Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 071726
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1126 AM MDT MON JUL 7 2014

.SHORT TERM...MONDAY THROUGH WEDNESDAY NIGHT

LOOKS LIKE SOME FOLKS ALONG THE NORTHERN BORDER OF THE AREA MAY BE
GETTING AN EARLY WAKE UP CALL AS A SHORTWAVE ALONG WITH A BIT OF JET
DYNAMICS HAVE FIRED UP SOME NOCTURNAL THUNDERSTORMS AROUND THE
NORTHERN EDGE OF THE RIDGE. SATELLITE IMAGERY SHOWS A DECENT MASS OF
THUNDERSTORMS DEVELOPING IN NORTHEASTERN WYOMING BUT MOST OF THIS
SHOULD STAY EAST OF THE COUNTY WARNING AREA. A FEW THUNDERSTORMS
WILL CONTINUE THROUGH THE NIGHT BEFORE ENDING BEFORE DAYBREAK. WE
WILL ADD ISOLATED CONVECTION UNTIL AROUND 5 AM OR SO.

WITH A COLD FRONT MOVING THROUGH THE AREA...WE EXPECT A COOLER
DAY TODAY BY AROUND 7 TO 10 DEGREE FOR MOST AREAS EAST OF THE DIVIDE
WITH FLOW BECOME MORE NORTH TO NORTHEASTERLY. AS FOR THE CHANCE OF
CONVECTION...BOTH THE NAM AND GFS HAVE REALLY BACKED OFF ON IT. THIS
DOES MAKE SENSE WITH THE COOLER AIR AS WELL AS THE BEST LIFT MOVING
AWAY AS THE SHORTWAVE MOVES INTO THE DAKOTAS. HOWEVER...THERE WILL BE
DECENT MOISTURE AROUND. AT THIS POINT...WE TRIMMED POPS BUT DID NOT
REMOVE THEM FROM ALL AREAS. THE BEST CHANCE WILL BE IN THE MOUNTAINS
AS WELL AS ACROSS THE EAST WHERE THERE WILL BE SOMEWHAT BETTER
MOISTURE AND A BIT MORE INSTABILITY. ANY CONVECTION SHOULD END THIS
EVENING.

IT LOOKS LIKE MUCH THE SAME SITUATION FOR TUESDAY WITH TEMPERATURES
CLOSE TO TODAY`S LEVEL. AGAIN...THE MODELS HAVE BACKED OFF ON
PRECIPITATION CHANCES WITH THE NAM COMPLETELY DRY WITH ANY MONSOONAL
MOISTURE HOLDING IN COLORADO. THE GFS IS A BIT WETTER BUT ONLY OVER
THE MOUNTAINS THAT WOULD BE FAVORED WITH SURFACE UPSLOPE EASTERLY
FLOW...LIKE THE ABSAROKAS. AT THIS POINT...WE HAVE WENT HALFWAY WITH
TRIMMING POPS FROM SOME AREAS BUT NOT REMOVING THEM COMPLETELY.

THE PATTERN LOOKS TO CHANGE JUST A BIT AS WE HEAD TOWARD WEDNESDAY
AS THE RIDGE THAT RETROGRADED TO THE WEST OF THE AREA BEGINS TO MOVE
BACK EASTWARD. FLOW ALSO LOOKS TO SWITCH FROM EASTERLY TO MORE WEST
TO SOUTHWESTERLY. THIS WILL BRING A RETURN TO WARMER TEMPERATURES
WITH MANY BASIN LOCATIONS AGAIN APPROACHING OR TOPPING THE 90 DEGREE
MARK. AS FOR THE CHANCE OF CONVECTION...THE NAM IS INTRODUCING SOME
MONSOONAL MOISTURE TO THE EQUATION ACROSS MUCH OF THE COUNTY WARNING
AREA. THE GFS ALSO HAS IT BUT TO A LESSER DEGREE. AT THIS
POINT...CONTINUITY LOOKED TO BE HANDLING IT PRETTY DARN WELL SO WE
MADE FEW IF ANY CHANGES FOR WEDNESDAY OR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

MODELS IN GOOD AGREEMENT WITH THE BIG PICTURE TONIGHT. UPPER HIGH
WHICH IS FORECAST TO BE OVER THE SRN ROCKIES ON THURSDAY STRENGTHENS
AND REDEVELOPS OVER NV OVER THE WEEKEND INTO EARLY NEXT WEEK.
MONSOONAL MOISTURE IS STILL EXPECTED TO ROTATE AROUND THE RIDGE AXIS
AND INTO OUR AREA FOR SEVERAL DAYS. WHAT`S MORE INTERESTING THOUGH
IS THE DEVELOPMENT OF A NW FLOW ALOFT EARLY NEXT WEEK COMBINED WITH
SEVERAL DISTURBANCES WHICH DROP SE INTO THE NRN HIGH PLAINS...WITH
A FEW RIPPLES POTENTIALLY DROPPING SE ACROSS WYO COUNTRY. POTENTIAL
FOR SEVERAL WEAK COLD FRONTS TO DROP SOUTH AND BRING IN A MOIST
ELY FLOW EAST OF THE DIVIDE IS CERTAINLY POSSIBLE IN THIS PATTERN.
COMBINATION OF HIGHER LOW LEVEL MOISTURE LEVELS COMBINED WITH
FAVORABLE SHEAR PROFILE...NW ALOFT AND E-SE LOW LEVELS COULD MAKE
FOR A COUPLE ACTIVE THUNDERSTORM DAYS IN THE FAVORED NW FLOW AREAS
OF CENTRAL WYO. ADDED IN SOME CHANCE POPS FROM THE SRN ABSAROKAS
SEWD THROUGH FREMONT COUNTY IN THIS FAVORED PATTERN. WILL EXPAND
THIS WITH TIME IF PATTERN BECOMES MORE DEFINITE. STILL A LONG WAY OFF
BUT POTENTIAL IS THERE AND SINCE THE ECMWF IS SHOWING THE DETAILS
ALREADY DECIDED IT WAS WORTH MORE THAN THE GENERIC ISOLD.
OTHERWISE...WARM TO VERY WARM TO START THE PERIOD BUT LIKELY
COOLER IN THE DEVELOPING NW FLOW WITH COOLER MID LEVELS AND
INCREASED LL MOISTURE...ESPECIALLY EAST OF THE DIVIDE.

.AVIATION.../18Z ISSUANCE/

A COLD FRONT ALONG THE CONTINENTAL DIVIDE WILL PUSH SOUTH THROUGH THE
WEST OF SOUTHERN WYOMING THIS AFTERNOON AND EVENING.  VFR CONDITIONS
ARE EXPECTED TO PREVAIL AT THE AIRPORTS THROUGH 18Z TUESDAY. ALONG
AND NEAR THE CONTINENTAL DIVIDE AND OVER AND NEAR THE NORTHERN MOUNTAINS
ISOLATED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO DEVELOP. AREAS OF NORTHEAST WINDS OF 15 TO 20 KTS WITH GUSTS
AROUND 25 KTS WILL BE ENCOUNTERED NORTH OF THE COLD FRONT.
THROUGH THE EVENING LOCAL MVFR CEILINGS MAY FORM ALONG AND NEAR
THE NORTHERN AND EAST FACING SLOPES AS A LAYER OF STRATOCUMULUS DEVELOPS
ALONG THE FRONTAL BOUNDARY ALOFT ENHANCED BY UPSLOPE LIFT. AT THIS TIME
IT IS UNCERTAIN THAT THE MVFR CEILINGS WILL IMPACT ANY AIRPORTS DIRECTLY
BUT THE BEST CANDIDATES FOR THIS WILL BE KCOD...KBYG...KCPR...KTHP
AND KLND. FEW CLOUDS ARE EXPECTED TO MAKE IT OVER THE CONTINENTAL
DIVIDE WITH MOSTLY CLEAR CONDITIONS ANTICIPATED IN THE WEST AND
SOUTHWEST.

.FIRE WEATHER...

FIRE CONDITIONS SHOULD IMPROVE ACROSS MOST AREAS EAST OF THEN DIVIDE
AFTER THE PASSAGE OF A COLD FRONT WITH COOLER TEMPERATURES AND
HIGHER RELATIVE HUMIDITY. GUSTY WINDS MAY BELOW AT
TIMES...ESPECIALLY IN THE AFTERNOON AND ACROSS PORTIONS OF JOHNSON
COUNTY AS WELL AS THE WIND RIVER AND BIG HORN BASINS. ISOLATED
THUNDERSTORMS MAY OCCUR IN EASTERN AREAS AND THE MOUNTAINS.
TEMPERATURES AND HUMIDITY SHOULD BE FAIRLY SIMILAR ON TUESDAY. FLOW
WILL TURN WEST TO SOUTHWEST FOR WEDNESDAY AND BRING A RETURN OF
WARMER TEMPERATURES AND LOWER HUMIDITY AS WELL AS THE CHANCE FOR
AFTERNOON THUNDERSTORMS.

&&

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

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...HATTINGS






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