766
FXUS63 KFSD 052321
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
621 PM CDT TUE MAY 5 2026
KEY MESSAGES
- AREAS OF FROST ARE EXPECTED TONIGHT ESPECIALLY NORTH OF I-90.
BOTH A FREEZE WARNING AND FROST ADVISORY WILL BE IN EFFECT
FROM 1 AM THROUGH 7 AM CDT FOR PORTIONS OF THE AREA. MAKE
SURE TO COVER/BRING IN ANY SENSITIVE VEGETATION!
- ADDITIONAL AREAS OF FROST WILL BE POSSIBLE BY THURSDAY
MORNING. HOWEVER, SLIGHTLY LESS COLD TEMPERATURES AND HIGHER
DEW POINT DEPRESSION MAY LIMIT COVERAGE/EXTENT.
- AFTER BELOW NORMAL TEMPERATURES THROUGH WEDNESDAY, NEAR TO
ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO THE WEEKEND WITH
HIGHS MAINLY IN THE 60S TO 70S.
DISCUSSION
ISSUED AT 120 PM CDT TUE MAY 5 2026
CURRENTS & TONIGHT: ANOTHER MILD AND BREEZY DAY CONTINUES! TAKING A
LOOK ACROSS THE AREA THIS AFTERNOON, CLOUD COVER CONTINUES TO FILTER
IN AS BREEZY NORTHWESTERLY WINDS PERSISTS WITH GUSTS BETWEEN 20-30
MPH. WHILE DRIER CONDITIONS THIS AFTERNOON COULD PROMOTE SOME
LOCALLY ELEVATED FIRE CONCERNS, GREENER FUELS AND MILDER
TEMPERATURES WILL LIKELY KEEP ANY FIRE DANGER RISK IN THE LOW TO
MODERATE CATEGORIES. OTHERWISE, THE MAIN CONCERN TONIGHT CONTINUES
TO BE THE POTENTIAL FOR FROST/FREEZE CONDITIONS. WITH THE RETURN OF
NEAR TO SUB-FREEZING TEMPERATURES (26-32 DEGREES) AND LIGHTER
SURFACE WINDS TONIGHT, AREAS OF FROST ARE EXPECTED TO DEVELOP ACROSS
MOST AREAS ESPECIALLY ALONG AND NORTH OF I-90. WHILE THERE IS
STILL SOME UNCERTAINTY WITH COVERAGE MAINLY DUE TO 5-10 DEGREE
DEW POINT DEPRESSION, STILL THINKING THE CONDITIONS WILL DO JUST
ENOUGH FOR SENSITIVE PLANTS TO BE AFFECTED. AS A RESULT, HAVE
COLLABORATED WITH NEIGHBORING OFFICES TO ISSUE BOTH A FREEZE
WARNING AND FROST ADVISORY FROM 1 AM TO 7 AM CDT. MY THOUGHTS
ARE THE WARNING IS IN PLACE WHERE CONFIDENCE IS HIGHEST ON SUB-
FREEZING TEMPERATURES AND WIDESPREAD DEVELOPMENT WITH SMALL DEW
POINT DEPRESSIONS. THE ADVISORY IS IN PLACE FOR AREAS WHERE
PATCHY TO SCATTERED AREAS OF FROST ARE POSSIBLE. WITH ALL THIS
IN MIND, MAKE SURE TO COVER/BRING IN ANY SENSITIVE VEGETATION!
WEDNESDAY-THURSDAY: LOOKING INTO THE MIDWEEK, LINGERING COLD AIR
ADVECTION (CAA) AND NORTHWESTERLY SURFACE WINDS WILL KEEP THE MILDER
STRETCH GOING THROUGH AT LEAST WEDNESDAY NIGHT WITH HIGHS IN THE LOW
TO UPPER 50S AND OVERNIGHT LOWS IN THE LOW TO MID 30S. SIMILAR TO
TONIGHT, WE COULD SEE ADDITIONAL CHANCES FOR FROST BY THURSDAY
MORNING. HOWEVER, BORDER-LINE TEMPERATURES AND A HIGHER DEW POINT
DEPRESSION (8-12 DEGREES) WILL LIKELY MAKE COVERAGE MORE PATCHY THAN
SCATTERED WITH THE MAIN FOCUS BEING ALONG OUR RIVER VALLEYS. BY
THURSDAY, WE'LL START TO TREND WARMER AS A WEAKENING RIDGE AND A
RETURN TO SOUTHWESTERLY TO WESTERLY FLOW BRINGS AN INFLUX OF WARMER
AIR TO THE AREA. THIS WILL LEAD TO BEAUTIFUL CONDITIONS AS HIGHS
PEAK IN THE 60S TO LOW 70S FOR THE DAY WITH LIGHTER WINDS.
THE WEEKEND ONWARDS: HEADING INTO THE EXTENDED PERIOD, AN ACTIVE
PATTERN WILL ONCE AGAIN RETURN AS CONTINUOUS NORTHWESTERLY FLOW
ALOFT HELPS USHER IN MULTIPLE WAVES THROUGH OUR AREA. THE STRONGEST
OF WHICH LOOKS TO ARRIVE BETWEEN SATURDAY TO SUNDAY. WHILE THERE IS
STILL SOME VARIABILITY AMONG LONG-RANGE GUIDANCE, THIS STILL LOOKS
LIKE OUR BEST CHANCES (20%-30%) FOR AREAS ALONG AND SOUTH OF I-90 TO
SEE RAIN. THIS IS FURTHER AGREED UPON WITHIN ENSEMBLE GUIDANCE WITH
MOST MEMBERS SHOWING A 30%-60% CHANCE FOR AT LEAST MEASURABLE
PRECIPITATION. LASTLY, WE'LL CONTINUE OUR WARMING TREND THROUGH
MONDAY WITH HIGHS MAINLY IN THE 60S TO LOW 70S.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 621 PM CDT TUE MAY 5 2026
VFR CONDITIONS ARE EXPECTED TO PREVAIL THIS PERIOD. BREEZY
NORTHWESTERLY WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT.
SCATTERED TO BROKEN MID-LEVEL CLOUDS WILL ALSO PERSIST THROUGH THE
PERIOD. AFTER SUNRISE, WINDS BECOME NORTHWEST AROUND 10 KTS. WINDS
CONTINUE TO DIURNALLY INCREASE IN THE AFTERNOON WITH GUSTS OF 15-20
KTS EXPECTED.
FSD WATCHES/WARNINGS/ADVISORIES
SD...FROST ADVISORY FROM 1 AM TO 7 AM CDT WEDNESDAY FOR SDZ064>067-
070-071.
FREEZE WARNING FROM 1 AM TO 7 AM CDT WEDNESDAY FOR SDZ038>040-
052>062.
MN...FROST ADVISORY FROM 1 AM TO 7 AM CDT WEDNESDAY FOR MNZ090.
FREEZE WARNING FROM 1 AM TO 7 AM CDT WEDNESDAY FOR MNZ071-072-
080-081-089-097-098.
IA...FROST ADVISORY FROM 1 AM TO 7 AM CDT WEDNESDAY FOR IAZ001>003-
012>014-020>022.
NE...NONE.
DISCUSSION...05
AVIATION...AJP
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