FXUS63 KABR 290250
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
850 PM CST SAT NOV 28 2009

.UPDATE...
HIGH CLOUDS HAVE LINGERED OVER THE AREA A LITTLE LONGER THAN
EXPECTED. THESE CLOUDS HAVE KEPT TEMPERATURES A LITTLE WARMER THAN
ANTICIPATED. LATEST SATELLITE LOOP SHOWS THE BACK EDGE OF THE
CLOUDS MOVING INTO THE AREA AT THIS TIME. EXPECT TEMPERATURES TO
CATCH UP TO EXPECTED VALUES LATER THIS EVENING. HAVE ADJUSTED THE
RATE OF FALL OF TEMPERATURES BUT WILL NOT CHANGE OVERNIGHT LOW
VALUES. NO UPDATE IS PLANNED AT THIS TIME.

&&
.PREV DISCUSSION...
.SHORT TERM...TONIGHT THROUGH 12Z TUESDAY.
MAIN FCST CHALLENGE FACING THE NEAR TERM IS TEMPS THROUGH THE
PERIOD. 

SFC COLD FRONT/UPPER 500HPA AND 700HPA TROFS HAVE PUSHED EAST OF
THE CWA...WITH WEAK CAA ALL DAY LONG. TEMPS HAVE STRUGGLED TO
CLIMB UNDER THICK CIRRUS SHIELD...HOWEVER THIS CIRRUS SHIELD WILL
ALSO PREVENT TEMPS FROM BOTTOMING OUT TOO FAR OVERNIGHT. 

PCPN WISE...KABR 88D CONTS TO SHOW SOME VERY WEAK RETURNS ALONG
THE MO RIVER...BUT HAVE A FEELING THAT IT IS TAPPING MORE CLOUD
COVER THAN PCPN. WITH NO APPRECIABLE FORCING NOTED THROUGH THE
LAYERS...AND DWPT DEPRESSIONS ON THE ORDER OF 10 DEGREES C OR
SO...ANYTHING THAT IS FALLING IS MOST LIKELY EVAPORATING PRIOR TO
HITTING THE GROUND. LEFT MENTION OF A FEW FLURRIES ACROSS THE ERN
CWA THIS EVENING...WITH SFC TEMPS COOLING FLURRIES MAY STAND A
BETTER CHANCE OF REACHING THE GROUND...BUT AFT 03Z EXPECT ANY PCPN
CHANCES TO BE LESS THAN SLIGHT CHC POP WORTHY...SO HAVE REMOVED
MENTION. 

THE MODELS AGREE ON SFC HIGH BEGINNING TO PUSH IN FROM THE WEST
LATE IN THE DAY SUNDAY...AS 500HPA AND 700HPA HEIGHTS BEGIN A SLOW
RECOVERY. POSITIVE 700HPA THETA-E ADVECTION RETURNS TO THE WESTERN
PART OF THE CWA...WITH 850HPA TEMPS FORECAST TO RETURN TO ABOVE
ZERO CELCIUS READINGS BY 12Z MONDAY. THE WAA CONTS INTO TUESDAY
MORNING WHEN MAIN 850HPA THERMAL RIDGE PUSHES INTO THE CWA. 

WITH THE EXCEPTION OF SOME ISOLD FLURRIES THIS EVENING ACROSS THE
EAST...THE NEAR TERM LOOKS TO REMAIN DRY AND QUIET. TEMP
WISE...DID RAISE TEMPS SUNDAY NIGHT AND AGAIN MONDAY NIGHT AS WAA
AND MIXING WINDS SHOULD ENABLE TO TEMPS TO STAY A BIT HIGHER THAN
PREVIOUSLY FORECASTED. 

.LONG TERM...TUESDAY THROUGH FRIDAY
MAIN THEME IN THE EXTENDED REMAINS THE ONSET OF MUCH COLDER AIR AS
UPPER FLOW BECOMES NORTHERLY. UPPER TROUGH SETS UP OVER THE GREAT
LAKES REGION BY THE MIDDLE OF NEXT WEEK...WITH COLD AIR BEING
DRAWN DOWN FROM CANADA. ALL MODELS SHOWING 850MB TEMPS DROPPING
DOWN INTO THE TEENS BELOW ZERO FOR THE MIDDLE AND END OF NEXT
WEEK. THIS SUGGESTS HIGHS IN THE 20S AND 30S. 12Z MEX GUIDANCE
NUMBERS HAVE BECOME COLDER THAN THE 00Z RUN AND IS NOW SHOWING
HIGHS IN THE 20S FOR MUCH OF THE CWA DURING THE MIDDLE AND END OF
NEXT WEEK. HAVE LEFT THE EXTENDED PERIOD DRY BUT WILL HAVE TO
WATCH FOR POSSIBILITY OF FLURRIES OR LIGHT SNOW SHOWERS ACROSS THE
FAR EASTERN CWA WEDNESDAY INTO THURSDAY. AS LARGE UPPER LOW SETS
UP OVER THE GREAT LAKES WILL HAVE TO CONTEND WITH WRAP AROUND
CLOUDS AND MOISTURE WHICH COULD LEAD TO THIS. BUT MODELS ARE
GENERALLY SHOWING THIS TO SET UP EAST OF THE AREA...IT WILL ALL
DEPEND ON JUST WHERE MAIN CIRCULATION SETS UP. 

&&

.AVIATION...
VFR CONDITIONS ARE THE RULE ACROSS THE AREA TONIGHT. IN THE EAST
SOME FOG HAS FORMED ALONG THE MINNESOTA BORDER. KATY CURRENTLY HAS
A 2 F TEMPERATURE DEW POINT SPREAD SO FOG IS AT LEAST POSSIBLE
TONIGHT. UPSTREAM WINDS ARE STAYING IN THE 10 KT RANGE UNDER THE
APPROACHING HIGH PRESSURE SYSTEM. EXPECT WINDS WILL KEEP LOW LAYER
MIXED ENOUGH TO PRECLUDE AN AREA OF DENSE FOG SETTLING IN.

&&

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

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

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