404
FXUS63 KUNR 172055
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
155 PM MST SUN NOV 17 2024
KEY MESSAGES
- BAND OF LIGHT PRECIPITATION MOVES THROUGH MONDAY, TAPERING OFF
TUESDAY MORNING
- CONFIDENCE INCREASING FOR MULTI-DAY HIGH WIND EVENT TUESDAY AND
WEDNESDAY
DISCUSSION
(THIS EVENING THROUGH SUNDAY)
ISSUED AT 145 PM MST SUN NOV 17 2024
20Z SURFACE ANALYSIS HAD A COUPLE OF WEAK TROUGHS OVER THE CWA
WITH WEST/SOUTHWEST LOW LEVEL FLOW. PLENTY OF SUNSHINE PER 0.5KM
VISIBLE SATELLITE LOOP. WATER VAPOUR MATINEE HAD UPPER LOW
SPINNING OVER NORTHWEST MEXICO AND UPPER TROUGH PLOWING INTO THE
NORTHWEST CONUS/SOUTHWEST CANADA. THESE FEATURES ARE THE MAIN
FORECAST CONCERN.
TONIGHT/MONDAY MORNING, MEXICO UPPER LOW MOVES WESTERN KS AS
NORTHWEST CONUS UPPER TROUGH SLIDES THROUGH THE NORTHERN ROCKIES.
LEE SURFACE TROUGH DEVELOPS AND PUSHES INTO NORTHEASTERN WY. A BIT
OF RAIN/SNOW MAY DEVELOP ALONG THE FRONT MONDAY MORNING.
MONDAY AFTERNOON THROUGH WEDNESDAY, UPPER LOW RACES NORTHEAST
INTO THE UPPER MIDWEST AS ROCKIES UPPER TROUGH SHIFTS EAST AND
MERGES WITH UPPER LOW. SURFACE LOW TRACKS FROM CENTRAL KS TO
NORTHERN MN BY 12Z TUESDAY AS IT OCCLUDES UNDER MERGING UPPER
TROUGH/LOW, AND THEN SPINS INTO CENTRAL CANADA. SURFACE TROUGH
MOVES THROUGH REST OF CWA AS DEVELOPING COLD FRONT MONDAY
AFTERNOON/EVENING. BAND OF POST FRONTAL 800-600MB FRONTOGENESIS
CREATES LIGHT PRECIPITATION, QUICKLY CHANGING TO SNOW (50% CHANCE
>1" OVER FAR WESTERN CAMPBELL COUNTY AND HIGHER BLACK HILLS) AS
COLDER AIR FILTERS IN. LITTLE OR NO ACCUMULATION FROM SOUTHWEST
INTO SOUTH-CENTRAL SD. TIGHT PRESSURE GRADIENT EXPECTED LATE
MONDAY NIGHT/TUESDAY WITH >50% CHANCE OF >50MPH WIND GUSTS ON THE
WESTERN SD PLAINS PER 40-55KT 850-700MB FORECAST WIND PROFILES.
SOME REDUCTION IN WIND EXPECTED TUESDAY NIGHT, BUT AS SECONDARY
SURFACE TROUGH ROTATES THROUGH CWA IN RESPONSE TO PINWHEELING
UPPER LOW, SHOULD SEE ANOTHER DAY OF STRONG WINDS WEDNESDAY
PARTICULARLY FROM KD07-KICR. HIGH WIND WATCHES HOISTED TO ACCOUNT.
THERE IS A NARROW WINDOW OF POTENTIAL BLOWING SNOW (WHERE IT
SNOWS) LATER MONDAY NIGHT/EARLY TUESDAY, BUT ALGORITHMS NOT COMING
UP WITH MUCH SO WILL NOT HIGHLIGHT. TEMPERATURES WILL BE TRICKY
MONDAY GIVEN UNCERTAINTY IN COLD AIR ADVECTION MONDAY AFTERNOON,
BUT SHOULD BE CLOSE TO GUIDANCE TUESDAY AND WEDNESDAY.
UPPER RIDGE REBOUNDS FOR THE END OF THE WEEK, BUT STILL
SEASONALLY COOL WITH POTENTIAL FOR A BACK DOOR COLD FRONT/LOW
LEVEL EASTERLY FLOW. NEXT SYSTEM ARRIVES NEXT WEEKEND BUT IT
LOOKS PROGRESSIVE IN NATURE RIGHT NOW.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1040 AM MST SUN NOV 17 2024
EXPECT VFR CONDITIONS TO PREVAIL ACROSS ALL TERMINALS THROUGH THE
VALID TAF PERIOD. BREEZY SOUTHWESTERLY WINDS SUSTAINED 20 KNOTS
WITH GUSTS UP TO 30 KNOTS IS EXPECTED AT THE KGCC TERMINAL THROUGH
23Z. INCREASING CLOUDS ARE PROGGED TO MOVE ACROSS THE KGCC
TERMINAL THROUGH 12Z WITH A WIND SHIFT TO THE NORTHWEST OCCURRING
AROUND 16Z. EXPECT WIND SPEEDS IN THE 10-12 KNOT RANGE WITH GUSTS
UP TO 25 KNOTS WITH THAT WIND SHIFT.
UNR WATCHES/WARNINGS/ADVISORIES
SD...HIGH WIND WATCH FROM LATE MONDAY NIGHT THROUGH WEDNESDAY
AFTERNOON FOR SDZ001-012-013-026-031-072-073-078.
HIGH WIND WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY AFTERNOON
FOR SDZ002-014-032-043-044-046-047-049-077.
WY...NONE.
DISCUSSION/KEY MESSAGES...HELGESON
AVIATION...AW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page