136  
FXUS65 KRIW 210534  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
1034 PM MST THU FEB 20 2025  
   
KEY MESSAGES  
 
- MINOR TRAVEL IMPACTS TO I-80 WITH LIGHT SNOW SHOWERS LINGERING  
ACROSS SOUTHERN WY LATE THIS EVENING.  
 
- WARMING AND DRY TREND THROUGH THE WEEKEND AND INTO EARLY NEXT  
WEEK AHEAD OF THE NEXT UPPER LEVEL DISTURBANCE. TEMPERATURES  
EXPECTED TO SOAR WELL INTO THE 40S AND 50S LATE WEEKEND INTO  
EARLY NEXT WEEK.  
 
 
   
DISCUSSION  
 
ISSUED AT 1245 AM MST THU FEB 20 2025  
 
CURRENT IR DEPICTS THE NEXT QUICK MOVING SHORTWAVE ACROSS THE  
NV/ID/UT TRIPOINT AS IT PUSHES EAST. WV SHOWS A WEAK FINGER OF  
THE PFJ SUPPORTING IT OFF THE PACIFIC NORTHWEST COAST AS THE  
MAIN PFJ EXTENDS OUT OF CANADA INTO THE GREAT PLAINS, WHERE THE  
COLDEST OF THE AIR IS LOCATED. A LEESIDE LOW OUT OF IDAHO WILL  
SLOWLY PUSH INTO FAR SOUTHWESTERN REACHES OF THE STATE THROUGH  
THE EARLY THURSDAY MORNING HOURS WITH A WEAK SURFACE BOUNDARY  
EXTENDING TO THE SOUTH OVER NORTHEASTERN UT INTO NORTHWESTERN  
CO. THIS WILL KEEP MUCH OF THE MOISTURE MAINLY ALONG AND SOUTH  
OF THE I-80 CORRIDOR THROUGH MUCH OF THURSDAY. HIGHEST SNOW  
RATES WILL BE ACROSS THE HIGHER TERRAIN OF SOUTHERN LINCOLN  
COUNTY BEFORE SUNRISE THROUGH MOST OF THE MORNING BUT MORE  
LIMITED IN MINOR ACCUMULATIONS FURTHER EAST ALONG THE I-80  
CORRIDOR. 60-70 PERCENT PROBABILITIES OF 2 INCHES OR MORE IN THE  
LOWER ELEVATIONS FROM KEMMERER TO RKS WITH A FEW POCKETS OF  
BETTER 4 INCH ACCUMULATIONS SOUTH OF RKS IN SOUTHWESTERN PARTS  
OF SWEETWATER COUNTY. THIS IS WHERE THERE WILL BE THE VERY LOW  
CHANCE (<10%) FOR ANY 6 INCHES OR MORE TO WARRANT THE ONGOING  
ADVISORIES TO BE UPGRADED TO A WARNING. REGARDLESS, MINOR TRAVEL  
IMPACTS ALONG I-80 FROM ALMOST TO WAMSUTTER AND INTO UINTA  
COUNTY CAN BE EXPECTED. NORTH OF WEST WIND GUSTS UP TO 20 TO 30  
MPH AFTER NOON IN THIS AREA WILL CREATE A BIT OF A CROSSWIND  
THAT COULD LIMITED VISIBILITY WITH THE LINGERING SNOW IN THE  
AFTERNOON. OTHERWISE, SNOW WILL TAPER OFF TOWARDS SUNSET AND  
PUSH EAST AND SOUTHEAST BY MIDNIGHT.  
 
FOR OTHER AREAS OF THE CWA, SOME PATCHY FOG ACROSS THE WIND  
RIVER BASIN IS POSSIBLE (30-40%) AFTER THIS RECENT SNOW BUT WILL  
ALL BE DEPENDENT ON CLOUD COVER AND IF IT CLEARS ENOUGH BY  
DAYBREAK THURSDAY MORNING. THIS WILL BE MORE PREVALENT COME  
FRIDAY MORNING WITH MORE CLEARING AS RIDGING BUILDS IN LATER  
THURSDAY AND THROUGH THE WEEKEND AS WELL. THE MAIN TAKEAWAY FOR  
WEEK'S END AND THE WEEKEND WILL BE WARMING AND DRY CONDITIONS  
EXPECTED. A WIDER SPREAD OF 40S EAST OF THE DIVIDE SATURDAY WITH  
30S WEST TO EVEN SOME 50S TO THE EAST SUNDAY. NBM INPUT SEEMS A  
BIT HIGH AT THIS POINT BUT EVEN BLENDING IN SOME OTHER MORE  
RELIABLE MODEL DATA, STILL HAS SOME OF THESE VALUES MORE LIKELY  
THAN NOT EVEN THROUGH MONDAY AHEAD OF THE NEXT SYSTEM.  
 
THE UPPER LEVEL RIDGE STARTS TO BREAK DOWN AND BROADEN COME  
SUNDAY AS THE PFJ DIPS BACK A FURTHER SOUTH THROUGH MONTANA THAT  
WILL OPEN UP THE NORTHWEST PACIFIC ONCE AGAIN FOR THE WESTERN  
MOUNTAINS INTO EARLY NEXT WEEK. THIS WILL INCREASES SNOW  
CHANCES WEST OF THE DIVIDE THROUGH MID WEEK BEFORE THE MAIN  
TROUGH PUSHES EAST OVERNIGHT TUESDAY INTO WEDNESDAY. THIS WILL  
BRING SOME SNOW CHANCES AND COOLER TEMPERATURES EAST OF THE  
DIVIDE BUT WARMING ONCE AGAIN BY WEEK'S END. THIS FAR OUT,  
LONGER TERM MODELS DO NOT SUGGEST ANYTHING SIGNIFICANT IN TERMS  
OF SNOWFALL BUT MINOR ACCUMULATIONS FOR MOST AREAS WEST OF THE  
DIVIDE AND SPREADING TO THE BIGHORNS WEDNESDAY. EVEN AS THE  
SYSTEM PUSHES EAST, IT MIGHT EVEN JUST BE LIQUID PRECIPITATION  
WITH THE ABOVE FREEZING TEMPERATURES (EVEN THOUGH COOLER) FOR  
THE LOWER BASINS EAST OF THE DIVIDE. TIME WILL TELL, BUT MARCH  
IS NEAR WITH THE START OF SPRING NOT THAT FAR INTO THE FUTURE.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/  
 
ISSUED AT 1033 PM MST THU FEB 20 2025  
 
LIGHT SNOW SHOWERS LINGER ACROSS SOUTHERN WY TO START THE PERIOD BUT  
WILL GRADUALLY DISSIPATE WITH LITTLE TO NO IMPACT AT TERMINALS. VFR  
CONDITIONS ARE EXPECTED TO PREVAIL THROUGHOUT THE PERIOD WITH THE  
ONLY CONCERN BEING A CHANCE FOR PATCHY FOG NEARBY KJAC AND KCPR.  
CONFIDENCE IS LOW FOR KCPR WHICH IS WHY NO PREVAILING LOW CLOUDS OR  
FOG ARE IN THE TAF. CURRENTLY A LOW/MID LEVEL CLOUD DECK OF BKN030-  
060 HANGS ACROSS MOSTLY ALL TERMINALS BESIDES KCPR. FOG CHANCES WILL  
LARGELY DEPEND ON HOW QUICKLY CLOUDS CAN CLEAR OUT THROUGH THE  
OVERNIGHT INTO FRIDAY MORNING. CLOUDS WILL BE WIDELY SCATTERED FOR  
MUCH OF FRIDAY INTO THE END OF THE TAF PERIOD. A LIGHT BREEZE WILL  
DEVELOP DURING THE EVENING FRIDAY BRINGING A SLIGHT INCREASE IN  
WINDS FOR SOME TERMINALS BUT NOTHING OF CONCERN.  
 
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 11 PM MST THIS EVENING FOR  
WYZ027>030.  
 
 
 
 
 
DISCUSSION...LOWE  
AVIATION...DZIEWALTOWSKI  
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