000
FXUS63 KAPX 111324
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
824 AM EST WED DEC 11 2013

.SYNOPSIS...
ISSUED AT 403 AM EST WED DEC 11 2013

THROUGH THE REMAINDER OF THE WEEK...SURFACE BOUNDARIES WILL
PERIODICALLY MOVE THROUGH THE REGION...REINFORCING THE COLD CANADIAN
AIR MASS AND LAKE EFFECT REGIME ALREADY IN PLACE OVER NORTHERN
MICHIGAN. THIS PATTERN WILL GENERATE AN EXTENDED PERIOD OF SNOW AND
COLD TEMPERATURES THIS WEEK...WITH WINTRY WEATHER CONTINUING INTO
THE UPCOMING WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 403 AM EST WED DEC 11 2013

SYNOPSIS...MIDNIGHT SURFACE ANALYSIS SHOWS A LAKE AGGREGATE-AIDED
CYCLONIC FLOW PATTERN ACROSS THE GREAT LAKES AS A BONE-CHILLING
ARCTIC AIR MASS KEEPS ITS GRIP ON CANADA AND THE NORTHERN TIER OF
THE COUNTRY.  SURFACE TEMPERATURES OF -10F TO -20F AND COLDER FOUND
ACROSS MUCH OF CANADA AND EXTENDING INTO THE NORTHERN PLAINS/
NORTHERN MINNESOTA.  LAKE INFLUENCE EVIDENT IN LOW LEVEL THERMAL
RIDGING (EXTENDING PAST 850MB) EXTENDING FROM LAKE HURON NORTHWEST
ACROSS LAKE SUPERIOR).  LAKE SNOW SHOWERS HAVE BEEN UBIQUITOUS WITH
THIS COLD OUTBREAK...WITH MULTI-BAND CONVECTION OFF LAKES SUPERIOR/
MICHIGAN.  00Z APX SOUNDING INVERSION HEIGHT JUST BELOW 800MB/
-21C.  KAPX VWP SHOWS LOW LEVEL WINDS OVER NORTHERN LOWER MICHIGAN
HAVE BECOME DUE WEST...WITH MOST OF THE SIGNIFICANT SNOW SHOWER
ACTIVITY NORTH OF M-72 AS A RESULT.  OVER LAKE SUPERIOR ONE MONSTER
BAND THAT EARLIER DROPPED ACROSS FAR NORTHWEST CHIPPEWA COUNTY NOW
FOCUSING MORE TO THE WEST AS WINDS OVER LAKE SUPERIOR HAVE VEERED
MORE TOWARD 300 DEGREES.  BUT ADDITIONAL MULTIPLE BANDS STARTING TO
BEND TOWARD WHITEFISH BAY.  MEANWHILE...WATER VAPOR IMAGERY SHOWS A
VORTICITY CENTER ALONG EASTERN PORTIONS OF THE NEBRASKA/KANSAS
BORDER...WITH THE NORTHERN PORTION OF THE COMMA HEAD AUGMENTED BY AN
EAST-WEST ORIENTED POTENTIAL VORTICITY ANOMALY EXTENDING FROM THE
EASTERN DAKOTAS TO EAST OF LAKE SUPERIOR.  THIS FEATURE ALONG WITH
SOME RIGHT REAR QUADRANT JET DYNAMICS IS SPREADING LIGHT SNOW ACROSS
NORTHEAST IOWA/SOUTHEAST MINNESOTA/SOUTHWEST WISCONSIN...AND APPEARS
TO BE TAKING AIM ON CENTRAL/SOUTHERN LOWER MICHIGAN GIVEN WESTERLY
MID LEVEL FLOW.

PV ANOMALY WILL DROP SOUTHEAST ACROSS MICHIGAN TODAY...WITH A SECOND
PIECE OF ENERGY DIVING SOUTHEAST ACROSS MICHIGAN TONIGHT.  ARCTIC
HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS/MIDWEST.  LAKE
AGGREGATE EFFECTS WILL CONTINUE TO MODIFY LOCAL BOUNDARY LAYER FLOW
AS COLD ADVECTION CONTINUES ACROSS THE UPPER LAKES WITH SUB-500DM
1000-500MB THICKNESSES TODAY.  SO COLD TEMPERATURES AND LAKE EFFECT
ISSUES WILL CONTINUE TO DOMINATE LOCAL FORECAST CONCERNS THROUGH THE
SHORT TERM PERIOD.

TODAY/TONIGHT...EASTERN UPPER: EVOLUTION OF LOW LEVEL CONVERGENCE
ASSOCIATED WITH LAKE AGGREGATE TROUGHING WILL CONTROL CHARACTER OF
LAKE BANDS OFF LAKE SUPERIOR.  THIS CONVERGENCE IS FORECAST TO
STRENGTHEN AND SHIFT SOUTH INTO CHIPPEWA COUNTY THIS MORNING AS COLD
DRAINAGE WINDS DEVELOPS OUT OF ONTARIO AND SHIFTS WINDS AROUND TO
NORTHEAST.  STRONG SNOW BAND NORTH OF THE SOO ON MONTREAL RIVER
RADAR MAY BE INDICATIVE OF THIS PROCESS.  THIS MAY MANIFEST ITSELF
LATER THIS MORNING/EARLY AFTERNOON AS ONE DOMINANT BAND THAT
STRETCHES ACROSS PARTS OF LUCE/CHIPPEWA AND PERHAPS FAR EASTERN
MACKINAC COUNTY.  GIVEN IMPRESSIVE RADAR RETURNS ALREADY NORTH OF
THE SOO (35-40DBZ)...IF HEAVIER SQUALLS ARE ABLE TO ANCHOR OVER A
GIVEN LOCATION FOR SEVERAL HOURS...SNOW TOTALS COULD BE SUBSTANTIAL
(ADDITIONAL ACCUMULATIONS BY EARLY EVENING AROUND A FOOT).  ALL
DEPENDS ON HOW MUCH LOW LEVEL FLOW WOBBLES AROUND THROUGH THE DAY.
MOST LIKELY TARGET AREA FOR SIGNIFICANT SNOWS WILL BE FROM AROUND
BRIMLEY WEST AND NORTHWEST.  SNOW BANDS MAY START TO PUSH BACK NORTH
AGAIN TONIGHT AS FLOW BACKS MORE TO THE WEST...BRINGING THE SNOW
FOCUS BACK TO FAR NORTHWEST CHIPPEWA COUNTY DURING THE NIGHT.  STILL
LOCALLY HEAVY ACCUMULATIONS AROUND THE SOUTH AND WEST SIDE OF
WHITEFISH POINT TONIGHT.  NEEDLESS TO SAY...GIVEN THIS POTENTIAL
LAKE EFFECT SNOW WARNING FOR CHIPPEWA COUNTY WILL RIDE ON.

NORTHERN LOWER: CURRENT WESTERLY BOUNDARY LAYER FLOW FORECAST TO
MAKE A SMALL SHIFT TO MORE NORTH OF WEST THIS MORNING...WITH LOW
LEVEL CONVERGENCE WEAKENING A BIT.  INSTABILITY STILL IMPRESSIVE AS
INVERSION HEIGHTS CLIMB TOWARD 750MB WITH COLD ADVECTION...THOUGH
WITH 850MB TEMPERATURES FALLING BELOW -20C THIS WILL LIKELY IMPACT
SNOWFLAKE PRODUCTION TO SOME DEGREE (POSSIBLY LESS DENDRITES AND
MORE PLATES THAT DON`T ACCUMULATE AS READILY).  WILL STICK WITH 2-5
INCHES ACROSS ANTRIM/OTSEGO COUNTIES TODAY...WITH HIGHER AMOUNTS
POSSIBLY SNEAKING INTO KALKASKA/CRAWFORD COUNTIES AS WELL.  ALSO
CONCERNED ABOUT LEELANAU COUNTY...GETTING SOME DECENT RETURNS THERE
THIS MORNING AND LIKELY SOME BLOWING/DRIFTING ISSUES.  SO WILL
EXPAND THE LAKE SNOW ADVISORY INTO LEELANAU/KALKASKA/CRAWFORD
COUNTIES FOR TODAY...AND STRETCH EMMET/CHEBOYGAN ADVISORY THROUGH
THIS MORNING WITH CONTINUED DECENT BANDING ALONG/SOUTH OF M-68.
SNOW SHOWERS WILL CONTINUE TONIGHT...LIKE ACROSS LAKE SUPERIOR WINDS
WILL PROBABLY BACK A BIT MORE WESTERLY...THUS THE SAME AREAS
(ALONG/NORTH OF M-72) WILL BE MOST IMPACTED BY SNOW BANDS WITH
SEVERAL ADDITIONAL INCHES EXPECTED.

TEMPERATURES NOT EXPECTED TO MOVE MUCH TODAY...STUCK IN THE SINGLE
DIGITS AND TEENS.

&&

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 403 AM EST WED DEC 11 2013

ANOTHER DAY...SAME OLD STORY...AND THINK...THIS WILL GO ON FOR A FEW
MORE MONTHS YET AND REMEMBER WINTER HAS NOT OFFICIALLY EVEN STARTED
YET. SNOW AND COLD LOVERS REJOICE AS THE OVERALL PATTERN WITH
EASTERN PACIFIC RIDGING FORCING DOWNSTREAM TROUGHING ACROSS OUR NECK
OF THE WOODS CONTINUES FOR THE MOST PART THROUGH THE EXTENDED
FORECAST PERIOD (THE NEXT SEVEN DAYS ANYWAYS). THIS WILL CONTINUE TO
YIELD MORE LAKE EFFECT SNOW SHOWERS...AND ADDITIONAL ACCUMULATIONS
FOR THE USUAL CULPRITS...EASTERN UPPER AND NORTHWEST LOWER THROUGH
MUCH OF THURSDAY NIGHT. A LESS ACTIVE DAY IS SLATED FOR FRIDAY...BUT
THERE COULD STILL BE SOME LIGHTER SNOWS AS MILDER AIR
ATTEMPTS....AND I STRESS ATTEMPTS TO PUSH NORTHWARD (WHICH LOOKS TO
GAIN LITTLE TO NO TRACTION). THEN WAIT...THERE IS MORE GOOD
NEWS...SOUTHERN JET STREAM BRANCH ENERGY TRIES TO TRANSPORT SOME
MOISTURE UP FROM THE SOUTH...LIKELY LEADING TO AT LEAST SOME LIGHT
SNOW SATURDAY. PLUS ADD IN A TROUGH DROPPING DOWN FROM THE NORTH
SUNDAY AND BAM YOU WILL ANOTHER CHANCE OF MORE SNOW. PLUS DON`T
FORGET THERE COULD ALWAYS BE SOME ADDITIONAL BOOST OFF OF THE BIG
LAKES AS THE AIR MASS REMAINS VERY COLD...THOUGH WIND FIELDS ARE
RATHER WEAK AND VARIABLE SO DON`T EXPECT ANYTHING TO OUTLANDISH TO
BREAK OUT. HIGH PRESSURE WILL ATTEMPT TO SHUT DOWN THE LAKE EFFECT
MACHINE MONDAY...BUT LIKELY ONLY TEMPORARILY SLOW IT DOWN. ANOTHER
AMBITIOUS LOOKING ALBERTA CLIPPER LOOKS TO THEN RE-ENERGIZE LAKE
EFFECT ACTIVITY BY TUESDAY. SO AS YOU CAN SEE THE VERY ACTIVE
PATTERN WILL CONTINUE...ALONG WITH THE COLD TEMPERATURES. THE MAIN
FORECAST CONCERNS REVOLVE AROUND POPS AND SNOWFALL ACCUMULATIONS.

THURSDAY INTO THURSDAY NIGHT...LAKE EFFECT SNOW SHOWERS CONTINUE
WITH PLENTY OF OVER LAKE INSTABILITY REMAINING. ACTIVITY WILL LIKELY
BE ENHANCED BY ANOTHER ALBERTA CLIPPER OR TWO MOVING ACROSS THE
REGION. THE MEAN FLOW LOOKS TO GENERALLY REMAIN OUT OF THE
WEST...THOUGH PERHAPS A SUBTLE VEERING INTO THE WEST NORTHWEST
THURSDAY NIGHT. FAVORED FLOW AREAS COULD SEE ANOTHER FEW INCHES OF
ACCUMULATION DURING THIS TIME...WITH AN INCH OR LESS ELSEWHERE.
HIGHS IN THE MIDDLE TEENS TO AROUND 20. LOWS IN THE SINGLE DIGITS
ABOVE ZERO TO THE MIDDLE TEENS ALONG THE MICHIGAN LAKESHORE.

FRIDAY INTO FRIDAY NIGHT...BATTLE BETWEEN ARCTIC HIGH PRESSURE
TRYING TO NOSE DOWN FROM THE NORTH AND MILDER AIR TO THE SOUTH.
NORTHERN MICHIGAN LOOKS TO BE CAUGHT IN BETWEEN POSSIBLY LEADING TO
A LITTLE LIGHT SNOW. THOUGH THE HIGH IS EXPECTED TO MOSTLY WIN OUT
FRIDAY NIGHT SETTING THE STAGE FOR A COLD NIGHT. REMAINING COLD WITH
HIGHS ONLY RANGING FROM THE UPPER SINGLE DIGITS FAR NORTH TO THE
LOWER 20S SOUTH. LOWS RANGING FROM THE SINGLE DIGITS ABOVE AND BELOW
ZERO NORTH TO THE MIDDLE TEENS ALONG THE SOUTHERN LAKESHORES.

SATURDAY AND SUNDAY...EXTENDED MODELS HAVE MORE OR LESS SETTLED ON A
SOLUTION OF TRACKING A STORM SYSTEM BY TO OUR SOUTH WHICH WILL LEAD
TO DECENT CHANCES FOR MORE MAINLY LIGHT SNOW ON SATURDAY (THOUGH
THERE MAY BE SOME LAKE ENHANCEMENT OFF OF LAKE HURON DUE TO AN
EASTERLY FLOW). THE SNOW MAY LINGER INTO SUNDAY AS WELL AS A
NORTHERN STREAM TROUGH DROPS DOWN ACROSS THE REGION. TEMPERATURES
ARE EXPECTED TO REMAIN COLD WITH HIGHS RANGING FROM THE TEENS TO
LOWER 20S AND LOWS FROM THE SINGLE DIGITS TO THE MIDDLE TEENS SUNDAY
NIGHT AND THE SINGLE DIGITS ABOVE AND BELOW ZERO SUNDAY NIGHT.

MONDAY AND TUESDAY...IT THEN LOOKS LIKE HIGH PRESSURE WILL TRY TO
NOSE INTO THE REGION TO START NEXT WEEK...THOUGH THE LAKE EFFECT
MACHINE MAY STILL BE RUNNING (WITH A MORE NORTHERLY COMPONENT TO THE
LAKE EFFECT BANDS). A DECENT LOOKING ALBERTA CLIPPER SYSTEM LOOKS TO
THEN RECHARGE LAKE EFFECT FOR MONDAY NIGHT INTO TUESDAY AS WELL AS
BRING ANOTHER SHOT OF MODIFIED ARCTIC AIR (OH GOODY). HIGHS MONDAY
AGAIN IN THE TEENS TO LOWER 20S THEN PERHAPS THE MILDER MIDDLE TO
UPPER 20S TUESDAY (WE WILL SEE ON THAT ONE).  11/00Z EXTENDED MODELS
DO HAVE SOME HOPE WITH TROUGHING TEMPORARILY BREAKING DOWN...WHICH
WOULD BRING MODERATING TEMPERATURES IN FOR LATE NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 824 AM EST WED DEC 11 2013

IT`S DECEMBER...IT`S COLD...AND LAKE SNOW SHOWERS CONTINUE NEAR
AND AROUND THE TERMINAL SITES. WITH THE EXPECTED WEST/NORTHWEST
WIND FLOW THROUGH THE EVENING...THE WORST CONDITIONS WILL BE
AROUND THE TVC TERMINAL WHERE PERIODIC IFR VISIBILITIES ARE
LIKELY. FOR THE OTHER SITES (PLN/MBL/APN)...COULD SEE BRIEF
PERIODS OF HEAVY SNOW AS A FEW BANDS SNEAK NEARBY...BUT NOTHING
WORSE THAN A BRIEF PERIOD OF IFR. ANY SNOW THAT FALLS WILL BE VERY
DRY AND FLUFFY...AND WITH WINDS PICKING UP ONE AGAIN FROM THE
WEST (A FEW GUSTS TO 20 KNOTS)...SOME BLOWING SNOW IS POSSIBLE.
BACKING WINDS TO THE SOUTHWEST OVERNIGHT SHOULD PUSH SOME BETTER
SNOWS BACK TOWARD THE PLN TERMINAL LATER TONIGHT.

&&

.MARINE...
ISSUED AT 403 AM EST WED DEC 11 2013

GUSTY WEST/NORTHWEST WINDS EXPECTED TO CONTINUE ON LAKES MICHIGAN/
HURON TODAY...WITH A CONTINUATION OF SMALL CRAFT ADVISORIES WITHIN
THESE NEARSHORE ZONES.  WHITEFISH BAY/ST. MARY`S RIVER MORE
DIFFICULT GIVEN PROXIMITY TO LAKE AGGREGATE THERMAL RIDGING AND
RESULTANT LOWER SURFACE PRESSURES.  SOME SUGGESTION THAT NORTHEAST
DRAINAGE WINDS WILL SPILL OFF THE ONTARIO PLATEAU AND ACROSS
WHITEFISH BAY AT SOME POINT THIS MORNING.  WINDS AT SOO ONTARIO
STILL SCREAMING ALONG AT NEAR 30KTS...SO THIS IDEA WILL PROBABLY
TAKE SOME TIME AND MAY ALSO ONLY BE SHORT LIVED.  SO WILL STRETCH
CURRENT WHITEFISH BAY SMALL CRAFT ADVISORY THROUGH TONIGHT...AND THE
LAKES MICHIGAN/HURON NEARSHORE ZONES THROUGH THURSDAY.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MIZ019>022-027-028.
     WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MIZ016-017.
     LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THURSDAY FOR MIZ008.
LH...SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR LMZ323-341-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR LSZ321.

&&

$$

SYNOPSIS...AJS
SHORT TERM...JPB
LONG TERM...AJS
AVIATION...LAWRENCE
MARINE...JPB