000
FXUS63 KABR 051733 AAC
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1133 AM CST THU DEC 5 2013

.UPDATE...
AVIATION DISCUSSION HAS BEEN UPDATED BELOW.

REDUCED SKY COVER TODAY AS THERE IS NOTHING BUT SUNSHINE ACROSS
THE REGION. WE ARE SEEING LAKE EFFECT CLOUD COVER IN ISOLATED
SPOTS ALONG THE MISSOURI RIVER...THEY MAY EVEN PRODUCE A FEW
FLURRIES. ARCTIC AIR IS IN PLACE OVER THE REGION AND TEMPS WILL
NOT RISE MUCH MORE TODAY...WITH HIGHS IN THE SINGLE DIGITS. BREEZY
NORTHWEST WINDS WILL PERSIST TODAY WHICH WILL PUSH WIND CHILL
VALUES INTO THE 15 BELOW TO 25 BELOW ZERO RANGE.

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
A VERY TIGHT PRESSURE GRADIENT REMAINS OVER THE REGION THIS
MORNING...WITH WINDS STILL GUSTING TO THE 35 TO 40 MPH RANGE ALONG
THE MISSOURI RIVER. COMBINED WITH THE ARCTIC AIRMASS MOVING INTO
THE REGION...A FEW OBS HAVE DROPPED INTO THE WINDCHILL ADVISORY
CRITERIA THIS MORNING. ALSO...GIVEN THE GUSTY WINDS...CONTINUED
TO MENTION BLOWING SNOW IN THE FORECAST...ALTHOUGH WEBCAMS AND OBS
INDICATE THAT VISIBILITY HAS IMPROVED SIGNIFICANTLY ACROSS THE
CWA.

AFTERNOON HIGHS ARE EXPECTED TO RISE JUST ABOVE ZERO...BEFORE
PLUMMETING AGAIN TONIGHT/FRIDAY MORNING. WHILE TEMPERATURES WILL
DEFINITELY BE COLD...IT IS STILL A TRICKY FORECAST DUE TO BREEZY
NORTHWEST WINDS PREVENTING THE BOUNDARY LAYER FROM COMPLETELY
DECOUPLING...BUT ALSO ACCOUNTING FOR FRESH SNOWCOVER ON THE
GROUND. A PRETTY DECENT SPREAD IN GUIDANCE WITH THE COLDEST
GUIDANCE SUGGESTING THE UPPER TEENS BELOW TO LOW TWENTIES BELOW
ZERO BY FRIDAY MORNING...WHERE AS THE WARMEST GUIDANCE IS ONLY IN
THE SINGLE DIGITS BELOW ZERO. TRENDED TOWARD THE COLDER END...BUT
DIDNT TAKE THE AREA INTO THE TWENTY BELOW CATEGORY FOR FRIDAY
MORNING. WIND CHILL VALUES SHOULD HAVE NO TROUBLE DROPPING INTO
ADVISORY CRITERIA.

FRIDAY NIGHT/SATURDAY MORNING IS STILL ON TRACK TO EXPERIENCE THE
COLDEST TEMPERATURES. THE SURFACE RIDGE WILL EXTEND OUT OF
MONTANA AND THEN FROM NORTHWEST TO SOUTHEAST ACROSS THE STATE OF
SOUTH DAKOTA. THIS SHOULD RESULT IN WINDS LESS THAN 5 MPH FOR MUCH
OF THE REGION...HOWEVER THE FAR EASTERN CWA MAY MAINTAIN A SURFACE
WIND SPEED SLIGHTLY GREATER THAN 5 MPH...IN WHICH CASE THE WIND
ADVISORY MAY NEED TO BE EXTENDED INTO SATURDAY MORNING FOR THIS
AREA. THE OTHER FACTOR SATURDAY MORNING WILL BE INCREASING CLOUD
COVER...AS AN UPPER LEVEL SHORTWAVE MOVES OVER THE REGION...AND
WEAK WARM AIR ADVECTION RETURNS TO SOUTHWEST AND SOUTH CENTRAL
CENTRAL SOUTH DAKOTA. DID BUMP TEMPERATURES UP JUST A FEW DEGREES
UNDER THE GREATEST FORECAST CLOUD COVER /ACROSS THE SOUTHWEST
CWA/...BUT STILL HAVE MUCH OF THE REMAINING CWA DROPPING TO NEAR
OR BELOW TWENTY BELOW ZERO.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY

A COLD AIRMASS WILL BE SITUATED OVERHEAD TO START OFF THE
PERIOD...WITH H85 TEMPERATURES FROM -15 TO -19C...HOWEVER ANOTHER
ARCTIC SURGE WILL HIT ON MONDAY...WITH H85 READINGS TO -27C. THIS
IS NOW A QUICK PUSH...AS A CLIPPER DEVELOPS OVER SOUTHERN
CANADA...RESULTING IN WESTERLY LOW LEVEL FLOW TO HELP MIX OUT THE
COLDEST AIR. UNCERTAINTY EXISTS AFTER MONDAY FOR TEMPERATURES AS
THE DETERMINISTIC ECMWF AND GFS BEGIN TO VARY WITH UPPER LEVEL
FLOW.

AS FOR PRECIPITATION CHANCES...EARLY IN THE PERIOD WILL SEE A
BROAD UPPER TROF UPSTREAM WITH WARM ADVECTION SNOW. THE AREA WILL
BE ON THE NORTHERN FRINGE OF ANY SNOWFALL.

&&

.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

VFR CONDITIONS EXPECTED FOR ALL SITES. THE CAVEAT IS SOME MVFR
RELATED LAKE EFFECT CLOUDS NEAR KPIR AND KATY WHICH WILL PERSIST
OFF AND ON THROUGH THE DAY. WINDS WILL REMAIN OUT OF THE
WEST/NORTHWEST BUT WILL GRADUALLY WEAKEN THROUGHOUT THE DAY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL 6 PM CST /5 PM MST/ FRIDAY FOR BROWN-
     BUFFALO-CAMPBELL-CLARK-CODINGTON-CORSON-DAY-DEUEL-DEWEY-
     EDMUNDS-FAULK-GRANT-HAMLIN-HAND-HUGHES-HYDE-JONES-LYMAN-
     MARSHALL-MCPHERSON-POTTER-ROBERTS-SPINK-STANLEY-SULLY-
     WALWORTH.

MN...WIND CHILL ADVISORY UNTIL 6 PM CST FRIDAY FOR BIG STONE-TRAVERSE.

&&

$$
UPDATE...TMT
SHORT TERM...SERR
LONG TERM...CONNELLY
AVIATION...SD

WEATHER.GOV/ABERDEEN