000
FXUS63 KABR 080215 AAA
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
815 PM CST FRI DEC 7 2007

.UPDATE...
MADE SOME MINOR UPDATES TO FORECAST TONIGHT BASED ON CURRENT
TRENDS. MSAS ANALYSIS INDICATING SFC RIDGE EXTENDING FROM NERN MT
SEWD THRU ERN SD. MEANWHILE...WATER VAPOR IMAGERY SHOWING STRONG
STORM SYSTEM CONTINUING TO ORGANIZE OVER THE DESERT SOUTHWEST. IR
IMAGERY SHOWING MID/HIGH CLOUDS OVER WYOMING TRYING TO MAKE A RUN
ACROSS SD...HOWEVER VERY DRY AIR IN PLACE ACROSS THE EAST
HINDERING EWD PUSH. ANOTHER BRUTALLY COLD NIGHT UPCOMING ACROSS THE JAMES
RIVER VALLEY...WITH READING FALLING INTO THE DOUBLE DIGITS BELOW
ZERO. FURTHER TO THE WEST...INCREASING HIGH CLOUDS WILL PRECLUDE
TEMP FREE FALLL SOMEWHAT. AS FOR PRECIPITATION...REGIONAL RADAR
MOSAIC SHOWING ECHOES CONFINED PRIMARILY OVER FAR SOUTHWEST SD AND
FAR NRN NE. CONTINUE TO PREFER THE DRIER LOOK OF THE GFS TONIGHT
AND SATURDAY...WITH BEST CHANCE OF LIGHT SNOW/FLURRIES ALONG AND
SOUTH OF HIGHWAY 14...WITH ANY ACCUMULATING SNOW SOUTH OF I-90.
PERSISTENT ARCTIC HIGH TO RESULT IN COLD TEMPS SATURDAY...SOME
10-20F BELOW NORMAL MOST LOCALES.

AVIATION DISCUSSION HAS BEEN UPDATED BELOW.


&&
.PREV DISCUSSION...
.SHORT TERM...THROUGH SUNDAY MORNING

HAVE MANAGED DOUBLE DIGITS IN THE JAMES VALLEY AND ALONG THE
SISSETON HILLS...IMPRESSIVE CONSIDERING THE -14F START IN
ABERDEEN. AT H85 LEVEL...TEMPERATURES STARTING AT -8C WITH WEAK
CAA...DROPPING AS LOW AS -14C OVER OUR NORTHEAST COUNTIES THIS
EVENING. CONSIDERING THE DROP OF 20F IN 4 HOURS LAST NIGHT AND LOW
START TO THIS EVENING...AND CLEAR SKIES EXPECTED MOST OF THE NIGHT...WILL
CONTINUE TO UNDERCUT GUIDANCE BY 10F TO 15F FOR THE JAMES
VALLEY/SISSETON HILLS. APPROACHING SYSTEM TO ADVECT HIGH CLOUD
DECK LATE TONIGHT...REACHING THE JAMES VALLEY/SISSETON HILLS BY 09Z.
SHOULD SEE SLOWER/LEVEL TEMPERATURE TREND PAST THIS POINT.

SLOW TEMPERATURE RECOVERY TOMORROW WITH CLOUD COVER AND LIGHT
NORTH WIND WITH HIGH PRESSURE OVER NORTH DAKOTA. CONTINUED HIGH
CLOUD INTO SATURDAY NIGHT WILL MODERATE READINGS SOMEWHAT...BUT
WITH LITTLE MOVEMENT OF ARCTIC AIRMASS AND DRY LOW LAYERS WILL
CONTINUE TO UNDERCUT MODEL GUIDANCE.

AS FOR SNOW POTENTIAL SATURDAY...WILL CONTINUE WITH GFS/ECMWF AS
MODELS OF PREFERENCE. PREVIOUSLY DISCUSSED ISSUES WITH NAM ATTEMPT
TO MOVE ARCTIC AIRMASS THE DECIDING FACTOR.

SREF PWAT ANOMALY OF 3 TO 4 STANDARD DEVIATIONS NOTED WITH
DEVELOPING SYSTEM...WHILE DRY ARCTIC AIRMASS WITH PWAT
VALUES A STANDARD DEVIATION BELOW SITS OVER NORTH DAKOTA. THE CWA
RESIDES BETWEEN THE TWO...TRENDING TOWARDS THE DRIER SIDE. SERIES
OF FRONTOGENETIC BANDS WILL SWEEP NORTHWARD SATURDAY...BUT MAINLY
AT THE H6/H5 LEVELS. LITTLE LIFT APPEARS REALIZED BELOW THE H7
LEVEL EXCEPT ALONG OUR SOUTHERN PERIPHERY. CONTINUE TO SEE
MODERATE CONDENSATION PRESSURE DEFICITS BELOW THIS LEVEL AS WELL.
WILL LIKELY SEE SERIES OF SNOW BANDS MOVE INTO CENTRAL SOUTH
DAKOTA BEFORE DISSIPATING AS DRIER AIR IS ENTRAINED. GFS SOUNDINGS
ACROSS NORTHERN SOUTH DAKOTA SUPPORT THIS WITH SNOW GROWTH
REGIONS WELL ABOVE AN APPARENT H7 TO H85 DRY LAYER. FURTHER
SOUTH...WILL NOT ISSUE HEADLINES FOR LYMAN/JONES/BUFFALO COUNTIES
DESPITE GFS SOUNDINGS THAT SUGGEST SNOW GROWTH CLOSER TO SURFACE
THROUGH 06Z SUNDAY AS ONLY 3 ENSEMBLE MEMBERS SUGGEST ENOUGH
LIQUID TO APPROACH SNOW ADVISORY CRITERIA ALONG THE I90 CORRIDOR.


.LONG TERM...12Z SUNDAY THROUGH FRIDAY.
BIGGEST FORECAST CHALLENGE IN THE EXTENDED DEALS WITH PCPN CHANCES
MONDAY NIGHT INTO TUESDAY...AND TEMPS THROUGHOUT.

FIRST OFF..DEALING WITH MODELS...THE NAM APPEARS TO BE TO STRONG
WITH WAA TAKING PLACE THROUGH THE FIRST PART OF THE
EXTENDED...WITH EXCELLENT AGREEMENT BETWEEN THE EC AND GFS. BASED
ON TRACK RECORD OF THE GFS...HAVE USED IT AS THE MODEL OF CHOICE
FOR THE EXTENDED PERIOD.

12Z SUNDAY BEGINS WITH THE CWA BETWEEN NORTHERN AND SOUTHERN
STREAMS. SFC HIGH REMAINS ENTRENCHED ACROSS ND/MN AND NORTHERN SD
THROUGH THE WEEKEND WITH COND PRESSURE DEFICITS INDICATING
PTCLOUDY SKIES THROUGH THE WEEKEND. WITH LIGHT WINDS AND GOOD
SNOWPACK ACROSS MUCH OF EASTERN SODAK...HAVE LOWERED MAX/MN T
GRIDS A BIT MORE FOR THE SUNDAY/MONDAY TIME FRAME. LITTLE IF ANY
MIXING ANTICIPATED...AND GOOD RADIATIONAL COOLING SETUP OVERNIGHT
SHOULD LEAD TO COOLER READINGS.

GFS IS NOW SHOWING A VERY SIMILAR SETUP FOR MONDAY NIGHT INTO
TUESDAY TO WHAT IS EXPECTED FOR TONIGHT. 7H TROF LIFTS OUT OF SW
CONUS WITH WAA RETURNING TO CWA. DIFFLUENT FLOW TAKES PLACE DURING
THE DAY TUESDAY...MAINLY ACROSS THE SRN 1/2 OF THE KABR CWA. THERE
IS SOME MINIMAL 7H FRONTOGENESIS THAT TAKES PLACE DURING THE DAY
TUESDAY...WITH A SLIGHT INCREASE IN PWATS ALSO BY 18Z TUESDAY. SFC
HIGH PRESSURE REMAINS FURTHER WEST OF THE REGION...WHICH WON`T
SHUT OFF THE NORTHWARD MOISTURE FLOW. HAVE INTRODUCED CHC/SLGT CHC
POPS FOR THE SOUTHERN 1/2 OF THE CWA BEGINNING LATE MONDAY NIGHT
THROUGH TUESDAY. THE EC ADVERTISES A BIT MORE OF A SPLIT FLOW
REGIME FOR THE TIME PERIOD...BUT AGREES IN GENERAL WITH PCPN CHCS
ACROSS THE SOUTHERN HALF OF THE AREA.

GFS THEN SHOWS A COLD FRONT SLIPPING SOUTH REINFORCING THE COOL
AIR ALREADY IN PLACE DURING THE DAY THURSDAY. ATTM LOOKS LIKE
FRONT IS DRY ALTHO THE EC IS HINTING AT LIGHT SNOW/FLURRIES
POSSIBLE.

WITH REGARDS TO HPC TEMPS...HAVE LOWERED THEM 3 TO 5 DEGREES
ACROSS THE BOARD BASED ON CURRENT SNOWPACK...EXPECTED SNOWFALL
ACROSS OUR FAR SW AND 85H TEMPS.



&&

.AVIATION...
VFR CONDITIONS WILL CONTINUE AT TERMINALS OVERNIGHT AS SFC HIGH
PRESSURE REMAINS PARKED ACROSS SD. SATELLITE TRENDS SHOWING MID-HIGH
CLOUDS MAKING A SLOW PUSH NWD INTO CENTRAL AND NERN SD AHEAD OF
DEVELOPING STORM SYSTEM OVER THE ROCKIES. SIMULATED IR PRODUCT
FROM 4KM CRAS APPEARS TO HAVE GOOD HANDLE ON CLOUD TREND ATTM SO
WILL FOLLOW FOR TIMING OF HIGH CLOUDS TONIGHT. FIRST IN A SERIES
OF WEATHER DISTURBANCES TO EJECT NEWD INTO THE PLAINS ON
SATURDAY. EXPECT CIGS TO GRADUALLY FALL FROM SOUTHWEST TO
NORTHEAST...HOWEVER VERY DRY AIR NEAR THE SFC SHOULD KEEP THE
MAJORITY OF CIGS ACRS NERN SD IN THE VFR CATEGORY. FAIRLY CONFIDENT
THAT PORTIONS OF CENTRAL SD WILL SEE AREAS OF LIGHT SNOW DEVELOP
BY MORNING...WITH MVFR CIGS/VSBYS LIKELY AT KPIR AFTER 14Z.
DEPENDING ON SURGE OF MOISTURE...COULD EVEN SEE OCCNL IFR VSBYS
/1-2SM/ BUT CONFIDENCE TOO LOW TO INCLUDE IN KPIR TAF ATTM.

&&

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

$$
UPDATE...FOWLE
SHORT TERM...CONNELLY
LONG TERM...HINTZ
AVIATION...FOWLE

----------------------------------------------------------------------

000
FXUS63 KABR 240943
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
343 AM CST MON DEC 24 2007

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
STRATUS DECK HANGING IN TOUGH ALONG THE JAMES VALLEY AND POINTS
EAST EARLY THIS MORNING...THUS KEEPING TEMPS WELL IN THE TEENS.
JUST TO THE WEST WHERE SKIES HAVE CLEARED TEMPS ARE IN THE SINGLE
DIGITS AND APPROACHING ZERO. WINDS HAVE ALSO SLACKENED AS HIGH
PRESSURE RIDGE AT THE SURFACE IS OVER CENTRAL SOUTH DAKOTA. STILL
EXPECTING BREAKS IN THE STRATUS OVER THE NEXT SEVERAL HOURS AS THE
ENTIRE DECK SHIFTS EAST. DID INCREASE SKY COVER THOUGH AT 12Z THIS
MORNING AS IT WILL MORE THAN LIKELY BE CLOUDIER THAN WHAT WAS
PREVIOUSLY FORECAST THIS MORNING. HIGH CLOUDS ALSO APPROACHING
FROM THE NORTHWEST IN ADVANCE OF WAA AHEAD OF NEXT SYSTEM. 

MID/HIGH CLOUDS WILL BE ON THE INCREASE TODAY AS WAA SPREADS OVER
THE AREA. TEMPS SHOULD BE ABLE TO WARM INTO THE 30S ACROSS CENTRAL
SD...COOLING INTO THE LOW 20S ACROSS THE EASTERN CWA. ALTHOUGH
WILL ONCE AGAIN SUFFER FROM A LACK OF MIXING AND A SNOWFIELD
ACROSS THE EASTERN CWA AND MAY HAVE TO LOWER HIGHS A COUPLE
DEGREES FOR MORNING UPDATE. MAIN CHALLENGE IN THE SHORT TERM
DEALS WITH PRECIP TYPE TONIGHT AND AREAL COVERAGE OF
PRECIPITATION. NAM CONTINUES TO BE QUICKER AND DRIER WITH THE
SYSTEM...ALTHOUGH NAM IS TYPICALLY A DRIER SOLUTION ANYWAY. EVEN
THOUGH IT IS THE DRIER SOLUTION...IT HAS INCREASED ITS QPF FROM
ITS RUN 6 HOURS AGO. AFTER EXAMINING BUFKIT AND MODEL
SOUNDINGS...AS WELL AS WAA/CAA PATTERNS AT 925/850 MB AND THEIR
TEMPERATURES...SEEMS AS IF THERE MAY BE A BRIEF PERIOD THIS
EVENING WHEN ALL RAIN COULD OCCUR ACROSS CENTRAL SD. SOUNDINGS
SATURATE ABOUT THE TIME WHEN SFC TEMPS SHOULD BE NEAR OR ABOVE
FREEZING OVER CENTRAL SD. ALSO...ONCE WINDS TURN WESTERLY THERE
SHOULD BE ENOUGH MIXING OF THE WARMER AIR ALOFT TO ALLOW SOME
LOCATIONS TO RISE ABOVE 32. HAVE THEREFORE ADDED A COUPLE HOURS OF
RAIN OR FREEZING RAIN MENTION FROM ABOUT 00Z-02Z ACROSS CENTRAL
SD. WILL ALSO KEEP AREA OF FREEZING RAIN OR SNOW ACROSS THE
CENTRAL PART OF THE STATE THIS EVENING...BUT WILL EXPAND THIS
POSSIBILITY EAST TOWARDS THE JAMES VALLEY. HAVE ALSO CHANGED
PRECIP TYPE TO ALL SNOW AFTER 06Z. STILL NOT EXPECTING MUCH IN THE
WAY OF ACTUAL PRECIPITATION WITH SNOW AMOUNTS GENERALLY UNDER AN
INCH OR TWO. ICE ACCUMULATIONS COULD BE A COUPLE HUNDREDTHS ACROSS
CENTRAL SD THIS EVENING. SREF MEMBERS ALSO SHOWING PROBS OF
FREEZING RAIN FROM ABOUT 30 PERCENT OR LESS...WITH A BULLSEYE OF
50 PERCENT RIGHT OVER ABR. WILL HAVE TO WATCH THIS TREND.

MODELS STARTING TO TREND TOWARDS INCREASED CLOUDINESS BEHIND THIS
SYSTEM FOR TUESDAY AND ESPECIALLY TUESDAY NIGHT AS RH FROM 850 AND
BELOW INCREASES. CRAS SATELLITE FORECAST IMAGERY ALSO HINTING AT
THIS SCENARIO. COULD BE ENOUGH MOISTURE AND LIFT ON THE BACKSIDE
OF THE WAVE TO PRODUCE A FEW FLURRIES OR LIGHT SNOW SHOWERS SO
LEFT LOW POPS IN THE FORECAST FOR TUESDAY NIGHT.


.LONG TERM...WEDNESDAY THROUGH SUNDAY.
MAIN FCST CHALLENGE FOR THE EXTENDED STILL DEALS WITH POTENTIAL
STORM SYSTEM AFFECTING THE AREA LATE IN THE WEEK. 

PRIOR TO THAT...THE MODELS ARE IN PRETTY FAIR AGREEMENT WEDNESDAY
AND WEDNESDAY NIGHT. UPPER TROF EXITS TO THE EAST OF THE REGION BY
WEDNESDAY MORNING...WITH S/W RIDGING TAKING PLACE THROUGH THURSDAY
MORNING. REGION DOESN'T UNDERGO STRONG WAA THROUGH THE TIME
PERIOD...AND WITH SPRAWLING SFC HIGH THROUGH THE AREA...A BIT
WORRIED ABOUT VENTILATION CAPABILITIES. SEEMS TO BE A PRIME
SITUATION WHERE LOW STRATUS DECK GETS TRAPPED UNDER INVERSION WITH
LITTLE SFC-850MB MIXING WIND TAKING PLACE. HAVE UPPED SKY COVER A
BIT WEDNESDAY/WEDNESDAY NIGHT AS WELL AS CONT TO UNDERCUT GUIDANCE
VALUES BY ABOUT A CATEGORY FOR HIGHS/LOWS. 

ATTENTION THEN TURNS TOWARD THE END OF THE WEEK. MODELS ARE STILL
PROGGING A LONG-WAVE TROF TO DROP INTO THE DESERT SW BEFORE
BEGINNING TO LIFT INTO THE MIDWEST BY FRIDAY. THE 00Z GFS STILL
REMAINS OUT OF SORTS WITH ITS ENSEMBLE MEMBERS...ALTHO THEY ARE
BEGINNING TO COME A BIT CLOSER TOGETHER. THE GFS ENSEMBLE MEMBERS
ARE SLOWER AND A BIT FURTHER WEST WITH THE FEATURE. BY 12Z FRIDAY
THE ENSEMBLE MEAN PLACES A SFC LOW IN EXTREME NW MO...WHILE THE
OPERATIONAL GFS HAS THE LOW NEAR CHICAGO. THE CANADIAN ENSEMBLES
AND 23/18Z DGEX AGREE WITH THE GFS ENSEMBLE SOLN...AT LEAST AT 5H.
THE LATEST EC SFC POSN AGREES MORE WITH THE OPERATIONAL GFS. HAVE
FOR THE TIME BEING LEFT CURRENT WX GRIDS AS IS...WITH THE
EXCEPTION OF SOME COSMETIC TWEAKS. IF THE GFS/CANADIAN ENSEMBLES
END UP BEING CLOSER TO REALITY...WILL NEED TO HAVE SOME POPS
INSERTED FOR FRIDAY...AT LEAST FOR THE MORNING. STILL TOO MUCH
UNCERTAINITY TO ALTER CURRENT FCST. 


&&

.AVIATION...
IFR CONDS ARE EXPECTED TO PERSIST FROM THE JAMES RIVER VALLEY AND
POINTS EAST THROUGH 15Z BEFORE BEGINNING A SLOW IMPROVEMENT. KABR
WILL BE THE FIRST TO CLIMB INTO MVFR STATUS BETWEEN 15Z AND
18Z...WITH KATY FOLLOWING FROM 17Z TO 20Z. FUTHER WEST...FOR KPIR
AND KMBG...VFR CONDS WILL CONT THROUGH 06Z TUESDAY. AN EXPANSIVE
AREA OF MID/HIGH LEVEL CLOUDS WILL OVERSPREAD THE AREA BY 00Z
TUESDAY WITH THE APPROACH OF THE NEXT STORM SYSTEM. SOME LIGHT
FREEZING RAIN OR LIGHT SNOW IS POSSIBLE FROM THE JAMES RIVER
VALLEY AND WEST AFT 06Z TUESDAY. 


&&

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

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

WEATHER.GOV/ABERDEEN

----------------------------------------------------------------------

000
FXUS63 KABR 211005
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
405 AM CST MON JAN 21 2008

.SHORT TERM...TODAY THROUGH WEDNESDAY
LIGHT SNOW CONTINUES TO FALL ACROSS THE SOUTHERN TWO-THIRDS OF THE
CWA BUT FLURRIES MAKING IT AS FAR NORTH AS THE ND/SD BORDER WITH
ABR CURRENTLY REPORTING 6SM BR...BUT THE BR IS ACTUALLY FLURRIES.
STILL PLENTY OF LIGHT SNOW UPSTREAM WITH KUNR RADAR SHOWING LIGHT
SNOW ALL THE WAY WEST TO THE BLACK HILLS. SFC OBS ALSO REVEAL
LIGHT SNOW BACK TO THE SAME AREA. RAISED POPS TO CATEGORICAL
ACROSS THE SOUTHERN CWA FOR A FEW HOURS THIS MORNING BEFORE
ACTIVITY DIMINISHES AND SHIFTS SOUTH IN RESPONSE TO DRIER AIR AND
SFC HIGH PRESSURE SLOWLY SLIDING SOUTH INTO THE AREA. WILL ALSO
INSERT SCT FLURRIES ACROSS THE NORTHERN CWA...EXCEPT FOR THE FAR
NORTHEAST WHERE AIR SHOULD REMAIN TOO DRY CLOSER TO THE SFC RIDGE
AXIS. WILL ALSO CANCEL THE WINTER WX ADVISORY AS BLOWING SNOW/WIND
AND WIND CHILLS JUST NOT AN ISSUE WITH THIS SYSTEM. WINDS
GENERALLY LESS THAN 10 MPH ACROSS THE ADVISED AREA AND ONLY
EXPECTING ANOTHER INCH AT MOST BEFORE SNOW ENDS LATER TODAY.
MURDO/CHAMBERLAIN WEB CAMS SHOW ONLY LIGHT SNOW BUT NO ISSUES WITH
BLOWING SNOW AND VSBYS APPEAR OK. TRENDED POPS TO LOW CHANCE AFTER
18Z TODAY AND CONFINED THEM TO THE SOUTHERN CWA. HAVE ALSO SLOWED
DOWN CLOUD DEPARTURE TODAY BASED ON SOUNDINGS AND CRAS FORECAST
SATELLITE IMAGERY. WILL STILL SEE GRADUAL DECREASE IN CLOUDS FROM
NORTHWEST TO SOUTHEAST THROUGHOUT THE DAY...BUT JUST NOT AS FAST
AS PREVIOUSLY EXPECTED.

STILL ON TRACK FOR TWO CLIPPERS SLIDING THROUGH THE AREA. ONE VERY
WEAK WAVE FOR LATE TONIGHT/TUESDAY MORNING AND KEPT SCT FLURRIES
MENTION ACROSS THE EXTREME NORTHEASTERN CWA. BETTER CHANCE FOR
LIGHT SNOW WILL BE ACROSS EASTERN ND AND NORTHERN MN. BETTER
LOOKING WAVE STILL SET TO MOVE SOUTHEAST THROUGH THE AREA TUESDAY
NIGHT. HAVE INCREASED POPS FOR THIS...ESPECIALLY ACROSS THE
WESTERN CWA. HAVE ALSO INCREASED SNOW ACCUMS SLIGHTLY. ANOTHER
SHOT OF ARCTIC AIR BEHIND THIS FRONT WITH INCREASED NORTHERLY
WINDS.

AS FOR TEMPERATURES...GUIDANCE HAS COME UP FOR HIGHS TODAY AND
HAVE FOLLOWED SUIT. UNDERCUT HIGHS TOO MUCH YESTERDAY ACROSS
CENTRAL SD AND PIR/MBG WERE ABLE TO WARM INTO THE TEENS EVEN WITH
SNOW/CLOUDS. TEMPS EARLY THIS MORNING STILL IN THE MID/UPPER
SINGLE DIGITS AND WITH CLOUDS...DO NOT EXPECT TEMPS TO FALL MORE
THAN A COUPLE DEGREES BEFORE SUNRISE. SHOULD THEREFORE BE ABLE TO
RISE TO AROUND 10 OR SO ACROSS CENTRAL SD THIS AFTERNOON. LOWS
TONIGHT TRICKY AS THERMAL RIDGE MOVES INTO THE AREA WHILE SFC
WINDS INCREASE. WILL DROP OFF QUICKLY THIS EVENING BUT EXPECTING
TEMPS TO STEADY OUT OR EVEN RISE A FEW DEGREES OVERNIGHT AS WAA
BUILDS AND WINDS INCREASE. RAISED LOWS A FEW DEGREES IN RESPONSE
TO THIS. TRICKY FORECAST BECAUSE FRESH COUPLE INCHES OF SNOW
ACROSS THE SOUTHWESTERN CWA WILL ALLOW TEMPS TO DROP QUICKLY THIS
EVENING. HARD TO FIND A BALANCE BETWEEN THIS AND THE WAA/WINDS.
CONCERNING WIND CHILLS...IT DOES APPEAR WE COULD FALL INTO
ADVISORY CRITERIA OVERNIGHT...BUT WILL LEAVE THE SPECIFICS FOR DAY
SHIFT SINCE THERE ARE UNCERTAINTIES IN TONIGHTS LOWS WHICH WOULD
AFFECT HOW LOW WIND CHILLS GET. IF LOWS END UP BEING A FEW DEGREES
WARMER THAN FORECAST /CURRENT MIN T GRID ACTUALLY UNDERCUTS MAV
GUIDANCE/ THEN CRITERIA MAY NOT BE MET. ALSO...AS WINDS
INCREASE...TEMPS MAY ACTUALLY RISE A FEW DEGREES. A BIT TOO EARLY
TO SORT THIS OUT AND WILL LET DAY SHIFT MONITOR TEMP TRENDS AND
MAKE THE FINAL CALL. REGARDLESS...WILL KEEP MENTION OF THE LOW
WIND CHILLS IN THE HWO AND ZONE FORECAST WILL MENTION THIS ALSO.


.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
ONE MORE COLD NIGHT IN THE EXTENDED WITH ARCTIC AIR OVER THE AREA
WITH A WARMING TREND FOR THURSDAY THROUGH SATURDAY. SURFACE HIGH
PRESSURE RIDGING SLIDING EAST OF THE CWA ON WEDNESDAY NIGHT WILL
RESULT IN LIGHT WINDS BECOMING SOUTH BY MORNING. AFTER A COLD DAY
WEDNESDAY...TEMPERATURES SHOULD FALL BELOW ZERO ACROSS MOST OF THE
CWA UNDER MOSTLY CLEAR SKIES FOR WEDNESDAY NIGHT. SOUTH WINDS WILL
BRING IN WARMER AIR FOR THURSDAY THROUGH FRIDAY WITH UPPER LEVEL
HIGH PRESSURE RIDGING SLIDING OVER THE REGION. MAY HAVE TO
INCREASE HIGHS SOME MORE FOR THURSDAY AND FRIDAY. OTHERWISE..THE
EC...DGEX AND GFS SHOW THE LARGE UPPER LOW STILL SPINNING OVER
CALIFORNIA AND OFF THE COAST EARLY ON IN THE PERIOD. SOME SHORT
WAVE ENERGY COMING OFF OF THIS LOW WILL TRACK NORTHEAST AND INTO
THE UPPER MIDWEST FOR FRIDAY AND FRIDAY NIGHT. THE MODELS SHOW
SOME DIFFERENCES IN THE TRACK AND STRENGTH WITH THIS. ADDED IN
SOME 20 POPS FOR FRIDAY ACROSS MUCH OF THE CWA. THE MODELS THEN
SHOW EVEN MORE IMPORTANT DIFFERENCES WITH THE TIMING...TRACK AND
STRENGTH OF THE UPPER LOW OVER CALIFORNIA FINALLY LIFTING
NORTHEAST INTO THE CENTRAL PART OF THE US SATURDAY AND SUNDAY. THE
EC WAS QUITE IMPRESSIVE WITH THE SURFACE LOW PRESSURE AREA BY
SUNDAY NIGHT AND MONDAY. KEPT IT DRY FOR NOW AND WILL HAVE TO WAIT
FOR LATER MODEL RUNS.


&&

.AVIATION...
WIDESPREAD LIGHT SNOW/FLURRIES WILL CONTINUE TO AFFECT ALL TAF
SITES THROUGH 18Z OR SO. EXPECT VISIBILITIES TO REMAIN GENERALLY
IN THE 3 TO 7 MILE RANGE. PIR AND ATY WILL OCCASIONALLY FALL TO
LESS THAN 3 MILES. OTHERWISE...EXPECT MVFR/VFR CEILINGS OF 2000
TO 5000 FEET TO REMAIN AT ALL TAF SITES THROUGH MUCH OF THE DAY
WITH THE CLOUDS BREAKING UP THIS EVENING AT MBG AND PIR AS
SUBSIDENCE AND DRIER AIR MOVES IN. EXPECT THE CLOUDS TO BREAK UP
AT ABR AND ATY LATE THIS EVENING AND OVERNIGHT.


&&

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

$$
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...MOHR

WEATHER.GOV/ABERDEEN

----------------------------------------------------------------------

000
FXUS63 KABR 290834
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
334 AM CDT MON SEP 29 2008

.SHORT TERM...TODAY THROUGH WEDNESDAY
COOL HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION AS TEMPS ARE
DROPPING INTO THE UPPER 30S ACROSS NORTH CENTRAL SOUTH DAKOTA.
THIS HIGH WILL CONTINUE TO BUILD ACROSS THE AREA THROUGH TONIGHT
AND MAIN FORECAST CONCERN ARISES TONIGHT IN LOW TEMPERATURES.
NEARLY IDEAL RADIATIONAL COOLING SETUP FOR TONIGHT WITH COOL HIGH
PRESSURE CENTERED DIRECTLY OVERHEAD...WITH MOSTLY CLEAR SKIES AND
LIGHT WINDS. GUIDANCE VALUES SHOWING OVERNIGHT LOWS GENERALLY FROM
35 TO 40 DEGREES...BUT FEEL THIS IS A BIT TOO WARM. ONLY FLY IN
THE OINTMENT FOR A PERFECT RADIATIONAL COOLING NIGHT IS
POSSIBILITY FOR CLOUD COVER ACROSS THE EASTERN CWA. CRAS FORECAST
SATELLITE IMAGERY AND RH FIELDS...AS WELL AS TIME HEIGHTS AND
SOUNDINGS ALL INDICATE PERHAPS SOME SCT CLOUDS ACROSS THE AREA
OVERNIGHT. IN FACT...MAV GUIDANCE BRINGS IN FEW/SCT/BKN CONDITIONS
AFTER 06Z TO THE EASTERN SITES. WILL THEREFORE HOLD OFF ON ANY
FROST ADVISORIES AT THIS TIME AND LET DAY SHIFT INVESTIGATE
FURTHER AND GET ONE LAST LOOK AT POTENTIAL FOR CLOUD COVER AND
JUST WHERE THE COOLEST TEMPS WILL BE. FOR RIGHT NOW HAVE INCLUDED
PATCHY FROST IN THE GRIDS FOR THE NORTHERN CWA AND IMAGINE A FROST
ADVISORY WILL BE NEEDED FOR SOME PORTION OF THE NORTHERN CWA AT
LEAST. WILL HIGHLIGHT POTENTIAL FOR FROST IN OTHER PRODUCTS AS
WELL. POTENTIAL EXISTS FOR FAVORED COOL SPOTS TO FLIRT WITH THE
FREEZING MARK BY EARLY TUESDAY MORNING.

THE REST OF THE SHORT TERM IS QUIET AS SURFACE HIGH PRESSURE WILL
BE IN PLACE ACROSS MUCH OF THE NORTHERN PLAINS. 


.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
AS EXPECTED MODELS CONTINUE TO ADVERTISE HIGHLY MERIDIONAL LONG
WAVE PATTERN OVER THE CONUS DURING MOST OF THE MEDIUM RANGE.
PROGRESSION AND BREAKDOWN OF THE PATTERN SHOULD COMMENCE NEXT
WEEKEND...BUT THAT IS MAINLY BEYOND THE SCOPE OF THIS PACKAGE.
WITH LONG WAVE RIDGE IN PLACE...FORECAST AREA SHOULD REMAIN DRY
UNTIL PERHAPS NEXT WEEKEND. TEMPERATURES CONTINUE TO BE THE MAIN
FORECAST CHALLENGE. ECMWF MAINTAINS MORE BACKDOOR COLD AIR ON
THURSDAY AND FRIDAY VS THE GFS. BECAUSE OF THE UNCERTAINTY IN THE
THERMAL PROGS...ONCE AGAIN DECIDED IT BEST TO KEEP
PERSISTENCE/CONSISTENCY IN THE TEMPERATURE FORECAST THROUGH THE
MEDIUM RANGE...WITH MAX AND MIN TEMPS GENERALLY BELOW MEX GUIDANCE
AND CLOSER TO HPC GUIDANCE.


&&

.AVIATION...
OVERALL EXPECT VFR CONDITIONS AT ALL TERMINALS THROUGH THE NEXT 24
HOURS. SOME AFTERNOON CUMULUS WILL BE POSSIBLE AT KATY/KABR
OTHERWISE LITTLE IF ANY CLOUD COVER IS ANTICIPATED. VSBYS SHOULD
BE UNRESTRICTED.  


&&

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

$$
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...TDK

WEATHER.GOV/ABERDEEN