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000
FXUS65 KRIW 020350
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
850 PM MST SAT MAR 1 2014

.UPDATE...

CANCELLED WSW FOR ZONE 19 AND NATRONA COUNTY...AS WELL AS YELLOWSTONE
AND ABSAROKA MTS ZONES. THE WEST CONTINUES TO GET SLAMMED
ESPECIALLY THE TETONS AND JACKSON HOLE. JACKSON AIRPORT VSBY AT 8
PM BACK DOWN TO A HALF OF A MILE. NO OTHER CHANGES...UPDATED WSW
AND GRIDS HAVE BEEN SENT.

A PNS WITH UPDATED SNOWFALL TOTALS HAS ALSO BEEN SENT.

&&

.PREV DISCUSSION... /ISSUED 557 PM MST SAT MAR 1 2014/

UPDATE...

CANCELLED MUCH OF THE WINTER STORM WARNING EAST OF THE DIVIDE...AND
REPLACED IT WITH A WIND CHILL WARNING THROUGH MIDNIGHT OVER THE
NORTHERN BIG HORN BASIN AND JOHNSON COUNTY. WINDS ARE EXPECTED TO
DECREASE TO LESS THAN 5 MPH BY MIDNIGHT...THUS DECIDED TO END THE
WIND CHILL WARNING AT THIS TIME. KEPT WARNING ONGOING FOR ZONE 19
AND NATRONA THROUGH MIDNIGHT...AS SATELLITE/RADAR SHOWS SOME ENHANCEMENT
CURRENTLY OVER THAT AREA...AS WELL AS WIND CHILLS IN THE 20 BELOW
TO 30 BELOW RANGE. THE WEST IS STILL GETTING PUMMELED WITH SNOW
WITH A REPORT AT WILSON OF ABOUT 10 INCHES OF NEW SNOW SINCE 7 AM.

UPDATED WSW AND GRIDS HAVE BEEN SENT.

PREV DISCUSSION... /ISSUED 151 PM MST SAT MAR 1 2014/

SHORT TERM...TONIGHT THROUGH SUNDAY

SNOWFALL HAS CONTINUED TO BE MOST IMPRESSIVE OVER THE WEST AND
SPOTTY IN THE EAST IN THE VERY COLD AIR.  PORTIONS OF THE TETONS
HAVE RECEIVED 30 TO 35 INCHES OF SNOW.  TEMPERATURES EAST OF THE
CONTINENTAL DIVIDE HAVE HOVERED IN THE SINGLE DIGITS ABOVE ZERO
TO THE SINGLE DIGITS BELOW ZERO TODAY AND WILL DROP TO 10 BELOW
TO LOCALLY 20 BELOW ZERO IN THE NORTH TONIGHT.  CLOUD COVER...FLURRIES
TO LIGHT SNOW AND FOG WILL KEEP TEMPERATURES FROM FALLING BELOW
20 BELOW ZERO. HOWEVER BRISK NORTHEAST WINDS WILL PRODUCE WIND
CHILLS OF 25 BELOW TO 35 BELOW ZERO. WILL LET WINTER WEATHER HIGHLIGHTS
GO THROUGH 5 AM. SNOWFALL WILL CONTINUE TO BE MORE LOCALIZED IN
THE EAST AND MORE CONSISTENT IN THE WESTERN MOUNTAINS. THE WEST
WILL CONTINUE TO SEE SOME LIGHT SNOW THROUGH SUNDAY WHILE THE EAST
SHOULD SEE AN END TO THE SNOW OUTSIDE OF THE MOUNTAINS...BUT
TEMPERATURES  WILL CONTINUE TO BE VERY COLD WITH THE ARCTIC AIR
REMAINING,

LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

MOST OF THE SNOW BONANZA SHOULD BE OVER WITH BY SUNDAY NIGHT BUT THE
LIKELIHOOD OF SNOWFALL WILL CONTINUE AT LESSER INTENSITY OVER
WESTERN WYOMING AS A FLAT RIDGE BUILDS INTO THE AREA BUT WITH THE
STRONG MOIST FLOW CONTINUING TO FEED IN OFF THE PACIFIC. THIS LIGHTER
SNOWFALL WILL CONTINUE THROUGH MONDAY AND MONDAY NIGHT. THEN ON
TUESDAY...THE NEXT SHORTWAVE TROUGH WILL STREAM THROUGH WITHIN THE
FAST WEST NORTHWEST FLOW PROVIDING AN INCREASE IN SNOWFALL COVERAGE
AND INTENSITY BY TUESDAY AND TUESDAY NIGHT IN THE WEST WITH AN
ASSOCIATED SURFACE LOW TRACKING SOUTHEAST ACROSS NE WY PUSHING SOME
OF THE PRECIP TO THE EAST OF THE DIVIDE. THIS FRONT COULD RESULT IN
SOME QUICK MODERATE TO HEAVY SNOW BURSTS OUT WEST WITH NEGATIVE
LIFTED INDICES PROGGED FOR AREAS WEST OF THE DIVIDE. THEN A RESPITE
FROM THE SIGNIFICANT SNOWFALL WEDNESDAY IN THE WEST AS ANOTHER FLAT
RIDGE BUILDS INTO THE AREA. THEN A MORE ROBUST SHORTWAVE TROUGH IS
SLATED TO PARADE ACROSS THE AREA THURSDAY FOR MORE PRECIP WEST OF
THE DIVIDE. NEGATIVE LIFTED INDICES ARE AGAIN EXPECTED IN NW WY WITH
THIS FEATURE. THIS WEATHER SYSTEM WILL BE WARMER THAN THE ONE ON
TUESDAY WITH MIXED PRECIP EXPECTED OUT WEST AS H7 TEMPS WARM TO -3C.
THIS WEATHER SYSTEM IS EXPECTED TO DELIVER A BETTER SHOT OP PRECIP
TO AREAS EAST OF THE DIVIDE WITH MOST OF THE PRECIP OCCURRING OVER
CENTRAL AND SOUTHERN WY. ANOTHER FLAT RIDGE FOR FRIDAY NIGHT BEFORE
ANOTHER VIGOROUS SHORTWAVE TROUGH DELVERS YET ANOTHER SHOT OF PRECIP
TO THE WEST SATURDAY AND SATURDAY NIGHT. A DRAMATIC WARM UP IS
EXPECTED MONDAY...ESPECIALLY ACROSS THE NORTHERN AND EASTERN ZONES
EAST OF THE DIVIDE WHERE THE ARCTIC AIR IS PRESENTLY MOST
ENTRENCHED. WE ARE GETTING INTO THE TIME OF THE YEAR WHEN BASIN
INVERSIONS ARE NOT AS STAGNANT WITH THE ELEVATING SUN ANGLE.
OTHERWISE EXPECT A GENERAL GRADUAL WARMING TREND THROUGHOUT THE REST
OF THE WEEK IN MOST AREAS.

AVIATION.../00Z ISSUANCE/

WIDESPREAD MVFR/LOW VFR CEILINGS...WITH PERIODS OF MVFR/IFR VSBY IN
SNOW ACROSS THE ENTIRE LOWER ELEVATIONS THROUGH 18Z. THE HEAVIEST
AND MOST WIDESPREAD SNOWFALL IS EXPECTED THROUGH 12Z. MOUNTAINS
WILL REMAIN OBSCURED...WITH LIFR CONDITIONS IN SNOW AND LOW CLOUDS
OVER MOUNTAIN PASSES. PARTIAL CLEARING WILL OCCUR AFTER 18Z...
ESPECIALLY EAST OF THE CONTINENTAL DIVIDE.

FIRE WEATHER...

NO FIRE WEATHER CONCERNS EXPECTED WITH WIDESPREAD SNOWFALL AND
COLD AIR THROUGH TONIGHT. WINTER STORM WARNINGS ACROSS THE AREA EXCEPT
FOR SWEETWATER AND LOWER ELEVATIONS OF SUBLETTE COUNTIES. LOW
MIXING HEIGHTS WITH POOR SMOKE DISPERSAL EXPECTED. SIGNIFICANT
SNOWFALL EXPECTED MOST AREAS. DRIER WEATHER WILL RETURN EAST OF
THE DIVIDE ON SUNDAY BUT TEMPERATURES WILL REMAIN VERY COLD.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 AM MST SUNDAY
WYZ012>016-023>025-027.

WIND CHILL WARNING UNTIL MIDNIGHT MST TONIGHT WYZ003-004-010-011.

&&

$$

UPDATE...WM
SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER