Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 170031
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
631 PM CST TUE DEC 16 2014

.UPDATE...
ISSUED AT 631 PM CST TUE DEC 16 2014

ADJUSTED MIN TEMPS DOWNWARD A BIT AS LOW END OF PREVIOUS FORECAST
WAS ALREADY BEING MET IN SOME SPOTS.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 425 PM CST TUE DEC 16 2014

21Z VISIBLE SATELLITE REVEALS A SFC LOW OVER WESTERN MICHIGAN
PULLING EASTWARD... WITH SURFACE HIGH CENTERED IN SOUTHERN MANITOBA...
AND A MID-TO-UPPER LEVEL TROF IN NORTHWESTERN MINNESOTA. THIS VORT
MAX WILL BE A FOCUS FOR ONGOING SNOW SHOWERS ACROSS OUR CWA IN THE
SHORT TERM. MODELS ARE IN AGREEMENT THAT THE CENTER OF THE LOW
WILL SLIDE TO SOUTHEAST WISCONSIN BY 12Z WEDNESDAY. WE HAVE BUMPED
POPS UP IN RESPONSE TO RATHER WIDESPREAD COVERAGE OF LIGHT SNOW
OVER MUCH OF THE CENTRAL AND EASTERN CWA PER LATEST KDLH IMAGERY.
OVERALL..THIS WILL BE A WIDESPREAD BUT LOW QPF EVENT..WITH
GENERALLY AN INCH OR LESS ACCUM THROUGH TONIGHT EXCEPT FOR THE
LAKE EFFECT RAMPING UP ALONG THE SOUTH SHORE.

WEAK SYNOPTIC SCALE LIFT AND ICE SEEDING FROM ABOVE SHOULD BE
SUFFICIENT TO ALLOW A RATHER RAPID RAMP UP OF LK EFFECT SNOW ALONG
THE SOUTH SHORE BY MIDNIGHT TONIGHT..AND THERE IS ALREADY SOME
EVIDENCE OF MORE ORGANIZED SHALLOW LAKE EFFECT STREAMERS ON THE
KDLH RADAR OVER THE WEST SIDE OF THE BAYFIELD PENINSULA. IRON AND
ASHLAND COUNTIES HAVE BEEN UPGRADED TO A WINTER STORM WARNING...
WITH 7 TO 11 INCHES POSSIBLE ACROSS THE GOGEBIC RANGE. COMBINATION
OF LONG N/NE FETCHES/-12 TO -14C AT 850/FAIRLY DEEP BOUNDARY LAYER
MOISTURE WITH HIGHER RH ABOVE IN THE 850-700 LAYER AND STRONGLY
CONVERGENT FLOW ALONG THE SOUTH SHORE ALL SEEM TO POINT TO THE
POTENTIAL FOR HIGHER SNOWFALL POTENTIAL. THE MOST INTENSE RATES
ARE EXPECTED LATER TONIGHT THROUGH WEDNESDAY MORNING. THE HIGHER
TERRAIN OF NORTHERN BAYFIELD COUNTY REMAIN UNDER A WINTER WEATHER
ADVISORY WITH LESSER AMOUNTS OF 4 TO 7 INCHES EXPECTED.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 425 PM CST TUE DEC 16 2014

MUCH OF THE EXTENDED PERIOD LOOKS RATHER QUIET. HOWEVER...THERE IS A
MORE SIGNIFICANT LOW AT THE END OF THE PERIOD THAT MAY BRING SNOW
ACCUMULATION TO THE NORTHLAND.

LAKE EFFECT SNOW WILL BE DECREASING QUICKLY WEDNESDAY EVENING AS
DRIER AIR MOVES SOUTH AND THE FLOW BECOMES MORE ANTICYCLONIC.
WE LINGER SOME POPS ALONG PORTIONS OF THE SOUTH SHORE INTO THE
EVENING...BUT GIVEN DRIER AIR AND LESS FAVORABLE LOW LEVEL
INSTABILITY...WE DO NOT EXPECT ANY SIGNIFICANT ACCUMULATION
WEDNESDAY NIGHT.

MOST OF THE MODELS SHOW A SHORTWAVE MOVING THROUGH PORTIONS OF THE
NORTHLAND FRIDAY...AS AN UPPER TROUGH MOVES NEAR/OVER THE
REGION. WE ADDED SOME POPS OR FLURRIES TO PORTIONS OF NORTHERN
MINNESOTA FRIDAY THEN WENT DRY FRIDAY NIGHT INTO SATURDAY NIGHT.
THERE MAY BE A NEED TO KEEP SOME FLURRIES/LIGHT SNOW INTO THE
WEEKEND AS SEVERAL MORE SHORTWAVES ROTATE THROUGH THE AREA.
HOWEVER...THEY DO NOT LOOK TO BE STRONG ENOUGH TO CAUSE MUCH
ACCUMULATION. WE HAD A DRY FORECAST GOING AND WILL LEAVE IT THAT WAY
UNTIL SUNDAY WHEN WE HAVE SOME LOW POPS OVER FAR NORTHERN MN.

BOTH THE GFS/ECMWF CONTINUE TO FORECAST A STRONGER LOW PRESSURE
SYSTEM BY EARLY NEXT WEEK OVER THE REGION. THERE ARE DIFFERENCES IN
THE TRACK OF THE LOW...BUT BOTH MODELS DO SHOW IT NEAR/OVER THE
NORTHLAND. THIS SYSTEM HAS THE POTENTIAL TO CAUSE SEVERAL INCHES OF
SNOW ACCUMULATION DURING A BUSY TRAVEL PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 528 PM CST TUE DEC 16 2014

A MIX OF VFR/MVFR CIGS WITH AREAS OF LIGHT SNOW REDUCING VSBYS
INTO THE MVFR RANGE. THESE CONDITIONS WILL PERSIST THROUGH THE
FORECAST.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  11  23  10  25 /  80  30  10  10
INL   7  20  -1  20 /  60  30   0   0
BRD   9  21  11  22 /  10  10  10   0
HYR  14  23   8  26 /  60  20  10  10
ASX  17  24  13  27 /  80  60  20  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR WIZ003-004.

     WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ002.

LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST WEDNESDAY FOR LSZ121-
     145>148.

     SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ140>142.

&&

$$

UPDATE...GSF
SHORT TERM...MCLOVIN/MILLER
LONG TERM...MELDE
AVIATION...GSF






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