FXUS63 KABR 300228
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
828 PM CST SUN NOV 29 2009

.UPDATE...
TEMPERATURES SEEMED TO DROP OFF FASTER THAN ORIGINALLY
ANTICIPATED. THEREFORE DROPPED OVERNIGHT LOW A FEW DEGREES.
HOWEVER...WITH THE WARMER AIR MOVING IN OVERNIGHT...HAD
TEMPERATURES WARM EVER SO SLIGHTLY AFTER MIDNIGHT. THOSE WERE THE
ONLY CHANGES NECESSARY.

&&
.PREV DISCUSSION...
.SHORT TERM...TONIGHT THROUGH 12Z WEDNESDAY
MAIN FCST CHALLENGE THROUGH THE NEAR TERM STILL REVOLVES AROUND
THE TEMPERTURES. 

MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE NEAR TERM. AREA
OF LOW CLOUDS SITUATED ACROSS THE EASTERN CWA THIS MORNING WILL
CONTINUE TO SHIFT SOUTH AND EAST AWAY FROM THE CWA. 500HPA HEIGHTS
BEGIN TO REBOUND ACROSS THE REGION AS 850HPA WAA MOVES OVER THE
ENTIRE CWA BY 06Z MONDAY. A MINOR IMPULSE DROPPING THROUGH THE
500HPA FLOW WILL BRING PTCLDY/MOCLOUDY SKIES TO THE CWA OVERNIGHT
WHICH WILL HELP TO KEEP TEMPS UP AGAIN OVERNIGHT. 

AS UPPER 500HPA AND 700HPA S/W RIDGES MOVE OVER THE CWA DURING THE
DAY MONDAY...COND PRESSURE DEFS INDICATE SOME CIRRUS STREAMING
OVER THE CWA. GIVEN THE STRENGTH OF THE WAA SEEN AT 850HPA...HAVE
CONTINUED TO NUDGE UP TEMPS FOR THE DAY MONDAY. IN
ADDITION...WESTERLY SFC FLOW IS ALWAYS A GOOD WARMING WIND FOR
CENTRAL AND ERN SODAK THIS TIME OF YEAR...SO DON'T THINK
AFOREMENTIONED CIRRUS SHIELD WILL AFFECT TEMPS TOO MUCH. THIS
SHOULD ALSO EQUATE TO AN EQUALLY MILD MONDAY NIGHT...AS SFC
PRESSURE GRADIENT BEGINS TO TIGHTEN SOMEWHAT DUE TO APPROACHING
SFC LOW OUT OF WESTERN CANADA. THE GFS AND NAM AGREE ON POSITION
AND SPEED OF THE 500HPA AND 700HPA LOWS AS THEY DROP INTO EXTREME
NERN NORTH DAKOTA BY 00Z WEDNESDAY. THE GFS IS A BIT QUICKER ON
CLOSING OFF THE 500HPA LOW WHEN COMPARED TO THE NAM...BUT LITTLE
IF ANY DIFFERENCES RESULT AT THE SURFACE DUE TO THIS. 

THE SFC LOW IS EXPECTED TO DRAG A COLD FRONT THROUGH THE CWA LATE
IN THE MORNING/EARLY AFTERNOON ON TUESDAY. VERY STRONG CAA TAKES
PLACE WITH INCREASING SUBSIDENCE BEHIND FRONT. SHOULD SEE A FAIRLY
BREEZY DAY ON TUESDAY...WITH TEMPS STEADY ALL AFTERNOON LONG.
BEGAN A SLOW FALL TO THE HOURLY TEMPS TUESDAY AFTERNOON ACROSS THE
NORTHWEST AND NORTH CENTRAL PART OF THE CWA TUESDAY
AFTERNOON...BUT NOT ALL THAT DRAMATIC. WITH RESPECT TO PCPN...BEST
FORCING/LIFT/MOISTURE ALL RESIDE NORTH OF THE CWA ON TUESDAY...SO
AM STILL COMFORTABLE LEAVING PCPN OUT OF THE FORECAST. 

.LONG TERM...WEDNESDAY THROUGH SATURDAY
LARGE UPPER TROUGH SETS UP OVER THE GREAT LAKES REGION DURING THE
EXTENDED PERIOD AND ALLOWS COLD CANADIAN AIR TO FILTER SOUTHWARD
INTO THE NORTHERN PLAINS. DID NOT MAKE MANY CHANGES AT ALL TO
MAX/MIN TEMPS AS 850MB TEMPS HAVE BEEN PRETTY CONSISTENT OVER THE
PAST SEVERAL MODEL RUNS. TEMPS AT THIS LEVEL IN THE TEENS BELOW
ZERO WOULD SUGGEST 20S/30S FOR HIGHS AND TEENS TO PERHAPS SINGLE
DIGITS FOR LOWS. COLDEST MORNING LOOKS TO BE EITHER FRIDAY OR
SATURDAY AS SFC RIDGE DRIFTS ACROSS THE AREA. ALTHOUGH...THERE ARE
STILL DIFFERENCES AS TO WHEN THIS RIDGE MOVES THROUGH THE REGION.
GFS IS ABOUT 24 HRS FASTER WITH THE SFC HIGH THAN THE EC. EXTENDED
PERIOD SHAPING UP TO BE DRY BUT STILL WATCHING FOR POTENTIAL OF A
FEW FLURRIES OR VERY LIGHT SNOW SHOWERS THAT MAY SKIRT THE FAR
EASTERN CWA WEDNESDAY THROUGH THURSDAY. CONFIDENCE IN THIS REMAINS
RATHER LOW AT THIS POINT AS THE EASTERN CWA WILL BE ON THE FAR
WESTERN EDGE OF DEEPEST MOISTURE. WILL LEAVE FORECAST DRY AT THIS
TIME. 

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PERSIST TONIGHT AND INTO MONDAY. BY
MORNING CEILINGS AOA 6000 FEET WILL MOVE IN. WINDS WILL REMAIN OUT
OF THE SOUTHWEST AND WEST AS WELL. 

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

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

WEATHER.GOV/ABERDEEN