173
FXUS63 KABR 242330 AAA
AFDABR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
530 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 525 PM CST TUE DEC 24 2024
SEE UPDATED AVIATION DISCUSSION BELOW.
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 /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 525 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 TONIGHT AND THROUGH THE DAY WEDNESDAY, ALONG WITH
IFR/MVFR VSBYS IN FOG. THE AREAS ALONG AND WEST OF THE MISSOURI
RIVER WILL SEE SOME IMPROVEMENT IN CIG LEVELS LATE TONIGHT, BEFORE
RETURNING TO IFR LEVELS WEDNESDAY MORNING. VSBYS WILL IMPROVE TO
MVFR LEVELS ACROSS THE AREA AROUND MIDDAY ON WEDNESDAY, THEN TO
VFR LEVELS LATE WEDNESDAY AFTERNOON.
ABR WATCHES/WARNINGS/ADVISORIES
SD...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR SDZ004>007-
009>011-016>020-022-023-036-037-051.
MN...NONE.
SHORT TERM...VIPOND
LONG TERM...CONNELLY
AVIATION...PARKIN
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