689
FXUS63 KFSD 031124
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
524 AM CST MON FEB 3 2025
KEY MESSAGES
- VERY LIGHT PRECIPITATION REMAINS POSSIBLE THROUGH THE BULK OF
THE MORNING HOURS THIS MORNING ALONG AND NORTH OF HIGHWAY-14.
- NEAR TO BELOW NORMAL TEMPERATURES IS EXPECTED FOR MUCH OF THE
UPCOMING WEEK.
- TWO CHANCES FOR PRECIPITATION ARE POSSIBLE THIS WEEK. CHANCE
FOR LIGHT FREEZING DRIZZLE AND SNOW ON WEDNESDAY (20-40% CHANCE)
AND ANOTHER CHANCE FOR SNOW ON SATURDAY (40-80% CHANCE).
DISCUSSION
ISSUED AT 308 AM CST MON FEB 3 2025
LIGHT SNOW CONTINUES TO FALL NORTH OF THE AREA THIS MORNING.
LOCATIONS ALONG HIGHWAY-14 REMAIN DRY ALTHOUGH SOME VERY LIGHT SNOW
IS POSSIBLE INTO THE MID MORNING HOURS. MINOR IF ANY ADDITIONAL SNOW
ACCUMULATIONS IS EXPECTED. THE REST OF TODAY WILL BE MOSTLY CLOUDY
WITH NEAR TO BELOW AVERAGE HIGHS FROM THE UPPER TEENS ALONG HIGHWAY-
14 DOWN TO THE MID 30S ALONG HIGHWAY-20. LOW TEMPERATURES WILL FALL
TO THE SINGLE DIGITS TO LOW TEENS THANKS TO A COLD SURFACE HIGH
SLIDING NORTH OF THE AREA. WINDS WILL BE SLIGHTLY ELEVATED THROUGH
THE NIGHT DUE TO A TIGHTER SURFACE PRESSURE GRADIENT (SPG) IN PLACE.
THIS WILL PUSH WIND CHILLS DOWN TO -15F TO 0F ACROSS THE AREA,
MAKING FOR A COLD MORNING ACROSS THE AREA.
TUESDAY WILL BE A RINSE AND REPEAT OF MONDAY AS 925 MB TEMPERATURES
REMAIN IN THE NEGATIVE TEENS ALOFT. MIXING THESE TEMPERATURES TO THE
SURFACE WILL RESULT IN HIGHS FROM THE TEENS TO UPPER 20S FROM NORTH
TO SOUTH. THE SPG WILL BE RELAXING THROUGHOUT THE DAY AS THE
PREVIOUSLY MENTIONED HIGH DEPARTS TO THE EAST. THIS WILL STILL
RESULT IN COLDER WIND CHILLS THROUGHOUT THE DAY WITH VALUES DOWN TO
THE POSITIVE SINGLE DIGITS TO TEENS. LOW TEMPERATURES WILL FALL TO
THE SINGLE DIGITS AND TEENS OVERNIGHT.
THE NEXT CHANCE FOR PRECIPITATION COMES ON WEDNESDAY AS AN UPPER
WAVE EJECTS FROM THE ROCKY MOUNTAINS AND INTO THE PLAINS. THE EXIT
REGION OF THE UPPER LEVEL JET WILL RESULT IN STRENGTHENING WARM AIR
ADVECTION (WAA) ACROSS THE FORECAST AREA. THIS IS DUE TO THE JETS
INDIRECT THERMAL CIRCULATION BRINGING A RETURN OF BROAD SOUTHERLY
FLOW AT 850 MB. HIGHS AT THIS TIME LOOK TO WARM TO THE MID 20S TO UP
TO ABOUT FREEZING (32F). AT THE SAME TIME, 850 MB TEMPERATURES LOOK
TO WARM TO JUST ABOVE 0C ALOFT, CREATING A WARM NOSE MAINLY FOR
LOCATIONS EAST OF I-29 BUT ESPECIALLY ACROSS NORTHWEST IOWA. WITH
SOUTHERLY FLOW IN PLACE, SOME MOISTURE WILL BE ADVECTED INTO THE
AREA, SETTING THE STAGE FOR MIXED PRECIPITATION. HOWEVER, THE
QUALITY OF MOISTURE DOES APPEAR TO BE LACKING AS SHOWN IN THERMAL
PROFILES. GIVEN A MAINLY DRY DENDRITIC GROWTH ZONE (DGZ) ACROSS
NORTHWEST IOWA, THINK THAT LIGHT FREEZING DRIZZLE WILL BE THE
PREDOMINANT PRECIPITATION TYPE ACROSS IN THIS AREA. COULD SEE
FREEZING DRIZZLE BLEED OVER INTO ADJACENT PARTS OF SOUTHWEST
MINNESOTA AS WELL. HOWEVER, THE DGZ LOOKS TO BE BETTER SATURATED
ACROSS SOUTHWEST MINNESOTA WHERE LIGHT SNOW IS POSSIBLE. THE CHANCES
(~30% CHANCE) FOR LIGHT SNOW WILL EXTEND WEST/NORTHWESTWARD TO
INCLUDE MOST OF I-90 UP TO HIGHWAY-14. IN TERMS OF PRECIPITATION
TYPE, THE NBM SHOWS ABOUT A 30% CHANCE FOR FREEZING RAIN ACROSS
PARTS OF NORTHWEST IOWA. IN TERMS OF AMOUNTS, THE ENSEMBLES ONLY
SHOW A 20-40% CHANCE FOR EXCEEDING A TENTH OF AN INCH OF LIQUID QPF.
IN TERMS OF PRECIPITATION TYPE, THE NBM SUGGESTS A SIMILAR
PROBABILITY OF 20-40% FOR ICE ACCUMULATIONS TO EXCEED A HUNDREDTH OF
AN INCH EAST OF I-29. THESE PROBABILITIES QUICKLY DIMINISH FOR FIVE
HUNDREDTHS AND A TENTH OF AN INCH OF ICE. FOR SNOW, THE PROBABILITY
IS HIGHER, UP TO A 40-60% CHANCE FOR EXCEEDING A TENTH OF AN INCH.
HOWEVER, THESE PROBABILITIES ALSO DIMINISH FOR RECEIVING AN INCH OR
MORE. THE GENERALLY LACKING SATURATION AND PROBABILITIES SUPPORT THE
NOTION THAT THIS WILL BE A LIGHT PRECIPITATION EVENT. COULD SEE
GUSTY WINDS WEDNESDAY NIGHT THOUGH AS THE PRECIPITATION PUSHES
EASTWARDS AND A SHOT OF COLD AIR ADVECTION (CAA) IS DELIVERED ACROSS
THE FORECAST AREA. MEDIUM RANGE GUIDANCE SHOWS WINDS OF 40 TO UP TO
60 KNOTS AT 850MB. HOWEVER, QUESTIONS REMAIN AS TO HOW HIGH MIXING
WILL BE ABLE TO REACH UP TO. OTHERWISE, TEMPERATURES WILL FALL TO
THE SINGLE DIGITS AND TEENS OVERNIGHT.
THURSDAY AND FRIDAY LOOK QUIET WITH HIGHS MODERATING TO THE 20S,
30S, AND POTENTIALLY UP TO 40F ON FRIDAY. HOWEVER, ANOTHER UPPER
LEVEL WAVE WILL PUSH INTO THE NORTHERN PLAINS LATE FRIDAY THROUGH
SATURDAY. THERE IS UNCERTAINTY REGARDING HOW THIS WAVE WILL EVOLVE
AMONGST THE DETERMINIST MODELS. CHANCES FOR PRECIPITATION LOOK
DECENTLY HIGH AT THIS TIME WITH THE ENSEMBLES SHOWING A BROAD 40-80%
CHANCE FOR EXCEEDING A TENTH OF AN INCH OF LIQUID PRECIPITATION.
HOWEVER, THE HIGHEST PROBABILITIES LIE NORTH OF THE FORECAST AREA.
HAVE STUCK WITH MODEL BLENDED POPS AT THIS TIME BUT WILL KEEP AN EYE
ON THIS SYSTEMS POTENTIAL OVER THE COMING DAYS. HIGH TEMPERATURES
LOOK TO REMAIN IN THE UPPER 20S TO UPPER 30S WITH LOWS FALLING TO
THE SINGLE DIGITS AND TEENS.
NO BREAK IN THE NEAR SEASONAL TEMPERATURES FOR SUNDAY AND MONDAY AS
HIGHS REMAIN IN THE TEENS, 20S, AND LOW 30S WITH LOWS FALLING TO THE
SINGLE DIGITS AND TEENS. COULD SEE LOWS FALL TO BELOW 0F MONDAY
NIGHT BUT THIS IS QUITE UNCERTAIN AT THIS TIME.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 524 AM CST MON FEB 3 2025
HIGH LEVEL CIRRUS AND LOW LEVEL STRATUS BEGIN THE TAF PERIOD. THE
STRATUS IS SITTING AT MVFR/IFR LEVELS AND IS CURRENTLY ALONG AND
NORTH OF I-90. THE STRATUS WILL SINK SOUTHWARDS THROUGH THE REST OF
THE MORNING HOURS AND IS EXPECTED TO REACH KSUX. WHILE NO
PRECIPITATION IS EXPECTED BENEATH THE STRATUS, FLURRIES ARE
POSSIBLE, ESPECIALLY ALONG HIGHWAY-14. LATEST MODELING HAS THE
STRATUS LIFTING DURING THE AFTERNOON HOURS BACK TO VFR LEVELS. WHILE
THAT TREND HAS BEEN INCLUDED IN ALL TAFS, THERE IS UNCERTAINTY IN
THAT THE STRATUS COULD LINGER AT MVFR/IFR LEVELS FOR A LARGE PART OF
TODAY. TRENDS WILL BE MONITORED.
IN TERMS OF WINDS, BREEZY NORTHERLY WINDS IS EXPECTED TODAY WITH
GUSTS UP TO AROUND 20 KNOTS. THE WINDS WILL SLOWLY TURN BACK TO OUT
OF THE NORTHEAST DURING THE OVERNIGHT HOURS WITH SPEEDS UP TO ABOUT
10 KNOTS. THE STRATUS SHOULD LIFT BY THIS PERIOD OF TIME BUT AS
STATED EARLIER, TRENDS WILL BE MONITORED.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...MEYERS
AVIATION...MEYERS
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