Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 290541
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1141 PM MDT SUN SEP 28 2014

.SHORT TERM...TONIGHT THROUGH MONDAY

THE UPPER LEVEL CUT OFF LOW OVER NEVADA WILL SPREAD DRYING INTO
THE SOUTH...SHIFTING THE HEAVIER PRECIPITATION GRADUALLY TO THE
NORTH THROUGH THE NIGHT. THE KICKER TROUGH IS CURRENTLY
APPROACHING THE BRITISH COLUMBIA COAST...WHICH WILL GET THE CUT
OFF MOVING NORTHEAST LATER TONIGHT AND CONTINUING THROUGH MONDAY.
THE CUT OFF WILL MOVE INTO NORTHERN UTAH AND SOUTHERN IDAHO
CONTINUING SPREAD A DRY SLOT INTO SOUTHERN AND CENTRAL WYOMING
MONDAY. THE DRY SLOT WILL PARTIALLY FILL IN WITH CONVECTION MONDAY
AFTERNOON BUT THE BEST CHANCES FOR PRECIPITATION WILL BE IN THE
NORTH AND OVER THE WESTERN MOUNTAINS CLOSER TO THE COLD POOL
ALOFT. SOME WARMING IS INDICATED WITH MORE SUNSHINE AS PARTIAL
CLEARING OCCURS.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY

THE BEST LIFT AND DYNAMICS WILL BE SHOULD BE SHIFTING EAST OF THE
COUNTY WARNING AREA BY MONDAY NIGHT. HOWEVER...THERE REMAINS A BIT
OF A FORECAST DILEMMA AS TO HOW MUCH PRECIPITATION MAY WRAP BACK
AROUND INTO EASTERN PORTIONS OF THE COUNTY WARNING AREA. THE NAM HAS
BEEN FAIRLY CONSISTENT IN KEEPING THE BULK OF THE PRECIPITATION EAST
OF THE AREA. THE GFS HAS IT CLOSER BUT HAS ALSO SHIFTED A BIT
FURTHER EAST. EVEN THE LATEST EUROPEAN...WHICH HAS BEEN THE WETTEST
HAS SHIFTED EAST. SO CONFIDENCE IS A BIT HIGHER THAN ONLY LIGHT
PRECIPITATION WOULD FALL. MEANWHILE...OUT WEST SOME LIGHT OROGRAPHIC
SHOWERS MAY CONTINUE BUT AMOUNTS WILL BE LIGHT. SNOW LEVELS MAY FALL
TO AROUND 8000 FEET OUT WEST BUT AGAIN WITH A LACK OF MOISTURE
LITTLE SNOW ACCUMULATION IS EXPECTED.

THE MAIN LOW WILL BE NORTHEAST OF THE AREA IN THE DAKOTAS BY
TUESDAY. HOWEVER...IT STILL LOOKS UNSETTLED AND LINGERING MOISTURE
AND CYCLONIC CURVATURE REMAINS OVER THE REGION. IN
ADDITION...ANOTHER SHORTWAVE WILL MOVE INTO THE WEST AND BRING SOME
ADDITIONAL LIFT AND ANOTHER CHANCE OF SHOWERS. THERE IS NOT A
TREMENDOUS AMOUNT OF MOISTURE WITH IT BUT THERE WILL BE SOME
SHOWERS. IT SHOULD BE A BIT LESS WET EAST OF THE DIVIDE BUT STILL A
COOL AND DAMP DAY.

YET ANOTHER SYSTEM THEN DROPS IN FROM THE NORTHWEST ON WEDNESDAY.
AGAIN...NOT A TON OF MOISTURE TO WORK WITH. HOWEVER...HEIGHTS ARE
FAIRLY LOW SO MOST AREAS SHOULD HAVE A CHANCE OF SHOWERS ONCE AGAIN.
BY THURSDAY WE HAVE A BIT OF A CONUNDRUM. THE LAST OF THE NORTHWEST
FLOW SYSTEMS WILL MOVE THROUGH. HOWEVER...BOTH THE EUROPEAN AND NOW
THE GFS HAVE BACKED OFF A BIT AND KEEPS MOST OF THE PRECIPITATION TO
THE NORTH AND EAST OF THE AREA AS RIDGING BUILDS NORTHWARD ACROSS
THE ROCKIES. FOR NOW...WE KEPT THE CHANCE OF SHOWERS IN FOR NORTHERN
PORTIONS OF THE AREA BUT FUTURE SHIFTS MAY WANT TO THINK ABOUT
REMOVING THEM. TRANQUIL WEATHER IS THEN EXPECTED FRIDAY INTO NEXT
WEEKEND AS RIDGING BUILDS ACROSS THE ROCKIES AND BRINGS SUNSHINE
ALONG WITH WARMING TEMPERATURES.

&&

.AVIATION.../06Z ISSUANCE/

ANOTHER WAVE ROTATING AROUND THE UPPER LOW WILL RESULT IN ANOTHER
LARGE AREA RAIN WITH EMBEDDED THUNDER MOVING FROM SOUTH TO NORTH
ACROSS THE ENTIRE AREA FROM NOW UNTIL 12Z...WITH STRATUS AND FOG
/MVFR AND IFR/ IN MANY PLACES BEFORE AND AFTER THE CONVECTION. THESE
LOW CEILINGS AND FOG SHOULD LIFT BY BETWEEN 16Z AND 18Z IN MOST
AREAS. THEN THE COMBINATION OF DAYTIME HEATING AND AN UPPER LOW
MOVING OVER THE AREA WILL RESULT IN ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS DEVELOPING ACROSS THE ENTIRE AREA...WITH AN
EMPHASIS ACROSS THE WEST. MUCH OF THIS ACTIVITY SHOULD DISSIPATE BY
AROUND 03Z TUESDAY. SOME FOG/STRATUS IS EXPECTED AGAIN TONIGHT...BUT
NOT NEARLY AS WIDESPREAD AS WHAT OCCURS THIS MORNING.

&&

.FIRE WEATHER...

COOL WET WEATHER WILL CONTINUE TONIGHT WITH PARTIAL CLEARING ON
MONDAY BEFORE MORE SHOWERS MOVE INTO THE WESTERN AND NORTHERN
MOUNTAINS CONTINUING THROUGH TUESDAY.  MIXING HEIGHTS WILL REMAIN
LOW WITH GENERALLY POOR SMOKE DISPERSAL.

&&

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

&&

$$

SHORT TERM...C.BAKER
LONG TERM...AR
AVIATION...WM
FIRE WEATHER...C.BAKER









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