UPPER HIGH EXPANDS OVER THE CENTRAL ROCKIES ON TUESDAY WITH H5
HEIGHTS RISING AROUND 60DM ACROSS WYOMING.  THIS WILL BRING HOT
TEMPERATURES WITH HIGHS IN THE LOWER TO MID 90S ACROSS MOST CENTRAL
BASINS ON TUESDAY WITH POSSIBLY SOME TRIPLE DIGITS ON WEDNESDAY.
THUNDERSTORM ACTIVITY WILL BE ISOLATED AND CONFINED TO THE EXPANDING
PERIPHERY OF THE UPPER HIGH ACROSS THE NORTHERN MOUNTAINS AND FAR
NORTH ON TUESDAY.

UPPER LOW WILL DROP SOUTH ALONG THE B.C. COAST AND SETTLE NEAR
VANCOUVER ISLAND ON TUESDAY BEFORE GETTING KICKED INLAND.  GFS IS
SLOWER AND MORE AMPLIFIED ON LATEST RUN BRINGING THIS SYSTEM OVER
FOUR CORNERS UPPER HIGH.  ECMWF CONTINUES TO TREND FURTHER NORTH
WITH OPERATIONAL RUN AND EC ENSEMBLE MEAN IN GOOD AGREEMENT.
FORECAST REFLECTS THE ECMWF SOLUTION THAT RESULTS WEAKER...LESS
NOTICEABLE...COLD FRONTAL PASSAGE WITH THIS SYSTEM WEDNESDAY NIGHT
AND THURSDAY...SO LESS WIND AND LESS OF A COOLDOWN ON THURSDAY.

AFTER A BRIEF FLATTENING OF FOUR CORNERS HIGH ON THURSDAY...IT
EXPAND BACK NORTH FRIDAY AND THROUGH THE WEEKEND FOR MAINLY DRY
WEATHER WITH ABOVE NORMAL TEMPERATURES.


&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE CONTINENTAL DIVIDE...KCPR/KRIW/KLND/KWRL/KCOD

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ISOLATED SHOWERS AND
STORMS WILL OCCUR FROM 20Z UNTIL 06Z SATURDAY IN THE ABSAROKA AND
BIG HORN MOUNTAINS. A FEW OF THESE WILL DRIFT EAST ACROSS THE LOWER
ELEVATIONS OF THE NORTH. GUSTY OUTFLOW WIND TO 40 MPH WILL BE THE
MAIN THREAT TO AVIATION. A FEW SHOWERS MAY LINGER OVER THE BIGHORN
MOUNTAINS AFTER 06Z SATURDAY.

WEST OF THE CONTINENTAL DIVIDE...KJAC/KBPI/KPNA/KRKS

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ISOLATED SHOWERS AND
STORMS WILL OCCUR IN FAR SOUTHERN WY FROM 20Z UNTIL 04Z SATURDAY.
THE MAIN THREAT WILL BE THE GUSTY OUTFLOW WIND TO 40 MPH. THE
ACTIVITY SHOULD REMAIN SOUTH OF THE KRKS AIRPORT.
&&

.FIRE WEATHER...

A WARMING TREND WILL CONTINUE TODAY WITH WARM TO HOT TEMPERATURES
CONTINUING INTO THE WEEKEND. ANOTHER UPPER LEVEL DISTURBANCE AND
WEAK FRONT  WILL MOVE OVER THE TOP OF THE RIDGE TODAY AND MAY BRING
ISOLATED THUNDERSTORMS TO NORTHERN AND EASTERN AREAS OF THE COUNTY
WARNING AREA AS WELL AS THE HIGHER ELEVATIONS. HIGH PRESSURE SHOULD
KEEP MOST AREAS DRY ON SATURDAY WITH THE EXCEPTION OF SOUTHERN
SWEETWATER COUNTY WHERE SOME MONSOONAL MOISTURE WILL BRING THE
SLIGHT CHANCE OF A THUNDERSTORM. CHANCES OF THUNDERSTORMS WILL
INCREASE FROM SOUTH TO NORTH ON SUNDAY AFTERNOON AND EVENING AS DEEP
MONSOONAL MOISTURE SPREADS NORTHWARD ACROSS THE STATE. RELATIVE
HUMIDITY WILL CONTINUE TO LOWER TODAY WITH GUSTY BREEZES MAINLY WEST
OF THE DIVIDE POSSIBLY ENHANCING FIRE DANGER. GUSTY BREEZES WILL
THEN MOVE EAST OF THE DIVIDE TOWARD THE WIND RIVER BASIN AND FROM
THE RED DESERT THROUGH NATRONA COUNTY FOR SATURDAY AND SUNDAY.
&&

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

$$

SHORT TERM...HATTINGS
LONG TERM...AEM
AVIATION...AR
FIRE WEATHER...HATTINGS








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