Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 230303 AAA
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
903 PM CST SAT NOV 22 2014

.UPDATE...
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.

MADE A COUPLE CHANGES TO P-TYPE FORECAST TONIGHT BASED OFF
OBSERVATIONS AND 18Z GFS/NAM SOUNDINGS IN BUFKIT. SWITCHED P-TYPE
TO RAIN-ONLY FOR THE OVERNIGHT. LOW LEVEL WAA AND SURFACE MOISTURE
ADVECTION ONGOING BENEATH BKN-OVC MID AND HIGH CLOUDS SHOULD KEEP
TEMPERATURES AT OR ABOVE 32F OVERNIGHT. SNOW/FREEZING RAIN SEEMS
LIKE A RATHER LOW PROBABILITY OCCURRENCE TONIGHT. ALSO ADJUSTED
COVERAGE/TIMING OF FOG MENTION OVER THE EASTERN CWA AHEAD OF AN
APPROACHING SURFACE TROF...WHERE TEMP/DEWPOINT SPREADS HAVE
FALLEN TO 3 DEGREES OR LESS.


&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT

A WARM FRONT WILL CONTINUE TRACKING EAST ACROSS THE REGION THIS
EVENING...WHICH WILL KEEP OVERNIGHT LOWS FAIRLY MILD. FORECASTING
LOWS TRICKY THIS EVENING AS AMOUNT OF CLOUD COVER AND MIXING WILL
GREATLY AFFECT READINGS. MODELS CONTINUE TO INDICATE POTENTIAL FOR
AREAS OF LIGHT PRECIP OVERNIGHT...AND DEPENDING ON TEMPS IT WILL
BE EITHER RAIN OR SNOW. GENERALLY WENT WITH 20/30 POPS TONIGHT.
ATTENTION THEN TURNS TO SUNDAY AND THE RATHER GUSTY WINDS THAT
WILL DEVELOPING BY LATE MORNING OVER WESTERN AND CENTRAL SOUTH
DAKOTA. DECIDED TO ISSUE A WIND ADVISORY FOR THE MISSOURI VALLEY
REGION BASED ON FORECAST WIND SPEEDS...NUMERICAL GUIDANCE AND
BUFKIT SOUNDINGS. WILL ALSO LEAVE IN THE MENTION OF RAIN OR SNOW
SHOWERS AS THE SHORTWAVE AXIS MOVES THROUGH DURING THE AFTERNOON.


.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
MAIN CHALLENGE FOR MED/LONG TERM FCST REVOLVES AROUND PCPN
TIMING...LOCATION AND MODEL DIFFERENCES.

MODELS ARE IN DECENT AGREEMENT WITH 500HPA TROF LOCATED ALONG THE
ERN DAKOTAS AT 00Z MONDAY. SFC LOW LOCATED WELL SOUTHEAST OF
CWA...BUT WRAPAROUND ON BACKSIDE...COUPLED WITH TIGHTENING SFC
PRESSURE GRADIENT...COULD MAKE FOR SOME TOUGH CONDITIONS SUNDAY
NIGHT IN LIGHT SNOW AND BLOWING SNOW...ESPECIALLY FOR THE FAR NE
PART OF THE CWA. WILL HAVE TO MONITOR FOR POTENTIAL HEADLINES.

SYSTEM PULLS AWAY DURING THE DAY MONDAY...WITH DIMISHING WINDS AND
SNOWFALL MOVING WEST TO EAST THROUGH THE DAY.

BIGGEST QUESTION IS GOING TO BE WEATHER TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING. GFS IS NOT NEARLY AS STRONG WITH SFC LOW
PRESSURE THAT DEVELOPS ON SAGGING COLD FRONT...WHILE THE EC SPINS
UP A FAIRLY POTENT SFC LOW DIVING SE. THE NAM AT 84 HOURS OFFERS
UP A SOLN THAT IS CLOSER TO THE GFS...WITH A MORE NORTHWARD TRACK
OF THE SFC LOW. THIS KEEPS MOST OF THE PCPN IN NORTH DAKOTA THAN
IN SOUTH DAKOTA. THIS WILL ALSO NEED TO BE WATCHED AS EC SOLN
WOULD CREATE SOME ISSUES...AGAIN IN THAT FAR NERN CWA
REGION...WITH LIGHT SNOW AND STRONG NW WINDS.

LASTLY...FOR THANKSGIVING...THE GFS KEEPS CANADIAN HIGH BOTTLED UP
IN SRN CANADA...WHICH ALLOWS SFC LOW TO DEVELOP ALONG STALLED COLD
FRONT DRAPED WEST-EAST ACROSS THE CWA. THE EC PUSHES THIS HIGH
MUCH FURTHER SOUTH. DIFFERENCE IS GFS SOLN SHOWS POTENTIAL FOR
MEASUREABLE SNOW THURSDAY...WHILE EC NOT SO MUCH. FOR NOW WILL
CONTINUE WITH SUPERBLEND SOLN.

TEMP WISE...LOOK FOR SUBSEASONAL TEMPS TO AGAIN PUSH INTO THE
REGION FOR THE BEGINNING OF THE WEEK...WITH LITTLE IF ANY RECOVERY
NOTED.


&&

.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

MID AND HIGH LEVEL CLOUDS WILL DRIFT ACROSS THE REGION TONIGHT AND
SUNDAY...BRINGING A LOW PROBABILITY OF SOME LIGHT RAIN TO THE
TERMINALS MAINLY BETWEEN NOW AND 15Z SUNDAY. IF IT LOOKS LIKE RAIN
IS ACTUALLY REACHING THE GROUND AT ANY TERMINAL WILL UPDATE TO ADD
RAIN MENTION. JUST NOT ENOUGH CONFIDENCE TO INSERT LIGHT RAIN
RIGHT NOW. THERE IS STILL A THREAT FOR SOME LIGHT...MAINLY
MVFR...FG/BR OUT AHEAD OF AN APPROACHING SURFACE TROF AT
KABR/KATY. WILL CONTINUE TO ADJUST FOG FORECASTS IN THE KABR/KATY
TAFS AS NEEDED. BY LATE SUNDAY MORNING...STRONG NORTHWEST WINDS
ARE EXPECTED TO PICK UP ACROSS CENTRAL SOUTH DAKOTA BEHIND THE
COLD FRONTAL PASSAGE. THESE STRONG WINDS WILL IMPACT THE KMBG/KPIR
TERMINALS.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 9 AM CST /8 AM MST/ TO 9 PM CST /8 PM MST/
     SUNDAY FOR CAMPBELL-CORSON-DEWEY-HUGHES-JONES-LYMAN-POTTER-
     STANLEY-SULLY-WALWORTH.

MN...NONE.
&&

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

WEATHER.GOV/ABERDEEN





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