302  
FXUS65 KRIW 010508  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
1108 PM MDT MON MAR 31 2025  
   
KEY MESSAGES
 
 
- SNOW OR A RAIN/SNOW MIX REMAIN LIKELY (70-90%) TONIGHT THROUGH  
WEDNESDAY. THE GREATEST SNOW ACCUMULATIONS WILL BE ACROSS THE  
WESTERN MOUNTAINS WHERE A WINTER WEATHER ADVISORY REMAINS IN  
EFFECT. SOME LIGHT ACCUMULATIONS EXPECTED ALONG THE I-80  
CORRIDOR.  
 
- CHANCES FOR SNOW OR A RAIN/SNOW MIX REMAIN POSSIBLE THROUGH  
THE FIRST HALF OF THE WEEKEND.  
 

 
   
UPDATE
 
 
ISSUED AT 843 PM MDT MON MAR 31 2025  
 
SHOWERS CONTINUE TO SPREAD EAST ACROSS SOUTHWEST WYOMING  
TONIGHT, WITH SNOWFALL ACCUMULATION FOCUSED ACROSS SWEETWATER  
COUNTY.SNOW WILL STILL BE PRODUCED IN BANDS OVERNIGHT, SO EXPECT  
VARYING CONDITIONS ALONG I-80 THROUGH THE NIGHT. TOTAL  
ACCUMULATIONS REMAIN WELL BELOW ADVISORY CRITERIA, SO NO  
ADJUSTMENT TO CURRENT HIGHLIGHTS.  
 
LATEST EVENING MODEL RUNS HAVE NOTED AN INCREASE IN NW FLOW  
DURING THE DAY TUESDAY ACROSS CENTRAL WY. THIS INCREASES THE  
CONFIDENCE OF A BAND OF RAINFALL DOWNWIND FROM THE BIGHORN  
MOUNTAINS TUESDAY AFTERNOON. THIS IS EXPECTED TO CONTINUE INTO  
TUESDAY EVENING, WHEN IT WILL CHANGE TO SNOW BEFORE ENDING. HAVE  
UPDATED FORECAST FOR TUESDAY TO ACCOUNT FOR INCREASE PRECIP  
AMOUNTS FOR JOHNSON AND NORTHERN NATRONA COUNTIES. REMAINING  
FORECAST REMAINS INTACT FOR THE EVENING.  
 

 
   
DISCUSSION
 
 
ISSUED AT 105 AM MDT MON MAR 31 2025  
 
BRIEF INDUCED RIDGING INTO EARLY MONDAY MORNING AS ANOTHER  
PACIFIC NORTHWEST TROUGH PUSHES CLOSER. THIS WILL OPEN THE  
PACIFIC MOISTURE ACROSS THE CWA AS SHOWERS WILL PUSH BACK IN  
FROM THE WEST SOON AFTER SUNRISE INTO THE MID MORNING HOURS.  
MOUNTAIN SNOW AND VALLEY RAIN EXPECTED AS THE SNOW LEVEL SHOULD  
REMAIN ABOVE THE 7000 FOOT MARK. SNOW AMOUNTS HAVE INCREASED  
SLIGHTLY BASED ON THE LATEST MODEL RUNS, AND AS SUCH, HAVE  
ISSUED WINTER WEATHER ADVISORIES FOR THE WESTERN MOUNTAINS WITH  
THE MAIN IMPACTS BEING TRAVEL OVER THE PASSES. 4 TO 8 INCHES IS  
THE HIGHEST PROBABILITY OF SNOWFALL (50-70%) FOR THESE AREAS  
WITH THE HIGHER AMOUNTS CONFINED TO THE HIGHEST TERRAIN UP TO A  
FOOT POSSIBLE (40-50%).  
 
HEADING INTO MONDAY AFTERNOON, THESE SHOWERS WILL PUSH EAST OF  
THE DIVIDE WITH MOUNTAIN SNOW ACROSS THE HIGHER TERRAIN AND  
LOWER VALLEY RAIN EXPECTED. LIMITED QPF AMOUNTS EXPECTED,  
THOUGH, WITH ONLY A COUPLE INCHES OF SNOW FOR THE HIGHER TERRAIN  
AND LESS THAN A TENTH OF LIQUID PRECIPITATION FOR LOWER  
VALLEYS. THE MOST INTERESTING PART OF THE MID TO LATE AFTERNOON  
HOURS, WILL BE THE POSSIBILITY OF LOCALIZED STORM ACTIVITY  
ACROSS SOUTHERN PORTIONS OF THE CWA FOR SWEETWATER COUNTY ALONG  
THE I-80 CORRIDOR. SOME CAPE VALUES UP TO 100-200 J/KG,  
INDICATIVE OF THIS OCCURRENCE, ALBEIT LOW. REGARDLESS, IMPACTS  
WILL BE LIMITED OUTSIDE OF A BRIEF DOWNPOUR.  
 
SHOWERS LINGER INTO TUESDAY, BUT OF LESS INTENSITY AS THE TROUGH  
AXIS DIPS SOUTH OF THE CWA WRAPPING IN THE EASTERLY FLOW FOR  
AREAS EAST OF THE DIVIDE LATE IN THE DAY. POSSIBLE VERY LIGHT  
SNOW AT THAT POINT FOR THE LOWER TERRAIN WITH MINIMAL  
ACCUMULATIONS POSSIBLE THROUGH THE OVERNIGHT HOURS. THIS WILL  
KEEP THE COOLER BUT SEASONABLE TEMPERATURES THROUGHOUT THE WEEK  
WITH THE MAIN FINGER OF THE PFJ WELL SOUTHWARD ACROSS THE DESERT  
SOUTHWEST. VERY ISOLATED SHOWERS POSSIBLE LINGER THURSDAY AND  
FRIDAY AS WELL BUT LIMITED IN NATURE AS UPPER LEVEL RIDGING  
STARTS TO BUILD IN FROM THE WEST. SLIGHTLY WARMER SATURDAY WITH  
THE MAIN WARMING TREND SUNDAY AND INTO EARLY NEXT WEEK AS THE  
AFOREMENTIONED RIDGE SETS MORE IN PLACE FOR THE UPPER ROCKIES.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
 
 
ISSUED AT 1107 PM MDT MON MAR 31 2025  
 
ACTIVE WEATHER CONTINUES FOR THE NEXT 24 HOURS AS A WEATHER SYSTEM  
PASSES THROUGH THE AREA. A BAND OF MODERATE TO HEAVY SNOW WILL  
CONTINUE TO STREAM ACROSS SWEETWATER COUNTY FOR THE NEXT FEW HOURS,  
WITH PREVAILING IFR CONDITIONS AT KRKS, BUT BRIEF PERIODS OF LIFR  
REMAIN POSSIBLE UNTIL 09Z. THIS BAND OF SNOW WILL SLIDE NORTHEAST  
IMPACTING KCPR BY 10-12Z, WITH PREVAILING MVFR CONDITIONS THROUGH  
TUESDAY MORNING INTO TUESDAY AFTERNOON. KEPT CONDITIONS MVFR,  
BECAUSE CONFIDENCE REMAINS LOW ON THE EXACT LOCATION OF THE HEAVIEST  
SNOW.  
 
BY LATE TUESDAY MORNING THROUGH TUESDAY AFTERNOON/EVENING CONVECTIVE  
RAIN/SNOW SHOWERS WILL DEVELOP ONCE AGAIN. THESE SHOWERS SHOULD NOT  
BE AS STRONG AS MONDAY AFTERNOON, BUT IFR CONDITIONS WILL OCCUR WHEN  
SHOWERS IMPACT TERMINALS. EVERY TERMINAL HAS A CHANCE (AT LEAST 30%)  
FOR IMPACTS FROM SHOWERS TUESDAY AFTERNOON/EVENING. WIND WILL  
INCREASE FOR MOST TERMINALS TUESDAY MORNING (10-20 KNOTS AND GUSTS  
20-30 KNOTS), WITH WIND MOSTLY SUBSIDING AFTER SUNSET. WIND WILL  
REMAIN ELEVATED AT KRIW/KCOD/KRKS/KWRL THROUGH TUESDAY EVENING.  
OCCASIONAL TO FREQUENT MOUNTAIN OBSCURATION WILL OCCUR THROUGH THE  
TAF PERIOD.  
 
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR  
THE LATEST INFORMATION ON ICING AND TURBULENCE FORECASTS.  
 

 
   
RIW WATCHES/WARNINGS/ADVISORIES
 
 
WINTER WEATHER ADVISORY UNTIL 6 PM MDT TUESDAY FOR WYZ001-012-  
014-024.  
 

 
 

 
 
UPDATE...STRAUB  
DISCUSSION...LOWE  
AVIATION...ROWE  
 
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