000
FXUS63 KABR 032120
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
320 PM CST TUE DEC 3 2013

.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT

MODELS ARE FINALLY BEGINNING TO LATCH ONTO A FAIRLY SIMILAR
SOLUTION...WHICH FEATURES A SFC LOW TRACK FURTHER SOUTH THAN WHAT
WAS SHOWN YESTERDAY. ALTHOUGH...THIS STILL SPELLS OUT SNOW ACCUMS
FOR THE CWA. SNOW HAS FINALLY MADE ITS WAY INTO THE NORTHEAST CWA
BUT NOT MUCH IN THE WAY OF ACCUMS YET. OVER CENTRAL SOUTH
DAKOTA...SNOW HAS BEEN FALLING ALL DAY WITH GENERALLY 2 OR 3
INCHES BEING REPORTED. MODELS SHOWING THE MAIN AREA OF SNOWFALL
TONIGHT LIFTING OUT OF NORTHERN NEBRASKA AND AFFECTING SOUTH
CENTRAL TO EAST CENTRAL SOUTH DAKOTA OVERNIGHT...THAN AS THE
SURFACE LOW MOVES NORTHEAST TOWARDS THE GREAT LAKES...SNOW WILL
AFFECT THE EASTERN PORTION OF SOUTH DAKOTA AND WESTERN MINNESOTA
THROUGH THE DAY WEDNESDAY. NORTHERLY WINDS WILL INCREASE THROUGH
THE NIGHT OVER CENTRAL SOUTH DAKOTA...WITH WINDS PICKING UP IN THE
JAMES VALLEY BY WEDNESDAY MORNING. THE STRONGER WINDS WILL MOVE
INTO AREAS EAST OF THE JAMES RIVER DURING THE DAY WEDNESDAY.
DETERMINING SNOW PLACEMENT AND AMOUNTS HAS BEEN ESPECIALLY HARD
WITH THIS SYSTEM AS MODELS HAVE TAKEN A LONG TIME TO LATCH ONTO
SIMILAR SOLUTIONS. HAVING SAID THAT THOUGH...STILL NOT A
TREMENDOUS AMOUNT OF CONFIDENCE WITH THIS FORECAST. IN
GENERAL...STORM TOTAL SNOW AMOUNTS IN THE GRIDS AND FORECAST SHOW
4 TO 8 INCHES...BUT FEEL SOME OF THE HIGHER AMOUNTS MAY BE A TAD
OVERDONE AND HAVE SOME QUESTIONS ABOUT THAT. CURRENT FORECAST
SHOWS HIGHEST AMOUNTS ACROSS THE EASTERN CWA AND SOUTHWEST ALONG
THE FSD/ABR CWA BORDER. UPGRADED THE WINTER WX ADVISORY TO A
WINTER STORM WARNING BASED ON TOTAL SNOW AMOUNTS CLOSE TO 6
INCHES...AND EVEN IF AMOUNTS FALL SHORT OF 6...THE IMPACTS OF
BLOWING SNOW AND REDUCED VISIBILITY COULD JUSTIFY A WARNING.
EXTENDED THE EASTERN PORTION OF THE CWA TO HAVE THEIR WARNING
EXPIRE AT 06Z THURS.


.LONG TERM...FRIDAY THROUGH TUESDAY

AN UPPER LEVEL TROUGH WILL BE ELONGATED FROM SOUTHEASTERN CANADA
TO THE PACIFIC NORTHWEST WHEN THE PERIOD STARTS. THIS TROUGH
GRADUALLY DIGS SOUTHWARD THROUGH THE DAY SATURDAY...THEN BEGINS TO
PUSH EASTWARD...SLOWLY TRACKING ACROSS THE PLAINS THROUGH THE END
OF THE PERIOD.

THE BIG STORY OF THE EXTENDED PERIOD WILL BE STRONG ARCTIC AIR
SETTLING IN OVER THE REGION. A 1045MB SURFACE HIGH WILL APPROACH
THE AREA ON FRIDAY...BECOMING CENTERED OVER THE NORTHERN PLAINS
SATURDAY MORNING. THE HIGH MOVES VERY LITTLE UNTIL SUNDAY. SOME
DIFFERENCES IN THE MODELS THEN SHOW UP CONCERNING A LOW PRESSURE
SYSTEM MOVING IN. THE GFS BRINGS IT IN FROM THE NORTHWEST AND
MOVES IT THROUGH RATHER QUICKLY AND DRY BEFORE HIGH PRESSURE MOVES
BACK IN ON MONDAY. THE ECMWF BRINGS THE LOW UP FROM THE SOUTHWEST
AND BRINGS SNOW TO THE AREA SUNDAY AFTERNOON AND SUNDAY NIGHT
BEFORE HIGH PRESSURE MOVES BACK IN. FOR NOW...HAVE OPTED TO KEEP
SOME SMALL POPS IN DURING THAT TIME FRAME TO ACCOUNT FOR THE
POSSIBILITY OF THE ECMWF BEING CORRECT. HIGH PRESSURE THEN
DOMINATES OVER THE AREA THROUGH THE END OF THE PERIOD.

VERY COLD AIR WILL BE ASSOCIATED WITH THE TWO STRONG SURFACE HIGHS
THAT ARE SET TO AFFECT THE REGION. H85 TEMPERATURES OF -15C TO -30C
WILL BE COMMON. GENERALLY LOOKING AT DAYTIME HIGHS IN THE SINGLE
DIGITS...WITH SOME LOCATIONS ACROSS THE NORTHERN CWA STRUGGLING TO
REACH ZERO FRIDAY AND SATURDAY. OVERNIGHT LOWS IN THE SINGLE
DIGITS BELOW ZERO TO THE TEENS BELOW ZERO WILL BE COMMON...WITH A
FEW -20S POSSIBLE FRIDAY NIGHT.


&&

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

IFR/MVFR CIGS WILL BE IN PLACE ACROSS MOST OF THE AREA THROUGH THE
TAF PERIOD. SNOWFALL WILL OCCUR OFF AND ON AS WELL...AND MAY
BECOME HEAVY AT TIMES. VSBYS WILL GENERALLY BE MVFR...BUT WILL
LIKELY FALL INTO THE IFR CATEGORY WITH THE HEAVIER BANDS OF SNOW.
LOOK FOR NORTHERLY WINDS TO INCREASE INTO THE 20 TO 35 MPH RANGE
TONIGHT...CONTINUING INTO THE MORNING HOURS ON WEDNESDAY.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM CST /5 PM MST/ WEDNESDAY FOR
     BROWN-BUFFALO-CAMPBELL-CORSON-DEWEY-EDMUNDS-FAULK-HAND-
     HUGHES-HYDE-JONES-LYMAN-MCPHERSON-POTTER-SPINK-STANLEY-
     SULLY-WALWORTH.

     WINTER STORM WARNING UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
     CLARK-CODINGTON-DAY-DEUEL-GRANT-HAMLIN-MARSHALL-ROBERTS.

MN...WINTER STORM WARNING UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR BIG
     STONE-TRAVERSE.

&&

$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN

WEATHER.GOV/ABERDEEN