FXUS63 KABR 011546 AAA
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
946 AM CST TUE DEC 1 2009

.UPDATE...
MADE A FEW ADJUSTMENTS TO THE TODAY PERIOD...INCLUDING EXPANDING
IN COVERAGE THE WIND ADVISORY THAT IS IN EFFECT UNTIL 6 PM CST.
ADDED ALL THE REMAINING NE SODAK/WC MN COUNTIES TO THE ADVISORY.
ALSO MADE A FEW MINOR MODIFICATIONS TO THE HOURLY TEMPS AND MAX T
GRID FOR TODAY...GIVEN THE STRENGTH OF CAA EXPECTED TODAY AND THE
LATEST COUPLE OF HOURS OF OBSERVED TEMPERATURE TREND. ALSO...BASED
OFF THE STRENGTH OF 850 TO 500HPA FRONTO-FORCING ACCOMPANYING THIS
STRONG COLD FRONT TODAY...COMBINED WITH SOME WEAK TO MODERATE
SYNOPTIC SCALE LIFT AND THERE MAY BE SOME ISOLATED TO SCATTERED
SPRINKLES DEVELOPING ACROSS THE MID-SECTION OF THE FORECAST AREA
THIS AFTERNOON...WORKING SLOWLY SOUTH AND EAST AS THE DAY WEARS
ON. SO...ADDED SOME ISOLATED SPRINKLES TO THE SOUTHERN HALF OF
ZONES FOR THE AFTERNOON HOURS.

&&
.PREV DISCUSSION...
.SHORT TERM...TODAY THROUGH THURSDAY
THE MODELS ALL AGREE REAL WELL ON THE BIG CHANGE IN THE WEATHER
THROUGH THE SHORT TERM. FOR TODAY...A SHORT WAVE DROPPING OUT OF
CANADA WILL MOVE ACROSS THE NORTHERN PART OF THE REGION ALONG WITH
ITS ACCOMPANYING SURFACE LOW PRESSURE AREA. BEHIND THIS AREA OF
LOW PRESSURE...A FAST MOVING COLD FRONT WILL BE SWEEPING SOUTHEAST
ACROSS OUR CWA THIS MORNING. A WARM POCKET OF AIR IN SOUTHEASTERN
MT/NORTHEAST WY EARLY THIS MORNING WILL BE MOVING EAST AND SOUTHEAST
AND ACROSS OUR CWA THIS MORNING. THUS...EXPECT TODAYS HIGHS ACROSS
OUR CWA WILL BE THIS MORNING AS THIS AIR MOVES THROUGH.
OTHERWISE...THE ISSUE TODAY WILL BE THE STRONG NORTHWEST WINDS
DEVELOPING. ALL INDICATIONS POINT TO STRONG WINDS DEVELOPING
ACROSS MUCH OF THE CWA BY NOON. FIRST...STRONG WINDS OF 25 TO 40
MPH WERE ALREADY OCCURRING ALONG AND BEHIND THE COLD FRONT IN
EASTERN MT THIS MORNING. SECOND...GOOD PRESSURE RISES WERE
OCCURRING BEHIND THE COLD FRONT. THIRD...TSCTS AND SOUNDINGS ALL
SHOW THESE STRONG WINDS MOVING ACROSS THE ABR CWA TODAY. EXPECT
THE SURFACE PRESSURE GRADIENT TO TIGHTEN UP THIS MORNING AND EARLY
AFTERNOON ACROSS THE CWA AS CAA KICKS IN AND THE LL LAPSE RATES
STEEPEN UP. THE MODELS SHOW WINDS OF 25 TO 45 KNOTS UP THROUGH
85H THROUGH THE DAY. ALSO...GOOD SUBSIDENCE WAS SHOWN ON TSCTS IN
THE LOW AND MID LEVELS. THUS...EXPECT WINDS TO INCREASE TO 25 TO
40 MPH ACROSS MUCH OF THE CWA THIS MORNING AND WILL ISSUE A WIND
ADVISORY FROM THE JAMES VALLEY AND WEST FROM 8 AM THROUGH 6 PM.
AFTER THE HIGHS OCCUR THIS MORNING...EXPECT STEADY OR FALLING
TEMPERATURES THIS AFTERNOON. AFTER THE HIGH LEVEL CLOUDS MOVE
ACROSS EARLY THIS MORNING...EXPECT SOME MIXING LAYER CLOUDS TO
FORM TODAY BUT SKIES OVERALL SHOULD BE PARTLY CLOUDY.

FOR TONIGHT AND ON THROUGH THURSDAY...THE MODELS SHOW A DEEP AND
BROAD TROUGH OF UPPER LEVEL LOW PRESSURE DEVELOPING IN EASTERN
CANADA INTO THE EASTERN US. OUR AREA WILL BE ON THE BACKSIDE OF
THIS UPPER TROUGH WITH OUR AIR COMING STRAIGHT OUT OF NORTHERN
CANADA. THROUGH THIS TIME PERIOD...EXPECT SEVERAL SHORT WAVES TO
DROP ACROSS THE REGION FROM THE NORTH ALONG WITH PROGRESSIVELY
COLDER PUSHES OF AIR THROUGH THURSDAY. ALONG WITH THE COLD AIR
WILL COME WIDESPREAD STRATUS COMING OUT OF CANADA ON WEDNESDAY AND
REMAINING THROUGH THURSDAY. WITH NO SIGNIFICANT LIFT WITH ANY OF
THE SHORT WAVES AND SURFACE COLD FRONTS...DONT EXPECT MUCH FOR ANY
SNOWFALL. JUST HAVE IN SOME SLIGHT CHANCES OF LIGHT SNOW OR SCT
FLURRIES WEDNESDAY THROUGH THURSDAY. TEMPERATURES WILL BE ON THE
DOWNTURN RANGING FROM 40S FOR HIGHS TODAY WITH MAYBE 20 TO 25 FOR
THURSDAY.

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
FOR THE FIRST TIME IN SEVERAL DAYS...THE EXTENDED MODELS ARE
FINALLY BEGINNING TO COME TO SOME AGREEMENT...EXCEPT FOR MONDAY
THAT IS. A BROAD UPPER TROUGH WILL BE OVER THE CENTRAL AND EASTERN
PART OF THE COUNTRY TO START THE PERIOD...WITH RIDGING OVER THE
WEST COAST. THE TROUGH REMAINS DOMINANT OVER THE AREA THROUGH THE
DAY FRIDAY...THEN THE NORTHERN PORTION OF THE TROUGH MESHES UP
WITH ANOTHER SHORTWAVE TROUGH TRACKING SOUTHWARD OVER WESTERN
CANADA. GENERAL BROAD TROUGHINESS SETS UP ACROSS THE ENTIRE
COUNTRY...WITH ELONGATED PVA FROM THE PACIFIC NORTHWEST ACROSS THE
CENTRAL PLAINS TO THE NEW ENGLAND REGION. ON MONDAY...THE GFS
STRENGTHENS THE LOW OVER THE PACIFIC NORTHWEST AND DROPS IT TO
BECOME ELONGATED FROM WESTERN NORTH DAKOTA TO UTAH...WITH
SOUTHWESTERLY FLOW OVER THE CWA. THE ECMWF KEEPS NEARLY ZONAL FLOW
OVER THE NORTHERN PLAINS WITH THE LOW REMAINING OVER THE PACIFIC
NORTHWEST. THE GFS ENSEMBLES AT 500 MB REMAIN CLOSE UNTIL LATE
SUNDAY...BUT NONE OF THE MEMBERS REALLY TAKE ON A LOOK TOO SIMILAR
TO THE ECMWF.

AT THE SURFACE...BROAD HIGH PRESSURE WILL BE OVER THE ROCKIES AND
WESTERN PLAINS THURSDAY EVENING...WITH THE HIGH CENTER
STRENGTHENING OVER THE ROCKIES AND BROADENING EASTWARD DURING THE
NIGHT. THE HIGH PUSHES SOUTH AND EAST OF THE REGION FRIDAY...WITH
LOW PRESSURE DROPPING FROM WESTERN CANADA OVER THE NORTHERN AND
CENTRAL PLAINS. THE FRONT ASSOCIATED WITH THIS LOOKS TO MOVE
ACROSS THE CWA FRIDAY NIGHT. THE FRONT CONTINUES SOUTH AND EAST ON
SATURDAY WITH HIGH PRESSURE BEGINNING TO NOSE OVER THE PLAINS
BEHIND IT...THE MAIN HIGH CENTER REMAINING OVER NORTHWESTERN
CANADA. THIS HIGH CONTINUES TO PUSH SOUTHEASTWARD OVER THE PLAINS
SUNDAY...WITH THE MAIN CENTER TRACKING TO SOUTHWESTERN CANADA. ON
MONDAY...THE GFS DROPS THE HIGH SOUTH OVER THE PACIFIC NORTHWEST
AND NORTHERN ROCKIES...WITH IT ELONGATING EASTWARD ACROSS THE
NORTHERN PLAINS TO THE OHIO VALLEY. THE ECMWF BRINGS THE HIGH OVER
THE PLAINS BY EVENING...THEN PUSHES IT EAST OVERNIGHT AS LOW
PRESSURE STRENGTHENS OVER THE ROCKIES. ALL IN ALL...LOOKS AS
THOUGH ANY PRECIPITATION DURING THE PERIOD WOULD BE IN THE FORM
OF FLURRIES AT BEST WITH LITTLE IN THE WAY OF LIFT OR FORCING
AROUND. WITH THE FLURRIES BEING HARD TO TIME AND OF LITTLE
SIGNIFICANCE...HAVE OPTED TO LEAVE THE ENTIRE EXTENDED PERIOD DRY
AT THIS TIME.

TEMPERATURES WILL BE THE MAIN HIGHLIGHT OF THE PERIOD AS THE
COLDEST AIR OF THE SEASON MOVES IN. H85 TEMPERATURES WILL BE IN
THE TEENS BELOW ZERO...EVEN APPROACHING -20 BY MONDAY. EXPECT
HIGHS IN THE 20S EACH DAY...WITH NIGHTTIME LOWS IN THE SINGLE
DIGITS TO LOWER TEENS.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL TODAY AS SCT-BKN CLOUDS AOA 10K FEET
STREAM ACROSS THE REGION. THE ONE EXCEPTION TO THIS WILL BE KMBG
THIS MORNING. SOME MVFR CIGS ARE FILTERING DOWN BEHIND THE COLD
FRONT AOA 2500 FT. THESE SHOULD LIFT BY LATE MORNING. WEST TO
NORTHWEST WINDS BEHIND THE FRONT WILL INCREASE THIS MORNING AND GUST
TO 30 TO 40 KT. WINDS WILL REMAIN GUSTY THROUGH THIS AFTERNOON
WITH STRONGEST WINDS NEAR KMBG/KABR LATER TODAY. WINDS WILL
DIMINISH TONIGHT.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING 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 ADVISORY UNTIL 6 PM CST THIS EVENING FOR BIG STONE-TRAVERSE.

&&

$$
UPDATE...DORN
SHORT TERM...MOHR
LONG TERM...PARKIN
AVIATION...WISE

WEATHER.GOV/ABERDEEN