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000
FXUS63 KMPX 301825
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1225 PM CST SAT NOV 30 2013

.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 1135 AM CST SAT NOV 30 2013

VERY BENIGN PERIOD OF THE FORECAST. A WEAK CDFNT WILL CONTINUE TO
DROP SE ACRS THE REGION WITH A TRAILING MIDLVL SHORTWAVE TROF
AXIS. IT IS WITH THIS AXIS THAT MID-TO HIGH-LEVEL CLOUDS HAVE
SLIPPED INTO THE REGION. HOWEVER...SAID CLOUDS WILL EFFECTIVELY
SLIP ON OUT TNGT AS WEAK HIGH PRES SLIDES ACRS THE REGION
OVERNIGHT THRU THE FIRST HALF OF SUNDAY. SKIES WILL MAINLY CLEAR
OUT...BUT WITH WEAK FLOW ALOFT AND SFC HIGH PRES FORCING WINDS TO
DROP TO LGT/VRBL...IF NOT CALM...MOISTURE TRANSPORT OUT OF THE
AREA WILL BE NEARLY NON-EXISTENT. THIS WILL TRANSLATE TO THE
DEVELOPMENT OF LOW CLOUDS AND/OR FOG NEAR DAYBREAK SUN MRNG. THE
LOW CLOUDS WILL THEN SCOUR OUT DURG THE DAY TMRW...BUT MIDLVL
DECKS WILL REMAIN SO MOCLDY CONDS ARE EXPECTED BY LATE SUN AFTN.
MILD TEMPS WILL REMAIN IN PLACE THRU THE WEEKEND WITH NIL TEMP
ADVECTION. LOWS TNGT WILL DROP TO THE MID-TEENS TO LWR 20S
FOLLOWED BY HIGHS ON SUN THAT WILL HIT THE LOW-MID 30S.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 417 AM CST SAT NOV 30 2013

THE FOCUS FOR THE LONG TERM CONTINUES TO BE NUMEROUS PERIODS WITH
SNOW AND/OR RAIN CHANCES...FOLLOWED BY BITTER COLD TO END THE
WEEK. CONFIDENCE REGARDING THE EARLY TO MID WEEK SYSTEM HAS NOT
INCREASED...IN FACT IT HAS GONE DOWN IN THE LAST 24 HOURS. AT THIS
POINT...MONDAY NIGHT AND WEDNESDAY APPEAR TO BRING THE BEST
CHANCES FOR PRECIPITATION. CONFIDENCE CONTINUES TO BE QUITE HIGH
REGARDING THE TIMING AND INTENSITY OF THE BITTER COLD...HOWEVER.

AT THE BEGINNING OF THE PERIOD...SURFACE RIDGING WILL BE IN PLACE
WITH THE WEST COAST TROUGH STILL HUGGING THE PANHANDLE OF ALASKA.
TRANQUIL WEATHER WILL CONTINUE WITH HIGHS IN THE 30S.

BY SUNDAY NIGHT...A FINGER OF VORTICITY WILL EXTEND DOWN ACROSS
NODAK AND INTO CENTRAL MN. ISENTROPIC UPGLIDE AND MOISTURE WILL
INCREASE ON THE 295K SURFACE...BUT BOUNDARY LAYER AIR WILL NOT BE
PARTICULARLY MOIST DUE TO THE PROXIMITY OF HIGH PRESSURE OVER
WISCONSIN. MODELS HAVE BACKED OFF ON QPF AND POPS. COULD STILL SEE
SOME SNOW REACH THE GROUND AS GRADUAL SATURATION OCCURS NEAR THE
GROUND. THUS...PUSHED BACK THE TIMING OF THE HIGHER POPS TO AFTER
MIDNIGHT AND DID MAINTAIN 30-50 PERCENT ACROSS THE AREA...HIGHEST
ACROSS CENTRAL MN.

MODELS BEGIN TO DIVERGE ON THEIR SOLUTIONS AS THE TROUGH DIGS
INTO THE PACIFIC NORTHWEST MONDAY. THE EVOLUTION/SHAPE OF THIS
TROUGH WILL PROVE VERY IMPORTANT IN TIMING...WHERE THE SURFACE
LOW WILL TRACK...THERMAL FIELDS...AND RESULTANT RAIN OR SNOW
CHANCES. THE NAM IS MUCH MORE NEGATIVELY TILTED BY MONDAY NIGHT
THAN THE REMAINING GUIDANCE WHILE THE GEM IS THE LEAST. AS A
RESULT...THE NAM DEVELOPS A RATHER IMPRESSIVE INVERTED TROUGH FROM
NODAK INTO ALBERTA WITH A BAND OF HEAVY SNOW ACCOMPANYING
IT...EXTENDING INTO MN BY TUESDAY MORNING. WAS NOT PARTICULARLY
CONFIDENT IN THIS SOLUTION GIVEN THE NAM/S TENDENCY TO OVERDEVELOP
ALOFT FEATURES BEYOND 48 HOURS. THE 00Z GFS WAS ALSO THROWN OUT
DUE TO ITS VERY PROGRESSIVE LEAD TROUGH SWINGING THROUGH
TUESDAY...ESSENTIALLY SQUASHING ANY SURFACE SYSTEM DEVELOPMENT.
BETWEEN THE REMAINING MODELS OF THE GEM AND ECMWF...THE ECMWF HAS
SHOWN THE BEST RUN TO RUN CONSISTENCY AND STILL ADVERTISES AN
INVERTED TROUGH OF SORTS AND A MAIN SURFACE LOW TRACKING ACROSS
CENTRAL OR NORTHERN MN WEDNESDAY. PREFER THIS SOLUTION MOST FOR
NOW...ALTHOUGH THE SURFACE LOW MAY BE A BIT TOO FAR NORTH.

THE FIRST GOOD CHANCE OF PRECIPITATION WILL COME MONDAY NIGHT AS
ANOTHER FINGER OF VORTICITY AND INCREASING ISENTROPIC UPGLIDE
BISECT THE CWA. WITH HIGH PRESSURE WELL TO THE EAST...THE BOUNDARY
LAYER SHOULD NOT BE AS DRY AND THINK A NORTHWEST-SOUTHEAST
ORIENTED BAND OF PRECIPITATION WILL DEVELOP MONDAY EVENING.
THERMAL PROFILES ARE A BIT QUESTIONABLE WITH THE 0C ISOTHERM AT
925 MB INCHING INTO SOUTHWEST MN...BUT KEPT P-TYPE AS SNOW FOR NOW.
COULD SEE AN INCH OR TWO OVER MOST OF THE AREA...PARTICULARLY OVER
CENTRAL/ERN MN AND WRN WI.

USING PRIMARILY THE EC FOR THE MAIN SYSTEM TUESDAY NIGHT AND
WEDNESDAY...BUMPED TEMPS UP WED AS SOUTHERLY FLOW IN ADVANCE OF
THE INVERTED TROUGH SHOULD BRING MILDER AIR IN. THIS RESULTED IN
MORE RAIN MIXING IN BY AFTERNOON. STRONG COLD FRONT PUSHES THROUGH
WEDNESDAY EVENING WITH TEMPS PLUMMETING OVERNIGHT. EURO MOS GOES
FROM A HIGH OF 41 WED TO A LOW OF 9 AT MSP WED NIGHT. PRETTY
IMPRESSIVE.

BITTER COLD FOLLOWS FOR LATE WEEK. THURSDAY TEMPS WILL NOT RECOVER
AND WILL PROBABLY FALL STEADILY THROUGH THE DAY. BY FRIDAY...925
MB TEMPS RANGE FROM -15 TO -23C...SO NOT EXPECTING TEMPS TO RISE
OUT OF THE SINGLE DIGITS EXCEPT MAYBE NEAR THE IOWA BORDER.
OVERNIGHT LOWS THURSDAY NIGHT AND FRIDAY NIGHT WILL DROP BELOW
ZERO. GUSTY WEST WINDS WILL BRING WIND CHILLS DOWN INTO THE
TEENS...20S...AND MAYBE LOW 30S BELOW ZERO.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1135 AM CST SAT NOV 30 2013

VERY LITTLE AVIATION IMPACTS IN THIS TAF SET. DEPARTING CDFNT WITH
TRAILING UPPER LEVEL TROF WILL LEAVE MID- AND UPR-LEVEL CLOUDS...
INCLUDING BKN/OVC CIGS...IN PLACE THRU THE REST OF THIS AFTN INTO
THE EARLY EVE HRS. HOWEVER...AS THIS TROF DEPARTS AND WEAK HIGH
PRES ARRIVES...CLOUD COVER WILL DIMINISH BUT CLR SKIES GENERALLY
NOT EXPECTED DUE TO ADDITIONAL MOISTURE RESIDING OVER THE AREA. IN
FACT...UNDER THE NIGHTLY INVERSION...THERE IS A DECENT SHOT AT
SEEING MVFR CONDS...DEPENDING ON WHETHER IT IS THE FORMATION OF
BKN CEILINGS OR FOG NEAR SUNRISE. CONDS IMPROVE AFTER DAYBREAK
TMRW WHILE WINDS SWING AROUND TO SLY BY MIDDAY...WITH MIDLVL
CEILINGS REMAINING IN PLACE.

KMSP...GENERALLY VFR CONDS EXPECTED THROUGHOUT THIS SET THOUGH
THERE IS A CHANCE OF HAVING SOME MVFR VSBY AROUND DAYBREAK...
SIMILAR TO WHAT WAS EXPERIENCED THIS MRNG. OTHERWISE...MID- AND
UPR-LVL CEILINGS WILL PREVAIL THRU THE REST OF THIS AFTN BEFORE
SKIES PARTIALLY CLEAR OUT TNGT. LOWER CLOUDS RETURN DURG THE PRE-
DAWN HOURS BUT NOT EXPECTING MVFR CIGS TO DEVELOP...THOUGH THE
IDEA CANNOT BE RULED OUT. MIDLVL CIGS THEN PREVAIL THRU MIDDAY
TMRW.

/OUTLOOK FOR KMSP/
SUN NITE...VFR...POSSIBLY MVFR CIGS LATE WITH -SN. WINDS E/SE AT 5
KTS.
MON...CIGS/VSBYS LOWERING WITH -SN DEVELOPING. SE WINDS 10 KTS.
TUE...IFR/MVFR CIGS IN -SN...POSSIBLY MIXED WITH RA BY AFTN. SE
10-15 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...JPC
LONG TERM...BORGHOFF
AVIATION...JPC