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000
FXUS63 KAPX 040501
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1201 AM EST WED DEC 4 2013

.SYNOPSIS...
ISSUED AT 424 PM EST TUE DEC 3 2013

LIGHT TO MODERATE SNOW WILL CONTINUE TO OVERSPREAD NORTHERN MICHIGAN
INTO THIS EVENING...WITH LIGHT ACCUMULATIONS EXPECTED. THE SNOW WILL
GRADUALLY TURN TO A LIGHT WINTRY MIX LATER TONIGHT...EVENTUALLY
CHANGING OVER TO ALL RAIN ON WEDNESDAY...AS LOW PRESSURE AND WARMER
AIR CROSS THE REGION. PRECIPITATION WILL CHANGE BACK OVER TO SNOW
THURSDAY...AS A COLD FRONT BLASTS THROUGH THE REGION. ARCTIC AIR
WILL SETTLE INTO THE REGION BY FRIDAY AND INTO THIS WEEKEND...WITH
LAKE EFFECT SNOW SHOWERS FOR EASTERN UPPER AND NORTHWEST LOWER
MICHIGAN.

&&

.UPDATE...
ISSUED AT 956 PM EST TUE DEC 3 2013

ZONE OF ICY MIXED PRECIP HAS MOVED UP TO THE M-55 TIER OF
COUNTIES...BUT HAS LARGELY STALLED THERE. THAT IS AS
PROGGED...WITH SHORT-TERM MODELS HARDLY BUDGING THE SUB-700MB
THERMAL FIELDS FROM 00Z TO 06Z. THE COPIOUS AMOUNT OF PRECIP
BEING GENERATED (AND ACCURATELY SO) IS THE PRIMARY CULPRIT. THE
WARM NOSE WILL RESUME A NORTHWARD MARCH AFTER 06Z/1AM...LIKELY
BRINGING POTENTIAL MIXED PRECIP AS FAR AS M-32 BY 12Z/7AM.
HOWEVER...PRECIP WILL BECOME CONSIDERABLY LESS WIDESPREAD AS THIS
HAPPENS...AS DRIER MID-LEVEL AIR GETS DRAWN UP INTO
CENTRAL/SOUTHERN LOWER MI.

THE GIST OF THE EARLIER FORECAST UPDATE LOOKS FINE...WILL CONTINUE
TO PLAY WITH DETAILS BUT NO HUGE CHANGES ANTICIPATED. THE
ADVISORY WILL BE LEFT ALONE...COASTAL MANISTEE CO IS MOSTLY RAIN
BUT THE INTERIOR PROBABLY IS STILL ICY. THE SAGINAW BAY AREA IS
STILL AROUND FREEZING...AND MULTIPLE REPORTS OF I-75 BEING QUITE A
MESS IN ARENAC CO. SO NO NEED TO CANCEL ANYTHING (THOUGH THE TIP
OF NORTHERN LOWER MAY NOT QUITE GET THE SNOW AMOUNTS EARLIER
ADVERTISED).

UPDATE ISSUED AT 715 PM EST TUE DEC 3 2013

WARM NOSE ALOFT ENCROACHING ON SOUTHERN PORTIONS OF THE FORECAST
AREA...PER FZRA AT MBS (PER OBS) AND TUSTIN (PER BROADCAST MEDIA).
SNOW/SLEET MIX REPORTED BY NWS EMPLOYEE ON I-75 NEAR ARENAC/BAY CO
LINE. ALSO A LITTLE LIQUID REPORTED TO BE MIXING IN THE TVC
AREA...THAT LIKELY ASSOCIATED WITH VERY LIGHT PRECIP WHERE SHALLOW
WARM-RAIN PROCESSES ARE OCCURRING. NICE SLUG OF PRECIP DEVELOPING
IN CENTRAL LOWER/ADVANCING FROM EASTERN WI. EXPECT SMALL ICE
ACCUMS ALONG/SOUTH OF M-55 OVER THE NEXT FEW HOURS...WITH A SLEETY/
MIXY ZONE JUST NORTH OF THAT...AND JUST SNOW NORTH OF M-72. MOST
INTENSE PRECIP OF THE NIGHT EXPECTED OVER THE NEXT FEW HOURS. WILL
ADJUST FORECAST THESE THOUGHTS IN MIND.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 424 PM EST TUE DEC 3 2013

CURRENTLY, DEVELOPING SFC LOW IN THE SOUTHERN PLAINS WITH A
COMPLICATED SERIES OF INVERTED TROUGH/WARM FRONT/OCCLUDED FRONTS IN
THE NORTHERN PLAINS/UPPER GREAT LAKES. THE WARM FRONT SEEMS TO BE
STRETCHED OUT SOUTH OF US-10 AND HAS BEEN PRODUCING LIGHT SNOW,
PRIMARILY, WITH HEAVIER BURSTS OF SNOW THROUGH THE LATE AFTERNOON.
THE INITIAL BAND OF SNOW THAT CAME THROUGH IN THE MORNING, BROUGHT
2-3 INCHES OF SNOW NEAR THE LAKE MICHIGAN SHORELINE. SINCE THEN, THE
TEMPERATURES HAVE BEEN STAGNANT AROUND OR BELOW FREEZING ACROSS
NORTHERN MICHIGAN.

THE NEXT COUPLE OF HOURS (THROUGH 00Z)...THE LIGHT TO MODERATE SNOW
ACROSS AND BETWEEN THE M-32 AND M-72 CORRIDORS WILL SLOWLY DIMINISH
THROUGH THE EVENING WITH THE BACK END OF THE MAIN SNOW GETTING
TOWARD LAKE HURON BY 00Z. THE ONLY CONCERN IS THE F-GEN BAND OF WHAT
SEEMS TO BE LIGHT SNOW OUT OVER LAKE MICHIGAN AND INTO GRB, FOLLOWED
BY A LARGER AREA OF PRECIPITATION JUST CROSSING THE MISSISSIPPI
RIVER NEAR MSP AND ARX. THIS WILL PROBABLY BEGIN TO CROSS LAKE
MICHIGAN AROUND 00Z

REST OF TONIGHT (00Z THROUGH 12Z)...WHEN THE 12Z NAM CAME IN WITH
THE WITH THE PRECIPITATION BULL`S EYE DURING THE EVENING, IT SEEMED
TO BE A BIT OUT ON ITS OWN. HOWEVER, WITH THE AREA OF PRECIPITATION
THAT IS MOVING INTO WISCONSIN, AND THE SUBSEQUENT 12Z RUNS OF THE
GFS AND ECMWF SHOWING SOMETHING SIMILAR, HAVE CHANGED THE TUNE OF
THE PACKAGE. IT LOOKS LIKE THAT WITH THE WARM FRONT STUCK TO THE
SOUTH THE A DECENT AREA OF QG FORCING IN THE 700-500 MB LAYER WILL
SET UP ALONG IT (IT LOOKS LIKE SOME LFQ FORCING ON THE 500 MB JET).
THIS WILL PROPAGATE TO THE EAST THROUGH THE NIGHT AS IT STARTS ALONG
THE LAKE MICHIGAN SHORELINE IN NW LOWER AROUND 00Z, AND CONTINUES
EAST LEAVING NE LOWER BY 06Z. THE GFS LINGERS IT IN THE WEST A
LITTLE LONGER WITH THE PRECIPITATION UNTIL 12Z. HOWEVER THIS LOOKS
LIKE LIGHT TO MODERATE AMOUNTS OF SNOW IN THE 00-06Z PERIOD ON 2 OF
THE 3 MODELS. THIS LOOKS LIKE IT WOULD BE A SNOW EVENT, ALTHOUGH IT
LOOKS LIKE THE WARMER AIR WILL BEGIN TO MOVE INTO THE SW COUNTIES
AFTER 06Z, AND CHANGE ANY SNOW TO A MIX AND THEN TO ALL RAIN BY 09Z.
MODELS STILL GO WITH SNOW UNTIL 12Z ANYTHING NORTH OF M-32. SO SOME
SURPRISE HEAVY SNOW AMOUNTS WOULDN`T BE OUT OF THE QUESTION UNTIL
THE SNOW CHANGES OVER. E UPPER LOOKS LIKE IT WOULD MISS OUT ON THE
BULK OF THE PRECIPITATION AS THE FRONT DOESN`T DO MUCH OF A MOVE
UNTIL AFTER 12Z, AND THEN THE CHANGE OVER BEGINS TO MOVE ALONG
QUICKLY.

WEDNESDAY...WITH THE 500 MB JET STREAK/VORTMAX MOVING INTO W UPPER
THROUGH THE AFTERNOON, AND THE WARMER AIR STREAMING NORTH BY THE
AFTERNOON, IT COULD BECOME QUITE THE WASHOUT IN E UPPER AS THE
MODELS FORCING FROM THE DYNAMIC UPLIFT (500 VORT AND SFC LOW) AND
THE THERMAL LIFT FROM THE WARM FRONT, THERE COULD BE A BRIEF PERIOD
OF MODERATE RAIN THROUGH THE LATE AFTERNOON AND EVENING IN E UPPER.
A DECENT MID-LEVEL DRY SLOT (700-500 MB LAYER) PUSHES IN SOUTH OF
THE WARM FRONT PRODUCING A PERIOD OF DRIZZLE IN THE SOUTHERN
COUNTIES BY 00Z.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 424 PM EST TUE DEC 3 2013

OVERVIEW: THREE-WAVE HEMISPHERIC PATTERN IN PLACE TODAY WITH
STRONG LONG WAVE RIDGING FROM THE GULF OF ALASKA THROUGH THE
EASTERN PACIFIC...PUSHING VERY COLD AIR AND DEEP LONG WAVE
TROUGHING DOWN THROUGH CANADA AND INTO THE CONUS. SOME "WARMER"
AIR HAS/IS MAKING TEMPORARY INROADS INTO THE MIDWEST AND LOWER
LAKES REGION FOR THE SHORTER TERM. BUT POTENT SHORT WAVE DIGGING
INTO THE WESTERN CONUS WILL BE THE GAME CHANGER AS IT KICKS ITS
WAY THROUGH THE GREAT LAKES AND DRAGS EXTREMELY COLD AIR DOWN
THROUGH THE WESTERN CONUS AND THROUGH THE NRN PLAINS/GREAT
LAKES...LATER THIS WEEK AND THROUGH THE UPCOMING WEEKEND. BUT
GETTING THERE THROUGH MIDWEEK WILL BE INTERESTING AS STRONG STORM
SYSTEM TRACKING WEST OF THE STATE DRAGS WARM AIR INTO NORTHERN
MICHIGAN TEMPORARILY...FOLLOWED BY A POTENT COLD/OCCLUDED FRONT
PASSAGE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL RUN US THROUGH
THE GAMBIT OF PRECIP TYPES OVER THE NEXT 48 HOURS OR SO.

WEDNESDAY NIGHT...AFOREMENTIONED SHORT WAVE AND ASSOCIATED 150 + KNOT
UPPER JET FORECAST TO ADVANCE NORTHEAST UP THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY/WESTERN GREAT LAKES. COLD/OCCLUDED FRONT
SLATED TO PASS THROUGH THE CWA DURING THE COURSE OF THE NIGHT...AND
ANTICIPATE SFC TEMPS TO ESSENTIALLY PEAK RIGHT AROUND THE MIDNIGHT
TIMEFRAME (UPPER 30S TO MIDDLE 40S) BEFORE DROPPING BACK OFF TOWARD
THURSDAY MORNING. PRECIP-WISE...WARM ADVECTION/WIDESPREAD WARM
CONVEYOR BELT RAINFALL WILL BE ONGOING THROUGH WEDNESDAY EVENING
BEFORE A DRY SLOT PUNCHES UP THROUGH THE REGION. PRECIP MAY CUT OFF
ENTIRELY FOR A TIME LATER OVERNIGHT INTO THURSDAY MORNING.

THURSDAY THROUGH SATURDAY...BIG TRANSITION ON THURSDAY AS SECONDARY
COLD FRONT PASSES THROUGH THE REGION EARLY THURSDAY AND
SUBSTANTIALLY COLDER AIR OVERSPREADS THE GREAT LAKES. OVER LAKE
INSTABILITY AND WESTERLY FLOW LAKE EFFECT POTENTIAL WILL OF COURSE
INCREASE AS H8 TEMPS FALL TO AROUND -12C BY THURSDAY EVENING AND
FURTHER TO AROUND -16C TO -18C FOR FRIDAY. BUT...GUIDANCE IS ALSO
INSISTENT IN DRAGGING A WEDGE OF FAIRLY DRY AIR FROM THE PLAINS
ACROSS THE LOWER GREAT LAKES...WHICH WILL THROTTLE LAKE EFFECT SNOWS
TO A CERTAIN EXTENT. BETTER CONDITIONS ON LAKE SUPERIOR ALTHOUGH A
WESTERLY WIND REGIME DOES NOT FAVOR EASTERN UPPER MICHIGAN LAKE
SNOWS. SATURDAY...LARGE EXPANSE OF HIGH PRESSURE BUILDS ACROSS THE
REGION THROUGH THE DAY...SETTLING OVER THE GREAT LAKES SATURDAY
NIGHT. LOW LEVEL FLOW WILL VEER A BIT MORE NW AND MAY DRAG SOME
BETTER SNOW SHOWERS INTO EASTERN UPPER MICHIGAN THROUGH THE DAY. BUT
WEDGE OF DRY AIR HOLDS TIGHT ACROSS LOWER MICHIGAN AND CONTINUES TO
THROTTLE LAKE EFFECT SNOWS OVER NW LOWER MICHIGAN. FOR SATURDAY
NIGHT...LAKE EFFECT MAY WEAKEN/BREAK DOWN AS HIGH PRESSURE SETTLES
IN AND FLOW WEAKENS/BECOMES VARIABLE. POTENTIAL FOR ANOTHER VERY
COLD NIGHT WITH ANY SUBSTANTIAL CLEARING THAT MANAGES TO DEVELOP AND
HAVE LOWERED MIN TEMPS INTO THE SINGLE DIGITS. OVER GUIDANCE AREAS
THAT MANAGE TO AS  MAY VEER LOW LEVEL FLOW A BIT MORE WNW AS
DRAGGING SOME BETTER SNOW SHOWERS INTO EASTERN UPPER MICHIGAN.

SO OVERALL...WHILE IT WILL BE SNOWING...GUSTY AND MUCH COLDER
THROUGH THIS TIME...AT THIS POINT ITS NOT SHAPING UP TO BE A BIG
LAKE EFFECT SNOW EVENT. A FEW LOCATIONS (SAY ACROSS CHARLEVOIX/
ANTRIM/OTSEGO COUNTIES) MAY FARE OK AND SEE SOME DECENT LAKE SNOW
ACCUMULATIONS AND ANTICIPATE WE WILL ULTIMATELY NEED A HANDFUL OF
ADVISORIES. BUT DO NOT ANTICIPATE ANY WIDESPREAD WARNING SNOWS.

SUNDAY THROUGH TUESDAY...ANOTHER PIECE OF SHORT WAVE ENERGY AND
ASSOCIATED SFC LOW EXPECTED TO LIFT UP THROUGH THE REGION LATER
SUNDAY THROUGH MONDAY. EXTENDED GUIDANCE HAS SHOWN QUITE THE RANG
OF SOLUTIONS WITH THE TRACK OF THIS NEXT SYSTEM...RANGING FROM
TRACKING THROUGH THE U.P. TO SOMEWHERE THROUGH OHIO...ALTHOUGH
GFS/EURO 12Z SOLUTIONS ARE A LITTLE BETTER TODAY. OVERALL IDEA
REMAINS HOWEVER...ANOTHER STORM SYSTEM LIFTING THROUGH THE GREAT
LAKES DURING THIS TIME. FORTUNATELY GIVEN THE MAGNITUDE OF COLD AIR
THERE WILL BE NO PRECIP ISSUES WITH THIS NEXT SYSTEM...AND ITS NOT A
PARTICULARLY STRONG SYSTEM TO BEGIN WITH. ANOTHER PERIOD OF LIGHT TO
PERHAPS MODERATE SNOW SUNDAY NIGHT THROUGH MONDAY FOLLOWED BY A
REINFORCING SHOT OF EVEN COLDER AIR FOR TUESDAY (HIGHS SINGLE DIGITS
TO THE TEENS).

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1158 PM EST TUE DEC 3 2013

MVFR TO IFR. LLWS AT TIMES.

WARM FRONT IS LAID OUT ACROSS THE SOUTHERN GREAT LAKES.
WIDESPREAD PRECIP (MOSTLY SNOW) WILL GRADUALLY DIMINISH OVERNIGHT
AND WED MORNING TO DRIZZLE/FZDZ. PLENTY OF LOW CLOUDS THRU THE
FORECAST WITH MVFR TO IFR CONDITIONS.

EAST WINDS TONIGHT WILL VEER A BIT SE ON WEDNESDAY. LLWS MUCH OF
THE UPCOMING DAY AND INTO THE EVENING...WITH STRONG SE TO S WINDS
OFF THE DECK.

&&

.MARINE...
ISSUED AT 424 PM EST TUE DEC 3 2013

WITH THE GRADIENT TIGHTENING OVERNIGHT WITH THE SFC LOW MOVING
TOWARDS US, THE WINDS OVER THE LAKES, ESPECIALLY ALONG THE SOUTHERN
SHORE OF E UPPER (SEUL CHOIX PT. TO FALSE DETOUR)THE E TO ESE WINDS
WILL PRODUCE COASTAL CONVERGENCE AND BRING SMALL CRAFT GUSTS. AS THE
SFC LOW GOES BY THE COASTAL CONVERGENCE WILL DECREASE AS THE WINDS
TURN MORE SE AND THE SFC LOW GOES BY. WEDNESDAY NIGHT/THURSDAY, THE
WINDS TURN SW AND WE GET INTO HIGH END SMALL CRAFT CRITERIA. THERE
IS AN OUTSIDE CHANCE FOR GALES, BUT AT THIS POINT, IT SEEMS PRETTY
SMALL. THE WAVES WILL JUST BE BUILDING UP THROUGH THURSDAY
AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 6 AM EST WEDNESDAY FOR MIZ016>036-
     041-042.
LH...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LMZ341-342-
     344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LSZ321-322.

&&

$$

UPDATE...JZ
SYNOPSIS...NS
SHORT TERM...JL
LONG TERM...BA
AVIATION...JZ
MARINE...JL