119  
FXUS65 KRIW 191720  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
1020 AM MST TUE NOV 19 2024  
   
KEY MESSAGES  
 
- TROUGH HANGS AROUND TODAY, WHICH WILL KEEP SOME LIGHT SNOW  
SHOWERS AROUND MOUNTAIN RANGES. WIND WILL ALSO REMAIN STRONG  
TODAY, WITH WIDESPREAD GUSTS OF 25-35 MPH THIS AFTERNOON.  
TODAY WILL BE THE COLDEST DAY OF THE WEEK.  
 
- A RIDGE DEVELOPS OVER WY ON WEDNESDAY WITH A POTENTIAL BOMB  
CYCLONE (LOW) OFF THE PACNW COAST. THIS RIDGE WILL ALLOW A  
WARMING TREND THROUGH THIS WEEK INTO THIS WEEKEND BEFORE THE  
LOW COMES ONSHORE.  
 
- THE LOW AND ASSOCIATED TROUGH WILL BEGIN IMPACTING WY ON  
SATURDAY AND BROAD TROUGHING WILL REMAIN OVER THE REGION WELL  
INTO NEXT WEEK, SO BEYOND SATURDAY IT WILL BE COOL AND  
UNSETTLED.  
 
 
   
DISCUSSION  
 
ISSUED AT 1230 AM MST TUE NOV 19 2024  
 
SNOW SHOWERS LINGER THIS MORNING, MAINLY ACROSS WESTERN WY WHERE  
ANOTHER FEW INCHES OF SNOWFALL IS LIKELY (70%) AT THE HIGHER  
ELEVATIONS. UP TO ABOUT AN INCH OF ADDITIONAL SNOW REMAINS POSSIBLE  
(40%) FOR STAR VALLEY AND JACKSON VALLEY THROUGH THIS EVENING.  
TEMPERATURES SEEM TO BE TRENDING COLDER THIS MORNING, WITH IT  
ALREADY BELOW ZERO AT LAKE YELLOWSTONE BY MIDNIGHT. DID ADJUST MIN  
TEMPERATURES DOWN TO ACCOUNT FOR THIS. THE BACKSIDE OF THE TROUGH  
WILL PUSH THROUGH THIS EVENING, WHICH WILL SHUT OFF MOST SNOW SHOWER  
ACTIVITY THROUGH WEDNESDAY MORNING AS A RIDGE DEVELOPS OVER THE  
REGION. THE RIDGE AXIS WILL MOVE OVER THE STATE WEDNESDAY AFTERNOON,  
WHICH WILL ALLOW SOME WEAK MOIST SOUTHWESTERLY UPSLOPE FLOW TO  
DEVELOP ON THE BACKSIDE ACROSS NORTHWEST WY THROUGH THURSDAY  
EVENING. BY THAT TIME THE RIDGE SHOULD STRENGTHEN AND PUSH THE MOIST  
SOUTHWESTERLY FLOW FURTHER NORTH INTO MT. THE RIDGE WILL ALLOW FOR  
MUCH WARMER TEMPS THROUGH THE REST OF THE WEEK INTO THE WEEKEND.  
HIGH TEMPS EAST OF THE CONTINENTAL DIVIDE WILL RISE INTO THE UPPER  
40S TO MIDDLE 50S BY THURSDAY AND CONTINUE THROUGH SATURDAY. WEST OF  
THE CONTINENTAL DIVIDE HIGH TEMPS WILL AVERAGE MIDDLE 40S TO AROUND  
50 DEGREES DURING THIS SAME TIME FRAME.  
 
MODEL GUIDANCE IS SHOWING A BOMB CYCLONE OFF THE COAST OF THE PACNW  
THIS WEEK, WHICH WILL HAMMER THE PACNW WITH SNOW/RAIN/WIND.  
EVENTUALLY THIS WEATHER SYSTEM WILL MAKE IT TO WY, ALTHOUGH IT WILL  
BE A SHADOW OF ITS FORMER SELF. THE JET EXIT REGION ON THE SOUTHERN  
END OF THE TROUGH WILL PUSH INTO WY SOMETIME ON SATURDAY BASED ON  
CURRENT MODEL GUIDANCE. THIS WILL BRING SNOW CHANCES BACK INTO  
WESTERN WY WITH WEST/SOUTHWEST FLOW. BEYOND SATURDAY IT APPEARS THE  
JET STREAM WILL SLIDE SOUTH, WITH LARGE-SCALE TROUGHING ACROSS THE  
NORTHERN HALF OF THE US. THIS MEANS IT WILL BE COLDER AND REMAIN  
UNSETTLED, WITH MORE PRECIP CHANCES WELL INTO NEXT WEEK. MODEL  
GUIDANCE IS DEPICTING THIS TO BE A VERY BROAD AND DIFFUSE TROUGH,  
WITH SEVERAL AREAS OF MID TO UPPER-LEVEL ENERGY SCATTERED ABOUT FROM  
CANADA DOWN INTO THE NORTHERN PART OF THE US, SO FREQUENT SMALLER  
WEATHER SYSTEMS INSTEAD OF A COUPLE OF LARGE WEATHER SYSTEMS IS THE  
LIKELY (70%) OUTCOME OF THIS WEATHER PATTERN.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/  
 
ISSUED AT 1019 AM MST TUE NOV 19 2024  
 
LIGHT SNOW OVER THE FAR WESTERN WYOMING IMPACTING KJAC IS EXPECTED  
TO CONTINUE TO PUSH EAST AND DISSIPATE OVER THE NEXT FEW HOURS.  
OTHERWISE DRY AND VFR FLIGHT CONDITIONS ARE FORECAST TO PREVAIL  
THROUGH THE TAF PERIOD WITH GUSTY WEST/NORTHWESTERLY WINDS THIS  
AFTERNOON. GUSTY WINDS ARE EXPECTED TO DISSIPATE THIS EVENING WITH  
LIGHT WINDS PERSISTING THROUGH WEDNESDAY MORNING, EXCEPT AT KCPR  
WHERE WINDS WILL AGAIN GUSTY BY 16Z WEDNESDAY.  
 
 
   
RIW WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION...ROWE  
AVIATION...GERHARDT  
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