Area Forecast Discussion
Issued by NWS Duluth, MN

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614
FXUS63 KDLH 102348
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
548 PM CST WED FEB 10 2016

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 349 PM CST WED FEB 10 2016

A BATTLE BETWEEN AN ARCTIC HIGH PRESSURE AND LAKE EFFECT SNOW
PROCESSES TODAY INTO TONIGHT AS WELL AS A WEAKENING LOW PRESSURE
SYSTEM TO THE WEST DRIFTING SOUTHEASTWARD. LATE TODAY INTO TONIGHT
THE LAKE EFFECT SNOWFALL GENERALLY DIMINISHES ACROSS NORTHWEST
WISCONSIN AND ESPECIALLY ON SUNDAY AS LOW LEVEL WINDS TURN WESTERLY
WITH ENOUGH DIRECTIONAL SHEAR TO BREAK UP THE SHOWERS ON THE
WISCONSIN SIDE OF THE SOUTH SHORE. ELSEWHERE AN ELONGATED LOW
PRESSURE SYSTEM ACROSS THE NORTHERN PLAINS INTO THE MID MISSISSIPPI
VALLEY WILL WEAKEN BUT PARTS OF NORTH CENTRAL MINNESOTA WILL SEE
SOME MID AND HIGH LEVEL CLOUDS COMING ACROSS AS IT DRIFTS
EASTWARD...THOUGH AS HIGH PRESSURE BUILDS IN FROM THE NORTH CLOUD
COVER WILL GRADUALLY DIMINISH.

TONIGHT ANOTHER COLD ONE AS THE SFC HIGH BUILDS IN. WHILE CLOUD
COVER MAY INITIALLY LIMIT HOW FAST TEMPS FALL ACROSS NORTH CENTRAL
MINNESOTA...LOWS STILL PLUMMET TONIGHT TO 10 TO 20 BELOW ZERO AS THE
CLOUDS ARE EXPECTED TO DISSIPATE LATE TONIGHT/EARLY THURSDAY
MORNING. WINDS WILL BE LIGHT TO NEAR CALM DIRECTLY UNDER THE SFC
HIGH...BUT AS WITH YESTERDAY JUST A LIGHT WIND WILL CAUSE DANGEROUS
WIND CHILLS. DECIDED TO GO WITH ANOTHER ADVISORY IN THE SAME
LOCATIONS AS YESTERDAY...SAINT LOUIS LAKE AND COOK COUNTIES...WITH
THE STRONGEST WINDS EXPECTED ALONG THE NORTH SHORE RIDGE LINE AND
POSSIBLY ALONG THE IRON RANGE. AS LAKE EFFECT SNOW DISSIPATES WE
ANTICIPATE TO EXPIRE THE LAKE EFFECT SNOW ADVISORY AS PLANNED AT
00Z...BUT IF REPORTS INDICATE MODERATE SNOWFALL IS STILL OCCURRING IT
MAY NEED TO BE EXTENDED INTO THE EVENING.

FOR THURSDAY TWO SYNOPTIC-SCALE FEATURES WILL RESULT IN INCREASING
CLOUDS THROUGH THE DAY. FIRST AN UPPER LOW DRIFTING SOUTH OVER
HUDSON BAY AND AN ASSOCIATED COLD FRONT WILL DRIFT SOUTHWARD ACROSS
SASKATCHEWAN...MANITOBA...AND NORTHWEST ONTARIO ON THURSDAY. TO THE
WEST ANOTHER ELONGATED MID-LEVEL DISTURBANCE WILL SLIDE
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS INTO THE MID MISSISSIPPI
VALLEY THROUGH THE DAY. THIS SECOND SYSTEM WILL BE THE MAIN SOURCE
OF CLOUD COVER THROUGH THURSDAY...THOUGH SKIES WILL BE MOSTLY SUNNY
THROUGH AT LEAST THE EARLY AFTERNOON. LIGHT TO NEAR CALM WINDS WITH
HIGHS SLIGHTLY WARMER...IN THE TEENS EXCEPT ALONG THE TIP OF THE
MINNESOTA ARROWHEAD WHICH MAY REMAIN IN THE SINGLE DIGITS.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CST WED FEB 10 2016

THERE IS VERY LITTLE OVERALL CHANGE TO THE FORECAST REASONING FOR
THE EXTENDED PERIODS.  A STRONG REINFORCING SHOT OF ARCTIC AIR WILL
MOVE SOUTHWARD ACROSS THE ENTIRE REGION BEGINNING OVERNIGHT THURSDAY
NIGHT..WITH THE COLDEST AIR OF THE WINTER SEASON IN CONTROL OF THE
WEATHER FOR FRIDAY AND SATURDAY.

THE LATEST MEDIUM RANGE GUIDANCE CONSENSUS IS IN GENERAL AGREEMENT
WITH THE PAST COUPLE OF DAYS IN TAKING THE CORE OF THE COLDEST AIR
TO THE EAST OF THE DULUTH CWA EARLY IN THE WEEKEND. STILL..-23C TO -
28C TEMPS AT 850 MB WILL TRANSLATE ACROSS MUCH OF THE NORTHLAND.
THIS SHOULD BE SUFFICIENT TO RE-ENERGIZE THE LAKE EFFECT SNOW
MACHINE ACROSS THE BAYFIELD PENINSULA AND GOGEBIC RANGE FRIDAY INTO
SATURDAY MORNING.  WHILE CONFIDENCE IS FAIRLY HIGH THAT THERE WILL
BE AT LEAST SOME LIGHT ACCUMULATIONS..THERE ARE ALSO SOME LIMITING
FACTORS THIS TIME AROUND THAT INCLUDE THE OVERALL LACK OF LARGE
SCALE SYNOPTIC SUPPORT..AND FAIRLY DRY AIR UPSTREAM IN THE BOUNDARY
LAYER. STILL TRAJECTORIES WILL BECOME SUFFICIENTLY NORTHERLY TO
ALLOW FOR A 12-18 HOUR WINDOW OF POTENTIAL ACCUMULATION OF PERHAPS
UP TO A FEW INCHES..WITH THE GREATEST AMOUNTS IN THE HIGHER TERRAIN
OF ASHLAND AND IRON COUNTIES.

FRIDAY NIGHT LOOKS TO BE THE COLDEST NIGHT OF THE YEAR IN MANY
PLACES WITH GENERALLY CLEAR SKIES/LIGHT WINDS AND THE RIDGE AXIS
PARKED ALMOST DIRECTLY OVERHEAD WITH DEEP SNOW COVER.  THIS SHOULD
ALLOW MANY OF THE FAVORED LOW LYING AND SHELTERED AREAS TO DIP INTO
THE -30F TO -35F RANGE SAT MORNING..WITH WIDESPREAD READINGS IN THE
-20SF.  THUS..WE HAVE LOWERED TEMPS ONCE AGAIN FROM THE PREVIOUS
FORECAST AND THE COLDEST GUIDANCE.  WHILE NOT AS COLD..CLEAR SKIES
SAT NIGHT FROM THE ARROWHEAD INTO NW WISCONSIN AHEAD OF INCREASING
CLOUDS SHOULD ALLOW FOR TEMPS BOTTOMING IN THE -20SF AGAIN IN THESE
AREAS..WITH PERHAPS STEADY OR SLOWLY RISING TEMPS LATE SAT NIGHT AS
CLOUDS AND LOW LEVEL WARM ADVECTION INCREASE.  DESPITE THE BITTERLY
COLD MORNINGS..DAY TIME TEMPS SAT SHOULD RECOVER A TAD MORE THAN
OTHERWISE MIGHT BE EXPECTED IN SUCH A COLD AIRMASS DUE TO THE LOWER
ALBEDO OF MOSTLY FORESTED AREAS..AND THE EVERY-SO-SLIGHTLY WARMER
FEB SUN..AS IS COMMON THIS TIME OF YEAR WITH CLEAR.

TRANSITION TO A WARMER AIRMASS WILL BEGIN LATE SAT NIGHT INTO MONDAY
WITH FAIRLY STRONG LOW LEVEL WARM ADVECTION AHEAD OF AN APPROACHING
WAVE.  THIS WILL SPREAD LIGHT SNOW ACROSS MUCH OF THE AREA..AND
WHILE HEAVY SNOW IS NOT ANTICIPATED..SOME AREAS COULD SEE A FEW
INCHES.  WE WILL ALSO HAVE TO PAY CLOSE ATTENTION TO THE POTENTIAL
FOR LOCALLY HEAVIER LAKE EFFECT SNOW ON THE NORTH SHORE OF LK
SUPERIOR AS FLOW BECOMES SOUTHERLY ON SUNDAY/SUNDAY NIGHT.  THE
AIRMASS WILL CONTINUE TO SLOWLY WARM THROUGH MID WEEK AS WEAK LOW
LEVEL WARM ADVECTION PERSISTS.  WHILE IT DOES NOT APPEAR THAT ANY
MAJOR WEATHER SYSTEMS ARE ON TAP FOR THE MON-WED TIME PERIOD..IT
SEEMS PLAUSIBLE THAT CLOUDS AND THE POTENTIAL FOR FLURRIES AND
EVENTUALLY SOME FREEZING DRIZZLE COULD LINGER AS INCREASINGLY WARMER
AIR IS BROUGHT ATOP A SNOW PACK THAT WILL BE VERY COLD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 543 PM CST WED FEB 10 2016

VFR CONDITIONS EXPECTED THROUGH THE PERIOD. RIDGE OF HIGH PRESSURE
BUILDING INTO THE AREA TO FINALLY CAUSE DIMINISHING LAKE EFFECT
SNOW...AND KEEP THE SHORTWAVE DIVING DOWN THE DAKOTAS AWAY FROM
THE TERMINALS. SOME MID CLOUDS....GENERALLY IN THE 5-10KFT RANGE
TO SLOWLY SLIDE INTO THE TERMINALS AFTER 06Z TONIGHT...CONTINUING
THROUGH THE REMAINDER OF THE PERIOD. LIGHT NORTH WINDS TO
GRADUALLY TURN WEST AFTER 12Z THURSDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH -11  12  -7   3 /   0   0   0   0
INL -17  10 -16  -2 /   0  10   0   0
BRD  -7  16  -3   6 /   0   0   0   0
HYR -14  13  -5   8 /   0   0   0   0
ASX  -6  13  -1   7 /  10  10  10  20

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...LAKE EFFECT SNOW ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ004.

MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 10 AM CST THURSDAY
     FOR MNZ011-012-019>021-037.

LS...NONE.
&&

$$

SHORT TERM...JJM
LONG TERM...MILLER
AVIATION...LE



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