973
FXUS63 KFSD 021130
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
630 AM CDT FRI MAY 2 2025
KEY MESSAGES
- SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE THROUGH THE JAMES
AND MISSOURI RIVER VALLEYS THIS MORNING. ADDITIONAL SHOWERS
ARE POSSIBLE FOR THE MISSOURI VALLEY THIS AFTERNOON. RAINFALL
TOTALS AROUND 0.25 INCHES OR LESS.
- PATCHY FROST IS POSSIBLE TONIGHT INTO EARLY SATURDAY WITH LOWS
IN THE MID AND UPPER 30S. GREATEST RISK IS ALONG AND EAST OF
I-29. COVER ANY SENSITIVE VEGETATION, OR BRING PLANTS
INDOORS.
- AN EXTENDED PERIOD OF WARM AND DRY WEATHER IS LIKELY THROUGH
THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK.
- LIGHT RAIN CHANCES RETURN BY MID NEXT WEEK, BUT CURRENTLY
EXPECT LOW RAINFALL TOTALS AND NO SEVERE WEATHER RISKS.
DISCUSSION
ISSUED AT 335 AM CDT FRI MAY 2 2025
CURRENTS-TONIGHT: TEMPERATURES THIS MORNING RANGE FROM THE UPPER 30S
(CLEAR SKIES) TO NEAR 50 (CLOUDS AND RAIN). SHOWERS CONTINUE TO MOVE
SOUTH THIS MORNING ALONG AN AXIS OF WAA AND THE BASE OF A MID LEVEL
WAVE AND UPPER LEVEL TROUGH. CAN'T RULE OUT SOME VERY ISOLATED
THUNDER WITH CAPE VALUES BELOW 200 J/KG. THIS AREA OF RAIN SINKS
SOUTH THROUGH THE MORNING HOURS WITH THE AFOREMENTIONED DYNAMICS.
ANOTHER AREA OF SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON ACROSS THE MO RIVER VALLEY TOWARD THE JAMES RIVER VALLEY
ALONG WEAK WAA, NARROW CORRIDOR OF VORTICITY, AND UPPER JET.
THUNDERSTORMS WILL BE SPARSE WITH LESS THAN 500 J/KG OF CAPE FROM
MOST MODELS (OTHER THAN THE 02.00Z NAM). THIS ACTIVITY WILL LARGELY
BE DIURNALLY DRIVEN AND SHOULD DIMINISH TOWARD/AFTER SUNSET.
ADDITIONAL RAINFALL AMOUNTS THROUGH THIS EVENING GENERALLY 0.25" OR
LESS.
TEMPERATURES TODAY WILL BE BELOW TO NEAR NORMAL, WITH HIGHS IN THE
MID 50S TO MID 60S. EXPECT THE COOLEST TEMPERATURES ALONG AND EAST
OF I-29 WHERE CLOUDS LINGER THE LONGEST. NORTHERLY WINDS TODAY WILL
BE A BIT BREEZY WITH GUSTS AROUND 20-25 MPH. SKIES CLEAR TONIGHT
WITH SURFACE HIGH PRESSURE MOVES IN AND UPPER TROUGH SLIDES EAST.
WINDS BECOME LIGHT AND VARIABLE, AND COMBINED WITH MOISTURE FROM
RECENT RAINFALL, MAY LEAD TO TO SOME PATCHY FOG INTO EARLY SATURDAY.
ENSEMBLE GUIDANCE SHOWS LESS THAN A 30% OF VISIBILITY BELOW 1 MILE,
MAINLY EAST OF I-29. GIVEN LOW CONFIDENCE, WILL KEEP MENTION OUT OF
THE FORECAST FOR NOW. LOWS TONIGHT IN THE MID AND UPPER 30S WHICH
MAY LEAD TO PATCHY FROST (ESPECIALLY ALONG AND EAST OF I-29). COVER
ANY SENSITIVE VEGETATION, OR BRING PLANTS INDOORS.
SATURDAY-MONDAY: VERY PLEASANT WEEKEND FOR OUTDOOR ACTIVITIES
EXPECTED! OMEGA BLOCKING PATTERN TAKES SHAPE THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK, KEEPING OUR AREA UNDER THE INFLUENCE OF HIGH
PRESSURE. SATURDAY IS EXPECTED TO BE THE COOLEST AND LEAST BREEZY,
WITH HIGHS IN THE UPPER 60S TO LOWER 70S. WINDS INCREASE FOR SUNDAY
AND MONDAY AS THE LOW PRESSURES WOBBLE TOWARD THE CENTRAL US,
COMPRESSING THE SPG OVER OUR AREA - WITH GUSTS AROUND 25 MPH. HIGHS
SUNDAY AND MONDAY IN THE 70S. LOWS DURING THIS TIME IN THE 40S.
SKIES REMAIN MOSTLY CLEAR.
TUESDAY-FRIDAY: OMEGA BLOCK BREAKS DOWN BY TUESDAY, WITH A REX
BLOCKING PATTERN DEVELOPING OVER THE PLAINS INTO LATE NEXT WEEK.
MODELS VARY IN WHERE/WHEN THE SURFACE LOW SETS UP, BUT MOST GUIDANCE
KEEPS IT AND THE BETTER RAIN AND THUNDERSTORM CHANCES OFF TO OUR
SOUTH. ENSEMBLE PROBABILITIES KEEP THE CHANCE FOR A TENTH OF AN INCH
OR MORE OF RAIN LOW (LESS THAN 30%) ALONG AND SOUTH OF US HWY 20.
SOUTHERLY FLOW KEEP TEMPERATURES ABOVE NORMAL THROUGH THE WEEK
DESPITE PRECIPITATION CHANCES. HIGHS IN THE 70S WITH LOWS IN THE
40S.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 624 AM CDT FRI MAY 2 2025
A MIX OF CONDITIONS THIS MORNING, WITH AN AREA OF MVFR/IFR
STRATUS DROPPING TOWARD THE US HWY 14 CORRIDOR THROUGH THIS
MORNING AND ANOTHER ACROSS SOUTHWESTERN MN. LOWER END VFR
CEILINGS EXIST WITH STRATUS UNDER HIGH CLOUDS FOR MUCH OF THE
AREA. CEILINGS IMPROVE LATER THIS MORNING AND INTO THE AFTERNOON
HOURS, WITH VFR CONDITIONS FOR THE LATTER HALF OF THE PERIOD.
SHOWERS AND THE POTENTIAL FOR VERY ISOLATED THUNDER CONTINUE
THROUGH THE MO RIVER VALLEY AND INTO NORTHWESTERN IA THIS
MORNING, DROPPING SOUTH OF KSUX BY ABOUT 15Z. ADDITIONAL SHOWERS
ARE POSSIBLE FOR CENTRAL SD INTO THE MO RIVER VALLEY THIS
AFTERNOON AND EVENING; HOWEVER, CONFIDENCE IS LOW IN COVERAGE SO
WILL OMIT FROM KHON FOR NOW. BRIEF MVFR (OR LOWER) CONDITIONS
ARE POSSIBLE WITH PRECIP. RAIN TAPERS OFF QUICKLY NEAR/AFTER
SUNSET.
NORTH-NORTHWESTERLY WINDS GUST AROUND 20 TO 25 KNOTS THROUGH THE
AFTERNOON AND EARLY EVENING. WINDS BECOME LIGHT AND VARIABLE
AFTER SUNSET.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...SG
AVIATION...SG
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