498
FXUS65 KRIW 190732
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1232 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 /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 948 PM MST MON NOV 18 2024
MOST TERMINALS WILL REMAIN AT VFR CONDITIONS THROUGH THE TAF PERIOD
WITH THE ONLY EXCEPTIONS BEING AT KJAC/KCPR. LINGERING LIGHT SNOW
SHOWERS TO START THE PERIOD MAY BRIEFLY LOWER VIS AND CEILINGS TO
IFR CONDITIONS AT KJAC/KCPR THROUGH 07Z TUESDAY. KJAC WILL SEE LOW
CEILINGS LINGER THROUGH MUCH OF THE TAF PERIOD WHILE THE OTHER
TERMINALS SHOULD SEE GRADUAL CLEARING OVERNIGHT. PROB30 GROUP IS IN
PLACE FOR KJAC TUESDAY MORNING DUE TO POSSIBLY SEEING ANOTHER ROUND
OF SNOW SHOWERS WHICH MAY BRIEFLY LOWER CONDITIONS DOWN TO MVFR/IFR
AT TIMES. WINDS WILL INCREASE DURING THE LATE MORNING ACROSS ALL
TERMINALS WITH WESTERLY GUSTS OF 20 TO 30 KNOTS THROUGH THE
AFTERNOON. WINDS DECREASE BY THE LATE AFTERNOON WITH A LIGHT BREEZE
LINGERING AT KCPR THROUGH THE END OF THE TAF PERIOD. THERE IS A
PROB30 FOR KCPR FROM 21Z TO 23Z DUE TO THE POSSIBILITY OF SOME
ISOLATED SNOW SHOWERS MOVING THROUGH THE AREA. VFR CONDITIONS
PREVAIL ACROSS ALL TERMINALS WITH CLEARING SKIES TO END 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
NONE.
DISCUSSION...ROWE
AVIATION...DZIEWALTOWSKI
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