858
FXUS63 KFSD 250719
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
219 AM CDT MON AUG 25 2025
KEY MESSAGES
- FALL-LIKE WEATHER PERSISTS TODAY AND CONTINUES THROUGH THE
MIDDLE OF NEXT WEEK. LOW TEMPERATURES MAY FALL WITH POSSIBLE
3-4 DEGREES OF RECORD FOR SOME LOCATIONS TONIGHT.
- WHILE A FEW SHOWERS MAY BE IN THE REGION THE UPCOMING DAYS,
THE NEXT APPRECIABLE RAIN RISK WON'T ARRIVE UNTIL NEXT
WEEKEND.
DISCUSSION
ISSUED AT 218 AM CDT MON AUG 25 2025
OUR TASTE OF FALL CONTINUES FOR THE NEXT FEW DAYS. TEMPERATURES AS
OF THE TIME OF THIS DISCUSSION ARE ALREADY INTO THE MID 40S TO LOWER
50S, AND EXPECT THEM TO FALL A FEW MORE DEGREES BY DAYBREAK. MAY
STILL GET WITHIN A FEW DEGREES OF RECORD LOW FOR SIOUX CITY THIS
MORNING.
SURFACE HIGH PRESSURE SLIDES EAST TODAY THROUGH TUESDAY NIGHT AND
NORTHWESTERLY FLOW ALOFT PREVAILS. COOLER TEMPERATURES THANKS TO
THESE FEATURES KEEP CONDITIONS BELOW AVERAGE - HIGHS IN THE MID 60S
TO MID 70S TODAY AND SLIGHTLY WARMER ON TUESDAY AS SURFACE FLOW
SHIFTS SOUTHERLY. FOR CLIMATOLOGICAL CONTEXT, TEMPERATURES ALOFT ARE
WITHIN THE COLDEST 1% WHEN COMPARED TO CLIMATOLOGICAL NORMALS. LOWS
TONIGHT FALL INTO THE MID 40S TO LOWER 50S, WHICH COULD FALL TO
WITHIN A FEW DEGREES OF RECORD COLD FOR SOME LOCATIONS. EXPECT
SLIGHTLY WARMER TUESDAY NIGHT. DRY CONDITIONS PREVAIL, WITH FAIR
WEATHER AND DIURNALLY DRIVEN CUMULUS CLOUDS DEVELOPING LATE MORNING
AND DIMINISHING AROUND SUNSET EACH DAY.
WEDNESDAY SEES THE RETURN OF CLOSER TO NORMAL TEMPERATURES, AS
SOUTHERLY SURFACE FLOW AND WAA AID IN WARMING US BACK INTO THE MID
70S TO MID 80S. SOME GUIDANCE, BOTH DETERMINISTIC AND ENSEMBLE,
INDICATES SOME LOW END (LESS THAN 20%) CHANCES FOR LIGHT RAIN
WEDNESDAY AND WEDNESDAY NIGHT WITH A WEAK SHORT WAVE MOVING THROUGH
THE AREA. HOWEVER, SOUNDINGS SHOW FAIRLY DRY SUB CLOUD LAYER, SO
CONFIDENCE IS LOW IN OCCURRENCE. IF ANY RAINFALL DEVELOPS, WOULD
EXPECT IT TO BE LIGHT (LESS THAN A TENTH OF AN INCH).
TROUGH AXIS ALOFT DEEPENS ACROSS THE EASTERN US LATE WEEK, WHICH
KEEPS OUR REGION IN A NORTHWESTERLY FLOW REGIME. A COUPLE OF SHORT
WAVES ARE PROGGED TO MOVE THROUGH THE OVERALL PATTERN, BUT WITH A
LACK OF MOISTURE THROUGH THE COLUMN, THINK THAT WE SHOULD STAY DRY.
TEMPERATURES REMAIN ON THE COOLER SIDE OF AVERAGE, WITH HIGHS IN THE
MID 70S TO MID 80S AND LOWS IN THE MID 50S.
THE START OF LABOR DAY WEEKEND MAY BE A BIT MORE ACTIVE WITH SHOWER
AND STORM CHANCES RETURNING THE REGION. GUIDANCE IS SPLIT SO DETAILS
REMAIN UNCERTAIN, BUT EXPECT A TROUGH AXIS OR STRONGER MID LEVEL
WAVE TO MOVE SOUTHEAST, WITH SURFACE LOW PRESSURE EJECTING OUT OF
THE ROCKIES. THERE MAY BE A COUPLE OF WAVES, WITH GUIDANCE VARYING
QUITE A BIT ON TIMING, LOCATION, AND STRENGTH. SEVERE WEATHER IS
UNLIKELY. CURRENT ENSEMBLE PROBABILITIES OF A TENTH OF AN INCH OR
RAIN OR MORE ARE AROUND 40% OR LESS IN ANY 24 HOUR PERIOD THROUGH
THE WEEKEND.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1047 PM CDT SUN AUG 24 2025
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD, WITH DIURNAL
CUMULUS REDEVELOP LATE MORNING-MIDDAY MONDAY AND DISSIPATING
AGAIN AROUND SUNSET. LIGHT NORTHERLY TO VARIABLE WINDS WILL
PREVAIL.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...SG
AVIATION...JH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page