666
FXUS63 KUNR 111103
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
503 AM MDT SUN OCT 11 2026
KEY MESSAGES
- PATTERN CHANGE TODAY AS COLD FRONT SETTLES IN LATER TONIGHT.
COOLER WITH PRECIPITATION CHANCES THROUGH THE WEEK.
UPDATE
ISSUED AT 952 PM MDT SAT OCT 10 2026
00Z SFC ANALYSIS DEPICTS SFC TROF ACROSS WESTERN SD INTO
NORTHEASTERN WY. SHOWERS AND ISOLATED STORMS HAVE DEVELOP OVER
NORTHWESTERN SD AND PORTIONS OF NORTHEASTERN WY. COOLER AIR TO THE
NORTHWEST WILL PUSH INTO THE AREA OVERNIGHT WITH HIGHS TOMORROW IN
THE MID 50S ACROSS NW SD TO THE 70S ACROSS SOUTH CENTRAL SD. COOLER,
MORE SEASONABLE TEMPS EXPECTED THROUGH NEXT WEEK. PRECIP CHANCES
WILL BE SLIM FOR MUCH OF THE WEEK UNTIL THE WEDNESDAY/THURSDAY
TIMEFRAME, THOUGH THERE STILL ISN'T MUCH CONSENSUS AMONG
DETERMINISTIC AND ENSEMBLE GUIDANCE.
DISCUSSION
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1236 PM MDT SAT OCT 10 2026
UPPER LEVEL ANALYSIS SHOWS BROAD SOUTHWESTERLY FLOW ACROSS THE
NORTHERN ROCKIES INTO THE NORTHERN PLAINS. DEEP TROUGHING IS NOTED
ACROSS THE WESTERN US WITH CLOSED UPPER LOW DROPPING INTO WA WITH
A SECOND CLOSED LOW OFF THE SOUTHERN CA COAST. SURFACE LOW
PRESSURE IS CENTERED OVER CENTRAL ND WITH A COLD FRONT EXTENDING
WESTWARD THROUGH SOUTHEASTERN MT, SLOWLY PUSHING INTO FAR
NORTHWESTERN SD. SURFACE WINDS IN NORTHWESTERN SD HAVE SHIFTED OUT
OF THE NORTHWEST, WITH WEST-SOUTHWESTERLY WINDS ACROSS THE REST
OF THE CWA. VERY HOT TODAY WITH WIDESPREAD 80S AND TO LOW 90S,
WARMEST ACROSS THE WESTERN SD PLAINS.
ISOLATED SHOWERS AND A FEW LIGHTNING STRIKES ARE POSSIBLE LATER THIS
AFTERNOON AND EVENING HOURS AS SHORTWAVE TROUGH PUSHES INTO THE
REGION. GIVEN DRY BOUNDARY LAYER, LACK OF APPRECIABLE MOISTURE, AND
ISOLATED COVERAGE, PRECIPITATION AMOUNTS WILL BE LIGHT AND SPOTTY.
HOWEVER, GUSTY WINDS ARE POSSIBLE WITH ANY PRECIPITATION CORES.
THE COLD FRONT WILL SETTLE SOUTHWARD INTO THE FORECAST AREA
TONIGHT. COOLER TEMPERATURES BEHIND THE FRONT, ALTHOUGH FRONTAL
POSITION A BIT UNCERTAIN SUNDAY. CURRENT THINKING IS THAT THE
FRONT WILL BE SLOW TO PUSH SOUTH OF THE AREA, ALLOWING FOR WARMER
TEMPERATURES ALONG SD/NE BORDER (70S) AND COOLER TEMPERATURES
NORTHWARD THROUGH SUNDAY AFTERNOON.
COLD FRONT WILL SHIFT SOUTH OF THE AREA BY MONDAY WITH COOLER, YET
NEAR SEASONABLE TEMPERATURES THROUGH THE REST OF THE WEEK. ACTIVE
SOUTHWESTERLY FLOW ALOFT COUPLED WITH MOISTURE INFLUX FROM THE
REMNANTS OF TROPICAL STORM RACHEL WILL SUPPORT PRECIPITATION CHANCES
LATE SUNDAY INTO MONDAY, ALTHOUGH BEST PRECIPITATION CHANCES WILL BE
DISPLACED NORTH AND NORTHWEST OF THE FORECAST AREA. A DEEP UPPER LOW
IS FORECAST TO PUSH THROUGH THE AREA LATE TUESDAY INTO WEDNESDAY
WITH ANOTHER CHANCE OF PRECIPITATION WEDNESDAY.
FORECAST CONFIDENCE WANES BEYOND WEDNESDAY WITH CONSIDERABLE SPREAD
AMONG THE MODELS/ENSEMBLES REGARDING THE SYNOPTIC EVOLUTION.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 459 AM MDT SUN OCT 11 2026
EXPECT MVFR TO LOCAL IFR CIGS ACROSS THE FAR NORTHWEST THIS
MORNING, TRENDING TO MVFR LATE THIS MORNING. SCT SHOWERS WILL
ALSO BE POSSIBLE ACROSS THE NORTHWEST THIRD. OTHERWISE, WINDS
WILL VEER AROUND TO THE ESE THROUGH THE PERIOD AHEAD OF THE NEXT
WAVE. A BATCH OF SHOWERS WILL MOVE THROUGH THIS EVENING, WITH
LOCAL MVFR CONDS POSSIBLE IN THE HEAVIER SHOWERS. EASTERLY UPSLOPE
FLOW WILL SUPPORT PATCHY FOG AND MVFR TO LOCAL IFR CIGS ON THE NW
SD PLAINS AND ALONG THE EASTERN BH FOOTHILLS TONIGHT.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
UPDATE...WONG
DISCUSSION...SE
AVIATION...JC
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