Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 212130
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
330 PM CST SUN DEC 21 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY AFTERNOON)
ISSUED AT 329 PM CST SUN DEC 21 2014

MAIN CONCERNS IN THE SHORT TERM REMAIN FOCUSED AROUND THE
INCOMING...LONG DURATION WINTER STORM EXPECTED TO IMPACT THE
NORTHLAND EARLY THIS WEEK WITH A WINTRY MIX OF SNOW...RAIN...SLEET
AND FREEZING DRIZZLE POSSIBLE.

A WINTER STORMS WATCH REMAINS IN EFFECT FOR THE ARROWHEAD INCLUDING
LAKE AND COOK COUNTIES...BUT THE TIME HAS BEEN ADJUSTED TO START
MONDAY NIGHT AND END WEDNESDAY MORNING. THE MAIN CONCERNS WITHIN THE
WATCH AREA WILL BE THE POTENTIAL FOR HEAVY SNOW ACCUMULATIONS.

AN INITIAL LEAD S/W IS ROTATING NEWD THROUGH THE UPPER MIDWEST AND
WRN ONTARIO THIS AFTERNOON AND WILL MOVE SLOWLY EWD TONIGHT AS WEAK
RIDGING ALOFT AND AN ASSOCIATED DRY SLOT PUSH IN FROM THE SOUTH
BEHIND THE WAVE AND AHEAD OF THE MAIN LOW PRESSURE SYSTEM SWINGING
THROUGH THE MIDWEST MON NIGHT THROUGH WEDNESDAY.

WILL SEE SNOW SHOWERS PERSIST THROUGH THIS EVENING WITH LIGHT
ACCUMULATIONS LIKELY. THE HEAVIEST SNOW AMTS TONIGHT WILL BE ACROSS
THE ARROWHEAD AND INTO PORTIONS OF NW WI WHERE AN ADDITIONAL 1 TO 2
INCHES IS POSSIBLE. AS THE UPPER WAVE SLIDES NEWD AND THE RIDGE
BUILDS IN...THE DRY AIR ALOFT WILL ALLOW THE COLUMN TO LOSE ICE
CRYSTALS AND CHANGE THE PRECIP FROM LIGHT SNOW OVER TO A LIGHT
FREEZING DRIZZLE. TEMPERATURES WILL ALSO WARM GRADUALLY THROUGH THE
NIGHT FROM THE LOWER 30S EARLY THIS EVENING TO THE MID 30S BY MON
MORNING. TEMPERATURES ALOFT WILL WARM AS WELL WITH A NOSE OF 0 TO +1
DEG C AIR LIFTS NWD INTO THE AREA AND ALLOWS THE PRECIP TO CHANGE
OVER TO A MIX OF RAIN/SNOW AND/OR SLEET DURING THE DAY MONDAY. WILL
LIKELY SEE WIDESPREAD SNOWFALL AMTS ON MONDAY RANGE FROM A HALF TO
ONE INCH...WITH CLOSER TO 2 TO 3 INCHES POSSIBLE OVER THE ARROWHEAD.
BETTER CHANCES FOR ACCUMULATING SNOW EXIST MON NIGHT THROUGH TUE
NIGHT.

PATCHY FOG WILL ALSO PERSIST TONIGHT AND INTO EARLY IN THE WEEK.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 PM CST SUN DEC 21 2014

EXTENDED RANGE FOCUS ON LONG WAVE TROUGH WITH CLOSED H50 THAT TRACKS
THROUGH THE CENTRAL PLAINS AND LIFTS INTO THE GREAT LAKES REGION
DURING THE TUESDAY/WEDNESDAY PERIODS.

ALTHOUGH MODELS ARE COMING INTO BETTER ALIGNMENT...THERE CONTINUES
TO BE RUN TO RUN DIFFERENCES IN TRACK OF THE LOW...WHICH WILL BE THE
DETERMINING FACTOR FOR PLACEMENT OF THE BEST FORCING AND HIGHEST
SNOWFALL AMOUNTS. AT THIS TIME...THE SFC LOW IS FCST TO TRACK OVER
WISCONSIN MONDAY NIGHT/TUESDAY...WHICH WILL PRODUCE GUST NORTHEAST
WINDS OVER LAKE SUPERIOR WHILE ROTATING A BAND OF SNOW LOCATED IN A
DEFORMATION ZONE ON THE ON THE NW FLANK OF THE LOW ACROSS MUCH OF
THE NORTHLAND. LATEST GUIDANCE IS SUGGESTING THAT A CORRIDOR OF QPF
AMOUNTS IN EXCESS OF A HALF INCH WILL BE FOUND DURING THIS TIME DUE
TO THE ABUNDANCE OF MOISTURE AND HIGH PWAT VALUES. ALTHOUGH DETAILS
HAVE YET TO BE REFINED AND SFC TEMPS MAY WARRANT SOME INITIAL MIXING
OF SNOW/RAIN/DRIZZLE...SNOWFALL TOTALS FOR THE MONDAY NIGHT THROUGH
WEDNESDAY MORNING TIME FRAME OF GENERALLY 4 TO 8 INCHES ARE EXPECTED
OVER THE NORTHLAND. THE GREATEST UNCERTAINTY IS IN THE WESTERN HALF
ZONES /NORTH CENTRAL MN/ WHERE A WEDGE OF DRY AIR WILL WRAP AROUND
THE LOW AND LIMIT SNOWFALL TOTALS.

DUE TO THE LONG DURATION OF THE SNOW...ANTICIPATING THAT A WINTER
WEATHER ADVISORY WILL BE NEEDED FOR MUCH OF THE FORECAST AREA DURING
THE MONDAY NIGHT INTO EARLY WEDNESDAY PERIODS.

LONG RANGE MODELS SHOW THE ACTIVE PATTERN THROUGH THE REMAINDER OF
THE EXTENDED FCST...WITH A PERSISTENT CYCLONIC FLOW AND EMBEDDED
SHORT WAVES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 227 PM CST SUN DEC 21 2014

IFR CONDITIONS WITH AREAS OF FOG AND DRIZZLE OR SNOW WILL PERSIST
THROUGH THE TAF PERIOD. SURFACE TEMPERATURES WILL HOVER AROUND AND
JUST ABOVE FREEZING THROUGH MONDAY...LIMITING ANY ICE
ACCUMULATION.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  33  35  33  36 /  70  90  80  80
INL  31  35  32  33 /  50  80  70  70
BRD  32  35  31  34 /  70  90  80  80
HYR  34  35  33  35 /  60  80  80  80
ASX  35  37  33  36 /  60  70  80  80

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE MONDAY NIGHT THROUGH LATE TUESDAY
     NIGHT FOR MNZ012-020-021.

WI...NONE.
LS...NONE.
&&

$$

SHORT TERM...BJT
LONG TERM...GRANING
AVIATION...GRANING






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