FXUS63 KABR 291625
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
1025 AM CST SUN NOV 29 2009

.UPDATE...
CURRENT FORECAST STILL LOOKS TO BE ON TRACK AS HIGH PRESSURE CONTS
TO PUSH IN FROM THE WEST. AREA OF LOW CLOUDS ARE STILL PERSISTING
ACROSS THE EASTERN PART OF THE CWA...AND TWEAKED SKY COVER GRIDS
TO ACCOUNT FOR THESE. STILL FEEL THAT THESE CLOUDS WILL ERODE/MOVE
OUT BY 20Z...LEAVING ALL THE CWA IN MOSUNNY/SUNNY CONDS. HOPEFULLY
THIS WILL LEAVE ENOUGH TIME FOR THE FCST HIGHS TO RECOVER ENOUGH
TO REACH FCSTD VALUES. 

UPDATED AVIATION DISCUSSION BELOW. 

&&
.PREV DISCUSSION...
.SHORT TERM...THROUGH TUESDAY

THE GOOD TIMES KEEP ROLLIN...WITH UPPER RIDGING ALOFT THROUGH THE
EXTENT OF THE SHORT TERM. THE ONLY CAVEAT...THE UPPER RIDGE WILL
BE SUPPRESS BY THE PASSAGE OF A SHORTWAVE LATE IN THE PERIOD. THE
MAIN INFLUENCE OF THIS WAVE WILL BE FELT DURING THE LONG TERM
HOWEVER...SO FOCUS WILL BE ON TEMPERATURES.

H85 COLD ADVECTION WILL PERSIST THROUGH THE MORNING...WITH WARM
ADVECTION BEGINNING TO TAKE HOLD ACROSS THE WEST LATE TODAY. LOW
CLOUDS FROM A KABR TO KHON WILL CONTINUE EAST AS WELL...CLEARING
THE CWA BY NOON. THAT SAID...EXPECT WITH FULL SUN MAV TEMPERATURES
OF MID TO LOW 40S ARE APPROPRIATE. SUPPRESSED MAX TEMPERATURES A
DEGREE OR TWO FROM THE JAMES VALLEY AND POINTS EAST BASED ON BIAS
CORRECTION AND POSSIBLE INFLUENCE OF AFOREMENTIONED CLOUD COVER.
STRONGER INTENSITY WARM ADVECTION EXPECTED OVERNIGHT WITH H85
TEMPERATURES INCREASING TO +1 TO +4C. AT THE SAME TIME...WILL SEE
CONTINUOUS CIRRUS OVERTOPPING THE RIDGE OVERNIGHT...SO FOLLOWED
PREVIOUS SHIFTS LEAD IN INCREASED OVERNIGHT TEMPERATURES. H85
TEMPERATURES CONTINUE THE SLOW/STEADY INCREASE INTO TUESDAY...BUT
THAT WILL COME TO A HALT WITH THE PASSAGE OF A COLD FRONT LATE.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
THE MODELS CONTINUE TO START OFF IN DECENT AGREEMENT...BUT THEIR
SOLUTIONS BECOME RADICALLY DIFFERENT DURING THE LATTER HALF OF THE
PERIOD. THE GFS ENSEMBLES ARE PRETTY EVENLY SPLIT BETWEEN THE GFS
AND ECMWF SOLUTIONS AS WELL. THEREFORE...WILL STICK WITH THE HPC
FORECAST AND MAKE NO CHANGES TO FRIDAY OR SATURDAY.

DURING THE FIRST HALF OF THE PERIOD...AN UPPER LEVEL TROUGH WILL
EXTEND FROM EASTERN CANADA TO THE NORTHERN PLAINS...THEN VERY
SLOWLY TRACKS EASTWARD WEDNESDAY AND THURSDAY. A SURFACE COLD
FRONT WILL BE SOUTH OF THE REGION TUESDAY EVENING...WITH HIGH
PRESSURE BEGINNING TO NOSE OVER THE WESTERN DAKOTAS. THE HIGH
CONTINUES TO BROADEN EASTWARD...AND BECOMES ELONGATED OVER THE
PLAINS WEDNESDAY AND THURSDAY. NO PRECIPITATION EXPECTED DURING
THE ENTIRE LONG TERM PERIOD.

SLIGHTLY BELOW NORMAL TEMPERATURES WILL OCCUR WEDNESDAY THROUGH
SATURDAY AS H85 TEMPERATURES REMAIN IN THE SINGLE DIGITS TO TEENS
BELOW ZERO. GENERALLY LOOKING AT HIGHS IN THE 20S TO LOWER 30S.
LOWS START OFF NEAR NORMAL TUESDAY NIGHT...BUT FALL BELOW NORMAL
WEDNESDAY AND THURSDAY NIGHT UNDER THE INFLUENCE OF THE SURFACE
HIGH...THEN RECOVER SOME LATE IN THE PERIOD.

&&

.AVIATION...
VFR CONDITIONS WILL PERSIST ACROSS KABR/KMBG/KPIR TERMINALS THRU
NEXT 24 HRS. ACROSS KATY TERMINAL...MVFR CIGS RANGING FROM 1500 TO
2500 FT WILL PERSIST THRU 18Z-19Z BEFORE BECOMING SKC.
THEREAFTER...VFR CONDITIONS ARE EXPECTED TO LAST THRU THE NEXT 24
HRS. 

&&

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

$$
UPDATE...HINTZ
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...TMT

WEATHER.GOV/ABERDEEN