Area Forecast Discussion
Issued by NWS Riverton, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KRIW 252128
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
228 PM MST WED FEB 25 2015

.SHORT TERM...TONIGHT THROUGH THURSDAY

AN ACTIVE DAY TODAY AS A COLD FRONT HAS MOVED ACROSS THE STATE AND
SOME SNOW HAS BEEN ONGOING. OF COURSE...ONE OF THOSE ANNOYING...PAIN
IN THE BUTT...IMPOSSIBLE TO PREDICT SNOW BANDS HAS DEVELOPED ACROSS
THE WIND RIVER BASIN. THE NAM IS DOING A REASONABLE JOB WITH THIS
TODAY THROUGH. IT SHOWS A GENERAL SLOW SOUTHWESTWARD DRIFT OF THE
BAND THROUGH THE AFTERNOON AND INTO THE EVENING HOURS.
ELSEWHERE...OTHER THAN BUFFALO AND PORTIONS OF THE BIG HORN RANGE
THE SNOW HAS BEEN FAIRLY SPARSE. SOME PERIODS OF SNOW SHOULD
CONTINUE INTO THE EVENING WITH SOME UPPER LEVEL SUPPORT FROM THE
LEFT FRONT QUADRANT OF A JET STREAK MOVING ACROSS THE AREA. WE
THROUGH ABOUT AN ADVISORY FOR THE LANDER FOOTHILLS BUT THE RADAR
TRENDS HAVE BEEN DECREASING OVER THE PAST 30 MINUTES SO WE WILL
STICK TO AN SPS AT THIS TIME. WITH UNSTABLE NORTHWEST FLOW SOME SNOW
SHOWERS WILL CONTINUE THROUGH THE NIGHT ALTHOUGH THE COVERAGE
SHOULD DECREASE AS WE HEAD INTO THE EVENING. AS FOR THE
ADVISORIES...THERE WAS ACTUALLY A BREAK BUT ANOTHER BATCH IS ON
THE WAY. FOR NOW...WE WILL PROBABLY LET THEM RIDE INTO THE EVENING
UNLESS OUR NEIGHBORS HAVE ANY DISAGREEMENTS. WE STILL FEEL THERE
COULD BE A PROBLEM WITH INTERSTATE 80 AS THE BAND MOVES SOUTHWARD
ACROSS SWEETWATER COUNTY AS WELL.

AS FOR TOMORROW...IT LOOKS TO BE SOMEWHAT LESS ACTIVE ALTHOUGH STILL
COLD AND UNSETTLED. WITH UNSTABLE NORTHWEST FLOW CONTINUING OVER THE
AREA AS WELL AS CYCLONIC CURVATURE REMAINING...WE HAVE CONTINUED THE
CHANCE OF SNOW SHOWERS ACROSS PORTIONS OF THE AREA. ONCE
AGAIN...PINPOINTING THEM AT THIS POINT IS NEARLY IMPOSSIBLE...BUT
MANY AREAS WILL HAVE A CHANCE. WITH FRESH SNOW COVER MANY AREAS WILL
STRUGGLE TO GET ABOVE FREEZING.


.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

SOME SNOW WILL LINGER OVER THE MOUNTAINS AND SOUTH WITH
CLEARING IN THE NORTH SPREADING SOUTH THROUGH THE NIGHT.
TEMPERATURES WILL BECOME QUITE COLD AGAIN AS VERY COLD CANADIAN
AIR MOVES IN AND COMBINES WITH STRONG RADIATIONAL COOLING.
FRIDAY A PACIFIC TROUGH MOVING RAPIDLY INLAND WILL START BRINGING
AREAS OF SNOW TO THE WEST WITH BREEZY TO WINDY AREAS EAST OF THE
CONTINENTAL DIVIDE.  TEMPERATURES WILL BEGIN TO WARM WITH DOWNSLOPE
WINDS OVER AND NEAR THE EAST SLOPES OF THE MOUNTAINS.  A CANADIAN
COLD FRONT WILL MOVE SOUTH BEHIND THE PACIFIC TROUGH FRIDAY NIGHT
AND SATURDAY WITH MORE AREAS OF SNOW DEVELOPING EAST OF THE
CONTINENTAL DIVIDE WHILE REMAINING OVER THE WESTERN MOUNTAINS.
THIS COLD FRONT WILL SWEEP SOUTH SATURDAY NIGHT WITH DRYING MOVING
INTO THE NORTH ON SUNDAY.  AGAIN VERY COLD AIR WILL INTRUDE FROM THE
NORTH.  SUNDAY NIGHT WILL BE COLD WITH CLEARING. THEN YET ANOTHER
PACIFIC TROUGH WILL RACE EAST MONDAY WITH SNOW MOVING BACK INTO THE
WEST AND WINDS INCREASING EAST OF THE CONTINENTAL DIVIDE WITH
DOWNSLOPE WARMING RETURNING...ONLY TO BE FOLLOWED BY ANOTHER CANADIAN
COLD FRONT MONDAY NIGHT AND TUESDAY SPREADING AREAS OF SNOW ACROSS
THE AREA EAST OF THE CONTINENTAL DIVIDE.  SNOW WILL BE RATHER
WIDESPREAD TUESDAY NIGHT WITH CLEARING ON WEDNESDAY WITH MORE COLD
CANADIAN AIR MOVING IN.  A VERY PROGRESSIVE PATTERN IS IN STORE WITH
TIMING ISSUES LIKELY THROUGH THE PERIOD...INCREASING SIGNIFICANTLY
WITH TIME.
&&

.AVIATION.../00Z ISSUANCE/

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

A COLD FRONT CONTINUES TO DROP SOUTHWARD ACROSS THE AREA. AREAS OF LOW
CLOUDS AND BANDS OF SNOW SHOWERS WILL CONTINUE THROUGH THE
EVENING...BECOMING LESS WIDESPREAD AND INTENSE AS THE NIGHT
PROGRESSES. HOWEVER...AREAS OF MVFR CEILINGS AND SOME LIGHT SNOW
IS EXPECTED THROUGHOUT THE TAF PERIOD. BREEZY TO WINDY NORTHERLY
WINDS WILL OCCUR THIS EVENING IN WAKE OF THE COLD FRONT...WITH WINDS
WEAKENING LATER TONIGHT.

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

A DISTURBANCE SLIDING SOUTH ACROSS THE AREA WILL RESULT IN SOME SNOW
SHOWER ACTIVITY...BUT NOT ENOUGH COVERAGE TO PREVAIL ANY LOW CLOUDS
OR VISIBILITIES AT THIS TIME. THE ONLY EXCEPTION WILL BE OVER THE
SOUTH...WHERE A COLD FRONT WILL SLIDE WEST ACROSS SWEETWATER COUNTY
LATE THIS AFTERNOON INTO EARLY EVENING WITH A DECENT CHANCE OF SNOW
ALONG AND BEHIND THE COLD FRONT. MVFR AND IFR CONDITIONS ARE LIKELY
TO DEVELOP AT KRKS STARTING AROUND 23Z AND LASTING A FEW HOURS.
ALSO...VERY WINDY NORTHEAST/EAST WINDS WILL DEVELOP IN THE EVENING
OVER SWEETWATER COUNTY. ISOLATED SHOWERS WILL BE POSSIBLE TOMORROW
AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS THE AREA.

&&

.FIRE WEATHER...

OCCASIONAL SNOW WILL CONTINUE INTO TONIGHT ALTHOUGH COVERAGE WILL
SHRINK INTO THE NIGHT GUSTY NORTH TO NORTHEASTERLY WINDS WILL ALSO
GRADUALLY DECREASE INTO THE NIGHT. A CHANCE OF SNOW SHOWERS WILL
LINGER INTO TOMORROW AS WELL WITH UNSTABLE NORTHWESTERLY FLOW
CONTINUING. HOWEVER...PINPOINTING THEM IS VERY DIFFICULT. WITH FRESH
SNOW COVER IN SOME OF THE BASINS INVERSIONS MAY FORM TONIGHT AND
INTO TOMORROW RESULTING IN LOW MIXING HEIGHTS AND POOR SMOKE
DISPERSAL.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT WYZ008>010.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...C.BAKER
AVIATION...HATTINGS
FIRE WEATHER...HATTINGS





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.