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000
FXUS65 KRIW 121725
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1125 AM MDT WED JUN 12 2013

.SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT

SHOWERS AND EMBEDDED THUNDERSTORMS CONTINUE AROUND MIDNIGHT ACROSS
FAR NORTHERN WYOMING AS DISTURBANCE AFTER DISTURBANCE CONTINUES TO
WORK AROUND THE EDGE OF THE PERSISTENT RIDGE OVER THE AREA. THE TERM
FOR THIS...THE SAME TITLE AS A CLASSIC JOHNNY CASH SONG...IS THE
RING OF FIRE. THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH THE DAY ACROSS NORTHERN PORTIONS OF THE AREA ALTHOUGH MOST
WILL BE IN THE AFTERNOON. NOT EVERYONE WILL SEE THUNDERSTORMS.
HOWEVER...ANY THUNDERSTORMS THAT FORM COULD BE COME QUITE STRONG IN
THE AREA GIVEN THE SHEAR PROFILES AND THE NOSE A JET STREAK
INCREASING FORCING IN THE AREA. THE BEST CHANCE LOOKS TO BE ACROSS
NORTHERN PORTIONS OF THE AREA WHERE THE BEST PARAMETERS WILL SET UP.
SPC HAS ISSUED A SLIGHT RISK FOR THIS AREA STRONG WINDS AND LARGE
HAIL ONCE AGAIN THE MAIN THREATS. HOWEVER...MODEL SOUNDINGS ARE
FAIRLY JUICY WITH PRECIPITABLE WATERS APPROACHING ONE INCH EAST OF
THE BIG HORN RANGE SO HEAVY RAINFALL WILL HAVE TO BE FACTORED IN AS
WELL. THE SOUTHERN BOUNDARY FOR THUNDERSTORMS ONCE AGAIN LOOKS
SOMEWHAT SIMILAR TO YESTERDAY WITH A SHARP DEW POINT BOUNDARY ACROSS
THE COUNTY WARNING AREAS WITH 30S OR LOWER FROM THE OWL CREEK AND
BRIDGER RANGES OVER TO CASPER AND SOUTHWARD WHILE DEW POINTS ARE
INTO THE UPPER 40S AND EVEN 50S FROM WORLAND OVER THE NORTHERN
NATRONA AND INTO JOHNSON COUNTIES. WE HAVE CONTINUED THE CHANCE INTO
PLACES LIKE CASPER AND RIVERTON ALTHOUGH THIS LOOKS TO BE THE
EXCEPTION RATHER THAN THE RULE. FURTHER SOUTH...IT LOOKS TO BE
ANOTHER VERY WARM AND DRY DAY WITH A GUSTY WIND AT TIMES. CONVECTION
SHOULD DECREASE IN COVERAGE TONIGHT BUT MAY CONTINUE MUCH OF THE
NIGHT ACROSS THE WEST.

BY THURSDAY THE RIDGE WILL SHIFT FURTHER TO THE EAST AND A COLD
FRONT WILL SLOWLY WORK ACROSS THE AREA. WITH SOMEWHAT DRIER AIR
WORKING IN AND PRECIPITABLE WATERS DROPPING SOMEWHAT THE COVERAGE OF
THUNDERSTORMS SHOULD BE LESS THAN ON WEDNESDAY. THERE IS STILL A
SLIGHT RISK ACROSS FAR NORTHEASTERN PORTIONS OF THE AREA. THERE WILL
BE MORE CAPPING TOMORROW BUT ANY STORMS THAT DO FIRE COULD ONCE
AGAIN BECOME STRONG WITH STILL A DECENT AMOUNT OF SHEAR AND THE COLD
FRONT PROVIDING SOME MORE LIFT. WITH THE TIGHTENING PRESSURE
GRADIENT WINDS COULD BECOME QUITE GUSTY ACROSS PORTIONS OF THE
AREA...ESPECIALLY THE FAVORED SOUTHWESTERN WIND CORRIDOR FROM THE
RED DESERT THROUGH CASPER. THE BEST CHANCE OF THUNDERSTORMS WILL
LIKELY SHIFT TO AREAS EAST OF THE BIG HORN RANGE WHERE THE DEEPEST
MOISTURE WILL BE FOUND. THURSDAY MAY TURN OUT TO BE WARMER THAN
WEDNESDAY WITH DOWNSLOPING FLOW IN MANY AREAS EAST OF THE DIVIDE
NEAR THE MOUNTAIN RANGES.

FRIDAY LOOKS TO BE A COOLER DAY ACROSS MOST OF THE REGION AND
DOWNRIGHT COOL IN THE WEST IF THE NAM IS CORRECT. THE GFS MOS NUMBER
IS ONLY IN THE 50S FOR JACKSON. A WEAK SYSTEM PASSING BY TO THE
NORTH WILL KEEP A SMALL CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS
NORTHERN AREAS. HOWEVER...WITH MOST OF THE ENERGY MOVING INTO
MONTANA COVERAGE IS EXPECTED TO REMAIN FAIRLY SPOTTY WITH MOISTURE
LOOKING FAIRLY LIMITED. HIGH TEMPERATURES SHOULD RUN AROUND 10 TO 15
DEGREES COOLER THAN ON THURSDAY WITH THE COLD ADVECTION BEHIND THE
FRONT.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

RIDGE BUILDS ACROSS THE ROCKIES DURING THE WEEKEND...AND THEN
GRADUALLY SHIFTS EAST INTO THE PLAINS MONDAY AND TUESDAY...AS A
STRONG UPPER LOW PUSHES INTO THE PACIFIC NORTHWEST. GLOBAL MODELS
NOW SHOW A BACKDOOR COLD FRONT PUSHING SOUTHWEST TO THE DIVIDE LATE
SATURDAY/SATURDAY NIGHT...AND REMAINING IN PLACE SUNDAY...BEFORE
WASHING OUT MONDAY. THIS RESULTS IN KEEPING TEMPERATURES MORE
SEASONAL THIS WEEKEND...ESPECIALLY EAST OF THE DIVIDE.
HOWEVER...MOISTURE REMAINS QUITE LIMITED AND LITTLE OR NO
PRECIPITATION IS EXPECTED WITH THIS FRONT. VERY DRY SOUTHWEST FLOW
IS THEN EXPECTED MONDAY AND TUESDAY AHEAD OF THE TROUGH SETTING UP
ACROSS THE WEST COAST. MEDIUM RANGE MODELS THEN SHOW THIS TROUGH
LIFTING NORTHEAST ACROSS INTERMOUNTAIN WEST AND NORTHERN ROCKIES
WEDNESDAY AND THURSDAY OF NEXT WEEK...WITH THE ASSOCIATED COLD FRONT
MOVING ACROSS THE AREA LATE WEDNESDAY/WEDNESDAY NIGHT TIME FRAME.
HOWEVER...MODELS KEEP MUCH OF THE AREA DRY SLOTTED AS THIS SYSTEM
PASSES NORTHWEST/NORTH OF THE AREA. BREEZY TO WINDY CONDITIONS ARE
EXPECTED TUESDAY AND WEDNESDAY. THESE WINDY CONDITIONS...COMBINED
WITH VERY LOW AFTERNOON HUMIDITY WILL ELEVATE FIRE WEATHER BEHAVIOR
AS FUELS CONTINUE TO DRY OUT PRETTY FAST.

&&

.AVIATION.../18Z ISSUANCE/

SOUTHWEST FLOW AT 15 TO 25KT ACROSS THE SOUTH AND SOUTHWESTERN
PORTION OF THE FORECAST AREA TODAY... AS MORE SHOWERS AND
THUNDERSTORMS MOVE INTO THE NORTH AND WEST...THERE WILL BE MORE VCTS
ACROSS THE WEST TODAY THAN THERE WAS ON TUESDAY WITH A BETTER CHANCE
OF -GS AND STRONG WIND GUSTS VCNTY KCOD KWRL AND KBYG...AS WELL AS
MVFR CONDITIONS IN RA. HIGHER BASED THUNDERSTORMS IN CENTRAL
WYOMING  WILL BE ABLE TO PRODUCE VERY STRONG OUTFLOW WINDS...HOWEVER
IT WILL LIKELY BE TOO DRY FOR STORMS AGAIN VCNTY KRKS AND KCPR. VCTS
HAVE BEEN KEPT OUT OF THE KRIW AND KLND TAFS SINCE THE BEST CHANCES
FOR THUNDER WILL OCCUR NORTH AND WEST OF THIS REGION...HOWEVER
EFFECT FROM DISTANCE THUNDERSTORMS TO THE NORTH AND WEST MAY BE FELT
AT TIMES IN THE FORM OF ERRATIC GUSTY WINDS. LATER...SHOWERS AND
STORMS WILL EXIT THE AREA AFTER 06Z EXCEPT FOR PERHAPS THE CODY AND
JACKSON AREAS WHICH COULD HAVE SHOWERS CLOSE BY THROUGH THE EARLY
MORNING HOURS...SO MAY EXTEND VCSH FOR 0Z ISSUANCE.

&&

.FIRE WEATHER...

A SERIES OF SYSTEMS WILL BRING SHOWERS AND THUNDERSTORMS ACROSS
NORTHERN AND WESTERN WYOMING OVER THE NEXT FEW DAYS.  WEDNESDAY MAY
SEE SOME STRONGER STORM DEVELOPMENT ACROSS NORTHERN WYOMING. THESE
STRONGER WIND MAY HAVE SIGNIFICANT AND ERRATIC WIND WITH INCREASED
HAIL...IN ADDITION TO PERIODS OF HEAVY RAINFALL. AREAS OF SOUTHERN
WYOMING WILL AGAIN HAVE A WARM AND GENERALLY DRY DAY WITH GUSTY WEST
TO SOUTHWESTERLY WINDS...WITH HUMIDITY AGAIN DIPPING INTO THE SINGLE
DIGITS THIS AFTERNOON. HOWEVER...TEMPERATURES WILL COOL OVER THE
NEXT COUPLE OF DAYS UNDER THE INFLUENCE OF THESE SYSTEMS.
&&

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

&&

$$

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