665  
FXUS63 KABR 261617 AAB  
AFDABR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE ABERDEEN SD  
1017 AM CST THU DEC 26 2024  
   
KEY MESSAGES  
 
- FOG IS EXPECTED TO DIMINISH SOME LATER TODAY BEFORE RETURNING  
AGAIN TONIGHT INTO FRIDAY MORNING. SOME OF THE FOG THIS MORNING  
COULD STILL BECOME LOCALLY DENSE WITH VISIBILITY DROPPING TO A  
QUARTER MILE OR LESS. A DENSE FOG ADVISORY REMAINS IN EFFECT FOR  
PARTS OF EAST CENTRAL SOUTH DAKOTA THIS MORNING.  
 
- VERY LIGHT PRECIPITATION (~20% CHANCE FOR MOISTURE) POTENTIAL  
WILL MOVE FROM WEST TO EAST TOWARD EASTERN SD/WESTERN MN LATE  
FRIDAY. A MIX OF PRECIPITATION TYPES (MAINLY EITHER VERY LIGHT  
RAIN OR VERY LIGHT FREEZING RAIN) IS POSSIBLE. IF ROAD SURFACES  
FAIL TO WARM ABOVE FREEZING, TRAVEL MAY BE IMPACTED.  
 
- TEMPERATURES WILL RUN AROUND 10 TO 20 DEGREES ABOVE NORMAL FROM  
TODAY THROUGH SUNDAY, BEFORE COOLING TO SOMETHING CLOSER TO  
NORMAL AT THE BEGINNING OF NEXT WEEK, PERSISTING INTO THE NEW  
YEAR.  
 
- THERE IS CURRENTLY AROUND A 40% CHANCE OF AN INCH OF SNOW MONDAY  
ACROSS CENTRAL SOUTH DAKOTA.  
 
 
   
UPDATE  
 
ISSUED AT 1010 AM CST THU DEC 26 2024  
 
WEB CAMS AND OBS REVEAL THERE CONTINUES TO BE AREAS OF FOG/DENSE  
FOG ACROSS THE GLACIAL LAKES REGION DOWN INTO THE KATY AREA. WILL  
CONTINUE WITH THE DENSE FOG ADVISORY UNTIL 18Z. OTHERWISE, THE SUN  
IS OUT IN ABERDEEN AS JUST ENOUGH SOUTH-SOUTHWEST WIND COMPONENT  
HAS HELPED SCOUR OUT THE EDGE IN THE JAMES RIVER VALLEY. MADE  
SOME ADJUSTMENTS TO SKY GRIDS TO BETTER MATCH RECENT SATELLITE  
TRENDS AND EXPECTATIONS OVER THE NEXT SEVERAL HOURS. EXPECTING  
HIGHS TO REACH THE MID/UPPER 30S AND 40S ALONG AND WEST OF THE  
JAMES RIVER WHERE MOSTLY SUNNY SKIES WILL PREVAIL. COOLER  
CONDITIONS FURTHER EAST WHERE CLOUDS WILL LINGER.  
 
 
   
SHORT TERM /TODAY THROUGH FRIDAY AFTERNOON/  
 
ISSUED AT 329 AM CST THU DEC 26 2024  
 
AT 3 AM CST, WEST OF THE JAMES RIVER VALLEY, SKIES ARE GENERALLY  
PARTLY TO MOSTLY CLEAR WITH TEMPERATURES HAVING COOLED INTO THE LOW  
TO MID 20S FOR THE MOST PART, DESPITE A WEST-COMPONENT BOUNDARY  
LAYER WIND DIRECTION (GENERALLY 5 TO 10 MPH). ACROSS AND EAST OF THE  
JAMES RIVER VALLEY, SKIES ARE OVERCAST, WITH SOME LIGHT FOG ONGOING  
OVER THE PRAIRIE COTEAU/SISSETON HILLS REGION OF THE CWA.  
TEMPERATURES UNDER THE CLOUDY SKY CONDITION HAVE REMAINED IN THE  
UPPER 20S TO LOWER 30S ON SOUTH WINDS 10 TO 20 MPH WITH SOME  
OCCASIONALLY HIGHER GUSTS.  
 
THERE IS A PRETTY ACTIVE POLAR JET STREAM HAPPENING OUT ACROSS THE  
WESTERN CONUS THIS MORNING. OVER THIS REGION, THE UPPER FLOW REMAINS  
RATHER WEAK AND BAGGY. THE SURFACE TROF THAT HAS WORKED ABOUT HALF-  
WAY THROUGH THE CWA WILL FADE AWAY TODAY, AS UPPER LEVEL HEIGHTS  
BEGIN TO RISE A LITTLE BIT. WITH NO END IN SIGHT TO THE NOTABLE LOW-  
LEVEL THERMAL INVERSION AND ALL THE LOW LEVEL MOISTURE TRAPPED UNDER  
IT, EXPECT STRATUS CLOUDS AND FOG POTENTIAL TO PERSIST. CONTINUING,  
FOR THE MOMENT, WITH A DENSE FOG ADVISORY OVER THE SOUTHEAST-MOST  
COUNTIES OF THE CWA, BASED ON POTENTIAL FOR VSBYS TO TANK BY SUNRISE  
THIS MORNING. VSBYS RIGHT NOW ARE NOT THAT BAD ACROSS THE  
SOUTHEASTERN ZONES. COLLABORATED THE CONTINUATION OF THE ADVISORY,  
THOUGH, IN CASE VSBYS DO END UP TANKING WITHIN THE NEXT FEW HOURS.  
THERE MAY BE SOME IMPROVEMENT IN VSBYS/FOG AND CLOUD-COVER OVER THE  
EASTERN HALF OF THE CWA DURING THE DAY TODAY, BUT WITH PLENTY OF LOW  
LEVEL MOISTURE AROUND AGAIN TONIGHT UNDER A STILL QUITE STRONG LOW  
LEVEL THERMAL INVERSION (SEE 00Z KABR RAOB) ON LIGHT SOUTH-  
SOUTHEASTERLY SURFACE WINDS, THERE IS YET ANOTHER NIGHT OF POTENTIAL  
FOG/LOW CLOUDS TO CONTEND WITH.  
 
WILL HAVE TO WAIT AND SEE IF THE ENERGY THAT IS PROGGED TO MOVE OVER  
THE REGION ON FRIDAY (AND ITS ASSOCIATED SURFACE TROF) WILL BE  
STRONG ENOUGH TO FORCE A WEST-COMPONENT SURFACE WIND/SURFACE TROF  
ALL THE WAY ACROSS THE CWA INTO MINNESOTA. IF THIS IS ABLE TO  
HAPPEN, THE LOW LEVEL MOISTURE AND THERMAL INVERSION SHOULD BE  
THWARTED, FOR AWHILE ANYWAY. THERE ARE STILL SOME ENSEMBLE-BASED  
(MAINLY HI-RES CAM) 20-ISH POPS HANGING AROUND HEADING INTO FRIDAY  
MORNING, WORKING FROM WEST TO EAST OVER THE CWA. P-TYPE, SHOULD ANY  
PRECIPITATION BE GENERATED AND ABLE TO REACH THE GROUND, IS EXPECTED  
TO EITHER BE RAIN OR FREEZING RAIN. BUT, AGAIN, QPF GUIDANCE AT THIS  
TIME IS "NON-MEASURABLE" FOR THIS POTENTIAL EVENT, MEANING NOT ALL  
THAT CONCERNED JUST NOW IF AN HOUR OR TWO OF VERY LIGHT FREEZING  
RAIN FRIDAY MORNING HAPPENS, AND IS CHASED AWAY BY TEMPERATURES  
WARMING TO ABOVE FREEZING.  
 
THE CWA IS STILL FORECAST TO RESIDE ON THE WARM AIR SIDE OF THINGS  
THROUGH THE SHORT TERM, SO BOTH HIGH AND LOW TEMPERATURES TODAY  
THROUGH FRIDAY SHOULD CONTINUE TO BE ABOUT 10 TO 20 DEGREES ABOVE  
NORMAL.  
 
 
   
LONG TERM /FRIDAY EVENING THROUGH WEDNESDAY/  
 
ISSUED AT 329 AM CST THU DEC 26 2024  
 
CHANCES FOR PRECIPITATION FRIDAY NIGHT INTO SATURDAY CURRENTLY LOOK  
TO STAY TO THE EAST, AND THE ABR FORECAST AREA NOW HAS POPS OF LESS  
THAN 15% ACROSS THE ENTIRE AREA. THE BIGGER OVERNIGHT IMPACT WILL  
COME IN THE FORM OF THE PERSISTENCE OF THE LOW-LEVEL MOISTURE THAT  
HAS BEEN OCCUPYING THE REGION THE LAST FEW NIGHTS GIVING THE AREA  
PATCHY FOG. THIS LOW-LEVEL MOISTURE SHOULD FINALLY MOVE OUT OF THE  
REGION ON SATURDAY, TAKING AWAY THE FOG AND LOW CLOUD DECKS.  
 
TEMPERATURES SATURDAY AND SUNDAY ARE FORECASTED TO RUN 10-20 DEGREES  
ABOVE NORMAL (WITH THE EXCEPTION OF AREAS COVERED BY FOG ON  
SATURDAY). FORECASTED HIGHS OF UPPER 30S TO UPPER 40S WILL MOST  
LIKELY BE IN THE TOP 10 ON RECORD, BUT STILL WELL SHY OF THE TOP  
SPOT (UPPER 50S TO LOW 60S AT THE FIVE CLIMATE SITES). TEMPERATURES  
ARE SET TO RETURN TO NORMAL OR JUST ABOVE NORMAL ON MONDAY.  
 
WE CONTINUE TO KEEP OUR EYE ON MONDAY'S SYSTEM, WHEN PRECIPITATION  
ON THE NORTH SIDE OF A LOW PRESSURE CENTER IS SET TO IMPACT SOUTHERN  
SOUTH DAKOTA. A SLIGHT SHIFT NORTH IN THE TRACK OF THE LOW PRESSURE  
CENTER HAS INCREASED PROBABILITIES OF MEASURABLE PRECIPITATION OVER  
CENTRAL SOUTH DAKOTA TO APPROXIMATELY 40-50%. PROBABILITIES FALL OFF  
TRAVELING FURTHER NORTH, BUT THE ENTIRE FORECAST AREA WILL NOW HAVE  
AT LEAST A 10% CHANCE. QPF 25TH-75TH SPREAD FOR THIS EVENT IS AROUND  
0-0.15" FOR CENTRAL SOUTH DAKOTA, WHICH WHILE NOT PARTICULARLY  
LARGE, STILL OFFERS SOME ROOM FOR SOME DECENT VARIABILITY. MOISTURE  
ALOFT LOOKS TO BE ENOUGH TO SATURATE A LARGE PORTION OF THE PROFILE  
FROM THE DGZ AND ABOVE. WITH TEMPERATURES BELOW FREEZING THROUGH THE  
PROFILE AND SURFACE TEMPERATURES MAINLY SET TO BE BELOW FREEZING,  
SNOW IS MOST LIKELY THE MAIN PRECIPITATION TYPE HERE. GIVEN THE 90TH  
PERCENTILE QPF UP TO 0.25", A REASONABLE "WORST CASE SCENARIO" FOR  
THIS EVENT IS 2-3" OVER CENTRAL SOUTH DAKOTA. HOWEVER, ~1" IS  
CURRENTLY THE MOST LIKELY OUTCOME.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/  
 
ISSUED AT 521 AM CST THU DEC 26 2024  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
VFR CONDITIONS WILL PREVAIL TODAY AT KPIR, KMBG AND KABR. KATY IS  
EXPECTED TO EXPERIENCE IFR/LIFR CONDITION FROM BOTH LOW CIGS AND  
VSBYS THROUGH 18Z TODAY. BETWEEN 18Z AND 00Z, KATY MAY SEE VSBY  
IMPROVE, BUT THE LOW CIG IS LIKELY TO REMAIN. LATER TONIGHT, BOTH  
KATY AND KABR COULD SEE FOG/LOW STRATUS FORMING AT/NEAR THE  
TERMINAL.  
 
 
   
ABR WATCHES/WARNINGS/ADVISORIES  
 
SD...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR SDZ019-020-022-023.  
 
MN...NONE.  
 
 
 
 
UPDATE...TMT  
SHORT TERM...DORN  
LONG TERM...BC  
AVIATION...DORN  
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