912  
FXUS63 KFSD 180029  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
729 PM CDT WED AUG 17 2022  
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 207 PM CDT WED AUG 17 2022  
 
SURFACE RIDGE AXIS HAS SHIFTED A BIT FARTHER SOUTHEAST TODAY,  
ALLOWING FOR A STEADIER, THOUGH STILL RATHER LIGHT, SOUTH-SOUTHWEST  
RETURN FLOW INTO THE WESTERN AND NORTHERN PORTIONS OF THE CWA. HAVE  
SEEN A BROAD AREA OF CUMULUS DEVELOP THROUGH THE AFTERNOON, DRIVEN  
BY DIURNAL HEATING, WHICH SHOULD ALLOW THE CLOUDS TO DIMINISH TOWARD  
SUNSET. WILL BE A QUIET NIGHT, WITH PERHAPS SOME INCREASE IN CLOUDS  
AHEAD OF OUR NEXT SYSTEM. INCREASE IN CLOUDS AND OVERNIGHT WINDS  
SHOULD HOLD TEMPERATURES UP A LITTLE MORE, AND ALSO PRECLUDE FOG  
DEVELOPMENT AS WE HAVE SEEN IN RECENT NIGHTS, WITH LOWS IN UPPER 50S  
TO LOWER 60S.  
 
ATTENTION FOR THE NEXT COUPLE OF DAYS THEN TURNS TO SHORTWAVE WHICH  
HAS BEEN MOVING FROM EASTERN MT INTO WESTERN ND TODAY. SLOW MOVING  
UPPER LOW OVER NEW ENGLAND, COMBINED WITH A BROADER TROUGH CENTERED  
OVER HUDSON BAY, APPEARS TO HALT EASTWARD PROGRESSION OF TRAILING  
WAVES. THIS ALLOWS THE ND WAVE TO DIG SOUTHWARD INTO THE DAKOTAS AND  
MINNESOTA BY LATE THURSDAY.  
 
AHEAD OF THIS WAVE, SHOULD SEE A MILD THURSDAY, WITH SOUTHWEST FLOW  
AHEAD OF AN ASSOCIATED COLD FRONT HELPING KEEP TEMPERATURES SIMILAR  
TO TODAY, WITH HIGHS IN THE UPPER 70S-MID 80S. COULD SEE SCATTERED  
SHOWERS OR A FEW STORMS IN THE WARM ADVECTION AHEAD OF THE WAVE IN  
THE MORNING, MAINLY IMPACTING NORTHEAST PORTIONS OF THE FORECAST  
AREA. SLIGHTLY BETTER CHANCE FOR SCATTERED STORM DEVELOPMENT ALONG  
AND AHEAD OF THE COLD FRONT BY LATE AFTERNOON.  
 
ACCOMPANYING RETURN OF MOISTURE SHOULD LEAD TO AN INCREASE IN  
INSTABILITY AHEAD OF THE BOUNDARY, THOUGH SHEAR IS ON THE WEAK SIDE,  
SO NOT EXPECTING MUCH IN THE WAY OF A SEVERE THREAT MOST AREAS.  
HOWEVER, THE SUB-CLOUD LAYER IS ON THE DRY SIDE, LENDING TO AN  
INCREASE IN DCAPE VALUES WHICH MAY PROMOTE GUSTY WINDS WITH ANY  
STORMS THAT DEVELOP ALONG THE BOUNDARY LATE AFTERNOON INTO THE  
EVENING.  
   
LONG TERM
 
(THURSDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 207 PM CDT WED AUG 17 2022  
 
WAVE BECOMES MUCH MORE WRAPPED UP AS IT CONTINUES TO SLIDE SOUTHWARD  
TOWARD THE TRI-STATE AREA THURSDAY NIGHT, WITH THE RESULTING CLOSED  
UPPER LOW DRIFTING ONLY SLOWLY EAST-SOUTHEAST ACROSS NORTHERN IOWA  
THROUGH SATURDAY.  
 
PROXIMITY OF THE UPPER LOW WILL RESULT IN A COOL AND SOMEWHAT DAMP  
END TO THE WEEK. WHILE WE SHOULD SEE THE HIGHER CHANCES FOR A MORE  
WIDESPREAD RAIN, AND PERHAPS A FEW EMBEDDED STORMS, SWING THROUGH  
THE AREA AHEAD OF THE UPPER LOW ON FRIDAY, COULD CONTINUE TO SEE  
SCATTERED LIGHT SHOWERS LINGER INTO SATURDAY, AT LEAST FOR AREAS  
EAST OF I-29, AS MOISTURE AND WEAK INSTABILITY WRAPS AROUND THE BACK  
SIDE OF THE SLOWLY DEPARTING UPPER LOW.  
 
OVERALL, NOT EXPECTING A HEAVY RAIN THREAT WITH THIS WAVE, BUT  
PORTIONS OF THE AREA COULD SEE 2 DAY RAIN TOTALS UPWARDS OF A HALF  
INCH BY LATE SATURDAY. BOTH GEFS AND EC ENSEMBLES INDICATE THE BEST  
CHANCE FOR THESE HIGHER AMOUNTS ACROSS THE NORTHEAST HALF OF THE  
FORECAST AREA, GENERALLY NORTHEAST OF A KHON-KFSD-KSPW LINE. AS  
MENTIONED ABOVE, TEMPERATURES WILL REMAIN ON THE COOL SIDE DURING  
THIS TIME FRAME, WITH HIGHS GENERALLY IN THE 70S. HOWEVER, WITH THE  
ANTICIPATED RAINFALL/CLOUDS, THERE IS A POTENTIAL THAT READINGS WILL  
STRUGGLE TO TOP 70 NEAR/NORTH OF I-90 ON FRIDAY.  
 
BY MIDDAY SUNDAY, THE UPPER LOW SHOULD HAVE PULLED FAR ENOUGH EAST  
TOWARD THE GREAT LAKES TO LESSEN ITS INFLUENCE IN OUR CWA. THIS WILL  
BE FOLLOWED BY AN UPPER RIDGE BUILDING NORTHWARD THROUGH THE PLAINS,  
WHICH SHOULD BRING MORE SEASONABLE TEMPERATURES AND GENERALLY DRY  
CONDITIONS BACK TO THE REGION THROUGH THE FIRST HALF OF NEXT WEEK.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 710 PM CDT WED AUG 17 2022  
 
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THURSDAY MORNING.  
DISSIPATING DIURNAL CUMULUS WILL GIVE MOSTLY CLEAR SKIES EARLY THIS  
EVENING BEFORE ANVIL CIRRUS SPREADS IN FROM THE WEST OVERNIGHT.  
SCATTERED, HIGH BASED SHOWERS WILL SPREAD IN THURSDAY MORNING.  
COVERAGE AND CONFIDENCE IN SHOWERS IMPACTING TAF SITES IS TOO LOW  
TO INCLUDE IN TAF AT THIS TIME BUT COULD IMPACT HURON BY 12Z AND  
SIOUX FALLS BY LATE MORNING. BEST CHANCE OF RAIN AND HIGHER  
AMOUNTS IS NORTHEAST OF A MADISON TO SIOUX FALLS TO SPENCER LINE.  
 

 
   
FSD WATCHES/WARNINGS/ADVISORIES
 
 
SD...NONE.  
MN...NONE.  
IA...NONE.  
NE...NONE.  

 
 

 
 
SHORT TERM...JH  
LONG TERM...JH  
AVIATION...BP  
 
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