Area Forecast Discussion
Issued by NWS Duluth, MN

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970
FXUS63 KDLH 091754 AAD
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1154 AM CST TUE FEB 9 2016

.UPDATE...
ISSUED AT 1154 AM CST TUE FEB 9 2016

UPDATED AVIATION DISCUSSION FOR 18Z TAF ISSUANCE BELOW.

&&

UPDATE ISSUED AT 1052 AM CST TUE FEB 9 2016

UPDATED FORECAST AND CANCELLED BOTH THE WIND CHILL ADVISORY FOR
NORTHEAST MINNESOTA AND PARTS OF THE WINTER WEATHER ADVISORY.
AFTER A BRIEF TERRAIN-INDUCED BAND OF CLOUDS/SNOW THIS MORNING
ACROSS DOUGLAS/BAYFIELD COUNTY SKIES HAVE BEGUN TO CLEAR AND
LITTLE IF ANY ADDITIONAL SNOWFALL IS EXPECTED TODAY.

FARTHER EAST DECIDED TO HOLD ON TO BOTH THE WINTER WX ADVISORY
FOR ASHLAND COUNTY AND LAKE EFFECT SNOW WARNING FOR IRON COUNTY.
ASHLAND COULD HAVE BEEN CANCELLED AS A SPOTTER IN ODANAH /EAST OF
ASHLAND/ REPORTED SNOWFALL HAD ENDED AROUND 6 AM...CONFIRMED BY
SATELLITE AND AREA WEBCAMS...BUT SINCE A LAKE EFFECT IN IRON
COUNTY COULD DRIFT WEST INTO ASHLAND KEPT THE ADVISORY GOING FOR
NOW. IN IRON COUNTY STILL EXPECTING THE SNOWFALL TO LET UP FOR A
TIME THIS AFTERNOON AS MUCH DRIER AIR MOVES IN ALOFT. IT WILL
REDEVELOP TONIGHT...BUT WILL LIKELY LET THE LAKE EFFECT SNOW
WARNING EXPIRE ON TIME AT 21Z AND EITHER ISSUE A NEW LAKE EFFECT
SNOW ADVISORY OR NO ADVISORY AT ALL FOR THE EVENING SNOW
SHOWERS...SINCE WHILE THE SNOW WILL LIKELY RETURN IT WILL BE MUCH
LESS INTENSE IN NATURE.

OTHERWISE JUST MADE SOME SMALL ADJUSTMENTS TO INCREASE WINDS A
BIT.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 421 AM CST TUE FEB 9 2016

MAIN FORECAST CHALLENGES THIS MORNING INVOLVES SNOWFALL OVER
NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN TODAY AND TONIGHT...
AND THE POTENTIAL FOR DANGEROUS WIND CHILLS THIS MORNING IN NORTH-
CENTRAL AND NORTHEAST MINNESOTA.

DEPARTING CLIPPER WAS LOCATED OVER SOUTHERN ONTARIO THIS MORNING
WITH A BROAD AREA OF CYCLONIC FLOW EXTENDING WEST INTO MINNESOTA.
JUST TO THE WEST...THE INITIAL NOSE OF SURFACE HIGH PRESSURE WAS
ADVANCING INTO THE EASTERN DAKOTAS. ALOFT WINDS WERE GENERALLY
FROM THE NORTH TO NORTH-NORTHWEST ACROSS THE AREA. A LONGWAVE
RIDGE WAS BUILDING ACROSS THE WESTERN CONUS RESULTING IN SLOWLY
RISING HEIGHTS OVER MINNESOTA. ANOTHER LOBE OF VORTICITY WAS NOTED
ON WV SATELLITE IMAGERY OVER NORTHERN ONTARIO AND NORTHEAST
MANITOBA...AND WAS CAPTURED IN THE MODEL INITIALIZATIONS THIS
MORNING. AT 4 AM TEMPERATURES WERE MILDER THAN EXPECTED THANKS IN
LARGE PART TO THE SIGNIFICANT CLOUD COVER LINGERING OVER THE
REGION.

WITH LINGERING CLOUDS OVER MINNESOTA ZONES...TEMPS HAVE NOT
CRASHED AS MUCH AS EXPECTED YESTERDAY. WINDS ARE NOT QUITE AS
STRONG EITHER. LEFT THE WIND CHILL ADVISORY IN PLACE...BUT THINK
WIDESPREAD VALUES OF 10 TO 20 BELOW ZERO ARE MORE LIKELY THAN 25
BELOW OR COLDER. TIME WILL TELL...STILL SEVERAL HOURS BEFORE
SUNRISE. CLOUDS MAY QUICKLY ERODE DURING THE NEXT FEW HOURS
ALLOWING TEMPS TO PLUMMET.

THE NORTHWEST FLOW ACROSS NORTHEAST MINNESOTA CONTINUED TO SUPPORT
A TERRAIN INDUCED GRAVITY WAVE AND ASSOCIATED LIGHT SNOW ALONG
THE NORTH SHORE AND PORTIONS OF DOUGLAS AND BAYFIELD COUNTIES.
DURING THE PAST FEW HOURS THE INTENSITY OF THIS SNOW BAND HAS
DIMINISHED AND THE FEATURE HAS WOBBLED FARTHER EASTWARD INTO
NORTHERN BAYFIELD COUNTY. UPSTREAM THERE ARE INDICATIONS THAT THE
BAND IS REDEVELOPING NEAR GRAND MARAIS TO JUST WEST OF SILVER BAY.
HIGH RESOLUTION WRF-ARW MODEL GUIDANCE...INCLUDING THE LOCAL
DLHWRF...SEEM TO SUPPORT THE GRAVITY WAVE PERSISTING FOR MUCH OF
THE DAY. THE GOVERNING FACTOR REGARDING SNOWFALL WILL BE THE
LOCATION AND DEPTH OF CLOUD LAYER MOISTURE. EXPECT THE FEATURE TO
CONTINUE PRODUCING LIGHT SNOW THROUGH MUCH OF THE MORNING...
GRADUALLY DISSIPATING EARLY THIS AFTERNOON AS CLOUDS THIN WITH
THE APPROACHING RIDGE. ANOTHER PERIOD OF LIGHT SNOW IS POSSIBLE IN
NORTHEAST MINNESOTA AS VORT MAX DIVES SOUTHEAST ACROSS THE AREA
THIS AFTERNOON AND TONIGHT.

LAKE EFFECT SNOW CONTINUED OVERNIGHT AND IS EXPECTED TO PERSIST
THROUGHOUT TODAY INTO WEDNESDAY. SNOW INTENSITY SHOULD DIMINISH AS
THE LARGE SCALE MOISTURE SHIFTS EAST OF THE FAVORED LES AREAS THIS
AFTERNOON. WOULD NOT BE SURPRISED IF SOME AREAS NORTH OF THE
GOGEBIC RANGE PICKED UP ANOTHER 6 TO 8 INCHES OF SNOW TODAY AND
THIS EVENING BEFORE RATES SLOW CONSIDERABLY TONIGHT AND
WEDNESDAY. THINK LIGHT SNOW MAY SPREAD INLAND AGAIN THIS
AFTERNOON AND EARLY THIS EVENING AS AFORE MENTIONED VORT MAX
ROTATES THROUGH THE AREA. RESULTANT HEIGHT FALLS...STEEP LAPSE
RATES...AND COLD AIR ADVECTION SHOULD BE ABLE TO BRING LIGHT SNOW
SOUTH ACROSS SAWYER AND PRICE COUNTIES...WITH ACCUMULATIONS OF
LESS THAN ONE-HALF INCH EXPECTED. AFTER CONSULTING WITH
NEIGHBORS...AGREED TO LEAVE LAKE EFFECT SNOW WARNING EXPIRATION
TIME AT 21Z THIS AFTERNOON. THINK SNOW WILL BE CONTINUING... BUT
ALLOWING THE WARNING TO EXPIRE AND REPLACE WITH AN ADVISORY MAY BE
APPROPRIATE. DID EXTEND SNOW ADVISORY FOR BAYFIELD AND DOUGLAS
COUNTIES AS THE GRAVITY WAVE BAND WILL PERSIST THROUGH THIS
MORNING.

SURFACE AND UPPER LEVEL RIDGING BUILD INTO MINNESOTA TONIGHT AND
WEDNESDAY. WIND SPEEDS SHOULD BE LOWER WEDNESDAY MORNING AND EVEN
WITH COLDER TEMPERATURES EXPECTED...THINK WIND CHILLS WILL REMAIN
ABOVE ADVISORY CRITERIA. THE ONLY LINGERING QUESTION WILL BE THE
PERSISTENCE AND STRENGTH OF THE LAKE EFFECT SNOW IN ASHLAND AND
IRON COUNTIES. THINK ANOTHER 3 TO 5 INCHES NORTH OF THE GOGEBIC
RANGE IS NOT OUT OF THE QUESTION WITH NORTHERLY WINDS AND WARM AND
OPEN LAKE SURFACE.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 421 AM CST TUE FEB 9 2016

A SURFACE RIDGE AXIS WILL DROP ACROSS WESTERN MINNESOTA WEDNESDAY
NIGHT/THURSDAY BRINGING THE ARRIVAL OF WESTERLY WINDS AND DRIER AIR
TO BRING A BREAK IN THE ACCUMULATING LAKE EFFECT SNOW SHOWERS FOR
LOCATIONS ALONG THE SOUTH SHORE OF LAKE SUPERIOR. HOWEVER...
TRAJECTORIES RETURN TO THE NORTHWEST TO NORTH BRIEFLY DURING
FRIDAY/FRIDAY NIGHT PERIOD...AND A SMALL CHANCE SNOW SHOWERS MAY
SNEAK BACK INTO IRON COUNTY. LONG RANGE MODELS ARE IN AGREEMENT A
BROAD 1040HPA CANADIAN HIGH PRESSURE BUILDS OVER THE REGION
THROUGH SATURDAY...BRINGING CLEARING SKIES AND A TRANSITION TO A
RETURN FLOW.

THE NEXT FEATURE OF INTEREST TO IMPACT THE FORECAST AREA WILL BE A
CLIPPER THAT BRING SNOW CHANCES TO THE REGION FOR THE
SUNDAY THROUGH MONDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1154 AM CST TUE FEB 9 2016

ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD SOUTHWARD THROUGH
MIDDAY WEDNESDAY. MAINLY VFR CONDITIONS EXPECTED..WITH THE
EXCEPTION OF KHIB AND KHYR. KHYR WILL REMAIN ON THE FAR WESTERN
PERIPHERY OF LAKE EFFECT CLOUD PLUME COMING OFF OF WESTERN LAKE
SUPERIOR FOR ANOTHER FEW HOURS..BUT IS EXPECTED TO SCATTER OUT BY
20-21Z. AT KHIB..WINDS HAVE BACKED TO 320-330..AND WITH TEMPS
WARMING ABOVE ZERO..THE MVFR CLOUD PLUMES FROM MINING OPS TO THE
NW OF THE AIRPORT SITE HAVE DECREASED AND BEEN SHUNTED OFF TO THE
EAST OF THE AIRFIELD. HOWEVER..THERE IS AT LEAST SOME POTENTIAL
FOR REDEVELOPMENT OF THESE PLUMES THIS EVENING FOR A FEW HOURS AS
WINDS TURN FROM NW TO NE AND TEMPS FALL AS THE ARCTIC SHALLOW
INVERSION/NOCTURNAL BOUNDARY LAYER BECOMES RE-ESTABLISHED. WIND
GUSTS THIS AFTERNOON HAVE BEEN LOWERED 3-5 KNOTS FROM THE PREV
FORECAST AT ALL SITES PER CURRENT OBS..AND MOST WINDS SHOULD
DIMINISH TO LESS THAN 5-8 KNOTS 22-01Z THIS EVENING..WITH PERHAPS
SOME LOCAL GUSTINESS HANGING ON LATER INTO THE EVENING AT KDLH.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH   7 -13   6 -13 /  10  10   0   0
INL   2 -19   3 -19 /   0  10   0   0
BRD   9 -11   9 -12 /   0  10  10   0
HYR   9 -10   8 -15 /  10  10  10   0
ASX  10  -4   9  -6 /  50  30  30  20

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...LAKE EFFECT SNOW WARNING UNTIL 3 PM CST THIS AFTERNOON FOR
     WIZ004.

     WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR WIZ003.

MN...NONE.
LS...NONE.
&&

$$

UPDATE...MOORE/MILLER
AVIATION...MILLER



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