Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 280516
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1116 PM MDT SUN JUL 27 2014

.SHORT TERM...TONIGHT THROUGH SUNDAY

WARM AND DRY CONDITIONS WILL CONTINUE TODAY...WITH THE DRY PORTION
PERSISTING THROUGH MONDAY MORNING ACROSS THE AREA. A SURGE OF
MOISTURE EMBEDDED IN THE RIDGE OF HIGH PRESSURE WILL BEGIN TO MOVE
OVER THE AREA DURING THE EARLY AFTERNOON HOURS OF MONDAY. CLOUD
COVER WILL INCREASE...WITH SOME LIGHT SHOWER ACTIVITY POSSIBLE OVER
THE WESTERN MOUNTAINS.

PWATS ASSOCIATED WITH THE THE SURGE OF MOISTURE CONTINUE TO INCREASE
THROUGH THE AFTERNOON. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
ARE POSSIBLE...MAINLY OVER WESTERN AND SOUTHERN WYOMING. GUSTY WIND
AND BRIEF PERIODS OF HEAVY RAIN WILL BE POSSIBLE WITH STORM ACTIVITY
TOMORROW AFTERNOON.

AREAS EAST OF THE DIVIDE WILL NOT SEE AS MUCH CLOUD COVER
INCREASE...AND WILL HAVE ANOTHER DAY OF WARMING TEMPERATURES. AREAS
WEST OF THE DIVIDE WILL SEE SLIGHTLY COOLER TEMPERATURES IN RESPONSE
TO THE UPCOMING SYSTEM.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY

THE FIRST PART OF THE LONG TERM WILL FEATURE WETTER CONDITIONS AS
DEEPER MONSOONAL MOISTURE MOVES NORTHWARD FROM COLORADO AND UTAH TO
COVER THE AREA FROM SOUTH TO NORTH. IN ADDITION...700 MILLIBAR FLOW
WILL TURN MORE LIGHT NORTH TO EAST...DEPENDING ON WHICH MODEL YOU
BELIEVE. MONDAY AFTERNOONS CONVECTION SHOULD WANE IN MOST AREAS WITH
THE LOSS OF DAYTIME HEATING...BUT PROBABLY NOT DIE OUT COMPLETELY AS
PRECIPITABLE WATER VALUES CLIMB.

THINGS LOOK TO BECOME FAIRLY ACTIVE ON TUESDAY AS DEEPER MOISTURE
MOVES OVER MUCH OF THE COUNTY WARNING AREA. BOTH THE NAM AND GFS
SHOW BETTER COVERAGE OF CONVECTION ACROSS THE SOUTHERN PORTIONS OF
THE COUNTY WARNING AREA. THE GFS BRINGS IT A BIT FURTHER NORTH BUT
THE PATTERN IS FAIRLY SIMILAR. THIS IS ALSO SHOWED IN THE
PRECIPITABLE WATER VALUES WHERE THE GFS HAS A BROAD AREA OF GREATER
THAN 1.00 INCHES ACROSS THE SOUTHERN TWO THIRDS OF THE ARA. THE NAM
IS SOMEWHAT DRIER BUT STILL WET ENOUGH TO PRODUCE THUNDERSTORMS. IF
THERE IS SOME GOOD NEWS...IT IS THAT THE CHANCE OF SEVERE WEATHER
WILL BE LIMITED AS CLOUD COVER SHOULD LIMIT HEATING. IN
ADDITION...MOST JET ENERGY WILL BE OFF TO THE NORTH AND EAST OF THE
COUNTY WARNING AREA. THE BEST CHANCE OF ANY STRONGER THUNDERSTORMS
WOULD BE IN NORTHEASTERN AREAS WHERE THE AREA WOULD BE CLOSER TO THE
RIGHT REAR QUADRANT OF THE JET AND MORE DAYTIME HEATING WITH LESS
CLOUD COVER. HOWEVER...THERE IS A THREAT FOR HEAVY RAIN WITH THE
STORMS WITH THE AMPLE MOISTURE. IN ADDITION...WITH LIGHT MID LEVEL
WINDS STORMS WILL BE SLOW MOVING AND COULD PRODUCE LOCAL FLOODING
PROBLEMS. STILL A BIT EARLY TO DEFINITELY CALL FOR IT...BUT
SOMETHING TO WATCH. STORMS SHOULD ONCE AGAIN DECREASE AT NIGHT BUT
NOT DIE OFF COMPLETELY.

WITH SOMEWHAT DRIER AIR SINKING BACK OVER THE AREA ON
WEDNESDAY...THE CHANCE OF THUNDERSTORMS SHOULD DECREASE A BIT.
HOWEVER...WITH CONTINUED DIFLUENCE ALOFT THE CHANCE WILL REMAIN.
BOTH MODELS ALSO SHOW THE AXIS OF DEEPEST QPF SHIFTING WEST TOWARD
THE WESTERN MOUNTAINS BY WEDNESDAY. CONTINUITY HAD THIS COVERED
FAIRLY WELL SO WE MADE FEW CHANGES. THIS TREND LOOKS TO CONTINUE FOR
THURSDAY WITH THE HIGHEST POPS ACROSS THE WESTERN MOUNTAINS. AS FOR
FRIDAY AND BEYOND...WE HAVE FEW CHANGES TO CONTINUITY. IT STILL
LOOKS LIKE SOME DISTURBANCES RIDING OVER THE TOP OF THE RIDGE AND
BRINGING SOME CHANCES OF MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS...ESPECIALLY IN THE WEST. THIS FAR OUT HOWEVER...AS IS
TO BE EXPECTED...DETAILS AND EXACT TIMING ARE MUDDY.

&&

.AVIATION.../06Z ISSUANCE/

INCREASING HIGH CLOUDINESS IS EXPECTED TO BEGIN OVERSPREADING THE
AREA FOR THE REMAINDER OF THE NIGHT. THEN A COMBINATION OF GULF
MOISTURE PUSHING WEST...AND MONSOONAL MOISTURE PUSHING NORTH INTO
THE AREA WILL DRAMATICALLY INCREASE THE FUEL FOR THUNDERSTORMS
MONDAY. ALTHOUGH INSTABILITY WILL REMAIN RELATIVELY WEAK OVER THE
AREA...A DISTURBANCE IN THE MONSOONAL FLOW AND DAYTIME HEATING WILL
BE SUFFICIENT FOR ISOLATED TO LOCALLY SCATTERED CONVECTION ACROSS
THE ENTIRE AREA. THE BEST SHOT FOR THUNDERSTORMS WILL BE ROUGHLY
ALONG AND SOUTHWEST OF KJAC-KPNA-50NE KRKS LINE...WHILE THE LEAST
AMOUNT OF COVERAGE/CHANCE FOR TS IS EXPECTED IN THE INTERIOR
PORTIONS OF THE BIG HORN BASIN FROM KWRL-KPOY. ALSO CONVECTION IS
EXPECTED TO BE BEGIN 1-3 HOURS EARLIER OVER THE WEST AND
SOUTH...BEFORE SPREADING/DEVELOPING EAST OF THE DIVIDE. SHOWERS AND
THUNDERSTORMS WILL BE SLOW MOVERS DUE LIGHT STEERING CURRENTS. THE
RELATIVELY HIGH BASED ACTIVITY ESPECIALLY AT THE ONSET...AND STEEP
LOW/MID LEVEL LAPSE RATES COULD ALSO RESULT IN SOME STRONG WIND
GUSTS AND SMALL HAIL. CONVECTION WILL LINGER IN SOME AREAS THROUGH
MUCH OF MONDAY NIGHT.

&&

.FIRE WEATHER...

DRY CONDITIONS WILL LAST OVER THE AREA THROUGH MONDAY MORNING.
BEGINNING EARLY MONDAY AFTERNOON...A SURGE OF MOISTURE WILL MOVE
OVER PORTIONS OF THE FORECAST AREA WHICH ARE WEST OF THE DIVIDE.
THIS MOISTURE WILL INCREASE CLOUD COVER AND INITIATE SOME SHOWERS
AND THUNDERSTORMS OVER THE AREA. EXPECT SLIGHTLY COOLER TEMPERATURES
AS WELL WITH ELEVATED HUMIDITY. AREAS EAST OF THE DIVIDE WILL ALSO
SEE INCREASED HUMIDITY IN RESPONSE TO THE ADDED MOISTURE.
HOWEVER...SHOWERS AND THUNDERSTORMS ARE NOT ANTICIPATED.
ADDITIONALLY...CLOUD COVER INCREASE IS NOT ANTICIPATED TO BE AS
SIGNIFICANT...ALLOWING TEMPERATURES TO CONTINUE THEIR WARMING TREND.
REGARDLESS TO SIDE OF THE DIVIDE...WIND IS EXPECTED TO BE LIGHT.

&&

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

&&

$$

SHORT TERM...BRANHAM
LONG TERM...HATTINGS
AVIATION...WM
FIRE WEATHER...BRANHAM







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