FXUS63 KABR 262138
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
338 PM CST SAT DEC 26 2009

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
UPPER LOW CONTINUES TO SPIN OVER WISCONSIN THIS
AFTERNOON...WRAPPING AROUND LIGHT SNOW INTO THE REGION AND
PROVIDING FOR CONTINUED WINDY CONDITIONS. WILL LET ALL HEADLINES
EXPIRE AT 00Z THIS EVENING BUT WILL HAVE TO MONITOR FOR POSSIBLE
EXTENSION OF WINTER WX ADVISORY IF WINDS TAKE LONGER THAN EXPECTED
TO DIMINISH. ALTHOUGH...A GENERAL WEAKENING IN WIND SPEEDS ARE
EXPECTED AFTER DARK. WINDS WILL DECREASE INTO THE 15 TO 20 MPH
RANGE AFTER 00Z BUT MAY STILL BE A BIT STRONGER THAN THIS WEST OF
THE MISSOURI RIVER. ANY SNOW ACCUMULATIONS THIS EVENING AND
OVERNIGHT WILL BE ABOUT AN INCH OR LESS. BY SUNDAY MORNING PRECIP
WILL BE REDUCED TO JUST SCT FLURRIES OR VERY LIGHT SNOW SHOWERS
WITH LITTLE IF ANY ACCUMS. WINDS WILL ALSO HAVE DIMINISHED TO
AROUND 15 MPH WHICH WILL IMPROVE VSBY CONDITIONS ACROSS THE AREA.
MONDAY INTO MONDAY NIGHT SFC HIGH WILL BUILD INTO THE REGION.
TUESDAY MORNING LOWS LOOKING RATHER COLD AS SFC HIGH WILL BE IN
PLACE. HAVE DECREASED LOWS SOME AND MAY NEED TO DROP EVEN MORE
DEPENDING ON HOW MUCH CLOUD COVER IS IN PLACE.

.LONG TERM...TUESDAY THROUGH SATURDAY
LATEST OPERATIONAL AND ENSEMBLE MODEL SOLUTIONS CONTINUE TO
DEPICT A TRANSITION TO A POSITIVE PNA PATTERN OVER THE US...WITH A
MEAN RIDGE ALONG THE WEST COAST AND CORRESPONDING MEAN TROUGH OVER
THE EASTERN TWO THIRDS OF THE CONUS. AS SUCH...THE MEAN FLOW
PATTERN OVER THE NORTHERN PLAINS WILL GENERALLY BE OUT OF THE
WEST/NORTHWEST...RESULTING IN MAINLY DRY CONDITIONS. THE
GFS/ECMWF/GEM DO INDICATE SEVERAL WEAK SHORTWAVES ROTATING THROUGH
THE AREA...WITH THE MOST SIGNIFICANT WAVE ON THU NIGHT AND FRIDAY.
EVEN SO...NOT EXPECTING ANYTHING MORE THAN PERHAPS A FEW FLURRIES
WITH THESE FEATURES.

THE BIGGER CHALLENGE IN THE EXTENDED WILL BE
TEMPERATURES...ESPECIALLY CONSIDERING THAT A MAJORITY OF THE UPPER
MIDWEST NOW HAS A SIGNIFICANT SNOWPACK. 925MB TEMPS IN THE -6C TO
-10C RANGE WILL FAVOR TEMPS A FEW DEGREES BELOW NORMAL ON TUE/WED.
IN THE WAKE OF THE UPPER LEVEL DISTURBANCE AND ACCOMPANYING COLD
FRONT ON WEDNESDAY NIGHT...TEMPS ARE EXPECTED TO FALL EVEN FURTHER
AS 925 TEMPS FALL INTO THE NEGATIVE TEENS. IN FACT...LOW
TEMPERATURES THURSDAY NIGHT AND FRIDAY NIGHT ARE LIKELY TO FALL
WELL INTO THE TEENS BELOW ZERO AS WINDS DECOUPLE AND SKIES CLEAR.
THIS COLD AIRMASS THEN APPEARS TO STAGNATE OVER THE AREA...WITH NO
SIGNIFICANT WARM-UPS IN THE FORESEEABLE FUTURE.

&&

.AVIATION...
EXPECT A CONTINUATION OF PRIMARILY IFR/MVFR VSBYS AT ALL TERMINALS
THIS EVENING DUE TO A COMBINATION OF FALLING/BLOWING SNOW. VSBYS
MAY BRIEFLY FALL TO BELOW 1/2SM AT TIMES AT KPIR. NWLY WINDS OF 15
TO 30 KTS WILL PERSIST THROUGH ABOUT 03Z SUN...THEN SLOWLY SUBSIDE
OVERNIGHT. CIGS WILL CONTINUE TO BE VARIABLE...RANGING FROM VFR TO
IFR...DEPENDING ON INTENSITY OF SNOW. CONDITIONS WILL GRADUALLY
IMPROVE OVERNIGHT...WITH ANY LIGHT SNOW TAPERING TO FLURRIES BY
SUNDAY MORNING. 

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BROWN-
     BUFFALO-CAMPBELL-CLARK-CODINGTON-DAY-DEUEL-EDMUNDS-FAULK-
     GRANT-HAMLIN-HAND-HUGHES-HYDE-MARSHALL-MCPHERSON-POTTER-
     ROBERTS-SPINK-SULLY-WALWORTH.

     BLIZZARD WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR 
     CORSON-DEWEY-JONES-LYMAN-STANLEY.

MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BIG 
     STONE-TRAVERSE.

&&

$$
SHORT TERM...TMT
LONG TERM...FOWLE
AVIATION...FOWLE

WEATHER.GOV/ABERDEEN