400  
FXUS63 KABR 250529 AAC  
AFDABR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE ABERDEEN SD  
1129 PM CST TUE DEC 24 2024  
   
KEY MESSAGES  
 
- FOGGY CONDITIONS WILL CONTINUE TONIGHT INTO CHRISTMAS DAY.  
VISIBILITY AS LOW AS A QUARTER MILE OR LESS WILL BE POSSIBLE IN  
SOME AREAS. A DENSE FOG ADVISORY HAS BEEN ISSUED FOR PARTS OF  
THE AREA THIS EVENING THROUGH WEDNESDAY MORNING.  
 
- THERE IS ONLY AROUND A 20% CHANCE OF LIGHT RAIN FORECAST FRIDAY  
INTO EARLY SATURDAY OVER PARTS OF FAR NORTHEASTERN SD AND  
WESTERN MN. TEMPERATURES BY THAT POINT SHOULD BE ABOVE FREEZING.  
 
- TEMPERATURES WILL RUN AROUND 10 TO 20 DEGREES ABOVE NORMAL FROM  
THURSDAY THROUGH SUNDAY.  
 
 
   
UPDATE  
 
ISSUED AT 1124 PM CST TUE DEC 24 2024  
 
ADDED A FEW COUNTIES, ROBERTS, GRANT, SULLY AND HUGHES, INTO THE  
DENSE FOG ADVISORY. SEE UPDATED AVIATION DISCUSSION BELOW.  
 
UPDATE ISSUED AT 905 PM CST TUE DEC 24 2024  
 
NO MAJOR CHANGES TO THE FORECAST THIS EVENING. DENSE FOG HAS BEEN  
CONFINED TO WHERE THE DENSE FOG ADVISORY IS IN EFFECT SO FAR, BUT  
WILL CONTINUE TO MONITOR FOR THE NEED TO POSSIBLY EXPAND IT  
FURTHER TO THE WEST OR EAST. NO CHANGES MADE TO WINDS OR  
TEMPERATURES AT THIS TIME.  
 
 
   
SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/  
 
ISSUED AT 342 PM CST TUE DEC 24 2024  
 
FOGGY CONDITIONS WILL BE THE NAME OF THE GAME IN THIS PERIOD AS  
ABUNDANT LOW LEVEL MOISTURE IS PROGGED TO REMAIN IN PLACE TONIGHT  
INTO CHRISTMAS DAY. CURRENTLY, AREAS OF FOG CONTINUE TO PLAGUE PARTS  
OF THE FORECAST AREA THIS AFTERNOON. SFC OBS, SATELLITE TRENDS AND A  
REVIEW OF AREA WEBCAMS INDICATE THAT FOG IS MOST PREVALENT IN THE  
JAMES VALLEY AND PARTS OF THE BIG SIOUX VALLEY. SOME POCKETS OF THIS  
HAVE APPEARED DENSE AT TIMES. AND, TO A CERTAIN EXTENT, LOW CLOUDS  
OR REMNANTS OF FOG EXIST ALONG AND JUST EAST OF THE MISSOURI RIVER  
EARLY THIS AFTERNOON.  
 
THE UPPER FLOW PATTERN IS FEATURING AN UPPER TROUGH WORKING ACROSS  
THE EASTERN DAKOTAS THIS AFTERNOON. THIS WILL BE REPLACED BY A LOW  
AMPLITUDE SHORTWAVE RIDGE TONIGHT ACROSS OUR REGION AND QUICKLY  
FOLLOWED ON BY ANOTHER UPPER TROUGH THAT WILL SHIFT ACROSS THE  
NORTHERN HIGH PLAINS INTO THE NORTHERN PLAINS THE LATTER HALF OF  
CHRISTMAS DAY INTO EARLY THURSDAY. LOW LEVEL FLOW WILL REMAIN  
SOUTHERLY THROUGH MOST OF THIS PERIOD. SFC HIGH PRESSURE ACROSS THE  
WESTERN GREAT LAKES WILL REMAIN IN PLACE ACROSS THE LAKES THROUGH  
WEDNESDAY WHILE A LOW PRESSURE TROUGH SHIFTS EAST OFF THE HIGHER  
ELEVATIONS OF THE WEST INTO THE WESTERN AND CENTRAL DAKOTAS  
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. HIGH AMOUNTS OF LOW LEVEL  
MOISTURE EVIDENT IN SFC OBS THIS AFTERNOON WILL CARRY OVER INTO  
TONIGHT. FROM BUFKIT SOUNDINGS TO THE DETERMINISTIC AND ENSEMBLE  
MODEL SOLUTIONS ARE ALL IN FAVOR OF AREAS MAINLY ALONG AND EAST OF  
THE MISSOURI RIVER OF SEEING FOG THICKEN AGAIN OR REDEVELOP TONIGHT.  
HREF PROBABILITIES OF SEEING VISIBILITY A HALF MILE OR LESS RANGE  
FROM 40-80 PERCENT ACROSS MOST ZONES EAST OF THE MISSOURI TONIGHT  
INTO WEDNESDAY MORNING. OUR NORTHEAST ZONES MAY SEE THE FOG TAKE A  
WHILE LONGER TO SET IN LATER THIS EVENING INTO THE OVERNIGHT. WENT  
WITH A DENSE FOG ADVISORY FOR A DECENT PORTION OF CENTRAL AND  
NORTHEAST SOUTH DAKOTA, INCLUDING FROM MOBRIDGE TO MILLER EASTWARD  
TO BRITTON TO WEBSTER TO WATERTOWN. THIS HEADLINE WILL GO INTO  
EFFECT THIS EVENING AND CONTINUE UNTIL NOON WEDNESDAY.  
 
THE FOG SHOULD BEGIN TO IMPROVE TOWARD THE END OF THAT TIME FRAME.  
CAN'T RULE OUT SOME LINGERING POCKETS OF IT THROUGH THE AFTERNOON.  
THIS, ALONG WITH OVERCAST SKIES THAT LOOK TO PERSIST ON THE HOLIDAY,  
WILL KEEP A LID ON TEMPERATURES FROM WARMING TOO MUCH. ALTHOUGH, WE  
ARE SEEING SIGNS OF A GRADUAL REPLACEMENT OF AIR MASSES CLOSER TO A  
WARMER REGIME, DAYTIME HIGHS ARE LIKELY TO REMAIN RATHER COOL STILL  
FOR CHRISTMAS. WENT PRETTY CONSERVATIVE WITH MAX T'S ON WEDNESDAY,  
CLOSER TO NBM05 ESPECIALLY ACROSS THE EASTERN HALF OF THE FORECAST  
AREA.  
 
 
   
LONG TERM /THURSDAY THROUGH TUESDAY/  
 
ISSUED AT 342 PM CST TUE DEC 24 2024  
 
FOG IS WHAT WILL BE ON EVERYONES MIND, AND THE START OF THE EXTENDED  
LOOKS TO REMAIN DOMINATED BY A PATTERN THAT WOULD ALLOW FOR AN  
EXTENUATION OF THESE FOGGY CONDITIONS. MILD TEMPERATURES ALOFT,  
WITH GEFS 850MB TEMPS CLOSE TO A STANDARD DEVIATION ABOVE CLIMO, AND  
LIGHT SURFACE WINDS WILL KEEP THE RELATIVE HUMIDITY NEAR THE SURFACE  
AT CLOSE TO 100% WITH NOWHERE FOR THE MOISTURE TO GO THROUGH AT  
LEAST FRIDAY. FOR THE WEEKEND, WHILE THE OVERALL SURFACE PRESSURE  
PATTERN IS WEAK, GENERAL CONSENSUS IS THAT LIGHT WESTERLIES WILL  
DEVELOP OVER THE REGION. THIS WOULD TEND TO LIMIT WIDESPREAD FOG  
DEVELOPMENT OR PERSISTENCE THOUGH IT MAY TAKE TIME TO GET THE  
MOISTURE OUT OF HERE WITH WINDS OF ONLY ABOUT 5-10KTS. AND EVEN IF  
WE DO GET A BREAK FROM THE FOG, WITH THE LONGWAVE OVERHEAD, THE  
OVERALL CLOUD COVER WILL REMAIN QUITE HIGH.  
 
LATE IN THE WEEKEND WE SEE AN UPSTREAM RIDGE DEVELOP, BUT THAT FAILS  
TO PERSIST FOR VERY LONG ACROSS THE CENTRAL/NORTHERN PLAINS, AS IT  
IS QUICKLY REPLACED BY A WAVE MOVING RAPIDLY WEST TO EAST ACROSS THE  
CENTRAL ROCKIES. THE MAIN QUESTION THEREAFTER IS WHAT WILL BE THE  
RESULTANT COLORADO LOW TRACK, WITH THE DETERMINISTIC EC HAVING A LOW  
GOING THROUGH THE CENTRAL PLAINS, WHILE THE GFS IS TRYING FOR A  
STRONGER LOW IN THE THAT PUTS OUR CWA ON ITS NORTHERN PERIPHERY.  
CLUSTERS AT THIS POINT, ARE NOT REALLY IN LINE WITH ANY SPECIFIC  
CAMP, SO OVERALL CONFIDENCE ON QPF/WEATHER ASSOCIATED WITH THIS WAVE  
ARE FAIRLY LOW.  
 
IN THE INTERIM, THE WEAK, BAGGY TROUGH OVER THE WESTERN CONUS WILL  
SUPPORT A FEW WEAK SHORTWAVES WITH THE NBM PROBABILITY OF EXCEEDING  
0.01 INCHES OF QPF ONLY PEAKING OUT AROUND 50% ACROSS THE FAR EAST  
(WESTERN MN) DURING THE SATURDAY TIMEFRAME. OTHERWISE, GENERALLY IT  
REMAINS LOW CONFIDENCE FOR ANY OF THESE LIGHT SHOWERS/FLURRY EVENTS  
OVER THE NEXT SEVERAL DAYS.  
 
TEMPERATURES, LIKEWISE WILL BE LOWER CONFIDENCE DUE TO THE  
FOG/CLOUDS. UNFORTUNATELY IT WILL BE FAIRLY DIFFICULT TO REALIZE THE  
WARMER TEMPERATURES JUST OFF THE SURFACE WITH THE MOISTURE AND SNOW  
COVER DESPITE THE NBM RUNNING 15 TO 20 DEGREES ABOVE CLIMO.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/  
 
ISSUED AT 1124 PM CST TUE DEC 24 2024  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
IFR CIGS WILL REMAIN IN PLACE OVER ALL BUT THE FAR WESTERN PART OF  
THE AREA OVERNIGHT THROUGH WEDNESDAY MORNING, ALONG WITH LIFR/IFR  
VSBYS IN FOG. ALL BUT THE FAR EASTERN PART OF THE AREA, INCLUDING  
KATY, WILL SEE CIGS AND VSBYS IMPROVE TO VFR AROUND MIDDAY  
WEDNESDAY.  
 
 
   
ABR WATCHES/WARNINGS/ADVISORIES  
 
SD...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR SDZ004>011-  
016>023-034>037-051.  
 
MN...NONE.  
 
 
 
 
UPDATE...PARKIN  
SHORT TERM...VIPOND  
LONG TERM...CONNELLY  
AVIATION...PARKIN  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SD Page
The Nexlab MN Page
Main Text Page