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000
FXUS63 KAPX 051515
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1015 AM EST THU DEC 5 2013

.SYNOPSIS...
ISSUED AT 338 AM EST THU DEC 5 2013

COLDER AIR WILL MOVE INTO THE AREA TODAY BEHIND DEPARTING LOW
PRESSURE. DRY WEATHER WILL PREVAIL THIS MORNING...WITH A FEW LIGHT
LAKE EFFECT SNOW SHOWERS AND FLURRIES THIS AFTERNOON. COLD AIR WILL
CONTINUE TO FILTER INTO THE REGION RIGHT THROUGH THIS
WEEKEND...BRINGING ADDITIONAL LAKE EFFECT SNOW CHANCES TO THE
FAVORED SNOW BELT REGIONS. LOW PRESSURE WILL MOVE ACROSS THE AREA
SUNDAY NIGHT AND MONDAY...BRINGING A THREAT FOR MORE WIDESPREAD
SNOW. ANOTHER SURGE OF ARCTIC AIR WILL FOLLOW THIS SYSTEM NEXT WORK
WEEK...ONCE AGAIN PRODUCING LAKE EFFECT SNOW SHOWERS.

&&

.UPDATE...
ISSUED AT 1014 AM EST THU DEC 5 2013

THE PLAINS STORM SYSTEM WHICH MOVED INTO THE GREAT LAKES REGION
YESTERDAY...WILL CONTINUE TO EXIT NORTHEAST INTO JAMES BAY TODAY.
THIS SHIFT WILL ALLOW MUCH COOLER AND DRIER AIR TO FILTER BACK INTO
THE STATE THROUGH THE AFTERNOON. 850MB TEMPS OF -2C TO 1C AT 12Z
WILL FALL TO -10C BY 00Z THIS EVENING...GENERATING FALLING TEMPS
THROUGH THE AFTERNOON. PCPN CONCERNS TODAY WILL BE CONFINED TO LAKE
ENHANCEMENTS...THOUGH LIMITED IN AREAL COVERAGE AND AMOUNTS.
FACTORS LIMITING SOUTHWEST FLOW LAKE EFFECT TODAY...WILL BE
EXTREMELY DRY MID LEVELS ABOVE A SHALLOW INVERSION AROUND 3K FT
(MSTR GENERALLY BELOW THE -10C ISOTHERM).

OVERALL NO MAJOR CHANGES TO PREVIOUS FORECAST EXPECTED.

UPDATE ISSUED AT 622 AM EST THU DEC 5 2013

CHANGES THIS HOUR: TRACKING AREA OF MID LEVEL RETURNS ARRIVING
OVER MY SOUTHWESTERN ZONES IN AREA OF MID LEVEL DEFORMATION BEHIND
DEPARTING FRONT. AS THIS BRUSHES MY SOUTHERN ZONES THROUGH
9AM...WILL ADD SPRINKLE/FLURRY MENTION...BUT EXPECT IT TO BE OF
LITTLE CONSEQUENCE. OTHERWISE...HAVE BUMPED UP SKY COVER THROUGH
THE EARLY MORNING HOURS BASED ON RECENT SATELLITE/OBSERVATIONAL
TRENDS.

WELL...THAT WAS A QUICK WARM UP...WASN/T IT? TEMPS FALLING INTO
THE MID/UPPER 30S WITH SOME REPORTS OF SLICK SPOTS ON SECONDARY
ROADWAYS. EXPECT TEMPERATURES TO REACH FREEZING AND BELOW BETWEEN
9 AM AND NOON FROM WEST TO EAST.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 338 AM EST THU DEC 5 2013

HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WINDS TODAY OVER LAKE
MICHIGAN.  SLICK SPOT POTENTIAL TODAY AS TEMPERATURES FALL BELOW
FREEZING.

PATTERN SUMMARY:  EARLY MORNING SURFACE ANALYSIS PLACES 990 MB LOW
OVER WESTERN LAKE SUPERIOR WITH SURFACE COLD FRONT PUSHING THROUGH
NORTHERN MICHIGAN ALONG A LINE FROM SJX TO TVC TO CAD. FLOW ALOFT IS
BECOMING INCREASINGLY PARALLEL TO THE SURFACE FRONT...WITH THE
RESULTANT COLD ADVECTION BEHIND THE FRONT RELATIVELY GRADUAL.
STILL...LOOKING UPSTREAM OVER WISCONSIN WHERE TEMPERATURES ARE
FALLING INTO THE 20S AND 30S...THE STAGE IS CERTAINLY SET FOR A
MARKED COOLDOWN.  ON THE PRECIP SIDE OF THINGS...PRE-FRONTAL AREA OF
SHOWERS IS PUSHING EAST WITH RAPID DRYING ALOFT WITH MID AND UPPER
LEVEL MOISTURE DEPARTING WHILE SOME LOW LEVEL CLOUDINESS LINGERS.
FORECAST CHALLENGES THIS CYCLE WILL REVOLVE AROUND TEMPERATURE
TRENDS AND...GIVEN THEIR SUBSTANTIAL COOLING...THE DEVELOPMENT OF
LAKE EFFECT SNOW SHOWERS.

MODEL TRENDS: OVERALL AGREEMENT OUTSTANDING THROUGH 12Z FRIDAY...
WITH CONSENSUS FORMING A GOOD INITIALIZATION FOR THE COMING SHORT
TERM FORECAST.

THROUGH DAYBREAK: IMPRESSIVE SET OF WIND GUSTS IMMEDIATELY POST
FRONTAL...WITH SOME GUSTS REACHING 40 MPH /50 MPH AT GTLM4/ DURING
THE PAST HOUR.  STRONG WESTERLY WINDS WILL OVERSPREAD THE REGION
THROUGH DAYBREAK WITH SHOWER CHANCES QUICKLY DIMINISHING.
TEMPERATURES EXPECTED TO REMAIN ABOVE FREEZING THROUGH DAYBREAK.

TODAY: NOT AT ALL IMPRESSED BY LAKE EFFECT POTENTIAL IN THE ARRIVING
POST FRONTAL AIRMASS AS UPSTREAM OBSERVATIONS WHICH SHOW SINGLE
DIGIT DEWPOINTS ARRIVING OVER WISCONSIN...SIGNALING THE DRYNESS OF
THE INCOMING AIRMASS.  850-700 RH DROPS INTO THE 30 PERCENT
RANGE...WITH INVERSION HEIGHTS BELOW 3KFT /AND TEMPS IN THIS LAYER
NOT BELOW -12C UNTIL AFTERNOON/.  CERTAINLY EXPECT DRY CONDITIONS
THROUGH THE MORNING.  BY AFTERNOON...T8S FALL BELOW -10C WITH
TEMPERATURES NEAR THE TOP OF THE INVERSION LIKELY COLD ENOUGH TO
GENERATE A FEW SNOWFLAKES.  WILL THEREFORE CONTINUE LOW CHANCE POPS
FOR SHSN ALONG THE COAST OF NW LOWER...BUT NO ACCUMULATION
EXPECTED.

ICE:  WITH GOOD WINDS AND A RELATIVELY GRADUAL COOL DOWN...DON/T
EXPECT A FLASH-FREEZE SCENARIO...ALTHOUGH ANY SLUSH OUT THERE WILL
CERTAINLY HARDEN UP DURING THE DAY.  THEREFORE...TAKE CARE ON ANY
BACK ROADS TODAY AS THEY WILL LIKELY SLICKEN UP.

WINDS: MODEST ISALLOBARIC COMPONENT WILL ASSIST STRONG GRADIENT FROM
DEPARTING LOW IN THE PRESENCE OF STEEP /VERY/ LOW LEVEL LAPSE RATES
TO TAP 35KT WINDS AT H9 FOR THE STRAITS REGION AND ALSO NEAR
WHITEFISH POINT.  EXPECT WIND GUSTS TO AROUND 40MPH IN THESE LOCALES
WITH GUSTS 30-35MPH ELSEWHERE.  CERTAINLY WILL ADD A CHILL TO THE
INCOMING COLDER AIRMASS.

TEMPERATURES:  GOING NOWHERE TODAY UNDER CONSISTENT COLD ADVECTION.
HIGHS HAVE ALREADY OCCURRED FOR THIS 24 HOUR PERIOD...WITH DAYBREAK
TEMPERATURES A LITTLE ABOVE FREEZING.  TEMPERATURES WILL FALL THROUGH
THE 20S DURING THE DAY WITH TEMPERATURES APPROACHING 20 BY SUNSET.

TONIGHT: COLD ADVECTION CONTINUES WITH A VERY GRADUAL VEERING TO THE
LOW LEVEL WINDS.  THE MOISTURE DROUGHT WILL CONTINUE...HOWEVER...
WITH RH/S IN THE 850-700 REMAINING IN THE 20-30 PERCENT RANGE.  MERE
COOLING OF THE LOW LEVEL PROFILE /T8S FALL TO -15 OVERNIGHT/ SHOULD
ALLOW FOR MORE OF THE SHALLOW UNSTABLE LAYER TO REACH INTO THE
DENDRITIC GROWTH ZONE...WITH AN UPTICK IN SHSN ACTIVITY EXPECTED.
LOCAL SIMILAR SOUNDING ALGORITHM CERTAINLY UNIMPRESSED WITH SETUP
OVERNIGHT...WITH SIMILAR PAST EVENTS PRODUCING UNDER 1" OF SNOW.
LIKELY POPS ARE IN ORDER FOR WESTERLY FLOW AREAS...ESPECIALLY AFTER
MIDNIGHT GIVEN THE ONGOING COLD ADVECTION.  EXPECT OVERNIGHT SNOW
TOTALS TO REMAIN LESS THAN 1"...CONFINED TO LOCATIONS INCLUDING
HARBOR SPRINGS...CHARLEVOIX...BELLAIRE AND MUCH OF LEELANAU COUNTY.

WITH MUCH MORE SUBSTANTIAL FETCH OVER LAKE SUPERIOR...BANDING WILL
BE WELL-UNDERWAY AND MAY GET CLOSE TO WHITEFISH POINT NEAR THE VERY
END OF THE PERIOD 12Z FRIDAY.  WILL CARRY CHANCE POPS AFTER
MIDNIGHT...BUT CERTAINLY SOMETHING TO WATCH AS A DEVIATION OF
BANDING TO THE SOUTH COULD CERTAINLY BRING ROBUST LAKE EFFECT INTO
THIS LOCATION...CERTAINLY MORE IMPRESSIVE THAN WHAT WILL BE GOING ON
FURTHER SOUTH.

TEMPERATURES: CLOUD COVER WON/T HELP KEEP TEMPS UP FOR TOO MANY
LOCATIONS GIVEN AFOREMENTIONED POOR LAKE EFFECT RESPONSE.  THE
GRADIENT WILL REMAIN UP...HOWEVER...WHICH SHOULD KEEP TEMPS FROM
GETTING TOO OUT OF HAND OVERNIGHT.  THEREFORE...WILL KEEP TEMPS
GENERALLY IN THE LOWER/MIDDLE TEENS...WARMEST BENEATH THE BAND OF
LAKE CLOUDS IN NORTHWEST LOWER.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 338 AM EST THU DEC 5 2013

PHASE ONE TRANSITION TO A MUCH COLDER PATTERN WILL BE ABOUT COMPLETE
AS WE HEAD INTO THE BEGINNING OF THE LONG TERM PORTION OF THE
FORECAST. DEEP NEGATIVE EAST PACIFIC OSCILLATION (-EPO) TO
BLAME...WITH RESULTANT HIGHLY AMPLIFIED EAST PACIFIC RIDGE/WESTERN
NOAM TROUGH COUPLET LAYING THE TRACKS FOR A VISIT FROM THE POLAR
EXPRESS. AS MENTIONED THE PAST COUPLE DAYS...LACK OF ANY APPRECIABLE
DOWNSTREAM BLOCKING/ ASSOCIATED MAINTENANCE OF SOUTHEAST RIDGING
WILL HELP KEEP THE TRULY COLD TEMPERATURE ANOMALIES OFF TO OUR WEST
AND NORTH THROUGH THIS WEEKEND. SUCH DOES OPEN THE DOOR FOR A RATHER
ACTIVE PERIOD...FIRST VIA LAKE EFFECT PROCESSES INTO THE BEGINNING
OF THIS WEEKEND...FOLLOWED BY A MORE WIDESPREAD SNOW EVENT SUNDAY
NIGHT INTO MONDAY. PATTERN BECOMES MUCH MORE PROGRESSIVE
THERE-ON-AFTER AS -EPO BREAKS DOWN. UNFORTUNATELY...THIS LOOKS TO
OPEN THE DOOR FOR THE COLDEST AIR OF THIS ARCTIC OUTBREAK TO SPREAD
ACROSS THE NORTHERN LAKES...AND...YOU GUESSED IT...MORE LAKE EFFECT
SNOW. NOT ALL IS DOOM AND GLOOM...HOWEVER...WITH SAID PROGRESSION
LOOKING AT ALLOW A MODERATING TREND AS WE HEAD INTO THE LATTER HALF
OF NEXT WEEK. FORECAST CHALLENGES ARE MANY...BUT NO DOUBT SNOW
AMOUNTS AND TEMPERATURE TRENDS TAKE CENTER STAGE THROUGH THE PERIOD.

COLD WEST FLOW WILL BE THE NAME OF THE GAME FRIDAY INTO THE START OF
THE WEEKEND AS CENTER OF ARCTIC HIGH DRIFTS DOWN INTO THE NORTHERN
PLAINS. THERMAL PROGS CONTINUE TO SUPPORT HIGHS BOTH FRIDAY AND
SATURDAY STRUGGLING THROUGH THE UPPER TEENS AND INTO THE
LOWER/MIDDLE 20S. WIND DO NOT LOOK EXCEPTIONALLY STRONG...WHICH
SHOULD HELP KEEP WIND CHILL READINGS MOSTLY ON THE POSITIVE SIDE OF
ZERO. SYNOPTIC SUPPORT ESSENTIALLY NON-EXISTENT FOR PRECIP...LEAVING
MORE OF A PURE LAKE EFFECT PROCESS FOR SNOWS. ONE WOULD THINK WITH
ALL THIS COLD AIR AND STILL RELATIVELY WARM LAKE WATERS LAKE SNOWS
WOULD BE RATHER ROBUST. HOWEVER...THAT EXTREME TEMPERATURE
DIFFERENCE (DELTA T/S AROUND 20C) IS ABOUT THE ONLY THING GOING FOR
LAKE SNOWS...ESPECIALLY THROUGH EARLY FRIDAY AFTERNOON. UPPER JET
RIGHT OVERHEAD NEVER A GOOD SIGN FOR LAKE PROCESSES...AS IS DEEP DRY
LAYER ABOVE SQUASHED OVER-WATER BOUNDARY LAYER (SUB H8 INVERSION ON
BUFR SOUNDINGS). DUE WEST FLOW MEANS NO LAKE SUPERIOR HELP FOR
NORTHWEST LOWER...WITH EVEN SLIGHTLY BACKED WIND FIELDS OVER EASTERN
UPPER VIA LAKE AGGREGATE TROUGHING DIRECTING LAKE SUPERIOR ACTIVITY
INTO ONTARIO. THUS...SIMPLY NOT OVERLY OPTIMISTIC ABOUT ACCUMULATING
SNOW CHANCES THROUGH MUCH OF FRIDAY. LAKE SNOW CONCERNS RATCHET UP
SOME LATER FRIDAY INTO THE FIRST PART OF SATURDAY...ESPECIALLY FOR
THE SNOW BELTS OF EASTERN UPPER. FLOW VEERS EVER SO SLIGHTLY PER ALL
GUIDANCE...WITH NICE FORCED LOW LEVEL CONVERGENCE CHANNEL SLIDING
SOUTH INTO NORTHWEST CHIPPEWA COUNTY. PAST SEVERAL RUNS OF THE NAM
VERY DISCONCERTING FOR AREAS AROUND PARADISE/WHITEFISH POINT...WITH
STRONG SUPPORT FOR A DOMINATE SOUTHERN LAKE SUPERIOR BAND TO IMPACT
THAT AREA OVERNIGHT FRIDAY INTO EARLY SATURDAY. NAM POINT SOUNDING
FOR PARADISE RAMPS UP THE CONCERN...WITH SATURATED LAYER TO H7
INVERSION AND DEEP/STRONG OMEGA PEGGED RIGHT IN THE DGZ. IF THIS
COMES TO FRUITION...COULD ENVISION SNOWFALL RATES IN EXCESS OF TWO
INCHES PER HOUR (IF NOT MORE). OF COURSE...THAT`S ONLY ONE PART OF
EQUATION FOR SNOWFALL AMOUNTS...WITH DURATION OF HEAVIEST SNOW BEING
THE OTHER. THAT LOOKS TO BE A TOUCH MORE TRICKY...AS BAND MAY REMAIN
A TOUCH TRANSIENT. MUCH TOO EARLY FOR ANY HEADLINES...BUT WILL RAMP
UP THIS CONCERN IN THE LATEST RENDITION OF THE HAZARDOUS WEATHER
OUTLOOK. NOT NEARLY AS IMPRESSIVE FOR THE NORTHWEST LOWER LAKE
BELTS. FLOW DOES SUPPORT SOME GREEN BAY HELP...AND THERE IS GOOD
UNIDIRECTIONAL W TO SLIGHTLY WNW FLOW THROUGH THE CBL. THAT CBL DOES
SPIKE UP TO H8 OVERNIGHT FRIDAY...ALTHOUGH DEEP DRY LAYER ABOVE DOES
PROTRUDE DOWN INTO THE TOP OF THE MIXED LAYER. WEAK OMEGA NOTED IN
THE DGZ...WHICH IS WELL WITHIN THE CLOUD LAYER. SNOW SHOWERS FOR
FAVORED AREAS SHOULD INCREASE IN INTENSITY...WITH AT LEAST SOME DESCENT
FLUFF FACTOR. UPSHOT TO THE ABOVE...WOULD EXPECT AT LEAST A FEW
INCHES OF SNOW IN THE NORTHWEST LOWER SNOW BELTS...WITH LOCALLY
HIGHER AMOUNTS EASILY ATTAINABLE IF BANDING STRUCTURES BECOME
STATIONARY (A REAL POSSIBILITY GIVEN WIND FIELDS).

BRIEF BREAK WITH THE SNOWS EXPECTED LATER SATURDAY THROUGH SUNDAY AS
HIGH PRESSURE BUILDS THROUGH THE REGION. ATTENTION THEN TURNS TO
ENERGY KICKING OUT OF BASE OF WESTERN TROUGH...SPINNING UP LOWER
MISSISSIPPI VALLEY LOW PRESSURE AS IT DOES SO LATER SUNDAY. THIS
SYSTEM ROCKETS NORTH NORTHEAST...WITH EXCELLENT INTRA AND INTER
MODEL AGREEMENT IT PUSHES ACROSS THE LAKES SUNDAY NIGHT INTO EARLY
MONDAY. AIRMASS PLENTY COLD ENOUGH TO SUPPORT AN ALL SNOW SCENARIO.
MUCH TOO EARLY TO GET TOO SPECIFIC ON AMOUNTS...ALTHOUGH LACK OF
PHASING WITH ADDITIONAL ENERGY DIVING OUT OF CANADA/DISCONNECT WITH
DEEPER MOISTURE LYING ACROSS THE SOUTHEAST STATES/AND SIMPLE FAST
MOVEMENT ARGUES FOR A LESS THAN HIGH IMPACT SYSTEM. EARLY PROGS
SUGGEST MORE OF AN ADVISORY TYPE SNOW SCENARIO. SURGE OF EVEN COLDER
AIR FOLLOWS THIS SYSTEM AS SAID SECONDARY SHORTWAVE PLOWS THROUGH
THE REGION. H8 TEMPERATURES PLUMMETING PERHAPS BELOW -20C SUPPORTS
HIGHS STRUGGLING TO GET OUT OF THE LOWER/MIDDLE TEENS TUESDAY. LAKE
SNOWS COULD BE RATHER ROBUST...MORE SO THROUGH VISIBILITY
RESTRICTION THAN ACCUMULATION (DGZ LIKELY BELOW THE CLOUD
BASE...RESULTING IN PIXIE-DUST TYPE SNOWS). NO MATTER HOW YOU SLICE
IT...AN IMPRESSIVE SURGE OF MID-WINTER WEATHER IS ON THE
WAY!

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 622 AM EST THU DEC 5 2013

SUMMARY: LOW PRESSURE DEPARTING THE GREAT LAKES REGION WILL ALLOW
FLYING CONDITIONS TO IMPROVE TODAY UNDER GUSTY WEST WINDS.  LIGHT
LAKE EFFECT SNOW SHOWERS WILL BEGIN TO DEVELOP THIS AFTERNOON AND
EVENING...POTENTIALLY IMPACTING FLYING CONDITIONS OVER NORTHWEST
LOWER MICHIGAN.

RESTRICTIONS: MVFR CIGS WILL HOLD FOR A FEW HOURS BEFORE
LIFTING/SCATTERING AND ALLOWING VFR CONDITIONS TO TAKE HOLD.  VFR
CONDITIONS WILL PERSIST THROUGH THIS AFTERNOON AND EVENING...BEFORE
INCREASING AMOUNTS OF LAKE CLOUDINESS BRING A POTENTIAL RETURN TO
MVFR CIGS AT TVC/PLN WITH SHSN LIKELY TO BRING SOME VSBY
RESTRICTIONS TO PLN.

SNOWFALL RATES/SNOW CHARACTER:  SNOWFALL RATES WILL BE VERY LOW
OVERNIGHT WITH AVERAGE SNOW TO LIQUID RATIOS.

WINDS: WEST WINDS 18G28KTS FOR THE DAY TODAY WILL DIMINISH TO
10G18KTS THIS EVENING...AND THEN 10KTS OVERNIGHT.


&&

.MARINE...
ISSUED AT 338 AM EST THU DEC 5 2013

SUMMARY: LOW PRESSURE WILL LIFT NORTH OF THE WESTERN LAKES
TODAY...WITH A STRONG COLD FRONT PUSHING EAST.  THIS WILL CAUSE
LLEVEL WINDS TO VEER WESTERLY AND REMAIN GUSTY THROUGH FRIDAY BEFORE
HIGH PRESSURE ARRIVES FROM THE WEST...BRINGING QUIETER CONDITIONS
OVER THE LAKES.

HEADLINES: WILL ADD GRAND TRAVERSE BAY AND THE STRAITS TO THE
ONGOING LAKE MICHIGAN GALE WARNING BASED ON EARLY MORNING WINDS FROM
GTLM4 AND KMCD. SMALL CRAFTS WILL CONTINUE ELSEWHERE.  STRONGEST
WINDS SHOULD OCCUR BETWEEN NOW AND NOON TODAY BEFORE GRADUALLY
SUBSIDING.  SMALL CRAFT CONDITIONS WILL PERSIST OVER MOST NEARSHORE
AREAS THROUGH SATURDAY.  THE NEXT THREAT FOR GALE FORCE WINDS LOOKS
TO HOLD OFF UNTIL EARLY NEXT WEEK WHEN LOW PRESSURE MOVING EAST OF
THE GREAT LAKES MAY BRING WINDS CLOSE TO GALE FORCE.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
     LHZ346>349.
     GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LHZ345.
LM...GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LMZ323-341-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

UPDATE...SR
SYNOPSIS...MB
SHORT TERM...ARNOTT
LONG TERM...MB
AVIATION...ARNOTT
MARINE...ARNOTT