875
FXUS63 KABR 210858
AFDABR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
258 AM CST THU NOV 21 2024
KEY MESSAGES
- NORTHWESTERLY WINDS (GUSTING TO 30 MILES PER HOUR OVER
NORTHEAST SOUTH DAKOTA) DECREASE THROUGH THE DAY TODAY DOWN TO LIGHT
AND VARIABLE BY TONIGHT. WIND CHILL VALUES WILL STILL DROP INTO THE
SINGLE DIGITS THIS MORNING.
- TEMPERATURES WILL REMAIN 5-10 DEGREES BELOW NORMAL THROUGH
THURSDAY.
SHORT TERM /TODAY THROUGH FRIDAY AFTERNOON/
ISSUED AT 249 AM CST THU NOV 21 2024
CONDITIONS ARE BEGINNING TO CALM THIS EVENING AS A SURFACE HIGH
PRESSURE FROM THE NORTHWEST IS BEGINNING TO BUILD IN. CLOUDS FROM
THE LOWER PRESSURE CENTER STILL LINGER OVER THE AREA TONIGHT, MAINLY
OVER NORTHEASTERN SOUTH DAKOTA, BUT THEY WILL CONTINUE TO MOVE OUT
THROUGH TODAY GIVING WAY TO MOSTLY CLEAR SKIES. WINDS WILL DECREASE
THROUGH THE DAY TODAY AS A RESULT OF THE WEAKENING PRESSURE
GRADIENT, AND WILL EVENTUALLY SETTLE BELOW 5 KNOTS WITH VARIABLE
DIRECTION TOMORROW NIGHT.
HIGH TEMPERATURES TODAY WILL STRUGGLE TO GET ABOVE FREEZING WHERE
SNOW ACCUMULATED YESTERDAY, AND THEREFORE WILL LIKELY NOT BE ABLE TO
PROVIDE ANY SIGNIFICANT MELTING OF THE SNOWPACK. 850MB TEMPERATURES
DECREASING BELOW -10 ON FRIDAY WON'T HELP MATTERS, ALTHOUGH MODELS
SUGGEST THAT BETTER INSOLATION MAY GIVE THE AREA A COUPLE OF EXTRA
DEGREES CRITICAL TO PUSHING TEMPERATURES UP TO THE MELTING POINT FOR
A COUPLE HOURS.
LOW WIND SPEEDS, HIGH RADIATIVE COOLING, AND LINGERING LOW-LEVEL
MOISTURE COMBINE TO CREATE A GOOD SIGNAL FOR FOG DEVELOPMENT FRIDAY
MORNING. THE HIGHEST CHANCES FOR SOME PATCHY FOG WILL BE OVER THE
NORTHEASTERN CWA, BUT MAY ALSO DEVELOP OVER CENTRAL SOUTH DAKOTA AS
WELL.
LONG TERM /FRIDAY EVENING THROUGH WEDNESDAY/
ISSUED AT 249 AM CST THU NOV 21 2024
THE MAIN CHANGES WEATHER-WISE IN THE LONG TERM PERIOD WILL BE THE
SLIGHT CHANCES OF SNOW (MAINLY UNDER 25 PERCENT) ALONG THE ND/SD
BORDER FROM SUNDAY MORNING THROUGH SUNDAY NIGHT AND A COOLDOWN AS WE
MOVE INTO THE UPCOMING WORK WEEK. HIGHS MONDAY THROUGH THURSDAY WILL
BE IN THE 20S TO LOW 30S, TRENDING TO AROUND 5 DEGREES BELOW NORMAL
BY NEXT THURSDAY. NORMAL HIGH TEMPERATURES FOR THIS TIME OF YEAR
(AND THROUGH MID DECEMBER) DROP ABOUT HALF A DEGREE EACH DAY.
AS FOR THE OVERALL WEATHER PATTERN, WE'LL START OUT AT 00Z SATURDAY
WITH AN ELONGATED AREA OF LOW PRESSURE AT THE SURFACE ACROSS WY
THROUGH WESTERN NE/WESTERN KS. IT WILL PUSH ACROSS SOUTHERN SD
SATURDAY NIGHT WITH LITTLE MORE THAN A COUPLE KNOT WIND INCREASE OUT
OF THE NORTHEAST OVERNIGHT. OUR CLOUDS WILL REMAIN IN PLACE MAINLY
THANKS TO THE MORE SUBTLE 500MB WAVES ROUNDING THE RIDGE ACROSS
EASTERN MT/WY INTO THE WESTERN DAKOTAS. THE APEX OF THE RIDGE WILL
MOVE OVERHEAD BY 00Z SUNDAY AND QUICKLY SLIDE TO OUR EAST ACROSS MN
BY DAYBREAK SUNDAY, IN RESPONSE TO THE 500MB WAVE EJECTING EAST FROM
THE MAIN LOW OFF THE COAST OF WA/OR. THIS THROUGH WILL SLIDE ACROSS
SOUTH CENTRAL CANADA (SOUTHERN SASKATCHEWAN/MANITOBA) STRENGTHENING
TO A LOW DURING THE DAY SUNDAY. WHILE THERE ARE SOME MINOR
DIFFERENCES, THE STORY WILL BE PRECIPITATION ACROSS ND NEARING THE
SD BORDER FOR SUNDAY MORNING THROUGH SUNDAY NIGHT. LITTLE TO NO SNOW
IS EXPECTED AT THIS TIME ACROSS OUR AREA. COLDER AIR WILL MOVE IN
FOR THE WORK WEEK, SLIDING IN FROM CANADA AS EITHER ZONAL FLOW OF A
BROAD THROUGH SETS UP AVER THE NORTHERN TIER OF THE U.S. AS THE
500MB LOW OFF THE COAST OF THE PACIFIC NORTHWEST REMAINS IN PLACE
THROUGH AT LEAST TUESDAY. THERE IS LOWER CONFIDENCE IN THE SPECIFICS
PAST TUESDAY, MAINLY DUE TO THE MOVEMENT OF THE COASTAL LOW AND IF
IT OPENS UP AND MOVES OVER THE WESTERN U.S. BY MIDWEEK OR NOT.
ENSEMBLES SHOW A 20% CHANCE OF THE COASTAL TROUGH/LOW REMAINING IN
PLACE THROUGH 00Z THURSDAY.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1123 PM CST WED NOV 20 2024
TERMINALS KABR,KATY,KPIR,KMBG
SOME LINGERING LIGHT SNOW SHOWERS ARE POSSIBLE INTO THE OVERNIGHT
HOURS ACROSS THE FAR EASTERN PART OF THE AREA. MVFR CIGS WILL
REMAIN IN PLACE ACROSS THE EASTERN PART OF THE AREA OVERNIGHT,
THEN WILL GRADUALLY CLEAR OUT FROM WEST TO EAST DURING THE DAY
THURSDAY. KABR SHOULD SEE A RETURN TO VFR CONDITIONS AROUND
MIDDAY, AND KATY BY LATE AFTERNOON. CENTRAL SOUTH DAKOTA,
INCLUDING KMBG AND KPIR WILL SEE VFR CONDITIONS OVERNIGHT AND
THROUGH THE DAY THURSDAY.
ABR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
SHORT TERM...BC
LONG TERM...KF
AVIATION...PARKIN
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