494  
FXUS63 KFSD 191748  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
1248 PM CDT TUE MAY 19 2026  
   
KEY MESSAGES  
 
- SPRINKLES ARE POSSIBLE THIS AFTERNOON ACROSS SOUTHWESTERN  
MINNESOTA AND ADJACENT PORTIONS OF SOUTH DAKOTA AND IOWA.  
 
- FROST AND FREEZE CONDITIONS ARE EXPECTED TONIGHT INTO EARLY  
WEDNESDAY MORNING ACROSS THE AREA - TAKE PRECAUTIONS TO  
PROTECT SENSITIVE VEGETATION. FROST/FREEZE HEADLINES GO INTO  
EFFECT LATE TONIGHT.  
 
- COOLER CONDITIONS CONTINUE THIS WEEK. DRY WEATHER EXPECTED MID  
WEEK. ANOTHER ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS IS  
EXPECTED FROM THURSDAY AFTERNOON THROUGH FRIDAY. SEVERE  
WEATHER IS UNLIKELY. ENSEMBLE OUTPUT SUGGEST ABOUT A 10 TO 30  
PERCENT CHANCE FOR A HALF AN INCH OF RAIN DURING THIS TIME.  
 
 
   
DISCUSSION  
 
ISSUED AT 1245 PM CDT TUE MAY 19 2026  
 
COOL HIGH PRESSURE SETTLES INTO THE AREA TONIGHT AND WILL BRING A  
VERY GOOD CHANCE FOR TEMPERATURES TALL TO OR BELOW 35 FOR MOST OF  
THE AREA WITH TEMPERATURES AT OR BELOW FREEZING POSSIBLE NORTH OF I-  
90. THUS A FREEZE WARNING IS IN PLACE FOR HIGHWAY 14 AND NEARBY  
LOCATIONS IN SD WITH A FROST ADVISORY FOR THE REMAINDER OF THE AREA.  
 
ISOLATED POCKETS OF FOG WILL BE POSSIBLE EARLY WEDNESDAY MORNING BUT  
AT THIS TIME IT DOES NOT APPEAR AS THOUGH IT WILL BECOME MORE  
WIDESPREAD.  
 
A WEAK WAVE WILL MOVE THROUGH THE AREA ON WEDNESDAY WHICH COULD  
BRING A FEW SPRINKLES BUT OVERALL SHOULD MAINLY BE AN INCREASE IN  
MID LEVEL CLOUDS. OTHERWISE SLIGHTLY MORE MILD TEMPERATURES ARE  
EXPECTED AS SOUTHERLY FLOW DEVELOPS AND BRINGS HIGHS BACK INTO THE  
60S FOR MOST LOCATIONS.  
 
ANOTHER WEAK WAVE MOVES ACROSS NE ON THURSDAY AND COULD BRING SOME  
LIGHT SHOWERS TO THE MISSOURI RIVER CORRIDOR INTO NORTHWEST IA.  
PRECIPITATION AMOUNTS WILL BE LIGHT AS MOISTURE WITH THE SYSTEM IS  
VERY LIMITED.  
 
A BIT STRONGER AND MORE NEGATIVELY TILTED SYSTEM WILL SWING THROUGH  
ON FRIDAY BRINGING THE NEXT BEST CHANCE FOR RAINFALL. INSTABILITY  
VERY MINOR WITH CAPE VALUES GENERALLY 500 J/KG OR LESS. THE MODEL  
SOUNDINGS DO INDICATE THE POTENTIAL FOR SOME EFFICIENT RAINFALL  
HOWEVER SO MAYBE SOME HALF INCH OR SO AMOUNTS WILL BE POSSIBLE. THE  
LATEST ENSEMBLE OUTPUT INDICATING ABOUT A 10 TO 30 PERCENT CHANCE  
FOR MORE THAN A HALF AN INCH AND THE LATEST NAM IS INDICATING A  
COUPLE OF AREAS WITH MORE THAN A HALF AN INCH. LONG STORY SHORT,  
ONLY MINOR IMPACTS EXPECTED WITH NO SEVERE WEATHER.  
 
AS THIS SYSTEM MOVES NORTHEAST AND OUT OF THE AREA A FEW LINGERING  
SHOWERS WILL BE POSSIBLE ON SATURDAY, BUT WARMER TEMPERATURES WILL  
BEGIN TO WORK INTO THE REGION. SUNDAY THROUGH THE MIDDLE OF NEXT  
WEEK WILL SEE TROUGHINESS TO THE WEST AND RIDGING TO THE EAST,  
LEAVING THE AREA IN WARMER SOUTHERLY FLOW. WHILE THERE IS VERY  
LITTLE AGREEMENT, THERE SHOULD BE A COUPLE OF WEAKER WAVES THAT COULD  
BRING SHOWERS AND THUNDERSTORMS TO THE AREA, BUT FOR NOW CONFIDENCE  
IS TOO LOW TO INCLUDE IN THE FORECAST. OTHERWISE HIGHS SHOULD BE IN  
THE 80S WITH LOWS MAINLY IN THE 50S MONDAY THROUGH WEDNESDAY.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/  
 
ISSUED AT 1245 PM CDT TUE MAY 19 2026  
 
LINGERING MVFR CEILINGS ARE LIKELY EAST OF I-29 THROUGH ABOUT  
MID AFTERNOON, WITH THE ENTIRE AREA VFR AFTER THIS. SOME PATCHY  
FOG WILL BE POSSIBLE LATE TONIGHT INTO WEDNESDAY MORNING, BUT  
CONFIDENCE TOO LOW TO INCLUDE IN TAF. OTHERWISE GUSTS OF 25 TO  
30 MPH LIKELY THROUGH THE AFTERNOON BUT QUICKLY DIMINISH THIS  
EVENING.  
 
 
   
FSD WATCHES/WARNINGS/ADVISORIES  
 
SD...FROST ADVISORY FROM 1 AM TO 8 AM CDT WEDNESDAY FOR SDZ050-  
054>071.  
FREEZE WARNING FROM 1 AM TO 8 AM CDT WEDNESDAY FOR SDZ038>040-  
052-053.  
MN...FROST ADVISORY FROM 1 AM TO 8 AM CDT WEDNESDAY FOR MNZ071-072-  
080-081-089-090-097-098.  
IA...FROST ADVISORY FROM 1 AM TO 8 AM CDT WEDNESDAY FOR IAZ001>003-  
012>014-020>022-031-032.  
NE...FROST ADVISORY FROM 1 AM TO 8 AM CDT WEDNESDAY FOR NEZ013-014.  
 
 
 
 
 
DISCUSSION...08  
AVIATION...08  
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