000
FXUS65 KRIW 151754
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1140 AM MDT SAT JUN 15 2013

.SHORT TERM...SATURDAY THROUGH MONDAY NIGHT

IT LOOKS LIKE A NICE START TO THE WEEKEND FOR A VAST MAJORITY OF THE
COUNTY WARNING AREA WITH FLAT RIDGING AND STILL A RATHER DRY AIRMASS
REMAINING OVER THE REGION. THE RESULT WILL BE CHAMBER OF COMMERCE
WEATHER FOR MOST LOCATIONS WITH SUNSHINE AND ONLY SOME PASSING MID
TO HIGH LEVEL CLOUDS ALONG WITH NEAR TO SLIGHTLY ABOVE NORMAL
TEMPERATURES. MOISTURE WILL BE A BIT DEEPER OVER FAR SOUTHEASTERN
PORTIONS LIKE CASPER MOUNTAIN SO WE HAVE ALLOWED FOR SOME
AFTERNOON SPRINKLES BUT EVEN HERE MOST OF THE DAY WILL BE RAIN
FREE. WINDS WILL ALSO BE A LESS TODAY ALTHOUGH THERE WILL STILL BE
A BIT OF A WEST TO SOUTHWESTERLY BREEZE ACROSS SOUTHERN AND
WESTERN WYOMING.

THINGS MAY GET A BUT MORE ACTIVE FOR SUNDAY AS SOMEWHAT DEEPER
MOISTURE SPREADS BACK INTO THE AREA AND A WEAK...EMPHASIS ON WEAK...
COLD FRONT MOVING INTO THE AREA MAY BRING A FEW SHOWERS AND
THUNDERSTORMS FOR THE AFTERNOON AND EVENING. MOST OF THIS ACTIVITY
LOOKS TO STAY CONFINED TO THE HIGHER ELEVATIONS EAST OF THE DIVIDE
HOWEVER WITH HIGH ELEVATION HEAT SOURCE AND UPSLOPE WITH MOST OF THE
BASINS AND VALLEYS REMAINING LARGELY DRY. WITH DEEPER MOISTURE
MOVING INTO THE AREA FOR MONDAY AND HIGHER DEW POINTS AS A
RESULT...WE AGREE WITH THE PREVIOUS SHIFT ON THE COVERAGE OF THE
SHOWERS AND THUNDERSTORMS SO FEW CHANGES WERE MADE. CONDITIONS WEST
OF THE DIVIDE LOOK TO REMAIN LARGELY DRY AND WARM.

.LONG TERM...TUESDAY THROUGH SATURDAY
UPPER LOW NEAR 48N/137W EARLY THIS MORNING WILL BE OUR MAIN WEATHER
MAKER THIS PERIOD.  THIS LOW WILL SLOWLY PROGRESS INTO THE NW U.S.
TUESDAY NIGHT AND WEDNESDAY BEFORE LIFTING NE INTO NORTHERN MONTANA
THURSDAY AND FRIDAY.

CHANCES OF THUNDERSTORMS WILL REMAIN ACROSS THE NORTH AND EAST ON
TUESDAY WITH SURFACE HIGH PRESSURE OVER THE PLAINS AND E-SE FLOW
ADVECTING MOISTURE/INSTABILITY INTO THIS AREA.  A DRY SOUTHWEST FLOW
WILL PREVAIL ACROSS THE SOUTH AND WEST.

MOST OF WEST AND CENTRAL WYOMING WILL BE IN WARM SECTOR ON WEDNESDAY
WITH DRY SW FLOW ACROSS THE AREA...SFC LOW TO THE NORTH OVER
MONTANA.  THIS WILL THIS DRY SW FLOW TO PREVAIL ACROSS THE AREA ON
WEDNESDAY...THE WARMEST DAY DURING THIS PERIOD. STRONGER STORMS ARE
EXPECTED TO REMAIN MAINLY NORTH OVER MONTANA WITH ISOLATED STORMS
ACROSS THE FAR NORTH.  BREEZY TO WINDY CONDITIONS WITH SOME SINGLE
DIGIT RH/S WILL HEIGHTEN FIRE WEATHER CONCERNS ACROSS THE SOUTH AND
CENTRAL.

PACIFIC COLD FRONT WILL PUSH ACROSS THE AREA LATE
WEDNESDAY/WEDNESDAY NIGHT BRINGING COOLER TEMPERATURES ACROSS THE
NORTH AND WEST ON THURSDAY...WHILE THE SE THIRD OF THE CWA REMAIN
WARM...VERY DRY AND BREEZY/WINDY.

A COOLER AIRMASS WILL PREVAIL ACROSS THE AREA FRIDAY AND SATURDAY
WITH SLIGHT CHANCES OF SHOWERS AND STORMS ACROSS THE FAR NORTH.

&&

.AVIATION.../18Z ISSUANCE/

RELATIVELY BENIGN WEATHER EXPECTED ACROSS THE FORECAST AREA
THROUGH THE FORECAST PERIOD...GIVING WIDESPREAD VFR CONDITIONS.
WESTERLY FLOW ANTICIPATED...WITH SOME INCREASE IN WIND EXPECTED BY
21Z TODAY AT MOST TERMINALS WITH THE EXCEPTION OF KWRL AND KCOD. FOR
THOSE TERMINALS WITH WINDS...THEY  WILL WEAKEN WITH LOSS OF DAYLIGHT
THIS EVENING. INSERTED VCSH INTO KCPR TAF AS THERE IS A VERY SLIGHT
POSSIBILITY FOR CONVECTION WITH PRECIPITATION OVER AND NEAR CASPER
MOUNTAIN THIS EVENING.
&&

.FIRE WEATHER...

EXPECT A MORE STABLE DAY TODAY AFTER THE PASSAGE OF A COLD FRONT
TODAY. TEMPERATURES WILL AVERAGE 10 DEGREES COOLER THAN YESTERDAY. A
GUSTY WESTERLY BREEZE WILL BLOW ACROSS MUCH OF THE AREA WITH
RELATIVE HUMIDITY FALLING TO UNDER 15 PERCENT ACROSS MUCH OF THE
CENTRAL AND SOUTHERN ZONES. MAINLY DRY WEATHER WITH LESS WIND IS
EXPECTED FOR SATURDAY AS RIDGING BEGINS TO REBUILD ACROSS THE AREA.
INCREASED MOISTURE MAY BRING ISOLATED SHOWERS AND THUNDERSTORMS FOR
SUNDAY AFTERNOON AND EVENING.
&&

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

$$

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