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000
FXUS65 KRIW 180526
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1126 PM MDT MON JUN 17 2013

.SHORT TERM...TONIGHT THROUGH TUESDAY (ISSUED AT 240 PM)

SHOWERS AND THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS THE
MOUNTAINOUS AREAS OF THE FORECAST AREA THIS AFTERNOON. SOME STORMS
HAVE BEGUN TO MOVE INTO THEIR ADJACENT VALLEYS AND BASINS...MAINLY
ACROSS THE UPPER GREEN RIVER BASIN AND JOHNSON COUNTY. ADDITIONAL
STORM ACTIVITY IS ANTICIPATED THROUGH THE AFTERNOON...AND SHOULD
LINGER INTO THE EARLY EVENING HOURS. ACTIVITY WILL WANE WITH THE
LOSS OF DAYLIGHT THIS EVENING...BUT ACTIVITY WILL LINGER OVER THE
CENTRAL AND NORTHERN MOUNTAINS.

ANOTHER...STRONGER DISTURBANCE WILL MOVE OVER THE FORECAST AREA
TUESDAY AFTERNOON. STORMS ARE ANTICIPATED TO START DURING THE EARLY
AFTERNOON HOURS. SOME STORMS WILL SEE THE POTENTIAL TO BECOME
STRONG...ESPECIALLY DURING THE LATER AFTERNOON HOURS. STRONGER
THUNDERSTORMS MAY SEE THE POTENTIAL FOR VERY STRONG WIND GUSTS AND
LARGER HAIL. THESE STRONGER STORMS SEEM MOST FAVORABLE ACROSS
JOHNSON COUNTY...BUT THE EXTENT OF STRONGER STORM COVERAGE MAY NOT
BE REALIZED UNTIL LATE MORNING TUESDAY.

TEMPERATURES WILL WARM ACROSS THE AREA TUESDAY...WITH RELATIVE
HUMIDITY AGAIN DECREASING TO THE SINGLE DIGITS ACROSS SOUTHERN
WYOMING. WIND WILL INCREASE SOMEWHAT DURING THE AFTERNOON...BUT ARE
NOT EXPECTED TO BE SIGNIFICANT ACROSS THE BULK OF THE AREA. THE
EXCEPTION MIGHT BE SOUTHEASTERN SWEETWATER COUNTY.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY NIGHT

THE THUNDERSTORMS OF TUESDAY AFTERNOON LOOK TO CONTINUE INTO TUESDAY
EVENING BEFORE SLOWLY WANING WITH THE LOSS OF DAYTIME HEATING AND
DRIER AIR PUNCHING IN FROM THE WEST AND SOUTH. MADE FEW CHANGES TO
THE PLACEMENT OF THE STORMS WITH ACTIVITY MAINLY NORTH OF THE WIND
RIVER RANGE...CLOSELY FOLLOWING THE 0.50 PRECIPITABLE WATER LINE.

ON WEDNESDAY ACTIVITY LOOKS TO BE LESS THAN ON TUESDAY WITH MODELS
SHOWING MUCH DRIER AIR IN PLACE ACROSS THE COUNTY WARNING AREA WITH
PRECIPITABLE WATER VALUES FALLING TO UNDER 0.50 FOR ALL AREAS. ANY
CONVECTION WOULD LIKELY BE LIMITED TO NORTHWESTERN WYOMING WHERE
THERE WILL BE A BIT MORE MOISTURE TO WORK WITH AND SOMEWHAT MORE
INSTABILITY DUE TO A CLOSER PROXIMITY TO AN UPPER LEVEL LOW OVER
IDAHO. WITH A COLD FRONT APPROACHING AND MOVING THROUGH...THE
PRESSURE GRADIENT WILL TIGHTEN UP A BIT AND BRING SOME GUSTY WINDS
ACROSS AREAS EAST OF THE DIVIDE...ESPECIALLY ACROSS THE SOUTHWESTERN
WIND CORRIDOR FROM THE RED DESERT THROUGH ROCK SPRINGS. IT DOES NOT
LOOK LIKE HIGH WIND SINCE 700 MILLIBAR WINDS ARE NOT STRONG
ENOUGH...BUT SOME WIND GUSTS TO 40 TO 50 MPH ARE CERTAINLY POSSIBLE.
THERE COULD BE SOME ELEVATED FIRE DANGER IN THE AFTERNOON WITH
RELATIVE HUMIDITY FALLING BELOW 10 PERCENT BUT NO RED FLAGS AT THIS
TIME SINCE FUELS ARE NOT CRITICAL YET. THE DOWNSLOPING WIND WILL
BRING A WARM DAY WITH SOME BASINS SEEING HIGHS AROUND 90. LITTLE
CONVECTION IS EXPECTED EAST OF THE DIVIDE EXCEPT IN THE HIGHER
ELEVATIONS. COOLER AIR WILL ADVECT IN BEHIND THE FRONT FOR WEDNESDAY
NIGHT. IT COULD GET QUITE CHILLY IN THE WESTERN VALLEYS...WITH EVEN
SOME PATCHY FROST IN THE MORE PROTECTED SPOTS.

THURSDAY LOOKS TO BE A COOLER DAY BEHIND THE FRONT WITH LESS WIND AS
WELL. AS FOR ANY CHANCE OF CONVECTION...WE CAN NOT RULE SOMETHING
OUT IN THE FAR NORTHWEST BUT MOISTURE WILL BE LACKING SO FOR WE
TRIMMED POPS A BIT ACROSS NORTHERN WYOMING AND KEPT ANY ACTIVITY
DOWN TO SLIGHT CHANCE. AS A SIDE NOTE...THE SUMMER SOLSTICE IS AT
11:04 PM ON THURSDAY NIGHT SO THAT IS WHEN SUMMER ARRIVES.

AND NOW...TO CELEBRATE THE FIRST FULL DAY OF SUMMER...WE PRESENT THE
DISCUSSION OF FRIDAY WITH THE METEOROLOGICAL VERSION OF THE CLASSIC
OLD SCHOOL RAP SONG SUMMERTIME. SO...DRUMS PLEASE.

HERE IT IS...A PATTERN SLIGHTLY TRANSFORMED
A BIT OF A BREAK FROM THE LATE SPRING NORM
JUST A LITTLE WEATHER TO BREAK THE MONOTONY
OF ALL THE STRONG STORMS THAT HAVE GOTTEN TO BE
A LITTLE BIT OUT OF CONTROL AS THE DAY STARTS OFF COOL
BUT ENDS UP WARM ENOUGH TO GO SWIMMING AT THE POOL
GIVE ME A NICE GENTLE BREEZE
JUST ENOUGH TO RUFFLE THE LEAVES ON THE TREES
AND JUST LIKE THE DAY THAT HAS JUST PAST
IN JOHNSON COUNTY ISOLATED THUNDERSTORMS MAY BLAST
BUT ALL IN ALL AS AFTERNOON TEMPERATURES CLIMB
IT LOOKS NICE FOR THE FIRST DAY OF SUMMERTIME.

IN OTHER WORDS...THE UPPER LEVEL LOW WILL LIFT INTO MONTANA AND LOSE
SOME ITS INFLUENCE OVER THE WEATHER. A BIT MORE MOISTURE MAY HANG
AROUND FAR NORTHERN AND NORTHEASTERN WYOMING BUT ANY CONVECTION
SHOULD BE ISOLATED AT BEST WITH A VAST MAJORITY OF THE AREA RAIN
FREE. SATURDAY LOOKS LIKE A FAIRLY SIMILAR TODAY WITH ISOLATED
CONVECTION ACROSS THE FAR NORTH AND EAST WITH SLIGHTLY DEEPER
MOISTURE BRUSHING BY. TEMPERATURES WILL BE SOMEWHAT ABOVE NORMAL BUT
NOT UNUSUALLY SO. AS FOR SUNDAY AND MONDAY...CONTINUITY INDICATED
MAINLY ISOLATED ACTIVITY ACROSS MORE OF THE AREA WITH SOMEWHAT MORE
MOISTURE SPREADING IN. THE EUROPEAN LOOKS MAINLY DRY WITH THE RIDGE
AXIS OVER THE AREA BUT GIVEN UNCERTAINTY ONLY MINOR CHANGES WERE
MADE.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WILL OCCUR THROUGH 06Z WED. SHOWERS AND THUNDERSTORMS
WILL DEVELOP INITIALLY OVER AND NEAR THE MOUNTAINS AROUND 18Z.
SHOWERS AND STORMS WILL MOVE ACROSS THE LOWER ELEVATIONS DURING THE
AFTERNOON AND EVENING HOURS. THE BEST COVERAGE IS EXPECTED TO BE
OVER THE NORTH OF A LINE FROM KJAC TO KPNA TO KLND TO KCPR. MAINLY
ISOLATED ACTIVITY WILL OCCUR SOUTH OF THIS LINE. WIND GUSTS TO 40
KNOTS ARE LIKELY WITH STORMS. NORTH OF THE LINE MENTIONED ABOVE THE
THREAT FOR BRIEF HEAVY RAIN AND HAIL WILL ALSO OCCUR AND LOCAL MVFR
CONDITIONS IN STORMS. THE STORM ACTIVITY WILL END BY 06Z WED.

&&

.FIRE WEATHER...

SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS PORTIONS OF EASTERN
AND NORTHERN WYOMING THROUGH THE EVENING HOURS TONIGHT. ACTIVITY
WILL WEAKEN WITH LOSS OF DAYLIGHT...THOUGH SOME MAY LINGER OVER THE
CENTRAL MOUNTAINS. ANOTHER WARM AND DRY DAY IS EXPECTED ACROSS
SOUTHERN WYOMING ON TUESDAY...WITH HUMIDITY DECREASING INTO THE
SINGLE DIGITS. A SLIGHT INCREASE IN WIND IS ANTICIPATED DURING THE
AFTERNOON...BUT SHOULD NOT BE SIGNIFICANT. HOWEVER...STRONGER
THUNDERSTORMS MAY RETURN TO NORTHEASTERN WYOMING DURING THE
AFTERNOON. THE STRONGEST STORMS MAY HAVE THE POTENTIAL FOR STRONG
ERRATIC WIND AND LARGER HAIL. THE PROMINENT AREAS FOR THIS
DEVELOPMENT ARE JOHNSON AND NATRONA COUNTIES...WITH SOME POTENTIAL
OVER THE BIGHORN BASIN.

&&

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

&&

$$

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