585
FXUS65 KRIW 291118
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
518 AM MDT SAT MAR 29 2025
KEY MESSAGES
- RAIN SHOWERS WILL CONTINUE OVER JOHNSON AND NATRONA COUNTIES
THIS MORNING WITH A CHANCE (30%) CONTINUING THROUGH THE
AFTERNOON. RAIN SHOWERS WILL THEN DEVELOP OVER THE WESTERN
MOUNTAINS AND FAR SOUTHERN PORTIONS LATE THIS AFTERNOON. A
LIGHTNING STRIKE OR TWO COULD OCCUR IN THESE LATTER AREAS.
- WIDESPREAD PRECIPITATION IS FORECAST ACROSS THE AREA THIS
EVENING WITH RAIN TRANSITIONING TO A RAIN/SNOW MIX AND THEN
SNOW OVERNIGHT SATURDAY INTO SUNDAY. ALL SNOW IS EXPECTED IN
THE MOUNTAINS.
- A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THE EASTERN
SLOPES OF THE WIND RIVER AND BIGHORN MOUNTAINS AND THE
ABSAROKAS, STARTING 4PM SATURDAY FOR SNOW AMOUNTS BETWEEN
6-12 INCHES.
- A WETTER AND COOLER WEATHER PATTERN REMAINS IN PLACE THROUGH
THE FIRST HALF OF NEXT WEEK.
DISCUSSION
ISSUED AT 126 AM MDT SAT MAR 29 2025
SHOWERS HAVE PUSHED INTO NATRONA COUNTY EARLY THIS MORNING AS
EXPECTED, WITH A SFC REFLECTION OF THE MID LEVEL LOW EVIDENT ON
RADAR OVER WESTERN PORTIONS OF THE COUNTY. ADDITIONAL SHOWERS
OVER THE BIGHORN BASIN WILL ALSO CONTINUE THROUGH THE REST OF
THE MORNING. PRECIPITATION AMOUNTS OF 0.3" TO 0.5" OVER
JOHNSON/NATRONA COUNTIES THROUGH 18Z ARE STILL EXPECTED. SNOW
LEVELS LOOK TO DROP AS LOW AS 6500FT THIS MORNING, WHICH WILL
LEAD TO A FEW INCHES OF SNOW OVER THE BIGHORNS FROM THIS EVENT.
RAIN SHOWERS/MOUNTAIN SNOW WILL CONTINUE OVER JOHNSON COUNTY/THE
BIGHORNS THROUGH THE REST OF THE MORNING AND GRADUALLY END THIS
AFTERNOON. AT THE SAME TIME, ISOLATED SHOWERS WILL BECOME POSSIBLE
OVER THE WESTERN MOUNTAINS, WITH INCREASING CHANCES (20-40%) OVER
THE I-80 CORRIDOR LATE IN THE AFTERNOON. SHOWERS OF THE WIND RIVER
AND ABSAROKA MOUNTAINS WILL BEGIN TO SPREAD INTO THE WIND RIVER
BASIN THIS EVENING AFTER 00Z. RAIN SHOWERS/MOUNTAIN SNOW WILL BECOME
MORE WIDESPREAD OVER CENTRAL AND WESTERN PORTIONS THROUGH 06Z AS THE
REMNANTS OF AN UPPER LOW MOVE OVER THE CWA. PRECIPITATION WILL
CONTINUE THROUGH TONIGHT WITH RAIN CHANGING OVER TO SNOW FOR MOST
AREAS BETWEEN 06Z AND 09Z SUNDAY. THE MAIN LOW WILL TAKE A SIMILAR
TRACK AS THE MIDLEVEL CURRENTLY, MOVING ACROSS SWEETWATER COUNTY
TOWARD SOUTHERN NATRONA COUNTY BETWEEN 00Z AND 06Z SUNDAY. ANY SNOW
ACCUMULATION IN THE LOWER ELEVATIONS WILL OCCUR OVERNIGHT, WITH THE
BETTER ACCUMULATIONS STAYING IN GRASSY AREAS. CONFIDENCE FOR HIGHER
SNOWFALL TOTALS (6 TO 12 INCHES) ARE ALONG THE EAST SLOPES OF THE
BIGHORN AND WIND RIVER MOUNTAINS AND THE SOUTHERN END OF THE
ABSAROKAS. OTHERWISE, SNOWFALL AMOUNTS IN THE MOUNTAINS WILL RANGE
BETWEEN 3 TO 6 INCHES.
PRECIPITATION WILL END ACROSS MOST AREAS WEST OF THE DIVIDE, FROM
JACKSON TO WAMSUTTER, BETWEEN 12Z AND 15Z, AS THE MAIN TROUGH AXIS
EXITS EASTWARD OVER THE PLAINS. SNOW WILL CONTINUE ACROSS AREAS EAST
OF THE DIVIDE SUNDAY MORNING, ESPECIALLY ALONG AND EAST OF A LOVELL-
TO-CASPER LINE, WITH ANY SNOW REMAINING CONFINED TO GRASSY AREAS. AS
THIS MAIN AREA OF PRECIPITATION EXITS TO THE EAST, ADDITIONAL
ISOLATED SHOWERS WILL REDEVELOP ACROSS THE FORECAST AREA THROUGH THE
AFTERNOON.
A RIDGE WILL BUILD OVER THE REGION IRT ANOTHER STRONG UPPER LOW
MAKES ITS WAY TO THE PACNW. THIS WILL KEEP PACIFIC MOISTURE
STREAMING OVER THE REGION AND COULD RESULT IN RAIN SHOWERS AND
ISOLATED THUNDERSTORMS OVER WESTERN AND SOUTHERN PORTIONS AND SNOW
IN THE WESTERN MOUNTAINS. SOME OF THIS ACTIVITY COULD SPREAD EAST OF
THE DIVIDE MONDAY EVENING. TEMPERATURES WILL ALSO REMAIN NEAR
NORMAL. SIMILAR ACTIVITY WILL RETURN TUESDAY AND INCLUDE NORTHERN
PORTIONS OF THE FORECAST AREA, AS A TROUGH FROM THE UPPER LOW MOVES
OVER THE COWBOY STATE. THE REMNANTS OF THE MAIN UPPER LOW COULD
REACH THE AREA BY LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT,
KEEPING CHANCES FOR PRECIPITATION CONTINUING.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 517 AM MDT SAT MAR 29 2025
VFR CONDITIONS ARE EXPECTED ACROSS MOST TERMINALS TO START THE
PERIOD. THE ONLY EXCEPTION CURRENTLY IS KCPR WHERE A LOW CEILING
WILL LINGER THROUGH THE MORNING. A WEATHER SYSTEM MOVES INTO THE
REGION TODAY BRINGING ROUNDS OF PRECIPITATION AND MVFR TO IFR
CONDITIONS TO ALL TERMINALS AT TIMES. THIS MORNING LIGHT SHOWERS ARE
MOVING ACROSS CENTRAL WY WHICH MAY BRING BRIEF IMPACTS SHORTLY AFTER
THE START OF THE PERIOD TO TERMINALS SUCH AS KCPR, KLND, AND KRIW.
THESE SHOWERS MOVE OUT OF THE AREA BY THE LATE MORNING WITH ANOTHER
ROUND OF PRECIPITATION MOVING IN BY THE MID TO LATE AFTERNOON.
TERMINALS WEST OF THE DIVIDE WILL SEE SHOWERS BEGIN TO DEVELOP
AROUND 22Z SATURDAY WITH KJAC, KBPI, AND KPNA SEEING PROB30 GROUPS
SHORTLY AFTER 00Z SUNDAY. KRKS WILL SEE SHOWERS DEVELOP AROUND THIS
TIME AS WELL PREVAILING ACROSS THE AREA THROUGH THE REMAINDER OF THE
TAF PERIOD. TEMPERATURES AT KRKS ARE EXPECTED TO DROP NEAR OR BELOW
FREEZING BY AROUND 02Z SUNDAY CAUSING PRECIPITATION TO TRANSITION
OVER TO WET SNOW. EAST OF THE DIVIDE WILL SEE PRECIPITATION MOVE IN
AROUND 00Z SUNDAY WITH KLND AND KRIW SEEING SHOWERS DEVELOP FIRST.
PRECIPITATION GRADUALLY SPREADS EAST TO KCOD, KCPR, AND KWRL AFTER
03Z. TEMPERATURES WILL INITIALLY BE TO WARM FOR SNOW BUT ALL
TERMINALS ARE EXPECTED TO SEE A TRANSITION OVER TO SNOW SOMETIME
AFTER 06Z SUNDAY. MVFR TO IFR CONDITIONS WILL BE LIKELY
ESPECIALLY AFTER 06Z SUNDAY WITH NEAR AIRFIELD MINIMUMS POSSIBLE
AT KLND AND KCPR DUE TO MODERATE PERIODS OF SNOWFALL LOWERING
CEILINGS AND VISIBILITIES. SNOWFALL CONTINUES ACROSS ALL
TERMINALS EAST OF THE DIVIDE THROUGH THE END OF THE TAF PERIOD.
WINDS ARE EXPECTED TO REMAIN LIGHT BUT MAY BECOME BREEZY AT
TIMES ESPECIALLY AT KLND, KCPR, KRIW, AND KWRL POST FRONTAL
PASSAGE. MOUNTAIN OBSCURATION WILL BE PREVALENT THROUGH MUCH OF
THE TAF PERIOD.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON SMOKE, ICING, AND TURBULENCE FORECASTS.
RIW WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO NOON MDT
SUNDAY FOR WYZ002-015.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 PM MDT
SUNDAY FOR WYZ009.
DISCUSSION...LAVOIE
AVIATION...DZIEWALTOWSKI
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