580
FXUS65 KRIW 201001
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
301 AM MST WED NOV 20 2024
KEY MESSAGES
- ELEVATED FIRE WEATHER CONDITIONS FROM ROCK SPRINGS TO CASPER
THIS AFTERNOON DUE TO LOW RH AND GUSTY WIND.
- A RIDGE DEVELOPS OVER WY TODAY WITH A 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 OVERALL TROUGHING WILL REMAIN OVER THE REGION
WELL INTO NEXT WEEK, SO BEYOND SATURDAY IT WILL BE COOL AND
UNSETTLED.
DISCUSSION
ISSUED AT 1247 AM MST WED NOV 20 2024
RIDGING IS MOVING INTO THE REGION CURRENTLY. THE RIDGE AXIS WILL
MOVE OVER THE STATE THIS AFTERNOON, WHICH WILL ALLOW SOME WEAK MOIST
SOUTHWESTERLY UPSLOPE FLOW TO DEVELOP ON THE BACKSIDE ACROSS
NORTHWEST WY. MODEL GUIDANCE IS KEEPING THIS MOIST SOUTHWESTERLY
FLOW ACROSS NORTHWEST WY THROUGH THE REST OF THIS WEEK, WHICH WOULD
KEEP LIGHT SNOW SHOWERS IN THE AREA. THE RIDGE WILL ALLOW FOR MUCH
WARMER TEMPS THROUGH THE REST OF THE WEEK INTO THE WEEKEND, WITH
MOSTLY CLEAR SKIES ACROSS MUCH OF THE AREA. 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.
A BOMB CYCLONE DEVELOPED OFF THE COAST OF THE PACNW IN THE PAST 24
HOURS AND, WHICH WILL HAMMER THE PACNW WITH SNOW/RAIN/WIND THROUGH
THE REST OF THIS WEEK. 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 /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 300 AM MST WED NOV 20 2024
VFR CONDITIONS ARE EXPECTED ALL TERMINALS. WIND WILL GENERALLY
BE LIGHT, WITH THE EXCEPTION OF KCPR WHICH WILL SEE GUSTS OVER
25 KNOTS THROUGH MUCH OF THE PERIOD. CLOUDS WILL INCREASE LATE
IN THE PERIOD ACROSS WESTERN WYOMING, WITH A BROKEN HIGH DECK AT
KJAC AFTER 23Z. ANY PRECIPITATION OR LOWER CEILINGS SHOULD HOLD
OFF UNTIL AFTER 12Z THURSDAY.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...ROWE
AVIATION...HATTINGS
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