Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 150535
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1135 PM MDT MON APR 14 2014

.SHORT TERM...TONIGHT AND TUESDAY

LOW CLOUDS FINALLY ERODED AND DISSIPATED ACROSS THE SOUTHWEST
AROUND NOON. TEMPERATURES ARE STRUGGLING IN THESE AREAS WITH THE
SLOW START. OTHERWISE...WE`RE LOOKING GOOD. COOL AND BREEZY IN
AREAS BUT GOOD. WEAK...BRIEF SHORTWAVE RIDGING TONIGHT AHEAD OF
OUR SYSTEM THAT NOSES IN THE NORTHWEST TUESDAY AFTERNOON. WINDS
WILL BE ON THE INCREASE ACROSS THE WIND CORRIDOR LATER TONIGHT
THROUGH TUESDAY ALONG WITH THE CODY FOOTHILLS. MODERATE GAP FLOW
EVENT IN THE CODY FOOTHILLS WITH SOME WINDS LIKELY APPROACHING 50
MPH IN THE NORMAL AREAS. THE RKS TO CPR CORRIDOR WILL ALSO SEE
INCREASING BEFORE MORNING AND THEN INCREASING DURING THE DAY. NOT
HIGH WIND BUT SUSTAINED WINDS OF 25 TO 30 MPH IN SPOTS WITH GUSTS
OF 40 TO 50 MPH. COULD SEE A FEW GUSTS OVER 50 MPH ALONG OUTER DRIVE
LATER TUESDAY AFTERNOON AND IN THE NORMALLY WINDY SPOTS IN THE
RATTLESNAKE/GREEN MOUNTAINS AREA. THEN THE PATTERN STARTS TO
CHANGE AS THE CURRENT UPPER LOW NEARING THE B.C. COAST PUSHES
INLAND WHILE ANOTHER WAVE QUICKLY COMES IN OFF THE PACIFIC AND THE
RIDGE BUILDS BEHIND IT. THIS PERIOD JUST SEES THE BEGINNING OF
THIS SYSTEM WITH VALLEY RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS
MOVING MAINLY INTO THE FAR NORTHWEST LATER TUESDAY AFTERNOON.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY

LATEST MODEL TRENDS GO BACK TO THE PREVIOUS SOLUTION OF LARGELY
GRAZING THE NORTHERN THIRD OF THE REGION TUESDAY NIGHT AND
WEDNESDAY. YESTERDAY...THE MODELS WERE TRYING TO DIG THE UPPER
LEVEL TROUGH A BIT MORE FOR MORE OF A DIRECT HIT EAST OF THE
DIVIDE WITH A SUSTAINED PERIOD OF UPSLOPE ALONG THE WIND RIVERS
AND CASPER. SO...WHILE IT COULD PRODUCE SOME SIGNIFICANT
PRECIPITATION...WE JUST ARE NOT SURE EXACTLY WHO WILL BE UNDER THE
GUN. THE SYSTEM SHOULD MOVE OUT ON THURSDAY TAKING THE PRECIP WITH
IT FOR THE MOST PART. THE MODELS DIVERGE QUITE A BIT AGAIN AFTER
THURSDAY WITH THE GFS ADVERTISING STRONG COLD CORE CYCLOGENESIS IN
THE PLAINS WITH SOME COOL AIR AND SHOWERS HANGING AROUND WYOMING
WHILE THE EUROPEAN KEEPS THE FLOW ZONAL WITH MILD AIR STARTING TO
BUILD IN FROM THE SOUTH...TRENDING WARMER WHEN COMPARED WITH THE
PREVIOUS SOLUTIONS.

AS FOR NEXT FRIDAY...ALL GLOBAL MODELS WERE BRINGING ANOTHER STORM
SYSTEM INTO THE REGION...NOW IT APPEARS AS THOUGH IT IS WEAKER AND
MAY BE DELAYED UNTIL SATURDAY. GIVEN THE CHAOS IN THE MODELS RUN TO
RUN AND MODEL TO MODEL...CONTINUITY WAS KEPT WITH THE PREVIOUS
FORECAST FOR NOW. LOOKS LIKE A DECENT RIDGE WILL BUILD IN AT THE
END OF THE FORECAST PERIOD BRINGING LIGHTER WIND AND A NICE WARM
UP...AT LEAST FOR A DAY OR TWO.

&&

.AVIATION.../06Z ISSUANCE/

INCREASING HIGH CLOUDINESS FOR THE REMAINDER OF TONIGHT...AHEAD OF
AN APPROACHING DISTURBANCE. THIS WEAK DISTURBANCE IN THE NORTHWEST
FLOW WILL RESULT IN ISOLATED TO LOCALLY SCATTERED CONVECTION OVER
THE AREA TUESDAY AFTERNOON AND EVENING. THE BEST CHANCE WILL BE
ALONG AND NORTH OF A LINE FROM KJAC-KDUB-KCPR...BETWEEN 21Z TUESDAY
AND 06Z WEDNESDAY WITH A LATER START AND END TIME OVER THE EAST.
INSTABILITY IS VERY WEAK...SO NO OR VERY ISOLATED LIGHTNING STRIKES
ARE EXPECTED. BRIEF MVFR/IFR CONDITIONS WILL BE POSSIBLE IN THE
LOWER ELEVATIONS WITH CONVECTION. NORTHWEST AND NORTHERN MOUNTAINS
ARE EXPECTED TO BECOME OBSCURED IN THE AFTERNOON AND REMAIN OBSCURED
MUCH OF THE TIME TUESDAY EVENING.

WINDY WEST/SOUTHWEST WINDS WILL DEVELOP TUESDAY MORNING FROM KRKS TO
KCPR AND LAST THROUGH THE AFTERNOON. A PACIFIC FRONT AND DIURNAL
MIXING WILL RESULT IN BREEZY WEST TO NORTHWEST WINDS DEVELOPING
TUESDAY AFTERNOON ACROSS THE UPPER GREEN AND THE WIND RIVER BASIN.
BREEZY SOUTHERLY WINDS ARE EXPECTED TUESDAY AFTERNOON/EVENING AT
KJAC. A CANADIAN COLD FRONT IS EXPECTED TO PUSH SOUTH...EAST OF THE
DIVIDE TUESDAY EVENING CHANGING WINDS FROM SOUTHWEST OR WEST...TO
THE NORTH. THERE COULD BE A PERIOD OF MVFR CEILINGS NOT ASSOCIATED
WITH CONVECTION FOR A FEW HOURS AFTER FRONTAL PASSAGE...MAINLY OVER
JOHNSON AND NATRONA COUNTIES. HOWEVER CONFIDENCE IS NOT HIGH ENOUGH
TO PREVAIL MVFR CONDITIONS AT THIS TIME. IMPROVING CONDITIONS IN THE
LOWER ELEVATIONS ARE EXPECTED AFTER 06Z WEDNESDAY AS THE DISTURBANCE
PULLS AWAY AND THE BOUNDARY LAYER TRENDS DRIER AS THE FLOW BACKS TO
THE WEST.

&&

.FIRE WEATHER...

IT WILL WARM UP AND DRY OUT ON TUESDAY WITH THE DRIEST AIR BEING
IN THE SOUTHWEST WHERE AFTERNOON RH`S MAY DIP INTO THE TEENS ALONG
WITH STRONG WEST WINDS. WEST TO NORTHWEST WINDS WILL ALSO INCREASE
TONIGHT IN THE MOUNTAINS...CODY FOOTHILLS AND DUBOIS DOWN TO
CROWHEART. AN APPROACHING COLD FRONT WILL MOVE INTO THE NORTHWEST
CORNER LATER TOMORROW AFTERNOON AND ACROSS CENTRAL WYOMING
TOMORROW EVENING. GUSTY TO STRONG WEST TO SOUTHWEST WINDS WILL
OCCUR AHEAD OF THIS SYSTEM SHIFTING TO THE NORTH OR NORTHWEST BEHIND
IT. A PERIOD OF RAIN OR SNOW SHOWERS IS EXPECTED WITH THE FRONT...
ESPECIALLY ACROSS THE WEST AND NORTH HALF.

&&


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

&&

$$

SHORT TERM...SKRBAC
LONG TERM...ALLEN
AVIATION...WM
FIRE WEATHER...SKRBAC











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