Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 211200
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
600 AM CST FRI NOV 21 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM CST FRI NOV 21 2014

A RIDGE OF HIGH PRESSURE HAS MOVED EAST ACROSS MINNESOTA OVERNIGHT AND
IS NOW IN WISCONSIN. OVERNIGHT TEMPERATURES HAVE BOTTOMED OUT AT
MANY LOCATIONS UNDER PARTLY CLOUDY SKIES AND LIGHT WINDS. SUB-
ZERO READINGS WERE FAIRLY COMMON ACROSS CENTRAL MN THROUGH WESTERN
WI. NOW THAT THE RIDGE AXIS IS TO THE EAST...SOUTHERLY WINDS HAVE
BEGUN TO INCREASE. WARM AIR ADVECTION IS BEGINNING TO OCCUR ACROSS
SOUTHWESTERN MN...ESPECIALLY THANKS TO DOWNSLOPING OFF THE BUFFALO
RIDGE.

THE WARM AIR ADVECTION IS THE STORY IN THE SHORT TERM...WITH THE
SOUTHERLY WINDS EXPECTED TO INCREASE THROUGH THE DAY AND MODERATING
TEMPERATURES EXPECTED.  TODAY WILL BE QUITE A BIT WARMER THAN
YESTERDAY AS HIGHS SHOULD THE UPPER 20S ACROSS MOST OF THE
REGION...WITH LOWER 30S EXPECTED IN SW MN. ASSOCIATED WITH THE
SOUTHERLY WINDS AND WAA...CLOUDS WILL BUILD IN THROUGH THE DAY FROM
THE SOUTH.  LOW POPS ACROSS WESTERN WI AND FAR EASTERN MN REMAIN IN
THE FORECAST TONIGHT...WITH THE BEST FORCING LIMITED TO IOWA AND
SOUTHERN WI.  HOWEVER...THERE IS STILL SOME CONCERN OF A LIGHT WINTRY
MIX BEING SCATTERED ACROSS WESTERN WI AND SOUTHEASTERN MN TONIGHT.
NON DIURNAL TEMPERATURE TREND FOR TONIGHT...AS STRONG WARM AIR
ADVECTION CONTINUES.  LATE EVENING TEMPS WILL COMMONLY BE IN THE
UPPER 20S...BUT WILL INCREASE TO THE MID 30S FOR MUCH OF SOUTHERN MN
BY EARLY SATURDAY MORNING.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 403 AM CST FRI NOV 21 2014

FEW CHANGES WERE MADE IN THE LONG TERM FORECAST PERIOD...WITH A
CONTINUED FOCUS ON THE POTENTIAL FOR A WINTER STORM IN THE SUNDAY-
MONDAY TIMEFRAME.

FOR SATURDAY...IT STILL LOOKS LIKE THE BULK OF THE PRECIPITATION
WILL BE TO THE EAST/SOUTH OF THE FORECAST AREA...WHERE BETTER
FORCING AND MOISTURE TRANSPORT ARE PROGGED. WHILE CLOUD COVER IS
EXPECTED TO BE FAIRLY EXTENSIVE...SOUTH-SOUTHWEST LLVL FLOW AND
WARM AIR ADVECTION SHOULD YIELD NEAR NORMAL HIGHS IN THE MID/UPPER
30S...WHICH WILL BREAK THE STREAK FOR CONSECUTIVE SUB-FREEZING
DAYS. COULD SEE SOME LINGERING MORNING DRIZZLE GENERALLY EAST OF
INTERSTATE 35...BUT OVERALL A DRY AND MILD DAY IS EXPECTED.

SATURDAY NIGHT AND SUNDAY BOTH 21.00Z GFS AND ECMWF MODELS
FORECAST THE DEVELOPMENT OF A HIGH AMPLITUDE TROUGH OVER THE CENTRAL
CONUS...AS SOUTHERN AND NORTHERN STREAM TROUGHS MARRY. WARM AIR
AND MOISTURE ADVECTION WILL CONTRIBUTE TO VERY MILD LOW TEMPS ON
SATURDAY NIGHT...WITH READINGS IN THE UPPER 20S TO MID 30S.
CONTINUED MILD WEATHER IS EXPECTED FOR SUNDAY...WITH HIGHS
SNEAKING INTO THE 40S FOR A GOOD PORTION OF EAST CENTRAL AND SOUTH
CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN. COULD SEE SOME AREAS
OF DRIZZLE DEVELOPING UNDER THE LOW CLOUD DECK...PRIMARILY
ALONG/EAST OF THE INTERSTATE 35 CORRIDOR. THE GOOD NEWS IS THAT
TEMPERATURES IN THESE AREAS SHOULD STAY WILL ABOVE FREEZING
SATURDAY NIGHT AND SUNDAY...SO THE THREAT FOR FREEZING DRIZZLE IS
LOW.

SUNDAY IS THE DAY THAT SOUTHERN AND NORTHERN STREAM LOW PRESSURE
CENTERS MERGE. THE DRY SLOT IN BETWEEN LOOKS TO BE CENTERED OVER
THE AREA...SO WITH THE EXCEPTION OF FAR EASTERN MN AND WEST
CENTRAL WI...WE MAY NOT SEE MUCH PRECIP UNTIL LATER SUNDAY AND
MONDAY AS THE DEFORMATION AXIS SHIFTS OVER THE AREA. BY MIDNIGHT
MONDAY MORNING...LIGHT SNOW SHOULD BE FALLING AND WINDS SHOULD BE
ON THE INCREASE OVER WEST CENTRAL MN. BY AFTERNOON...SNOW SHOULD
BE FALLING AREA-WIDE WITH BLOWING SNOW BECOMING A BIG
CONCERN...ESPECIALLY ALONG/SOUTH OF THE MN RIVER VALLEY. SNOW
AMOUNTS DON/T APPEAR TO REACH WARNING CRITERIA AT THIS POINT...BUT
ANTICIPATED WINDS COULD NECESSITATE A HEADLINE FOR BLIZZARD
CONDITIONS.

A PAIR OF WEAK CLIPPER SYSTEMS ARRIVE FROM THE NORTHWEST ON
WEDNESDAY AND FRIDAY...WHEN A FEW SNOW SHOWERS WILL BE POSSIBLE.
THE MAIN HIGHLIGHT FOR THE THANKSGIVING HOLIDAY WILL BE THE BLAST
OF COLD AIR...WITH HIGHS RANGING FROM THE UPPER SINGLE DIGITS TO
THE MID TEENS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 547 AM CST FRI NOV 21 2014

INITIALLY QUIET CONDITIONS WITH VFR ACROSS THE BOARD.
HOWEVER...THINGS WILL CHANGE AS THE DAY PROGRESSES THANKS TO
STRONG WARM AIR ADVECTION ON THE BACKSIDE OF THE HIGH PRESSURE
RIDGE. MOST LOCATIONS ACROSS MN AND WESTERN WI ARE NOW OBSERVING
SOUTHERLY WINDS WHICH WILL BE THE DOMINANT DIRECTION THROUGH THE
TAF PERIOD. RAP AND NAM INDICATE EXPANDING SATURATION AT 925H THIS
AFTERNOON AND TONIGHT...SO EXPECTING TO SEE EXPANDING LOW STRATUS
FROM LATE THIS MORNING THROUGH SATURDAY MORNING. VIS LIMITATIONS
LOOK MOST PROMISING IN EASTERN MN AND WESTERN WI. CEILINGS SHOULD
CONTINUE TO LOWER TONIGHT...ESPECIALLY ACROSS THE EAST...WITH IFR
LIKELY AND LIFR POSSIBLE. SOME LIGHT PRECIP IS POSSIBLE IN WESTERN
WI...BUT LOW CONFIDENCE EXPLAINS SLIGHT CHANCE WORDING AND LACK OF
MENTION IN THE ACTUAL TAFS AT THIS TIME.

KMSP...LATEST GUIDANCE SUGGESTS THE MVFR CIGS ARRIVE AFTER DARK
AND CONDITIONS LOOK TO WORSEN OVERNIGHT AS RELATIVELY WARM AND
MOIST LOW LEVEL AIR FLOWS OVER THE PRESENT SNOW PACK. ANY PRECIP
TONIGHT LOOKS TO REMAIN TO THE SOUTHEAST...MAINLY IN WI.

/OUTLOOK FOR KMSP/
SAT...IFR POSSIBLE EARLY.  WINDS SSW 10G20 KT.
SUN...MVFR/IFR WITH FZDZ/RA POSSIBLE. WINDS SE 10 KT.
MON...MVFR/IFR WITH -SN/BLSN POSSIBLE. WINDS NW 25G30 KT.

&&

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

$$

SHORT TERM...SPD
LONG TERM...LS
AVIATION...SPD






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