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000
FXUS63 KAPX 061603
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1103 AM EST FRI DEC 6 2013

.SYNOPSIS...
ISSUED AT 420 AM EST FRI DEC 6 2013

COLDER AIR WILL CONTINUE TO SPILL ACROSS THE GREAT LAKES THROUGH
SATURDAY...BRINGING MAINLY LIGHT LAKE EFFECT SNOW SHOWERS. MORE
WIDESPREAD LIGHT SNOW IS EXPECTED SUNDAY NIGHT INTO THE FIRST HALF
OF MONDAY...AS WEAK LOW PRESSURE SNEAKS THROUGH THE REGION. THAT
SYSTEM WILL USHER IN EVEN COLDER AIR FOR MUCH OF NEXT WEEK...ALONG
WITH BETTER CHANCES FOR ACCUMULATING LAKE SNOWS.

&&

.UPDATE...
ISSUED AT 1103 AM EST FRI DEC 6 2013

STATUS QUO FORECAST THROUGH THE AFTERNOON...AS COLD AIR CONTINUES
TO SLOWLY FILTER IN ALOFT...WITH H8 TEMPS SLIDING TOWARD -17C INTO
EARLY EVENING. MOISTURE REMAINS QUITE ANEMIC...BUT THE ENTIRE
CLOUD DEPTH IS STUCK IN THE DGZ BELOW 850MB...MORE THAN SUFFICIENT
FOR THE PRODUCTION OF SOME PRETTY GOOD DENDRITES. HAVE SEEN SNOW
RATIOS UP AROUND 30-50 TO 1...AND THAT SHOULD CONTINUE THROUGH THE
AFTERNOON...WITH MAYBE AN INCH OR TWO OF VERY FLUFFY SNOW FOR
WEST/NORTHWEST FLOW REGIME. STILL WATCHING ONE QUITE PRONOUNCED
CONVERGENCE BAND JUST NORTH OF WHITEFISH POINT...BUT THAT HAS HELD
OFFSHORE SO FAR WITH SLIGHTLY BACKED FLOW OVER THE EASTERN U.P.
SHORT TERM GUIDANCE TRENDS SUPPORT A SLOW SOUTHWARD SINKING OF
THIS FEATURE INTO THE AFTERNOON/EVENING...BUT THIS WILL HAVE TO BE
WATCHED VERY CLOSELY...ESPECIALLY WITH THE POTENTIAL FOR QUITE A
FEW INCHES OF FLUFF SHOULD THE BAND MAKE IT ASHORE. THAT LOOKS
MOST LIKELY LATER TONIGHT AS LOW PRESSURE SLIDING OVER JAMES BAY
REINFORCES LOW LEVEL CYCLONIC FLOW OVER LAKE SUPERIOR...PERHAPS
HELPING TO PUNT THE BAND ASHORE. WILL DIG INTO THIS MORE CLOSELY
FOR EARLY AFTERNOON.

UPDATE ISSUED AT 654 AM EST FRI DEC 6 2013

NO UPDATED NEEDED. OCCASIONAL LIGHT SNOW AND FLURRIES WILL PERSIST
ACROSS NW LOWER...DID BRING SOME OF THIS ACTIVITY FURTHER INTO
CHIPPEWA COUNTY AS WINDS HAVE TEMPORARILY SHIFTED MORE NORTH OF
WEST. A FLUCTUATION WITH THE PASSING OF A SFC TROUGH. THIS
WAVERING IS EXPECTED THROUGH THE DAY.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 420 AM EST FRI DEC 6 2013

CURRENTLY...DEEP SFC LOW PRESSURE AND PARENT UPPER LOW SPINNING OVER
HUDSON BAY WITH FAST JET STREAM DIRECTLY OVERHEAD IN NRN
MICHIGAN...ALONG WITH AN AXIS OF DEEPER DRIER H8-H5 AIR OF LESS THAN
25 PERCENT. REGARDLESS...AS IS TYPICAL OF NRN MICHIGAN IN
WINTER...INVERSION BASED AT H8 IS TRAPPING LOW LEVEL MOISTURE COMING
IN OFF THE LAKES IN WESTERLY 1000-850MB WINDS. THIS IS RESULTING IN
CLOUDY SKIES AND OCCASIONAL LIGHT SNOW AND FLURRIES DOWNWIND OF THE
LAKES WITH MINIMAL ACCUMULATIONS. CLEAR SKIES WERE SEEN ACROSS
INTERIOR EASTERN UPPER...DUE TO AN OVERLAND FETCH. HIGHER CLOUDS
CONTINUE TO STREAM OVER MUCH OF NE LOWER IN SW FLOW ALOFT. WINDS
REMAIN GUSTY AS THE PRESSURE GRADIENT REMAINS FAIRLY TIGHT...AND
GUSTS CONTINUE UP TO 25 MPH...HIGHER OVER THE LAKES DUE TO BETTER
WINDS TAPPED FROM DEEPER INSTABILITY. TEMPS IN THE CLOUD WERE IN THE
UPPER TEENS TO AROUND 20 DEGREES...WHILE CLEAR AREAS WERE AS LOW AS
THE SINGLE DIGITS...WITH WIND CHILLS IN THE NEGATIVE SINGLE DIGITS.

TODAY AND TONIGHT...THE PATTERN DOESN`T REALLY CHANGE THAT MUCH...AT
LEAST TODAY. THE AIR MASS ACTUALLY DRIES A BIT INTO THE MORNING BUT
OCCASIONAL LIGHT SNOW AND FLURRIES WILL CONTINUE IN WEST LOW LEVEL
FLOW REGIMES. BY AFTERNOON AND ESPECIALLY TONIGHT...WINDS ARE
EXPECTED TO VEER TO A SLIGHTLY NORTH OF WEST DIRECTION...AND WHILE
THIS WILL NOT MEAN MUCH CHANGE IN SNOWFALL LOCATION ACROSS NRN
LOWER...IT WILL MEAN MORE SIGNIFICANT CHANGES ACROSS CHIPPEWA COUNTY
IN EASTERN UPPER. AFTER ACCUMULATIONS UNDER AN INCH TODAY IN THE
WESTERLY FLOW REGIMES...MORE SIGNIFICANT SNOWFALL WILL DEVELOP
TONIGHT.

CONTINUED COLD ADVECTION THROUGH THE DAY AND NIGHT...WITH MOISTURE
DEEPENING/INVERSION RISING TO 5500 FEET IN NW LOWER...AND TO A MUCH
MORE IMPRESSIVE 9KFT ACROSS CHIPPEWA COUNTY WILL RESULT IN AN UPTICK
IN SNOWFALL. PROBABLY NOT SO IMPRESSIVE IN NW LOWER...BUT CAN
FORESEE AN AVERAGE OF A HALF INCH TO AN INCH OF NEW SNOW TONIGHT
WITH CONTINUED CLOUDY SKIES DOWNWIND OF THE LAKES.
MEANWHILE...LONGER FETCH OFF LAKE SUPERIOR INTO CHIPPEWA COUNTY WILL
RESULT THE DEEPER MOISTURE. FAVORABLE H8 TEMPS IN THE MID TEENS
BELOW ZERO...AND FCST SOUNDINGS SUGGESTING STRONG LIFT OCCURRING
DIRECTLY IN THE DGZ WILL RESULT IN POTENTIAL LARGE SNOWFALL AMOUNTS.
THIS AIDED BY INCREASED LIQUID-SNOW RATIOS IN BULLS-EYED DGZ. THIS
IS MORE OF A SHORT TERM ISSUE...WHETHER OR NOT THE DGZ GETS HIT WITH
THE STRONGEST LIFT. HOWEVER..CANNOT FORESEE ALTERING THE 8 INCH+
AMOUNTS OVERNIGHT FOR AROUND PARADISE/WHITEFISH POINT. PER PREVIOUS
DISCUSSION...ANOTHER FLY IN THE OINTMENT WILL BE THE SHARPENING LAKE
INDUCED TROUGHING THAT MAY BE ABLE TO KEEP WINDS A BIT MORE
WESTERLY...KEEPING THE BEST SNOWFALL JUST OFFSHORE. DID LOWER
AMOUNTS ACROSS CENTRAL PORTIONS OF CHIPPEWA COUNTY DO TO THIS.

HIGHS TODAY IN THE UPPER TEENS/LOWER HALF OF THE 20S...WITH LOWS
TONIGHT TEENS IN LAKE EFFECT AREAS...TO AS COLD AS THE THE SINGLE
DIGITS.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 420 AM EST FRI DEC 6 2013

PIECES OF ARCTIC AIR WILL CONTINUE TO FLOW INTO THE REGION OVER THE
NEXT SEVERAL DAYS. THIS WILL LEAD TO BOUTS OF LAKE EFFECT SNOW
SHOWERS. SHIFTING WINDS AND VARYING AMOUNTS OF AVAILABLE MOISTURE
WILL LEAD TO DAILY FORECAST CHALLENGES OVER THE LOCATION AND
INTENSITY OF LAKE EFFECT SNOW SHOWERS AND THE RESULTANT
ACCUMULATIONS. MEANWHILE...A WEAK AREA OF LOW PRESSURE MOVING ACROSS
NORTHERN MICHIGAN IS EXPECTED TO BRING A MORE GENERAL WIDESPREAD
LIGHT SNOW TO THE ENTIRE FORECAST AREA SUNDAY NIGHT INTO EARLY
MONDAY.

SATURDAY...MAINLY LIGHT LAKE EFFECT SNOW SHOWERS WILL CONTINUE
SATURDAY...SAVE FOR THE CONTINUED POSSIBLY HEAVIER BAND NEAR
WHITEFISH POINT AND PARADISE (MEAN 850-700 MB RH NEAR 80 PERCENT)
WHERE SEVERAL MORE INCHES OF ACCUMULATION WILL BE POSSIBLE. THE FLOW
WILL BACK FROM WEST NORTHWEST INTO THE WEST. MOISTURE ACROSS
NORTHWEST LOWER WILL BE ALRIGHT BUT STILL NOTHING OUTLANDISH...WITH
850-700 MB RH GENERALLY AROUND 50 PERCENT. ACCUMULATIONS ACROSS
NORTHWEST LOWER SHOULD BE IN THE INCH TO POSSIBLY TWO INCH RANGE.
HIGHS IN THE UPPER TEENS TO LOWER 20S.

SATURDAY NIGHT...THE MEAN FLOW LIGHTENS UP AND MOISTURE DECREASES
BUT SOME LIGHT SNOW SHOWERS AND FLURRIES ARE EXPECTED TO CONTINUE AT
LEAST THROUGH THE FIRST HALF OF THE NIGHT. ACCUMULATIONS OF UNDER AN
INCH EXPECTED FOR THE MOST PART. LOWS IN THE SINGLE DIGITS ABOVE
ZERO FOR THE MOST PART.

SUNDAY INTO MONDAY...THERE MAY BE A SHORT LIVED BREAK IN THE ACTION
SUNDAY MORNING THEN MOISTURE WILL BEGIN TO INCREASE SUNDAY AFTERNOON
AS A WEAK AND SOMEWHAT MOISTURE DEPRIVED AREA OF LOW PRESSURE MOVES
ACROSS THE REGION THROUGH EARLY MONDAY. THIS SYSTEM IS EXPECTED TO
BRING A GENERAL INCH OR TWO OF ACCUMULATION. HIGHS IN THE UPPER
TEENS TO LOWER 20S SUNDAY AND THE MILDER MIDDLE 20S TO NEAR 30
MONDAY.

MONDAY NIGHT INTO TUESDAY...ANOTHER SHOT OF ARCTIC AIR DROPS INTO THE
REGION LEADING TO MORE LAKE EFFECT SNOW SHOWERS. AN ALBERTA CLIPPER
WILL ALSO MOVE BY TO THE NORTH TUESDAY. HIGHS TUESDAY IN THE MIDDLE
TEENS TO AROUND 20.

TUESDAY NIGHT INTO WEDNESDAY...A DECENT SLUG OF MOISTURE IS SHOWN TO
DROP DOWN FROM THE NORTHWEST AS WELL AS THE COLDEST AIR OF THE WEEK
(AS 850 MB TEMPS FALL INTO THE -22 TO -24 C). THIS MAY SET THE STAGE
FOR A MORE SIGNIFICANT AND MORE WIDESPREAD LAKE EFFECT EVENT FOR
WEST NORTHWEST FLOW FAVORED AREAS. HIGHS WEDNESDAY ONLY IN THE
MIDDLE TO UPPER TEENS AT BEST.

WEDNESDAY NIGHT INTO THURSDAY...LAKE EFFECT SHOULD CONTINUE...AT
LEAST IN A LIGHTER CAPACITY AS COLDER AIR CONTINUES ACROSS THE AREA
BUT MOISTURE BEGINS TO WANE. HIGHS THURSDAY IN THE UPPER TEENS TO
MIDDLE 20S.

FRIDAY...RIDGING ALONG WITH MODERATING TEMPERATURES MAY EVENTUALLY
LEAD TO A BREAK IN THE ACTION BY THE END OF NEXT WEEK. HIGHS IN THE
MIDDLE 20S TO NEAR 30.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 654 AM EST FRI DEC 6 2013

SHALLOW MOISTURE AND OVERLAKE INSTABILITY WILL CONTINUE TO BRING
OCCASIONAL LIGHT SNOW AND FLURRIES...PRIMARILY BETWEEN TVC/PLN.
THIS ACTIVITY WILL PERSIST THROUGH THE DAY...WITH AN UPTICK LATE
THIS AFTERNOON AND ESPECIALLY TONIGHT WITH A SLIGHT INCREASE IN
MOISTURE. MINOR ACCUMULATIONS OF SNOW OF A HALF INCH OR SO
TONIGHT.

WESTERLY WINDS THROUGH TONIGHT...GUSTING TO 20-22KTS.

&&

.MARINE...
ISSUED AT 420 AM EST FRI DEC 6 2013

OVERLAKE INSTABILITY AND A TIGHT PRESSURE GRADIENT...ALTHOUGH
WEAKENING...WILL BE ENOUGH FOR CONTINUED ADVISORY LEVEL GUSTS
THROUGH SATURDAY ACROSS MOST OF THE GREAT LAKES. HIGHER PRESSURE
THEN MOVES IN SATURDAY NIGHT AND ESPECIALLY SUNDAY FOR QUIETER
CONDITIONS. LOW PRESSURE ARRIVES SUNDAY NIGHT INTO MONDAY BUT STILL
NO ISSUES AS FAR AS WINDS. GRADIENT PICKS UP BEHIND THE DEPARTING
LOW MONDAY NIGHT FOR A RETURN TO POTENTIAL ADVISORIES.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LMZ323-341-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LSZ321.

&&

$$

UPDATE...LAWRENCE
SYNOPSIS...AS
SHORT TERM...SD
LONG TERM...AS
AVIATION...SD
MARINE...SD