Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 260448
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1148 PM EST TUE NOV 25 2014

.SYNOPSIS...
ISSUED AT 347 PM EST TUE NOV 25 2014

LAKE EFFECT SNOW SHOWERS WILL PERSIST ACROSS PARTS OF NORTHERN
MICHIGAN THIS AFTERNOON INTO THE OVERNIGHT HOURS. COLDER
TEMPERATURES ALONG WITH ADDITIONAL CHANCES FOR SNOW WILL CONTINUE
ALL THE WAY THROUGH THE REMAINDER OF THE HOLIDAY WEEK INTO THE FIRST
PART OF THE WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 347 PM EST TUE NOV 25 2014

ALWAYS A FUN CHALLENGE DURING THIS TIME OF YEAR AND INDEED TONIGHT
IS NO EXCEPTION...WITH THE MAIN FORECAST ISSUE BEING THE PLACEMENT
OF CLOUDS/LINGERING LAKE SNOW CHANCES AS WELL AS JUST HOW COLD TEMPS
MAY GET IN SOME AREAS. EARLY AFTERNOON ANALYSIS PLACES A STRONG SUB-
980MB LOW RACING NORTHEASTWARD INTO NEWFOUNDLAND BUT WITH PRONOUNCED
LOW LEVEL TROUGHING STRUNG BACK SOUTHWARD INTO THE GREAT LAKES AREA.
ALOFT...AN UPPER WAVE IS NOTED LIFTING THROUGH SOUTHEASTERN
ONTARIO...WITH EARLIER DEEPER MOISTURE/DEFORMATION FORCING FROM THIS
FEATURE DELIVERING QUITE THE SHOT OF SNOWFALL FOR MANY AREAS
OVERNIGHT (SAVE FOR EAST/SOUTHEAST COUNTIES). VISIBLE SATELLITE AND
STREAMLINE ANALYSIS PLACE STRONG LOW LEVEL CYCLONIC FLOW OVER
NORTHERN MICHIGAN...THOUGH WEAKENING WITH TIME...WHICH HAS
INTERACTED WITH DEPARTING DEEP MOISTURE AND PLENTIFUL LAKE
INSTABILITY TO GENERATE A SMATTERING OF HEAVIER LAKE SNOW BANDS...
PARTICULARLY INTO FAR NORTHWEST CHIPPEWA COUNTY AS WELL AS MUCH OF
NORTHWEST LOWER.

THE PRIMARY CHALLENGE FOR TONIGHT IS JUST HOW MUCH SNOW SHOWER
ACTIVITY WILL CONTINUE. SAID CYCLONIC FLOW WILL WANE QUICKLY THROUGH
THE EVENING AS LOW LEVEL RIDGING WORKS THROUGH THE LOWER
LAKES...HELPING GRADUALLY BACK OUR INITIAL NORTHWEST FLOW BACK TO
THE SOUTHWEST TOWARD MORNING...THOUGH WITH SPEED SHEAR OF LESS THAN
10 KNOTS. THAT SETUP MORE THAN NOT OFTEN LEADS TO SOME SNEAKY
MESOSCALE PROCESSES THAT MAKE THE FORECAST DIFFICULT. IN THIS
CASE...SUSPECT THAT WE WILL MAINTAIN WESTERLY FLOW LAKE SNOWS AS THE
WINDS BEGIN TO BACK THE FIRST HALF OF THE NIGHT...BUT PROBABLY WITH
A TREND TOWARD CLEARING INLAND AREAS AS WE LOSE THE FLOW AND LAND
BREEZES ATTEMPT TO SET UP.

ALL THE WHILE...PRONOUNCED THERMAL TROUGHING LOOKS TO LAY OUT
THROUGH THE STRAITS AND DOWN ACROSS LAKE MICHIGAN...POTENTIALLY
INTERACTING WITH SAID LAND BREEZES TO HELP SPIN UP A MESOSCALE
VORTEX OR TWO OVER THE LAND/WATER INTERFACE. HI-RES GUIDANCE HAS
BEEN INSISTENT ON THIS OCCURRING UP TOWARD THE TIP OF THE MITT
COUNTIES...WHERE WEAK LOW LEVEL SOUTHWEST FLOW INTERACTS WITH BACKED
FLOW THROUGH THE STRAITS TO FORCE STRONGER CONVERGENCE INTO PARTS OF
EMMET COUNTY...AND PERHAPS DOWN THE SHORE OF LAKE MICHIGAN COUNTIES.
WHILE CONFIDENCE IS RATHER LOW...DO SUSPECT SOME SNEAKY HEAVIER
AMOUNTS ARE POSSIBLE WHERE AND IF THIS FEATURE DEVELOPS. FOR MOST
OTHER AREAS...SUSPECT THERE COULD BE SOME QUITE CHILLY LOW TEMPS
WITH SOME CLEARING EXPECTED AND FRESH SNOW COVER. HAVE UNDERCUT ALL
GUIDANCE (AWAY FROM COASTAL LOCALES)...WITH THE POSSIBILITY THAT
SOME SPOTS COULD TANK WELL INTO THE SINGLE DIGITS. DEFINITELY A VERY
NEAR TERM ISSUE BUT THE POSSIBILITY IS THERE FOR A FEW UNLUCKY SPOTS
TO PUSH ZERO...PROVIDED OF COURSE WE CAN MANAGE SOME CLEARING.

.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 347 PM EST TUE NOV 25 2014

HIGH IMPACT WEATHER POTENTIAL: SEASONALLY ACTIVE NOVEMBER PATTERN
WITH SEVERAL SNOW CHANCES /GENERALLY LIGHT/ BUT SOME POTENTIAL
TRAVEL ISSUES.

LOW LEVEL RIDGING ATTEMPTS TO MOVE INTO THE GREAT LAKES ON
WEDNESDAY.  OVERNIGHT LAND BREEZES...PLENTY OF OVER-LAKE INSTABILITY
/850MB TEMPS -11C/ AND WEAK LOW LEVEL FLOW ALL POINT TOWARD MESO-
VORTICES ACROSS LAKE MICHIGAN AND LAKE HURON.  VARIOUS PIECES OF
GUIDANCE POINT TO THIS AS WELL.  VERY LOW CONFIDENCE IN TRYING TO
PIN DOWN THE DETAILS OF THESE FEATURES BUT WILL GENERALLY HAVE
HIGHER POPS ACROSS NORTHERN LAKE MICHIGAN TOWARD WESTERN MACKINAC
COUNTY...AS WELL AS ALONG LAKE HURON.  DRY OVER INLAND AREAS WITH
SOME PARTIAL SUNSHINE POSSIBLE...AT LEAST FOR A PORTION OF THE DAY.

WEDNESDAY NIGHT-THANKSGIVING...FORECAST BECOMES MORE MUDDLED AND
CHALLENGING AS NORTHERN STREAM SHORTWAVE SLIDES INTO THE NORTHERN
LAKES AND HELPS TO ENHANCED EXISTING LAKE-INDUCED TROUGHING.
INCREASE IN DEEPER SYNOPTIC MOISTURE WILL WORK WITH WEAK LOW LEVEL
SOUTHWEST FLOW TO ENHANCE THE SNOW FROM FAR NORTHWEST LOWER THROUGH
THE TIP OF THE MITT INTO THE STRAITS.  TO FURTHER COMPLICATE
THINGS...GUIDANCE ALSO HINTING AT ENHANCEMENT POTENTIAL OFF OF LAKE
HURON WITH LIGHT ONSHORE/DRAINAGE FLOW...SOME AGGREGATE SURFACE
TROUGHING UP ALONG THE COAST AND POSSIBLY A MESO-VORTEX SLIDING
ONSHORE. SNOW SHOWERS WILL INCREASE ACROSS MUCH OF THE AREA LATE
WEDNESDAY NIGHT INTO THANKSGIVING ALONG THE BOUNDARY SLIDING
THROUGH THE AREA. HIGH CONFIDENCE THAT MOST OF NORTHERN MICHIGAN
SHOULD SEE A PERIOD OF SNOW WITH FRONT...PROBABLY ON THE ORDER OF
1-2" /H7 MIXING RATIOS AROUND 1 G/KG/ WITH HIGHER AMOUNTS IN
ENHANCED AREAS. AS DEEPER SYNOPTIC MOISTURE STRIPS OUT...A QUICK
TRANSITION TO NW FLOW LAKE EFFECT OCCURS. NOT EXPECTING BIG
ACCUMULATIONS BUT ADDITIONAL MINOR ACCUMULATIONS POSSIBLE IN
FAVORED SNOW BELTS. MAY ALSO HAVE A PERIOD OF SOME GUSTY WINDS
/15-20 MPH/ BEHIND THE FRONT CREATING AREAS OF BLOWING SNOW AND
REDUCED VISIBILITIES. ALL IN ALL...A FAIRLY WINTRY THANKSGIVING
DAY ACROSS NORTHERN MICHIGAN.

THURSDAY NIGHT AND FRIDAY...ACTIVE AND CHALLENGING WEATHER CONTINUES
AS LONGWAVE PATTERN FLATTENS OUT WITH ADDITIONAL PACIFIC ENERGY
MOVING INTO THE UPPER MIDWEST.  SOME LINGERING LIGHT LAKE EFFECT
CLOSER TO THE LAKE MICHIGAN COAST THURSDAY NIGHT AS LOW LEVEL FLOW
BACKS TO THE SOUTHWEST.  AN IMPRESSIVE PUSH OF WARM AIR
ADVECTION/UPGLIDE SNOWS DEVELOPING ON FRIDAY AS WARM FRONT LIFTS
TOWARD THE SOUTHERN LAKES AND WEAK SURFACE LOW APPROACHES FROM THE
WEST.   PLENTY COLD ENOUGH H8 TEMPS FOR CONTINUED LAKE ENHANCEMENT
OVER PORTIONS OF LAKE MICHIGAN.

EXTENDED PERIODS...(FRIDAY NIGHT THROUGH MONDAY)

FRIDAY NIGHT: FAIRLY DECENT SHOT OF WARM AIR ADVECTION SNOW
CONTINUES TO PUSH NORTH AND EAST INTO SOUTHERN CANADA...WITH THE
LAST OF ANY LINGERING LIGHT SNOW PUSHING THROUGH THE STRAITS/EASTERN
UPPER BY 12Z SATURDAY.

SATURDAY THROUGH SATURDAY NIGHT: FAIRLY LOW CONFIDENCE DURING THIS
PERIOD AS MODEL SPREAD IS QUITE LARGE REGARDING THE MAGNITUDE OF
WARMER AIR RETURNING TO THE REGION ON SATURDAY. WITH THE RECENT
IMPROVEMENTS TO THE SNOW PACK ACROSS ALL OF NORTHERN MICHIGAN...
WOULDN`T BE SURPRISED TO SEE ANOTHER WAFFLE OR TWO IN TERMS OF THE
DEGREE OF WARM AIR...BUT WILL HEDGE TOWARD A RELATIVELY MILDER
SOLUTION WITH HIGHS INTO AT LEAST THE MIDDLE 30S.

SUNDAY THROUGH MONDAY: SURPRISE SURPRISE...A RETURN TO RATHER COLD
AIR IS EXPECTED BEHIND A COLD FRONT EXTENDING SOUTHWARD FROM SURFACE
LOW PRESSURE CENTERED NEAR JAMES BAY BY SUNDAY MORNING WITH ANY
MIXED PRECIP TRANSITIONING OVER TO ALL SNOW BEFORE ENDING. WITH THAT
COLD AIR COMES ANOTHER CHANCE FOR ACCUMULATING LAKE EFFECT SNOW
EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1145 PM EST TUE NOV 25 2014

VFR/HIGH MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU WEDNESDAY NIGHT AS HIGH PRESSURE REMAINS IN CONTROL.
SOME LINGERING LIGHT LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO
FALL OVER PORTIONS OF NW AND FAR NRN LWR MICHIGAN (PLN/TVC/MBL)
OVERNIGHT...WITH MAINLY DRY WEATHER EXPECTED FOR WEDNESDAY AS LOW
LEVEL WINDS SHIFT AROUND TO THE S/SE AHEAD OF OUR NEXT LOW
PRESSURE SYSTEM. THIS SYSTEM WILL INCREASE CHANCES OF LAKE ENHANCED
SNOW LATER WEDNESDAY NIGHT AND CONTINUING INTO THANKSGIVING.
LIGHT/CALM WINDS OVERNIGHT WILL BECOME EASTERLY UNDER 10 KTS ON
WEDNESDAY.

&&

.MARINE...
ISSUED AT 347 PM EST TUE NOV 25 2014

STRONGER NORTHWEST WINDS WILL DIMINISH QUICKLY THIS EVENING AS HIGH
PRESSURE ARRIVES OVER THE WATERS...WITH THAT LIGHTER FLOW PREVAILING
THROUGH WEDNESDAY NIGHT. A STRONG COLD FRONT IS EXPECTED TO ARRIVE
WITH A BURST OF SNOW AND GUSTY NORTHWEST WINDS EARLY THURSDAY...BUT
NO GALES ARE FORESEEN. A PERIOD OF STRONGER SOUTHWEST WINDS IS
LIKELY LATER FRIDAY AND THROUGH THE WEEKEND...WITH A LOW END CHANCE
FOR A FEW GALE GUSTS.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SYNOPSIS...MJG
SHORT TERM...LAWRENCE
LONG TERM...KEYSOR/GILLEN
AVIATION...MLR
MARINE...LAWRENCE



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