604
FXUS63 KFSD 301054
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
554 AM CDT FRI MAY 30 2025
KEY MESSAGES
- A RELATIVELY QUIET WEEKEND IS AHEAD, WITH HIGHS RISING INTO
THE 80S, FAIRLY LIGHT WINDS, AND VARIABLE SUNSHINE.
- HIGH LEVEL CANADIAN WILDFIRE SMOKE WILL BEGIN TO FILTER
THROUGH THE CENTRAL US ON FRIDAY, AND THICKEN THROUGH THE
WEEKEND. SOME GROUND LEVEL SMOKE OR REDUCED AIR QUALITY IS
POSSIBLE THIS WEEKEND.
- THUNDERSTORM RISKS RETURN LATE MONDAY AFTERNOON AND PEAK
MONDAY NIGHT. SEVERE WEATHER RISKS WILL BE POSSIBLE ESPECIALLY
WEST OF I-29 MONDAY NIGHT.
DISCUSSION
ISSUED AT 219 AM CDT FRI MAY 30 2025
THIS MORNING: A BIT OF WEAK LOW-LVL WARM ADVECTION CONTINUE TO
FILTER SOUTHWARD THROUGH THE WESTERN GREAT LAKES THIS MORNING,
PUSHING SCATTERED STRATUS THROUGH THE REGION. TEMPERATURES ARE
EXPECTED TO DROP INTO THE LOWER TO MIDDLE 50S BY DAYBREAK, RIGHT
AROUND SEASONAL NORMALS.
TODAY: WINDS ARE EXPECTED TO REMAIN QUITE LIGHT AND VARIABLE
THROUGH THE DAY AS A RIDGE OF SURFACE HIGH PRESSURES SLIDES ACROSS
THE TRI-STATE AREA THIS AFTERNOON. QUITE A BIT OF SUNSHINE EXPECTED
TODAY, BUT WE'LL BEGIN TO SEE SOME THICKENING OF A VERY HIGH LAYER
OF CANADIAN WILDFIRE SMOKE MOVING SOUTH. TEMPERATURES ARE EXPECTED
TO RISE EITHER SIDE OF THE 80 DEGREE MARK.
SATURDAY-SUNDAY: A QUIET WEEKEND IS AHEAD FOR THE PLAINS AND UPPER
MIDWEST. ONLY TWO CONCERNS IN THE SHORT TERM FORECAST. FIRST, A
COMPACT MID-LVL SHORTWAVE SLIDES THROUGH THE WESTERN DAKOTAS ON
SATURDAY. THIS WILL BE A FAIRLY MOISTURE STARVED SYSTEM, BUT AN
INCREASE OF MID-LVL CLOUDS IS LIKELY WEST OF THE JAMES RIVER
SATURDAY, POTENTIALLY ALSO BRINGING SPRINKLES TO THE REGION INTO
SATURDAY AFTERNOON.
THE OTHER STORY THIS WEEKEND WILL BE INCREASING OR THICKENING
WILDFIRE SMOKE, MOSTLY STUCK ALOFT. LATEST HRRR/RAP ALL BRING THIS
AREA OF MILKY SKIES DUE SOUTH THROUGH SUNDAY, AND HAVE ADJUSTED SKY
COVER ACCORDINGLY. SHORT TERM MODELS DO INDICATE SOME POTENTIAL FOR
SMOKE TO MIX DOWNWARD TOWARDS THE SURFACE LATE SATURDAY INTO SUNDAY,
SO BE PREPARED FOR POTENTIAL AIR QUALITY CONCERNS AT TIMES.
TEMPERATURES ARE CURRENTLY FORECAST INTO THE MIDDLE AND UPPER 80S,
BUT IT IS UNKNOWN IF A THICK SMOKE PLUME AND GENERALLY LIGHT
SURFACE WIND COULD HOLD BACK HIGHS.
MONDAY-TUESDAY: SHARP MID-LVL RIDGING MOVES EASTWARD MONDAY MORNING
AS TROUGHING BEGINS TO MOVE TOWARDS THE ROCKIES. A SURFACE COLD
FRONT WILL STRETCH SW TO NE ACROSS THE DAKOTAS EARLY MONDAY MORNING,
WITH INCREASING NORTHWARD MOISTURE TRANSPORT LIKELY PUSHING DEW
POINTS INTO THE UPPER 50S TO LOWER 60S AHEAD OF THIS BOUNDARY. A
MODERATELY UNSTABLE AIRMASS WILL DEVELOP AHEAD OF THIS FRONT AS
TEMPERATURES RISE TOWARDS THE LOWER 90S. SYNOPTIC SCALE LIFT
SHOULD REACH THE FRONT BY MID-LATE MONDAY AFTERNOON ALLOWING
CONVECTION TO QUICKLY DEVELOP AND GROW UPSCALE. WHILE DEEP LAYER
SHEAR REMAINS MARGINAL, REASONABLE DCAPE AND STEEPENING MID-LVL
LAPSE RATES SHOULD PRODUCE A RISK FOR HAIL/WIND AS STORMS MOVE
SOUTHEAST MONDAY NIGHT. LOCALLY HEAVY RAIN MAY ALSO BE POSSIBLE
GIVEN STORM PROPAGATION ALONG THE BOUNDARY AND PWAT VALUES AROUND
THE 90TH PERCENTILE OF MODEL CLIMATOLOGY.
THIS FRONT AND ASSOCIATED CONVECTION WILL SPREAD SOUTHEAST OVERNIGHT
MOVING SOUTHEAST OF THE CWA BY MID-DAY TUESDAY. LREF PROBABILITIES OF
MEASURABLE RAIN ARE VERY HIGH (>80%) INTO TUESDAY OWING TO
GREATER THAN TYPICAL CONFIDENCE OF RAIN AT THE 4-5 DAY
TIMESCALE. BEHIND THIS BOUNDARY, WE'LL LIKELY SEE CONSIDERABLE
CLOUD COVER WHICH SHOULD PULL HIGH TEMPERATURES SLIGHTLY COOLER.
WEDNESDAY-FRIDAY: MID-LVL FLOW FLATTENS THROUGH THE MIDDLE OF THE
WEEK, KEEPING DRY CONDITIONS IN THE REGION AND TEMPERATURES NEAR
NORMAL. WHILE HIGHLY UNCERTAIN, THE NEXT RISKS FOR SHOWERS AND
THUNDERSTORMS MOVES BACK TOWARDS THE REGION LATE NEXT WEEK.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 552 AM CDT FRI MAY 30 2025
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE UPCOMING TAF PERIOD.
SMOKE ALOFT WILL GRADUALLY THICKEN THROUGH THE DAY, AND WILL
INCLUDE A HIGH BASED CLOUD LAYER TO INDICATE IN TAFS. OTHERWISE
AS WINDS REMAIN LIGHT FROM THE WEST TO NORTHWEST, A SCATTERED
AFTERNOON CU FIELD MAY DEVELOP. WINDS TURN LIGHT AND VARIABLE
AGAIN TONIGHT, WITH SOME POTENTIAL FOR MID-LVL CLOUDS MOVING
THROUGH CENTRAL SD AFTER MIDNIGHT.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...DUX
AVIATION...DUX
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