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000
FXUS65 KRIW 061733
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1033 AM MST FRI MAR 6 2015

.UPDATE...ADDED 18Z AVIATION DISCUSSION BELOW

SHORT TERM...THURSDAY THROUGH SATURDAY NIGHT

ONCE AGAIN...THE PATTERN IS FAIRLY TRANQUIL IN THE SHORT TERM. ONE
DIFFERENCE TONIGHT IS THAT WITH A WARMER AFTERNOON ON THURSDAY AS
WELL AS SOME MID AND HIGH LEVEL CLOUD COVER MOVING OVER THE AREA HAS
KEPT TEMPERATURES HIGHER TONIGHT...EVEN IN AREAS WITH LITTLE WIND.
WITH HIGH PRESSURE STILL IN CONTROL...IT LOOKS FAIRLY SIMILAR TO
YESTERDAY. LIKE YESTERDAY...THERE WILL ALSO BE A GUST BREEZE IN THE
FAVORED AREAS. HOWEVER...TEMPERATURES WILL BE WARMER...EVEN IN AREAS
WITH SNOW COVER. WITH TEMPERATURES EXPECTED TO RISE ABOVE FREEZING
THERE SHOULD BE MORE MELTING TODAY. THIS LEADS TO FRIDAY NIGHT WHEN
THE MELTING SNOW COULD BRING PATCHY FOG. SOME CLOUD COVER COULD LIMIT
THIS SO WE WILL NOT PUT ANY IN THE GRIDS YET BUT THIS WILL HAVE TO
BE WATCHED.

THE ONLY CHANCE FOR PRECIPITATION...AND IT LOOKS LIKE A SMALL
CHANCE...WILL BE ON SATURDAY NIGHT AS A WEAK ALBERTA CLIPPER MOVES
THROUGH THE AREA. THIS SYSTEM APPEARS MOISTURE STARVED AND MOST OF
THE ENERGY WILL MISS THE AREA TO THE EAST. CONTINUITY HAD SOME
SLIGHT CHANCES IN THE BIG HORN RANGE AND THIS LOOKS REASONABLE.
ELSEWHERE...TEMPERATURES WILL CONTINUE THE SLOW WARMING TREND.
SUNDAY LOOKS DRY AS WELL. HIGH TEMPERATURES IN AREAS THAT HAVE BEEN
KEPT REFRIGERATED SOMEWHAT WILL BE TRICKY SINCE A LOT DEPENDS ON HOW
MUCH OF THE SNOW MELTS. FOR NOW...WE KEPT HIGH TEMPERATURES ON THE
COOL SIDE BUT THESE MAY NEED TO BE RAISED IF THE SNOW MELTS TO A
DECENT EXTENT.

LONG TERM...MONDAY THROUGH FRIDAY

A DRY NORTHWEST FLOW IS EXPECTED MONDAY AND TUESDAY.  THE 00Z GFS
HAS TRENDED TOWARDS THE ECMWF AND GEM...WITH A NORTHERN STREAM
SYSTEM REMAINING WELL NORTH AND EAST OF THE AREA NOW...WITH WEAK
UPPER RIDGING MOVING ACROSS THE REGION TUESDAY NIGHT/WEDNESDAY.
MEDIUM RANGE MODELS THEN SHOW A WEAK PACIFIC SYSTEM MOVING EAST
ACROSS THE AREA IN THE THURSDAY/FRIDAY TIME FRAME. GLOBAL MODELS ARE
MUCH WEAKER WITH THIS SYSTEM THAN THEY WERE 24 HOURS AGO. WILL HAVE
SLIGHT POPS...MAINLY OVER THE MOUNTAINS...WEDNESDAY THROUGH FRIDAY
WITH AN EMPHASIS ON THURSDAY. THE ECMWF AND GFS NOW SHOW WEDNESDAY
TO BE BONE DRY AHEAD OF THIS WEAK PACIFIC SYSTEM...BUT MODELS YESTERDAY
AND THE 00Z GEM TONIGHT SHOWED/STILL SHOW THE POSSIBILITY OF SOME
PACIFIC MOISTURE WORKING INTO THE WEST WEDNESDAY. THUS HAVE
DECIDED TO KEEP SOME SLIGHT MOUNTAIN POPS OVER THE WEST WEDNESDAY.

TEMPERATURES WILL BE ABOVE AVERAGE THROUGH THE EXTENDED.

AVIATION.../18Z ISSUANCE/

VFR CONDITIONS TO PREVAIL THROUGH 18Z SATURDAY. AREAS OF LLWS TO
REMAIN POSSIBLE ALONG THE EAST SLOPES OF THE ABSAROKA AND WIND
RIVER MOUNTAINS...VICINITY KDUB-KCOD...AND KLND-KRIW THROUGH 18Z.
OTHERWISE A GUSTY WIND WILL CONTINUE FROM KBPI/KPNA TO KRKS TO
KCPR THIS AFTERNOON...DECREASING AFTER 01Z THIS EVENING. WINDS ARE
NOT EXPECTED TO BE AS GUSTY SATURDAY...EXCEPT NEAR KCPR.

FIRE WEATHER...

TEMPERATURES WILL CONTINUE TO MODERATE TODAY AS A RIDGE OF HIGH
PRESSURE REMAINS OVER THE AREA. INVERSIONS WILL LIKELY PERSIST TODAY
ACROSS SNOW COVERED BASINS AND DEEPER VALLEYS WITH POOR SMOKE
DISPERSAL AND LOW MIXING HEIGHTS. A GUSTY BREEZE WILL CONTINUE EAST
OF THE ABSAROKAS AND FROM ROCK SPRINGS TO CASPER. SMOKE DISPERSAL
SHOULD IMPROVE THIS WEEKEND AND MIXING HEIGHTS SHOULD BE HIGHER AS
SNOW MELTS THIS WEEKEND AND INVERSIONS ERODE.

&&

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

$$

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