507
FXUS63 KFSD 030445
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1045 PM CST MON MAR 2 2026
KEY MESSAGES
- LIGHT RAIN AND DRIZZLE RISKS WILL ARRIVE LATE MONDAY AFTERNOON
AND CONTINUE INTO TUESDAY MORNING. RAINFALL AMOUNTS LESS THAN
0.10" EXPECTED. TEMPERATURES LIKELY REMAIN ABOVE FREEZING,
MITIGATING ANY LARGE SCALE ICING POTENTIAL.
- CONFIDENCE IS HIGH IN ANOTHER EXTENDED PERIOD OF WELL-ABOVE
NORMAL TEMPERATURES INTO NEXT WEEKEND.
- CONFIDENCE ALSO REMAINS HIGHER THAN NORMAL IN RETURNING RAIN
RISKS THURSDAY INTO FRIDAY DURING THE PASSAGE OF A FRONT. A
RUMBLE OR TWO OF THUNDER COULD ALSO BE POSSIBLE ESPECIALLY
OVER NW IOWA.
- PRECIPITATION AMOUNTS FOR THE END OF THE WEEK ARE STILL
FAVORED TO REMAIN LOW, WITH CURRENT PROBABILITIES OF >0.50"
ONLY 20 TO 30%. HOWEVER THIS MAY MARK THE MOST SIGNIFICANT
PRECIPITATION CHANCE WE'VE HAD FOR SOME TIME.
UPDATE
ISSUED AT 1043 PM CST MON MAR 2 2026
LIGHT RAIN SHOWERS CONTINUE TO PUSH EASTWARDS THROUGH THE FORECAST
AREA LATE THIS EVENING. WHILE THE BULK OF THE SHOWERS WILL COME TO
AN END JUST AFTER MIDNIGHT, DRIZZLE REMAINS POSSIBLE FOR THE REST OF
THE OVERNIGHT HOURS AS MORE EXPANSIVE LOW LEVEL STRATUS DEVELOPS.
THIS STRATUS WILL PREVENT TEMPERATURES FROM FALLING TOO MUCH MORE
FROM WHERE THEY CURRENTLY ARE. THUS, FREEZING DRIZZLE IS STILL NOT
EXPECTED THROUGH THE OVERNIGHT HOURS.
TUESDAY WILL BEGIN ON THE DREARY SIDE WITH LOW LEVEL STRATUS LOCKED
IN PLACE THROUGH THE MORNING HOURS. SATURATION IN THE DENDRITIC
GROWTH ZONE (DGZ) WILL EXIT THE AREA, LEAVING JUST THE STRATUS. THE
GOOD NEWS IS THAT THE STRATUS WILL LIFT A BIT AND BREAK APART SOME,
RETURNING PEAKS OF SUNSHINE TO THE AREA FOR THE AFTERNOON HOURS.
HOWEVER, WITH REMAINING LOW LEVEL MOISTURE IN PLACE, THE STRATUS
LOOKS TO RE-EXPAND ACROSS THE AREA. THERE COULD BE SOME LIGHT RAIN
SHOWERS ALONG AND SOUTH OF HIGHWAY-20 WHERE BETTER SATURATION AND
LIFT LOOKS TO LIE. OTHERWISE, LOW TEMPERATURES WILL AGAIN BE ON THE
WARM SIDE, ONLY FALLING TO MID TO LOW 30S.
THE MIDDLE OF THE WEEK CONTINUES TO LOOK WARM AND GENERALLY DRY AS
AN APPROACHING STRONGER UPPER LEVEL WAVE RESULTS IN MORE MERIDIONAL
FLOW ACROSS THE PLAINS. THIS WILL RESULT IN PERSISTENT WARM
ADVECTION THAT WILL WARM TEMPERATURES TO THE 50S AND 60S ON
WEDNESDAY AND THEN UP TO THE 60S TO POSSIBLY LOW 70S ON THURSDAY.
LATEST GUIDANCE STILL SHOWS PRECIPITATION OCCURRING WITH THIS WAVE
BUT LOOKS TO BEGIN EARLIER, NOW BEGINNING THURSDAY EVENING/NIGHT.
CHANCES FOR PRECIPITATION WILL PERSIST THROUGH FRIDAY BEFORE EXITING
THE AREA ON SATURDAY. LATEST DETERMINISTIC GUIDANCE STILL SHOWS THE
POTENTIAL FOR SOME WEAK INSTABILITY AND IS SUPPORTED BY THE
ENSEMBLES AS THEY SHOW A 40-60% CHANCE FOR INSTABILITY VALUES TO
EXCEED 500 J/KG. THE HIGHEST PROBABILITIES LOOK TO COME ON FRIDAY,
THUS SIGNALING THAT SOME CLAPS OF THUNDER ARE POSSIBLE. STILL
LOOKING AT CHANCES FOR RAIN TRANSITIONING TO RAIN/SNOW ON THE
BACKSIDE OF THE SYSTEM AFTER A COLD FRONT PASSES THROUGH THE
AREA.
DISCUSSION
ISSUED AT 1221 PM CST MON MAR 2 2026
THIS AFTERNOON: STRATUS CONTINUES OVER PORTIONS OF IA/MN AND FAR
EASTERN SD THIS AFTERNOON, THOUGH SATELLITE SUGGESTS THE CLOUD LAYER
IS QUITE THIN. TEMPERATURES HAVE AGAIN RISEN INTO THE 40S IN
MOST AREAS, COOLER OVER THE DEEPER SNOW PACK FROM THE WEEKEND
SNOW. FURTHER WEST, WE'RE SEEING THE DEVELOPMENT OF LIGHT
SHOWERS IN THE WEST RIVER AND PANHANDLE AREAS. THIS LIGHT RAIN
WILL CONTINUE ON AN EASTWARD PATH LATE THIS AFTERNOON, BUT WILL
BE FIGHTING A VERY PRONOUNCED DRY LAYER CENTERED AROUND 850MB.
TONIGHT: LIGHT RAIN/SPRINKLES WILL CONTINUE TO MOVE EASTWARD
THROUGH THE EVENING HOURS TIED TO A STRONGER VORT LOBE ALONG I-90.
AFTER THE PASSAGE OF THIS WAVE, SOUNDINGS SUGGEST THAT WE'LL LOSE
ICE IN THE ATMOSPHERIC COLUMN, AND WITH THE CONTINUATION OF VERY
WEAK ISENTROPIC LIFT AOB 800MB WE MAY BEGIN TO SEE DRIZZLE DEVELOP
INTO DAYBREAK TUESDAY. THERE REMAINS SOME FLUCTUATION IN OVERNIGHT
TEMPERATURE POTENTIAL. ASSUMING WE CAN WARM INTO THE UPPER 30S TO
LOWER 40S, EXPANDING STRATUS AFTER DARK MAY HELP BLANKET THE AREA
AND KEEP TEMPERATURES A FEW DEGREES ABOVE FREEZING AND MITIGATE ANY
ICING POTENTIAL. THE DETERMINISTIC NBM SEEMS TO BE BIASED BY THE
RECENT COLD OVERNIGHT PERIODS WITH HOURLIES AT OR BELOW THE 25TH
PERCENTILE. WITH THAT SAID, HAVE BLENDED IN MORE SHORT TERM CAMS
THAT KEEP HOURLIES NEAR OR JUST ABOVE FREEZING IN MOST AREAS.
CONFIDENCE REMAINS HIGH THAT QPF ITSELF WILL BE VERY LIGHT, WITH
ONLY A 30% PROBABILITY OF MORE THAN 0.10". MOST MAY SEE ONLY A
COUPLE HUNDREDTHS.
TUESDAY: WE'LL CONTINUE TO REMAIN UNDER THE INFLUENCE OF MID-LVL
VORTICITY INTO MID-DAY TUESDAY, WHILE THE INTRODUCTION OF A LIGHT
NORTHERLY WIND AOA 800 MB SHOULD LESSEN THE DEPTH OF THE LOW-LVL
MOISTURE LAYER AND GRADUALLY REDUCE THE DRIZZLE PRODUCTION POTENTIAL
SOUTH OF I-90. TEMPERATURES WARM INTO THE UPPER 40S TO 50S IN THE
AFTERNOON. AN UPPER TROUGH WILL EJECT SLOWLY EASTWARD INTO THE MID-
MISSOURI RIVER VALLEY TUESDAY NIGHT AND WEDNESDAY, WITH WEAK
CHANNELING OF LOW-LVL MOISTURE AND WEAK WARM ADVECTION BACK TO AREAS
SOUTH OF I-90 AND TOWARDS HIGHWAY 20 OVERNIGHT. THIS WILL CONTINUE
OR REINTRODUCE THE POTENTIAL FOR DRIZZLE TO SPITS OF RAIN INTO
WEDNESDAY MORNING. WITH TEMPERATURES AGAIN ABOVE FREEZING NO IMPACTS
ARE LIKELY.
WEDNESDAY: MID-LVL HEIGHTS BEGIN TO RISE ON WEDNESDAY, AND SURFACE
WINDS TURN BACK TO THE SOUTH THROUGH THE DAY. A THERMAL RIDGE WILL
DEVELOP OVER THE DAKOTAS AND POINT TOWARDS THE ARROWHEAD OF
MINNESOTA BY WEDNESDAY AFTERNOON. TEMPERATURES AT THE SURFACE
RESPOND BY JUMPING INTO THE 60S WEST OF THE JAMES RIVER AND 50S TO
THE EAST.
THURSDAY-FRIDAY: MEDIUM RANGE MODELS AND THEIR ENSEMBLES REMAIN IN
STRONG AGREEMENT FOR THE END OF THE WEEK, PUSHING A LONG WAVE
TROUGH OVER THE WEST COAST WEDNESDAY INTO THE PLAINS BY THURSDAY
AND FRIDAY. CLOSER TO HOME, THE INITIAL RESPONSE WILL BE DEEPER
LEE- SIDE TROUGHING THURSDAY WHICH WILL ALLOW THE THERMAL RIDGE
TO SLIDE EAST, BUT ALSO INCREASE THE SOUTHERLY SURFACE WINDS.
WHILE THE AIRMASS AHEAD OF THIS TROUGH IS WARM, ESAT TABLES
WOULD SUGGEST THAT THIS AIRMASS SITS AROUND THE 90TH PERCENTILE
OF CLIMATOLOGY CENTERED AROUND EARLY MARCH. MEANING, AT THIS
POINT, THE POTENTIAL FOR RECORDS REMAINS LOW THURSDAY AND
FRIDAY. ONE THING TO WATCH IS THE POTENTIAL FOR ANY STRATUS TO
LINGER ALONG OR EAST OF I-29, WHICH WOULD HAVE A LOWERING IMPACT
ON TEMPERATURES.
REGARDING PRECIPITATION, THIS IS WHERE SOME SLIGHT DEVIATIONS IN
GUIDANCE DEVELOP. BOTH EC/GFS/CMC SHOW THE POTENTIAL FOR THE LONG
WAVE TROUGH TO SPLIT, WITH A POSITIVELY TILTED TROUGH SAGGING
EASTWARDS INTO FRIDAY, AND ENERGY AT THE BASE OF THE TROUGH DIVING
SOUTHWARD. THIS SPLIT, WHILE UNCERTAIN, COULD DEVIATE THE MOISTURE
TRAJECTORY OF THIS SYSTEM. ON THE OTHER HAND, SOME GUIDANCE
(MOSTLY EC BUT SOME GFS MEMBERS) DOES BRING A MORE CONDENSED
AREA OF VORTICITY NORTHEASTWARD, ALLOWING AT LEAST SOME MOISTURE
AND INSTABILITY (~300-500 J/KG MUCAPE) TO FOCUS NEAR THE TRI-
STATE AREA. THE POTENTIAL RELEASE OF THIS INSTABILITY MAY BE
THE ONE KEY ASPECT OF THE FORECAST THAT COULD DRIVE UP QPF
POTENTIAL, WHICH BASED ON OTHER ENSEMBLE SOLUTIONS REMAINS LOW.
PROBABILITIES OF >0.1" HAVE RISEN TO NEAR 80%, WITH
PROBABILITIES OF >0.50" MUCH LOWER AT 20- 30%. NO MATTER WHAT,
THIS SYSTEM DOES AT LEAST HAVE THE POTENTIAL OF PRODUCING MORE
THAN A GROUND WETTING RAIN BY TIME IT ENDS LATE FRIDAY. THIS
SYSTEM ALSO HAS HINTS OF A SEPARATE DEFORMATION BAND TRYING TO
FORM OVER CENTRAL SD THAT COULD TURN INTO A RAIN/SNOW MIXTURE
DEPENDING ON TIMING.
SATURDAY-MONDAY: TEMPERATURES REMAIN VERY WARM HEADING INTO NEXT
WEEKEND WITH NO STRONG COLD ADVECTION BEHIND THE PASSING TROUGH
FRIDAY. BREEZY SOUTHWESTERLY WINDS ARE LIKELY NEXT WEEKEND, BUT
ESPECIALLY ON SATURDAY WHERE THE SPG INCREASES QUICKLY.
TEMPERATURES IN THE 50S AND 60S ARE EXPECTED, WITH THE CURRENT
NBM FORECAST SITTING CLOSER TO THE 75TH PERCENTILE OF THE
ENSEMBLE SOLUTIONS.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1043 PM CST MON MAR 2 2026
A FEW LIGHT RAIN SHOWERS PERSIST LATE THIS EVENING NEAR THE
IOWA/MINNESOTA BORDER. MID AND HIGH LEVEL CLOUDS PERSIST ACROSS THE
MAJORITY OF THE AREA WITH LOW LEVEL STRATUS DEVELOPING ACROSS THE
MISSOURI RIVER VALLEY. THIS STRATUS IS EXPECTED TO EXPAND NORTH AND
EASTWARDS THROUGHOUT THE NIGHT. THE STRATUS LOOKS TO LOWER TO
IFR/LIFR LEVELS AS WELL. THERE COULD BE SOME DRIZZLE BENEATH THE
STRATUS THOUGH CONFIDENCE IS TOO LOW TO INCLUDE IN A TAF. THE
STRATUS WILL STICK AROUND THROUGH THE MORNING HOURS BEFORE LIFTING
TO MVFR LEVELS AND AND SOMEWHAT BREAKING UP FOR THE AFTERNOON
TIMEFRAME. HOWEVER, THE STRATUS LOOKS TO FILL BACK IN DURING THE
EVENING TIMEFRAME TO END THE TAF PERIOD. THE STRATUS LOOKS TO REMAIN
AT MVFR LEVELS FOR THE END OF THE PERIOD BUT COULD SINK LOWER,
ESPECIALLY JUST AFTER THE PERIOD ENDS.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...MEYERS
DISCUSSION...DUX
AVIATION...MEYERS
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