FXUS63 KABR 150948
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
348 AM CST TUE DEC 15 2009

.SHORT TERM...TODAY THROUGH THURSDAY
ARCTIC HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN PLAINS EARLY
THIS MORNING...PROVIDING FOR VERY COLD TEMPERATURES. READINGS IN
THE CWA ARE IN THE SINGLE DIGITS AND TEENS BELOW ZERO. TEMPS ARE
ACTUALLY REMAINING A BIT WARMER THAN EXPECTED THANKS TO WINDS
AROUND 10 TO 15 MPH ALL NIGHT. HAVE INCREASED THIS MORNINGS LOWS A
FEW DEGREES. UNDER THE CENTER OF THE HIGH IN WESTERN ND AND
EASTERN MT...TEMPS HAVE REACHED THE 30S BELOW ZERO. EVEN NOTICED A
-40F AT JORDAN MT A FEW HOURS AGO. WIND CHILL VALUES ARE RANGING
FROM 25 TO 40 BELOW ZERO ACROSS THE CWA SO WILL LET THE WIND CHILL
ADVISORY RIDE THROUGH THE MORNING HOURS. EVEN SEEING AN AREA
ACROSS CORSON/DEWEY COUNTIES WHERE WIND CHILL VALUES HAVE BEEN
RANGING FROM -40 TO -45. DUE TO THE LOCALIZED NATURE OF THESE
VALUES AND THE EXPECTED LESSENING OF WINDS OVER THE NEXT COUPLE
HOURS...WILL NOT BE UPGRADING TO A WIND CHILL WARNING.

ARCTIC HIGH SLIDES SOUTHEAST OVER THE REGION TODAY...ENSURING
ANOTHER DAY OF VERY COLD TEMPERATURES. HIGHS WILL ONLY REACH THE
SINGLE DIGITS ACROSS THE EASTERN CWA. GOOD WAA PATTERN DEVELOPS
THIS AFTERNOON AND LASTS THROUGH THE OVERNIGHT HOURS AS THE SFC
HIGH DEPARTS. EVEN THOUGH WAA IS ONGOING TONIGHT...SFC WINDS STILL
EXPECTED TO BE RATHER LIGHT SO ANTICIPATING A FAIRLY GOOD DROP OFF
IN TEMPS AGAIN...MORE SO ACROSS THE EASTERN CWA. AS WAA
CONTINUES...WILL PROBABLY SEE STEADY THEN SLOWLY RISING TEMPS
AFTER 06Z AND HAVE CONSTRUCTED TEMP GRIDS TO REFLECT THIS. MET/MAV
GUIDANCE NUMBERS ALSO SHOWING STEADY/SLOWLY RISING TEMPS AFTER
06Z. A GRADUAL WARM UP IS EXPECTED THROUGH THE SHORT TERM AND BY
THURSDAY HIGH TEMPERATURES SHOULD BE NEAR SEASONAL NORMS. SHORT
TERM PERIOD LOOKS DRY AS THE NEXT SHORTWAVE WILL AFFECT THE AREA
AT THE START OF THE EXTENDED PERIOD.

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY NIGHT
DESPITE GFS AND ECMWF AGREEMENT THROUGH THE WORK WEEK...BOTH
MODELS DIVERGE WITH SOLUTIONS ONCE THE WEEKEND STARTS. IN
ADDITION...GFS ENSEMBLE MEMBERS DIVERGE QUITE A BIT ONCE THE
WEEKEND STARTS. THE GOOD NEWS IS CONFIDENCE IS STILL HIGH WITH THE
SYSTEM MOVING THROUGH THE END OF THE WORK WEEK. HOWEVER...TIMING
IS AN ISSUE WITH THE NEXT SYSTEM SET TO ARRIVE EARLY NEXT WEEK.
ECMWF WANTS TO BRING IT IN SUNDAY...BUT THE GFS HOLDS OFF UNTIL
MONDAY. PROBABLY THE REASON FOR THIS IS DISAGREEMENT BETWEEN
MODELS WITH THE PLACEMENT OF LOW PRESSURE SYSTEMS OVER THE
NORTHEAST U.S. AND PACIFIC COAST RESPECTIVELY. SINCE FORECAST
CONFIDENCE IS PRETTY LOW WITH THE SECOND SYSTEM...WENT WITH SLIGHT
POPS STARTING FIRST THING MONDAY MORNING...A BLEND BETWEEN THE TWO
MODELS.

&&

.AVIATION...
VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE PERIOD. EXPECT
SOME MID LEVEL CLOUDS AOA 10000 FEET AT TIMES TODAY.
OTHERWISE...WINDS WILL REMAIN PREDOMINATELY WESTERLY UNTIL THIS
AFTERNOON WHEN THEY BECOME MORE SOUTHERLY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR BROWN-
     BUFFALO-CAMPBELL-CLARK-CODINGTON-CORSON-DAY-DEUEL-DEWEY-
     EDMUNDS-FAULK-GRANT-HAMLIN-HAND-HUGHES-HYDE-MARSHALL-
     MCPHERSON-POTTER-ROBERTS-SPINK-SULLY-WALWORTH.

MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR BIG STONE-TRAVERSE.

&&

$$
SHORT TERM...TMT
LONG TERM...GIONTA
AVIATION...GIONTA

WEATHER.GOV/ABERDEEN