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000
FXUS65 KRIW 081918
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1218 PM MST SAT MAR 8 2014

.UPDATE...ISSUED HIGH WIND WATCH FOR NATRONA COUNTY AND SOUTHERN
FREMONT COUNTY FROM MIDNIGHT THROUGH 10 AM SUNDAY.

ISSUED HIGH WIND WATCH FOR ABSAROKA MOUNTAINS AND CODY
FOOTHILLS FROM 7 PM MST THROUGH 7 AM MDT SUNDAY MORNING.

SHORT TERM...SATURDAY THROUGH MONDAY NIGHT

POST FRONTAL LIGHT CONVECTIVE PRECIP/SNOW CONTINUES TO PUSH S AND
INTO SWEETWATER COUNTY TONIGHT...DIMINISHING AS IT DOES... AS COLD
MID/UPR LVLS KEEP THINGS UNSETTLED. ALTHOUGH FOG HAS ONLY SHOWN
BRIEFLY HERE AND THERE SO FAR...DRYING ALOFT OVR MOIST LLS ALONG
WITH SOME OTHER INDICATORS POINT TO FOG BLOSSOMING IN TWO TO THREE
HRS ACROSS FREMONT AND NATRONA COUNTIES...AT LEAST. HOWEVER...IT
WILL BE SOMEWHAT OF A RACE AS THE NEAR SFC IS ALSO SHOWING SIGNS OF
DRY AIR ADVECTION. WE WILL SEE WHO WINS THE SATURATION/DRYING RACE.

OTHERWISE...TODAY THROUGH SUN...THE ATMOSPHERE DRIES OUT STATE WIDE.
BRIGHT SUNSHINE WILL TAKE OVER THE STATE TODAY WITH HIGH TEMPS
CLIMBING BACK INTO THE UPPER 40S AND 50S E OF THE DIVIDE AND MOSTLY
40S WEST AFTER A COOL FRI. SAT NIGHT...W TO SW WINDS WILL ONCE AGAIN
BEGIN TO INCREASE OVR AND IN THE LEE OF THE ABSAROKA
MOUNTAINS...POSSIBLY GETTING DOWN INTO THE CODY FOOTHILL REGION. IT
IS LOOKING MUCH BETTER FOR HIGH WINDS ACROSS THAT AREA WITH VERY
STRONG T AND P GRADS ALONG WITH FAVORABLE STABILITY ALOFT FOR
MOUNTAIN WAVE FORMATION BY SUN MORNING. WINDS SHOULD ALSO PICK UP
AND BLOW OUT OF THE SW ACROSS THE USUAL SPOTS BETWEEN ERN FREMONT
AND NATRONA COUNTIES...ALTHOUGH THEY LOOK TO REMAIN LARGELY BELOW
WARNING LEVELS. WARMING WILL BE ON THE WAY TODAY AND EVEN BETTER
ON SUN E OF THE DIVIDE WITH NEAR 60 TO MID 60S COMMON AT LOWER
ELEVATIONS UNDER THE INFLUENCE OF MODEST RIDGING. SUNDAY W OF THE
DIVIDE...ALTHOUGH UNDER A MODEST RIDGE...EPAC MOISTURE WILL BEGIN
TO MOVE INTO THE WRN FA WITH FETCH/TRAJECTORY OF LOW/MID LVL FLOW
FAVORING TERRAIN FORCED PRECIP. IT CONTINUES TO LOOK LIKE UPR LVLS
(JET PROXIMITY) WILL BE INCREASINGLY FAVORABLE BY SUN NIGHT TO
START TO AID IN SOME MODEST UPR QG FORCING AHEAD OF THE NEXT LARGE
TROF DUE TO REPLACE THE RIDGE LATER ON MONDAY. MONDAY THEN THE UPR
LVLS BECOME MORE AND MORE DIVERGENT AS A STRONG SW TROF CONTINUES
TI IMPINGE ON THE WRN FA WITH THE MOST ROBUST UPR FORCING ARRIVING
MONDAY NIGHT. SFC FRONT WILL ALSO MOVE THRU THE REGION OVR NIGHT
MON INTO TUE MORNING BRINGING INCREASINGLY GOOD CHCS FOR BASIN
PRECIP E OF THE DIVIDE BY MIDNIGHT. MON W OF THE DIVIDE...SNOW
LVLS WILL START OUT IN THE WRN MOUNTAINS AROUND 7500 FT...DROPPING
THRU THE DAY. FREEZING RAIN IN THE VALLEYS MAY BE A POSSIBILITY
FOR A PERIOD MONDAY NIGHT WITH W TO SW FLOW KEEPING ABOVE SFC
TEMPS JUST WARM ENOUGH. E OF THE DIVIDE...IT MAY TAKE UNTIL TUE
MORNING AND AFTER FRONTAL PASSAGE TO GET PRECIP IN LIQUID QUICKLY
CHANGING OVR TO SNOW. IN THE BIGHORN MOUNTAINS...SNOW LVLS WILL
START AROUND 8000 FT...BUT WILL ALSO QUICKLY FALL TO BELOW 4K FT
POST FRONTAL AND AFTER MID NIGHT IN THE ERN PORTIONS OF JOHNSON
COUNTY. OVERALL...SNOW WILL BE MORE PLENTIFUL IN THE WRN MOUNTAINS
OVR THE 36 HR PERIOD ENDING TUE MORNING...WITH THE BIG HORNS
LOOKING TO GET ABOUT HALF. JOHNSON COUNTY AND THE CODY FOOTHILLS
LOOK TO MAKE OUT BEST AT THE LOWER ELEVATIONS WITH WHAT MAY BE LOW
END ADVISORY AMOUNTS.

LONG TERM...TUESDAY THROUGH SATURDAY

QUICK HITTING SNOWSTORM MOVES INTO CENTRAL AND SWRN WYOMING AT THE
END OF THE SHORT TERM AND THROUGH MUCH OF TUESDAY BEFORE DROPPING
SOUTH. MODELS GENERALLY ALL AGREE THAT SNOW WILL BE FALLING ACROSS
MUCH OF CENTRAL AND SWRN WYOMING AT THE START OF THIS PERIOD WITH
GRADUAL IMPROVEMENT FROM NORTH TO SOUTH AS THE DAY WEARS ON AND
INTO THE EVENING FOR THE SRN THIRD. COULD BE A DECENT EVENT WITH
SOME HIGHLIGHTS QUITE POSSIBLE AS WE GET CLOSER. NOT A LONG
DURATION EVENT BY ANY STRETCH BUT A 6 HOUR WINDOW OF POTENTIALLY
MODERATE TO HEAVY SNOW WITH A FEW HOURS OF LIGHT SNOW AT THE END.
SOME MODERATE TO STRONG N TO NE WINDS ARE ALSO EXPECTED. THE SKY
SHOULD CLEAR TUESDAY NIGHT LEADING TO SOME FOG FORMATION WITH
WARMING ALOFT...MOIST LOW LEVELS AND LIGHT WIND. REST OF THE
MEDIUM RANGE PERIOD LOOKS DRY WITH A ONLY A COUPLE WEAK CLIPPERS
FRIDAY AND SATURDAY THAT WE WILL HAVE TO KEEP AN EYE ON. THE ECMWF
IS STRONGER WITH THESE AND HAVE SOME LIGHT SNOW IN THE NRN
MOUNTAINS FRIDAY INTO SATURDAY FROM EACH ONE WITH A SMALL CHANCE
ACROSS THE LOWER ELEVATIONS OF OUR NERN ZONES.

AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 18Z SUNDAY.
WEST WINDS WILL INCREASE TONIGHT THROUGH SUNDAY MORNING WITH LOW
LEVEL WIND SHEAR ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS.
LOW LEVEL WIND SHEAR IS EXPECT TO OCCUR OVER KLND AND KCOD AIRPORTS.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE FORECAST
PERIOD WITH MAINLY HIGH CLOUDS INCREASING TONIGHT. WESTERLY
SURFACE WIND 12-22KTS AT KRKS THIS AFTERNOON THE ONLY WIND OF
CONCERN AT WESTERN TERMINAL SITES.

FIRE WEATHER...

NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. TODAY WILL BE HIGH AND
DRY ACROSS THE REGION WITH PLENTY OF SUNSHINE AND A WARMING TREND
BEGINNING...WITH TEMPERATURES RISING NEAR OR INTO MIDDLE 50S.
SUN...HIGH TEMPERATURES EAST OF THE DIVIDE WILL APPROACH OR EXCEED
THE 60S ESPECIALLY IN THE LOWER ELEVATIONS OF THE CENTRAL AND
EASTERN DISPATCH ZONES. WINDS WILL BEGIN TO GET GUSTY ONCE AGAIN
ACROSS THE USUAL WIND CORRIDOR OVER THE SOUTH AND SOUTHEAST
ZONES...AS WELL AS IN THE WIND RIVER AND ABSAROKA
MOUNTAINS...INCLUDING THE CODY FOOTHILLS...OVERNIGHT TONIGHT AND
THROUGH SUNDAY MORNING. THE NEXT PRECIPITATION PRODUCING SYSTEM WILL BEGIN
TO ARRIVE SUNDAY NIGHT IN THE WESTERN MOUNTAINS...PROPAGATING SLOWLY
EASTWARD ACROSS THE FORECAST AREA THROUGH THE DAY ON TUESDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM 7 PM MST THIS EVENING THROUGH SUNDAY
MORNING WYZ002-003.

HIGH WIND WATCH FROM MIDNIGHT MST TONIGHT THROUGH SUNDAY MORNING
WYZ019-020.

&&

$$

UPDATE...C.BAKER
SHORT TERM...BRAUN
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...BRAUN