062  
FXUS63 KABR 221103  
AFDABR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ABERDEEN SD  
503 AM CST SUN DEC 22 2024  
   
KEY MESSAGES  
 
- THERE IS A LOW (15-25%) CHANCE OF A LIGHT WINTRY MIX OF  
PRECIPITATION, INCLUDING RAIN AND FREEZING RAIN OVER NORTH CENTRAL  
SOUTH DAKOTA THIS AFTERNOON, AS WELL AS FREEZING RAIN OR SNOW OVER  
NORTHEASTERN SD INTO WEST CENTRAL MN THIS EVENING.  
 
- TEMPERATURES WILL RUN AROUND 5 TO 20 DEGREES ABOVE NORMAL THROUGH  
NEXT SUNDAY.  
 
 
   
UPDATE  
 
ISSUED AT 503 AM CST SUN DEC 22 2024  
 
AVIATION DISCUSSION UPDATED BELOW IN ACCORDANCE WITH THE 12Z TAFS.  
 
 
   
SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/  
 
ISSUED AT 234 AM CST SUN DEC 22 2024  
 
MAIN STORY IN THE SHORT TERM FORECAST IS THE POTENTIAL FOR SOME  
LIGHT PRECIPITATION THIS AFTERNOON CAUSED BY AN UPPER LEVEL  
SHORTWAVE. HI-RES GUIDANCE IS HESITANT TO BRING ANYTHING INTO THE  
ABR AREA, AND INSTEAD KEEPS THE BEST CHANCES UP IN NORTH DAKOTA.  
SOME LINGERING ENSEMBLE CHANCES OVER NORTH CENTRAL AND NORTHEASTERN  
SOUTH DAKOTA AND WESTERN MINNESOTA IN ADDITION TO A FEW CAMS STILL  
RESOLVING PRECIPITATION OVER THE AREA HAVE LED TO KEEPING SOME AREAS  
OF SLIGHT CHANCE POPS IN THE NORTH SUNDAY EVENING THROUGH NIGHT.  
 
IN TERMS OF PRECIPITATION TYPE, SOUNDINGS INDICATE THAT RAIN AND  
FREEZING RAIN ARE THE MOST LIKELY TYPE OVER NORTH CENTRAL SOUTH  
DAKOTA, WHILE SNOW AND FREEZING RAIN BECOME THE DOMINANT TYPES AS  
THE SYSTEM PROGRESSES EASTWARD. EVERYTHING IS DEPENDENT ON BOTH  
SURFACE TEMPERATURE AND MID-LEVEL MOISTURE THROUGH THE EVENT.  
SOUNDINGS ARE A LITTLE UNCLEAR ON THE LATTER, BUT GENERALLY SUGGEST  
THAT MOISTURE ALOFT NEEDED FOR SATURATION OF THE DGZ WILL NOT BE  
PRESENT AT THE BEGINNING OF THE EVENT BUT WILL INCREASE OVER  
NORTHEASTERN SOUTH DAKOTA AS THE EVENT CONTINUES. IN TERMS OF  
SURFACE TEMPERATURES, WARM AIR ADVECTION WILL KEEP TEMPERATURES  
ABOVE FREEZING OVER CENTRAL SOUTH DAKOTA, BUT THE SAME CANNOT BE  
SAID FOR THE NORTHEASTERN PART OF THE FORECAST AREA. FREEZING LINE  
FOR HIGH TEMPS AT THE SURFACE LOOKS TO SET UP IN A LINE NORTHWEST  
TO SOUTHEAST ACROSS MCPHERSON, EDMUNDS, BROWN, AND SPINK COUNTIES.  
TO SUMMARIZE, AT SOME POINT DURING THE EVENT (LIKELY ~0Z), A SWITCH  
FROM SUPERCOOLED WATER TO ICE NUCLEI WILL OCCUR, AND PRECIPITATION  
TYPES WILL CHANGE FROM RAIN AND FREEZING RAIN TO SNOW AND FREEZING  
RAIN. REGARDLESS OF WHAT TYPE PRECIPITATION ENDS UP AT, QPF VALUES  
ARE EXPECTED TO BE LOW, ONLY A COUPLE HUNDREDTHS OF LIQUID  
EQUIVALENT AT THE MOST.  
 
ON MONDAY, HIGH PRESSURE TO THE NORTH BEGINS TO BUILD INTO THE AREA.  
LIGHT NORTHERLY WINDS SWITCH TO SOUTHERLY THROUGH THE DAY MONDAY.  
CLOUD COVER OVER THE NORTHEASTERN FORECAST AREA WILL LIMIT HIGHS TO  
THE 20S OVER NORTHEASTERN SOUTH DAKOTA AND WESTERN MINNESOTA, WHILE  
RELATIVELY CLEARER SKIES OVER CENTRAL SOUTH DAKOTA WILL SUPPORT  
HIGHS IN THE 30S TO LOW 40S.  
 
 
   
LONG TERM /MONDAY EVENING THROUGH SATURDAY/  
 
ISSUED AT 234 AM CST SUN DEC 22 2024  
 
ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM  
FORECAST. WHILE MAINLY DRY WEATHER WILL CONTINUE, WE DO HAVE A  
COUPLE MENTIONS OF LIGHT PRECIPITATION THURSDAY NIGHT ON. THERE IS  
ONLY A 15-25% CHANCE OF A WINTRY MIX OVER OUR FAR SOUTHEASTERN  
COUNTIES THURSDAY NIGHT, AND THEN OVER OUR EASTERN COUNTIES FRIDAY  
NIGHT THROUGH SATURDAY.  
 
AS FOR THE OVERALL WEATHER PATTERN, WE'LL BE STARTING OUT AT 00Z  
TUESDAY WITH A 500MB RIDGE OVER THE DAKOTAS AND WESTERN MN. THIS  
WILL BE SHORT LIVED AS A SHORTWAVE TROUGH OVER WESTERN MT/WESTERN WY  
MOVES OVERHEAD TUESDAY INTO TUESDAY EVENING. ANOTHER RIDGE WILL  
QUICKLY SLIDE ACROSS THE CENTRAL TO NORTHERN PLAINS TUESDAY NIGHT  
INTO WEDNESDAY MORNING. A CHANGE TO THIS OSCILLATING PATTERN WILL  
COME WEDNESDAY AS A 500MB LOW OVER THE 4-CORNERS OF THE INTERIOR  
SOUTHWESTERN U.S. SHIFTS EAST ON THURSDAY INTO THURSDAY EVENING,  
ACROSS THE CENTRAL TO SOUTHERN PLAINS STATES. THERE CONTINUES TO BE  
SOME DISCREPANCIES BETWEEN MODELS ON HOW FAR NORTH-NORTHEAST THE LOW  
TRACKS. THE OPERATIONAL MODELS BRING THE SURFACE LOW ANYWHERE FROM  
EASTERN SD TO SOUTHWESTERN MO BY 18Z FRIDAY. THAT'S NEARLY A 475  
MILE DIFFERENCE. AS EXPECTED, THIS LEADS TO SIGNIFICANT VARIABILITY  
AND LOW CONFIDENCE IN SPECIFICS, LIKE CLOUD COVER AND ANY CHANCES OF  
PRECIPITATION, WHICH COULD BE ON THE INCREASE IN LATER FORECASTS. AS  
A RESULT, THERE WILL BE SEVERAL CHANGES TO THE FORECAST FOR THIS  
PERIOD. THE 00Z ENSEMBLE EC GUIDANCE IS CLUSTERING MORE TO  
PRECIPITATION CHANCES ON SATURDAY, AND THE GFS LOOKS TO BE TRENDING  
THE SAME WAY. THE SLIGHT CHANCE (15-25% CHANCE) OF PRECIPITATION  
OVER EASTERN SD/WEST CENTRAL MN LOOKS REASONABLE AT THIS TIME.  
STILL, THE OVERALL TREND STEADY TO INCREASING HIGH AND LOW  
TEMPERATURES WILL CONTINUE THROUGH AT LEAST FRIDAY, ON THE ORDER OF  
5 TO 20 DEGREES.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z MONDAY/  
 
ISSUED AT 503 AM CST SUN DEC 22 2024  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
THE NEXT SYSTEM IS EXPECTED TO MOVE ACROSS NORTH DAKOTA THIS  
AFTERNOON INTO THIS EVENING, WITH THE POTENTIAL TO DROP A WINTRY MIX  
OF PRECIPITATION OVER THE NORTHERNMOST PARTS OF CENTRAL AND  
NORTHEASTERN SOUTH DAKOTA. PROBABILITY OF PRECIPITATION FOR KMBG AND  
KABR IS LESS THAN 30%, SO HAVE OPTED TO LEAVE AND MENTION OF -RA, -  
FZRA, OR -SN OUT OF THE TAFS.  
 
MVFR CLOUD DECK WILL MOVE IN OVERNIGHT, WITH CEILINGS POTENTIALLY  
DROPPING TO IFR AT TIMES. MODEL GUIDANCE DOES HAVE A SIGNAL FOR SOME  
PATCHY FOG AT KMBG/KABR/KATY TOMORROW MORNING, BUT THERE IS STILL  
SOME UNCRATINTY. WINDS MAY BE STRONG ENOUGH TO KEEP VISIBILITIES UP,  
BUT WILL BE A BIT LIGHTER IN THE JAMES VALLEY, SO HAVE PUT A MENTION  
OF BR ACCOMPANIED BY 6SM VISIBILITIES IN THE KABR TAF.  
 
 
   
ABR WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
 
 
 
 
UPDATE...BC  
SHORT TERM...BC  
LONG TERM...KF  
AVIATION...BC  
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