High Wind Watch 9, NWS Riverton, WY

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1125 AM MDT FRI MAR 27 2015

.SHORT TERM...FRIDAY THROUGH SUNDAY NIGHT

A WEAK SHORTWAVE PASSING THROUGH THE AREA LATE THURSDAY NIGHT HAS
BEEN BRINGING SOME GUSTY WINDS TO PORTIONS OF THE AREA. THESE SHOULD
DECREASE THROUGH THE NIGHT AND INTO TOMORROW MORNING AS THE
SHORTWAVE MOVES AWAY AND THE PRESSURE GRADIENT RELAXES AS A RIDGE
BUILDS OVER THE AREA. THE RESULT WILL BE A MAINLY QUIET WEATHER DAY
WITH SOME PASSING MID AND HIGH LEVEL CLOUDS. TEMPERATURES WILL BE
QUITE WARM WITH SOME LOCATIONS RISING INTO THE 70S.

THINGS GET A BIT MORE ACTIVE FOR SATURDAY AS ANOTHER SHORTWAVE AND
ASSOCIATED COLD FRONT MOVES ACROSS THE AREA. HOWEVER...IT WILL NOT
BE IN THE FORM OF MOISTURE. MOST OF THE MOISTURE AND DYNAMICS WILL
MOVE BY TO THE NORTH OVER MONTANA. THERE COULD BE A FEW SHOWERS
ACROSS THE NORTH...BUT THIS WOULD BE THE EXCEPTION RATHER THAN THE
RULE. IT WILL BE IN FORM OF WIND. THE MODELS SHOW A 90 KNOT JET
STREAK APPROACHING THE NORTHWESTERN PORTION OF THE STATE. THIS PUTS
MUCH OF THE STATE IN THE RIGHT FRONT QUAD AND THEREFORE SOME
INCREASE IN UPPER LEVEL DIVERGENCE AND DOWNWARD MOMENTUM.  700
MILLIBAR WINDS INCREASE TO 50 TO 60 KNOTS ACROSS THE FAVORED AREAS
OF THE ABSAROKAS AND CODY FOOTHILLS. IT IS BORDERLINE FOR HIGH WIND
THERE ON SATURDAY SO WE WILL LET THE DAY CREW MAKE THE CALL. ANOTHER
AREA OF CONCERN IS NORTHERN JOHNSON COUNTY WHICH IS FAVORED IN
NORTHWEST FLOW AFTER COLD FRONT PASSAGES. OF MORE CONCERN IN THE
RISK FOR CRITICAL FIRE WEATHER. WITH LOW RELATIVE HUMIDITY EXPECTED
ACROSS MUCH OF THE AREA WITH CRITICAL FUELS...WE WILL HOIST A FIRE
WEATHER WATCH ACROSS THE LOWER ELEVATIONS ZONES WITH CRITICAL FUELS.
IT WILL BE QUITE WARM AS WELL WITH MANY LOWER ELEVATIONS AGAIN
SEEING HIGH TEMPERATURES INTO THE 70S.

CONDITIONS WILL ONCE AGAIN CALM FOR SUNDAY AS THE SYSTEM MOVES AWAY
AND RIDGING MOVES BACK ACROSS THE STATE. TEMPERATURES WILL FALL
SOMEWHAT BEHIND THE FRONT...AROUND 10 DEGREES FOR MANY AREAS BUT
THIS STILL PUTS MOST AREAS ABOVE SEASONAL NORMALS.

.LONG TERM...MONDAY THROUGH FRIDAY

DRY AND WARM CONDITIONS ARE EXPECTED MONDAY UNDER A FLAT UPPER
RIDGE. A COMPACT...BUT STOUT UPPER LOW WILL PUSH EAST ACROSS THE
EXTREME NORTHERN ROCKIES TUESDAY...WITH THE ASSOCIATED PACIFIC COLD
FRONT SWEEPING EAST ACROSS THE FORECAST AREA TUESDAY AFTERNOON AND
EVENING. ALTHOUGH THIS SYSTEM COULD BRING SOME CONVECTION ESPECIALLY
OVER THE NORTHWEST...THE MAIN IMPACT WILL BE EXTREME FIRE WEATHER
CONDITIONS TUESDAY AFTERNOON AND EVENING...WHERE FUELS ARE
CONSIDERED CRITICAL.

A COOLER AND MAINLY DRY DAY IS EXPECTED WEDNESDAY IN WAKE OF THE
PACIFIC COLD FRONT. THERE COULD STILL BE SOME FIRE WEATHER
CONCERNS...AS WINDS WILL REMAIN BREEZY...BUT COOLER CONDITIONS
SHOULD ALLOW FOR SLIGHTLY HIGHER RH.

GLOBAL MODELS SHOW A SHORTWAVE TROUGH DIVING SOUTHEAST INTO THE
INTERMOUNTAIN WEST THURSDAY...THEN INTO THE FOUR CORNERS REGION
THURSDAY NIGHT THEN EAST INTO THE CENTRAL PLAINS FRIDAY. THE CURRENT
PROJECTED TRACK OF THIS SYSTEM WOULD GIVE THE AREA A BETTER CHANCES
OF PRECIPITATION THAN EITHER SYSTEM ON SATURDAY OR TUESDAY. BOTH THE
00Z OPERATIONAL ECMWF AND GFS SOLUTIONS SHOW SOME UPSLOPE FLOW
DEVELOPING THURSDAY INTO THURSDAY NIGHT. WILL BROAD BRUSH SLIGHT
VALLEY/CHANCE MOUNTAIN POPS THURSDAY AND FRIDAY FOR NOW...AS TIMING
AND CONFIDENCE INCREASES.

WELL ABOVE AVERAGE TEMPERATURES ARE EXPECTED MONDAY AND
TUESDAY...WITH SEASONAL TEMPERATURES WEDNESDAY...WITH THE POTENTIAL
OF BELOW AVERAGE ON THURSDAY AND/OR FRIDAY.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH 12Z SATURDAY.
WINDS WILL INCREASE ACROSS THE WIND CORRIDOR...VICINITY 50SM NE
KRKS-KCPR...AND ALONG THE LEE SLOPES OF THE DIVIDE AFTER 06Z
SATURDAY AHEAD OF AN APPROACHING COLD FRONT.  THE COLD FRONT WILL
PUSH EAST ACROSS THE AREA LATE SATURDAY MORNING AND AFTERNOON.
BEHIND THE FRONT...NW WINDS WILL INCREASE WITH STRONG WINDS POSSIBLE
ACROSS JOHNSON CO SATURDAY EVENING INCLUDING KBYG.

&&

.FIRE WEATHER...

EXPECT ANOTHER WARM AND DRY DAY TODAY. HOWEVER...WINDS SHOULD
DECREASE THROUGH THE DAY SO CRITICAL FIRE WEATHER IS NOT EXPECTED.
ON SATURDAY...A COLD FRONT AND UPPER LEVEL DISTURBANCE WILL MOVE
ACROSS THE AREA. THE COMBINATION OF GUSTY WINDS AND LOW RELATIVE
HUMIDITY MAY BRING CRITICAL FIRE WEATHER TO LOWER ELEVATION ZONES
WITH CRITICAL FUELS. CONDITIONS SHOULD IMPROVE FOR SUNDAY WITH
COOLER TEMPERATURES AND LESS WIND.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING WYZ280-281-283.

&&

SHORT TERM...HATTINGS
LONG TERM...WM
AVIATION...AEM/LIPSON
FIRE WEATHER...HATTINGS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
212 PM MDT FRI MAR 27 2015

WYZ001>020-022>030-281100-
ABSAROKA MOUNTAINS-BIGHORN MOUNTAINS SOUTHEAST-
BIGHORN MOUNTAINS WEST-CASPER MOUNTAIN-CODY FOOTHILLS-
EAST SWEETWATER COUNTY-FLAMING GORGE-
GREEN MOUNTAINS AND RATTLESNAKE RANGE-JACKSON HOLE-LANDER FOOTHILLS-
NATRONA COUNTY LOWER ELEVATIONS-NORTH BIG HORN BASIN-
NORTHEAST JOHNSON COUNTY-OWL CREEK AND BRIDGER MOUNTAINS-
ROCK SPRINGS AND GREEN RIVER-SALT RIVER AND WYOMING RANGES-
SOUTH LINCOLN COUNTY-SOUTHEAST BIG HORN BASIN-
SOUTHEAST JOHNSON COUNTY-SOUTHWEST BIG HORN BASIN-STAR VALLEY-
TETON AND GROS VENTRE MOUNTAINS-UPPER GREEN RIVER BASIN-
UPPER GREEN RIVER BASIN FOOTHILLS-UPPER WIND RIVER BASIN-
WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST-
YELLOWSTONE NATIONAL PARK-
212 PM MDT FRI MAR 27 2015

...RED FLAG WARNING FOR PORTIONS OF CENTRAL WYOMING
SATURDAY AFTERNOON AND EVENING...

...HIGH WIND WATCH FOR THE LOWER ELEVATIONS OF JOHNSON COUNTY FOR
LATE SATURDAY AFTERNOON AND EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SATURDAY...ELEVATED TO EXTREME FIRE WEATHER CONDITIONS EXPECTED
WHERE FUELS ARE CRITICAL DUE TO WARM...DRY AND BREEZY CONDITIONS...
ESPECIALLY OVER THE WIND RIVER BASIN...LANDER FOOTHILLS...AND THE
LOWER ELEVATIONS OF JOHNSON AND NATRONA COUNTIES. THERE IS THE
POTENTIAL FOR STRONG WINDS IN THE LOWER ELEVATIONS OF JOHNSON
COUNTY BEHIND A COLD FRONT LATE SATURDAY AFTERNOON THROUGH SATURDAY
EVENING.

TUESDAY...ELEVATED TO EXTREME FIRE WEATHER CONDITIONS LIKELY WHERE
FUELS ARE CRITICAL.

WEDNESDAY...ELEVATED FIRE WEATHER CONDITIONS CONTINUE IN SOME AREAS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

TEAM RIVERTON