896
FXUS63 KFSD 190502
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1202 AM CDT TUE MAY 19 2026
KEY MESSAGES
- POCKETS OF DRIZZLE WILL CONTINUE THROUGH TUESDAY MORNING WITH
MAINLY LIGHT ACCUMULATIONS EXPECTED.
- AREAS OF FROST OR FREEZE WILL BE POSSIBLE BY WEDNESDAY
MORNING, WITH THE BETTER CHANCES NORTH OF I-90. MAKE SURE TO
COVER/BRING IN ANY SENSITIVE VEGETATION.
- COOLER CONDITIONS WILL PREVAIL THIS WEEK. DRY WEATHER
EXPECTED MID WEEK. ANOTHER ROUND OF STORMS WILL BE POSSIBLE
FROM THURSDAY THROUGH FRIDAY.
UPDATE
ISSUED AT 910 PM CDT MON MAY 18 2026
WHILE THE MAIN SEVERE RISK HAS NOW PUSHED EAST OF OUR AREA THIS
EVENING, SCATTERED LIGHT TO MODERATE SHOWERS WILL LIKELY PERSIST
INTO THE LATE EVENING AS A MID-LEVEL WAVE LIFTS THROUGH EASTERN SD
AND CENTRAL MN TONIGHT. GIVEN THE WANING MID-LEVEL SATURATION AND
LOWER CLOUD HEIGHTS ACCORDING TO SOUNDING, CAN'T RULE OUT A FEW
POCKETS OF DRIZZLE THROUGH TUESDAY MORNING AS WELL. WHILE THIS COULD
LEAD TO PERSISTENT DREARY CONDITIONS OVERNIGHT, ANY ACCUMULATIONS
WILL LIKELY BE ON THE LOWER SIDE WITH ANOTHER 0.10" OF AN INCH OR
LESS EXPECTED FOR MOST AREAS. OTHERWISE, SHOULD SEE CLOUD COVER
BEGIN TO GRADUALLY CLEAR FROM WEST TO EAST STARTING BY TUESDAY
MORNING. WITH LINGERING COLD AIR ADVECTION (CAA) ALOFT AND BREEZY
NORTHWESTERLY WINDS AT THE SURFACE, EXPECTED ANOTHER COOL DAY WITH
HIGHS MAINLY IN THE LOW TO UPPER 50S. WITH THIS IN MIND, MAKE SURE
TO TAKE A JACKET WHEN HEADING OUT ON TUESDAY AS THE COOLER AND
BREEZIER CONDITIONS COULD MAKE THINGS FEEL A BIT CHILLY AT TIMES
ESPECIALLY DURING THE FIRST HALF OF THE DAY.
DISCUSSION
ISSUED AT 1258 PM CDT MON MAY 18 2026
EARLY THIS AFTERNOON THE SURFACE TO 925 MB FRONT WAS ACROSS SOUTHERN
NE INTO SOUTHERN IA. GIVEN THE MARGINAL STRENGTH OF THE INCOMING
WAVE, THIS BOUNDARY SHOULD NOT LIFT FAR ENOUGH NORTH AND WEST
BY LATE AFTERNOON TO GET INTO THE AREA. THIS SHOULD LIMIT ANY
WIND AND TORNADO THREATS AND KEEP THEM OFF TO THE SOUTHEAST.
HOWEVER, SOME ELEVATED HAILERS WILL REMAIN POSSIBLE ACROSS
MAINLY NORTHWEST IA AS ELEVATED CAPE VALUES RAMP UP TO ABOUT
1000-1500 J/KG AND DEEP LAYER SHEAR IS A FAIRLY STRONG,
UNIDIRECTIONAL 40-50 KNOTS. THIS WOULD BE LIFTING A PARCEL FROM
ABOVE THE STRATUS LAYER, WHICH WOULD LIKELY BE IN ABOUT THE
800-750MB LAYER. THE BETTER CHANCES WILL BE FROM ABOUT 5 PM TO 9
PM.
AFTER THIS WAVE PUSHES THE REMAINING INSTABILITY OUT OF THE AREA
THIS EVENING, DRY AND COOL CONDITIONS ARE EXPECTED FOR TUESDAY AND
WEDNESDAY. THE ONLY CONCERNS ON THESE TWO DAYS WILL BE THE POTENTIAL
FOR FROST AND FREEZE CONDITIONS, MOSTLY NORTH OF I-90, AS SURFACE
HIGH PRESSURE IS IN PLACE. ANOTHER WEAKER WAVE MOVES THROUGH THE
AREA ON WEDNESDAY BUT FOR NOW THIS APPEARS TO BRING MAINLY MID LEVEL
CLOUD COVER.
THE NEXT BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME
THURSDAY NIGHT INTO FRIDAY NIGHT. AT THIS TIME SEVERE WEATHER LOOKS
TO REMAIN ISOLATED AS MODEL INSTABILITY FIELDS ARE HINTING AT 1000
J/KG CAPE OR LESS FOR THE MOST PART.
ONCE THIS WAVE PASSES A WARMING TREND SHOULD MOVE IN AS FLAT RIDGING
ALOFT DEVELOPS AHEAD OF A DEEPENING LOW PRESSURE IN THE NORTHERN
ROCKIES. SATURDAY SHOULD BE MILD, LIKELY IN THE 70S, WHILE SUNDAY
SEES THE BETTER CHANCE TO WARM INTO THE 80S.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1158 PM CDT MON MAY 18 2026
MAINLY MVFR TO IFR CONDITIONS WILL CONTINUE THIS TAF PERIOD.
TAKING A LOOK AT SATELLITE IMAGERY, AREAS OF MVFR TO LIFR
STRATUS CONTINUE TO BLANKET THE AREA WITH A FEW POCKETS OF
DRIZZLE. WHILE THESE CONDITIONS WILL LIKELY PERSIST IN THE
OVERNIGHT HOURS, SHOULD SEE GRADUAL IMPROVEMENTS FROM WEST TO
EAST BY MID-MORNING ON TUESDAY RETURNING THINGS BACK TO VFR
CONDITIONS. LASTLY, BREEZY NORTHWESTERLY WINDS WILL PERSIST
INTERMITTENTLY THROUGH TUESDAY EVENING TO END THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...05
DISCUSSION...08
AVIATION...05
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page