000
FXUS63 KAPX 031808
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
108 PM EST TUE DEC 3 2013

.SYNOPSIS...
ISSUED AT 325 AM EST TUE DEC 3 2013

PRECIPITATION CHANCES WILL INCREASE TODAY AS A WARM FRONT BEGINS TO
LIFT THROUGH MICHIGAN...WITH A WINTRY MIX EVENTUALLY CHANGING OVER
TO ALL RAIN ON WEDNESDAY...AS LOW PRESSURE CROSSES 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 1237 PM EST TUE DEC 3 2013

THE LIGHT SNOW IS BEGINNING TO DIMINISH IN NW LOWER AS THE MAIN
SNOW BANDS ARE PUSHING THROUGH NE LOWER. E UPPER IS JUST ON THE
EDGE OF THE SNOW, WITH VERY LIGHT SNOW TO NOTHING.

LOOKING DOWNSTATE THE WARMER AIR (I.E. ABOVE FREEZING) IS SOUTH OF
US-10 AND IS SLOWLY MOVING NORTH. THE SLOW ADVANCE IS EXPECTED TO
CONTINUE TODAY, AND THE LATEST GUIDANCE SUGGESTS THAT IT MAY NOT
BE UNTIL AFTER 09Z THAT WE START TO SEE MUCH IN THE WAY OF A
CHANGE OVER TO RAIN. SO WILL TWEAK THE TIMING AND INTENSITY OF THE
SNOW FOR THE AFTERNOON/EARLY EVENING. EVERYTHING ELSE SEEMS TO BE
ON TRACK.

UPDATE ISSUED AT 1040 AM EST TUE DEC 3 2013

MAKING SOME MID MORNING UPDATES AS THE SNOW MOVES THROUGH AHEAD OF
THE WARM FRONT. TEMPERATURES ARE GENERALLY RUNNING FROM AROUND
FREEZING AND COLD ACROSS THE FORECAST AREA THIS MORNING. THE EAST
FLOW IS PROVIDING MOISTURE INTO THE ONCOMING STORM SYSTEM. SO FAR
THE WARMER AIR HASN`T MADE IT VERY FAR NORTH INTO MICHIGAN, SO
SNOW HAS BEEN THE RULE AND IT LOOKS LIKE IT WILL CONTINUE,
ALTHOUGH VERY LIGHTLY AFTER THE INITIAL BAND, WITH THE LATEST NAM
AND GFS SHOWING SNOW AT CAD AND HTL THROUGH 00Z.

UPDATE ISSUED AT 633 AM EST TUE DEC 3 2013

CHANGES THIS HOUR: MINOR ADJUSTMENTS TO UP NEAR TERM POPS TO 100
PERCENT FROM FKS TO MBL GIVEN OBS FROM LDM CONFIRMING THAT
PRECIPITATION IS MAKING IT ACROSS LAKE MICHIGAN THIS FAR
NORTH...WITH AN EASTWARD EXPANSION EXPECTED OVER THE NEXT FEW
HOURS. SLOWED INCREASING CLOUDS JUST A TOUCH OVER EASTERN
UPPER/NORTHEAST LOWER BASED ON CURRENT TRENDS. FINALLY...CONTINUE
TO MATCH NEAR TERM TEMPERATURES WITH PLN NOW DOWN TO 7 WHILE
MBL/FKS REMAIN NEAR 30.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 325 AM EST TUE DEC 3 2013

HIGH IMPACT WEATHER POTENTIAL: SOME SLICK TRAVEL BOTH TODAY AND
TONIGHT GIVEN DEVELOPING SNOW AND SOME MINOR POTENTIAL FOR ICING
THIS EVENING AND TONIGHT.

PATTERN SUMMARY: EARLY MORNING WATER VAPOR IMAGERY REVEALS AN
ENERGY-LADEN NORTHERN STREAM ALONG THE NORTHERN PORTIONS OF THE
CONUS...WITH ONE WAVE OVER WISCONSIN RESPONSIBLE FOR AREA OF
PRECIPITATION MOVING TOWARDS NORTHERN MICHIGAN AS OF THIS
WRITING...WITH A MORE SUBSTANTIAL WAVE CARVING A DEEPER TROUGH
ACROSS THE WESTERN CONUS PROMISING CONTINUED ACTIVE WEATHER THROUGH
THE REMAINDER OF THE WEEK.  DRILLING DOWN TO THE SURFACE REVEALS A
WEAK RIDGE AXIS OVER THE WESTERN LAKES CONNECTED TO A MORE
SUBSTANTIAL HIGH OVER THE THE CANADIAN PRAIRIES.  AFOREMENTIONED MID
LEVEL DISTURBANCES ASSOCIATED WITH A SERIES OF WEAK LOW PRESSURE
SYSTEMS CONNECTED BY A QUASI STATIONARY FRONT EXTENDING FROM WEST TO
EAST SOUTH OF THE GREAT LAKES...POISED TO BEGIN MOVING NORTH AND
INCREASE PRECIPITATION CHANCES FOR OUR AREA.

MODEL TRENDS:  ECMWF/GGEM/UKMET CONTINUE TO BE THE MOST CONSISTENT
SOLUTIONS OF LATE WITH AMERICAN GUIDANCE SIGNIFICANTLY DEEPER AND
FASTER WITH THE DEVELOPING LOW...WITH SUBSTANTIAL RUN TO RUN JUMPS.
TRENDS IN THE AMERICAN GUIDANCE OVER THE PAST FEW CYCLES HAVE BEEN
TO MOVE TOWARDS THE ECMWF/GGEM/UKMET CONSENSUS AND THIS LATTER
CONSENSUS WILL BE HEAVILY FOLLOWED IN THE SHORT TERM PORTION OF THE
FORECAST.

THROUGH DAYBREAK: LOW CLOUDS HAVE THINNED IN MANY LOCATIONS ALLOWING
A QUICK DROP IN TEMPERATURES GIVEN LIGHT WINDS AND THIN SNOW PACK.
THIS TREND WILL BE SHORT-LIVED...HOWEVER...AS CLOUDINESS QUICKLY
BUILDS IN FROM THE SOUTH AND WEST ASSOCIATED WITH AREA OF ISENTROPIC
ASCENT/MID LEVEL FRONTOGENESIS.  CURRENT EXTRAPOLATION LINES UP WITH
NEAR TERM GUIDANCE TRENDS...BRINGING LEADING EDGE OF LIGHT SNOWFALL
TO MBL JUST BEFORE 12Z.  CAN ENVISION A FEW SLICK SPOTS FOR MORNING
TRAVEL WEST OF US-31 WITH A COATING OF SNOW POSSIBLE THROUGH 9 AM.

TODAY: TRICKY LIGHT PRECIPITATION FORECAST THROUGH TODAY AS MID
LEVEL VORTICITY CENTER CONTINUES TO WEAKEN AND SHEAR OUT AS IT
REACHES NORTHERN MICHIGAN.  AT THE SAME TIME...BAND OF MID LEVEL
FRONTOGENESIS ASSOCIATED WITH BAND OF ISENTROPIC ASCENT WILL ALSO
WEAKEN AS IT PUSHES EAST.  THIS DOES NOT SPELL MUCH IN THE WAY OF
SIGNIFICANT PRECIPITATION...BUT CAN/T ARGUE WITH MODELS STEADILY
PROGRESSING CURRENT BATCH OF PRECIPITATION NORTH AND EAST INTO THE
CWA THIS MORNING.  BEYOND THIS...MODEL TRENDS HAVE BEEN FOR SOMEWHAT
DEEPER MOISTURE TO REMAIN DURING THE AFTERNOON EVEN AS LIFT WEAKENS.

PTYPE:  WILL CONTINUE THE TREND BEGUN BY LAST NIGHT/S EVENING SHIFT
AND CONVERT ALL MORNING PRECIPITATION OVER TO ALL SNOW GIVEN DEEP
SATURATION AND TEMPS THROUGH THE COLUMN COLD ENOUGH TO SUPPORT ALL
SNOW.  GIVEN OUR TREND TOWARDS THE WEAKER ECMWF/GGEM...BELIEVE THAT
TEMPERATURES ALOFT WILL REMAIN AT OR BELOW FREEZING THROUGH EARLY
EVENING...WHICH SHOULD ALLOW ANY PTYPE QUESTIONS TO BE GOVERNED BY
SURFACE TEMPERATURES.  EXPECT THESE TO REMAIN AT OR BELOW FREEZING
THROUGH EARLY AFTERNOON...WHEN TEMPS ALONG THE COAST OF NW LOWER
SHOULD MOVE INTO THE MID 30S.  THUS...AS PRECIPITATION DWINDLES THIS
AFTERNOON...EXPECT A TRANSITION TO LIGHT SNOW/FLURRIES...WITH SOME
SPRINKLES/LIGHT RAIN POSSIBLE LATE ALONG THE COAST OF NORTHWEST
LOWER.  WHILE DRIZZLE/FREEZING DRIZZLE CHANCES AREN/T ZERO...TRENDS
FOR DEEPER MOISTURE MENTIONED ABOVE ARGUE AGAINST THIS SCENARIO.

ANY SNOW ACCUMULATIONS TODAY WILL REMAIN BELOW 1"...WHICH...WHEN
COMBINED WITH WANING DAYTIME ICING CONCERNS SHOULD PRECLUDE ANY NEED
FOR HEADLINES.

TEMPERATURES:  CLOUDS AND DEVELOPING PRECIPITATION WILL KEEP
TEMPERATURES MOVING SLOWLY TODAY...WITH HIGHS LIKELY OCCURRING LATE
IN THE DAY IN THE MID 20S OVER THE EASTERN UP...WITH THE LOWER 30S
OVER NORTHERN LOWER.

TONIGHT: NEXT WAVE IN THE MID LEVEL FLOW PUSHES THROUGH THE UPPER
MISSISSIPPI VALLEY AND COAXES A STRENGTHENING SOUTHWESTERLY LOW LEVEL
JET WHICH WILL HELP INTENSIFY A BAND OF WARM ADVECTION AND MID LEVEL
FRONTOGENESIS IN THE PRESENCE OF MID LEVEL -DIVQ.  GIVEN THE
PRECIPITATION WE SEE ON REGIONAL RADAR AT THIS TIME...SEE NO PROBLEM
IN THIS SETUP PRODUCING A SIMILAR /LIKELY A LITTLE MORE WIDESPREAD
AND ROBUST/ BAND OF PRECIPITATION THROUGH THE TONIGHT PERIOD.  WILL
THEREFORE UP POPS INTO THE CATEGORICAL AREA FOR THE PERIOD.

PTYPE:  FOLLOWING THE WEAKER ECMWF SOLUTION SUGGESTS THAT WARMING
ALOFT WILL BE FAIRLY SLOW THROUGH THE OVERNIGHT...WHICH SHOULD KEEP
THE SURFACE-BASED 0C LINE QUITE CLOSE TO THAT ALOFT.  WHAT THIS
INDICATES IS THAT THE WINDOW FOR ANY FREEZING PRECIPITATION IS QUITE
SMALL...PERHAPS IN SOME OF THE COLDER INTERIOR VALLEYS.  IMPACTS
FROM THIS LOOK MINOR AS THESE AREAS SHOULD HAVE SEEN SOME SNOW
EARLIER TO COAT ROADWAYS.  WOULD NOT BE SURPRISED IF WE MAKE IT
THROUGH THE NIGHT WITH SNOW SIMPLY TRANSITIONING TO RAIN AS IT
TAPERS TO SHOWERS.  SNOW ACCUMULATIONS THROUGHOUT EASTERN UPPER AND
NORTH CENTRAL AND NORTHEASTERN LOWER MICHIGAN LOOK TO REMAIN BELOW
2" WITH RELATIVELY POOR SNOW TO LIQUID RATIOS /IE WET SNOW/.  ICING
AMOUNTS LOOK TO BE LITTLE MORE THAN A TRACE.  THESE FACTORS AGAIN
SUGGEST THAT WHILE WE/LL HAVE TO DEAL WITH SOME SLICK TRAVEL...WE
WILL BE WELL BELOW ANY ADVISORY THRESHOLDS.

TEMPERATURES: UNDER ONGOING WARM ADVECTION/CLOUDS/PRECIPITATION...
EXPECT TEMPERATURES TO GRADUALLY CLIMB THROUGH THE NIGHT...BEGINNING
IN THE MID 20S OVER EASTERN UPPER TO THE MID 30S OVER THE COAST OF
NW LOWER...WITH ALL OF NORTHERN LOWER NEAR OR ABOVE FREEZING TOWARDS
DAYBREAK...AS TEMPERATURES HOLD JUST BELOW FREEZING OVER EASTERN
UPPER.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 AM EST TUE DEC 3 2013

AFTER A BRIEF REPRIEVE...ITS GONNA GET COLD AROUND THESE
PARTS...AGAIN. CAN THANK THE EASTERN PACIFIC OSCILLATION (EPO) FOR
THIS BIT OF GOOD NEWS...ITSELF PLUNGING INTO DEEP NEGATIVE STATE WITH
RAPID NORTHWARD RIDGE BUILDING UP AND BEYOND ALASKA. CLASSIC
RESPONSE DOWNSTREAM...WITH DEEP WESTERN/CENTRAL NOAM TROUGH
DEVELOPMENT OPENING AN AVENUE FOR TRUE ARCTIC AIR TO SURGE SOUTH.
CORE OF COLDEST AIR LOOKS TO REMAIN UPSTREAM OVER THE NORTHERN
PLAINS (SEE SUB ZERO HIGH TEMPERATURES MID-WEEK INTO THE
WEEKEND!)...AND GIVEN LACK OF NORTH ATLANTIC BLOCKING (+NAO)...MIGHT
JUST STAY THIS WAY AS AT LEAST SOME SEMBLANCE OF SOUTHEAST RIDING IS
MAINTAINED. IRONICALLY...LEAD SYSTEM USHERING IN THIS COLDER AIRMASS
LOOKS TO BE MORE OF A WET ONE THAN A WHITE ONE...WITH NOW MULTI
INTRA AND INTER MODEL TRENDS FOR OUR AREA TO GET INTO THE WARM
SECTOR WEDNESDAY/WEDNESDAY NIGHT AS LOW PRESSURE MOVES UP JUST TO
OUR NORTHWEST. HOWEVER (ALWAYS A "HOWEVER")...STILL PLENTY OF
POTENTIAL HEADACHES...MOST NOTABLE OF WHICH IS A WINTRY MIX CONCERN
EARLY WEDNESDAY FOR PARTS OF EASTERN UPPER MICHIGAN. STORY AFTERWARD
IS TIMING DOWNWARD TEMPERATURE SPIRAL AND WHAT LOOKS TO BE MULTIPLE
PERIODS OF LIGHT LAKE EFFECT SNOWS.

WILL SIDE HEAVILY WITH WHAT HAS BEEN ROCK-STEADY NON-NCEP GUIDANCE
FOR THE MID-WEEK SYSTEM. LOW PRESSURE WILL CONTINUE TO ORGANIZE OVER
THE CENTRAL PLAINS WEDNESDAY IN RESPONSE TO STRONG UPPER JET ENERGY
AND MID LEVEL SUPPORT RUNNING THROUGH THE INTERMOUNTAIN WEST. LARGE
SLOPE NOTED IN NORTHEAST EXTENDED WARM FRONT...WITH H8 FRONT
PROPELLING STEADILY NORTH INTO THE STRAITS AREA BY WEDNESDAY
MORNING...WITH ITS SURFACE LIKENESS RUNNING UP THROUGH CENTRAL
MICHIGAN. NICE OFF THE DECK CONVERGENCE ALONG ELEVATED PORTION OF
THE WARM FRONT...AND EXPECT AT LEAST SOME LIGHT PRECIP TO BE
ASSOCIATED WITH IT...ESPECIALLY ALONG AND NORTH OF M-32. AS FOR
TYPE...SOMEWHAT A MORE FORMIDABLE CHALLENGE. RELIED ON ECMWF SURFACE
TO H8 WET BULB TEMPS TO HELP ANSWER SUCH...WHICH BOTH SUGGEST
PRIMARILY LIGHT SNOW DURING THE MORNING ACROSS THE NORTH HALF OF
EASTERN UPPER...TRANSITIONING TO RAIN SOUTH OF THE MIGHTY MAC. NOT
TOO WORRIED ABOUT ANY FREEZING RAIN POSSIBILITIES AS SURFACE
TEMPERATURES LOOK TO BE SEVERAL DEGREES ABOVE FREEZING. RAIN/SNOW
LINE ADVANCES FURTHER NORTH THROUGH THE DAY AND EVENING AS ELEVATED
WARM FRONT PUSHES NORTH OF THE REGION...WITH ALL RAIN EXPECTED BY
WEDNESDAY EVENING FOR ALL AREAS. LOW PRESSURE PINWHEELING UP THROUGH
CENTRAL WISCONSIN INTO CENTRAL UPPER MICHIGAN OVERNIGHT WEDNESDAY
SUPPORTS A MUCH SLOWER COLD FRONTAL PASSAGE THAN EARLIER
ANTICIPATED...WITH THE FRONT NOT ARRIVING UNTIL EARLY THURSDAY
MORNING. MUCH OF NORTHERN LOWER LOOKS TO AT LEAST GET BRIEFLY IN THE
SURFACE WARM SECTOR...ALLOWING TEMPERATURES TO SPIKE INTO THE 40S
(MID 40S SOUTH SIDE OF THE SUNRISE SIDE). THESE MAY ACTUALLY BE A
TOUCH TOO CONSERVATIVE IF STRONGER LOW DEVELOPMENT SEEN IN SOME 00Z
GUIDANCE IS REALIZED.

AS MENTIONED EARLIER...CORE OF COLDEST TEMPERATURES LOOKS TO REMAIN
WELL UPSTREAM...SUGGESTING POST-FRONTAL CAA WILL NOT BE OVERLY
INTENSE HEADING INTO THURSDAY AND THURSDAY NIGHT. DEFINITELY COLD
ENOUGH TO ENTICE AT LEAST SOME LAKE RESPONSE...WITH CURRENT PROGS
SUPPORTING A WEST (NORTHER LOWER) TO WEST-NORTHWEST (EASTERN UPPER)
FLOW. AMOUNT OF SYNOPTIC MOISTURE SUPPORT IN SERIOUS DOUBT...
ESPECIALLY OVER NORTHERN LAKE MICHIGAN. LACK OF A LAKE SUPERIOR
CONTRIBUTION LIKELY TO ONLY HURT THE MOIST CONVECTIVE CAUSE FOR
NORTHWEST LOWER. SOMEWHAT BETTER MOISTURE ACROSS LAKE SUPERIOR...NOT
TO MENTION A MUCH BETTER FETCH LENGTH. WILL ADJUST POPS
ACCORDINGLY...TARGETING LIKELY WORDING FOR ONLY THE SNOW BELTS OF
EASTERN UPPER MICHIGAN (WITH SOME MINOR ACCUMULATIONS).

COLD AIR CONTINUES TO FILTER INTO THE REGION FRIDAY AND ON INTO THE
WEEKEND...WITH TEMPERATURES TRENDING SEVERAL DEGREES BELOW NORMAL AS
HIGHS STRUGGLE INTO THE LOWER AND MIDDLE 20S BY SATURDAY AND SUNDAY.
LAKE SNOWS EXPECTED TO CONTINUE IN FAVORED WEST TO NORTHWEST FLOW
AREAS. THAT SAID...SIMPLY NOT IMPRESSED WITH ACCUMULATION
POTENTIAL...ESPECIALLY FOR NORTHERN LOWER MICHIGAN...AS OFF THE DECK
MOISTURE PROFILES REMAIN SHALLOW AND SURFACE WIND TRAJECTORIES
SUPPORT PLENTY OF DRY AIR SPREADING FROM WISCONSIN. SNOW SHOWER
FORECAST FLAVOR INTRODUCED THURSDAY NIGHT WILL CONTINUE RIGHT INTO
SATURDAY...FEATURING HIGH POPS/BETTER SNOW ACCUMULATION POTENTIAL
FOR EASTERN UPPER MICHIGAN. FORECAST UNCERTAINTY INCREASES
SUBSTANTIALLY HEADING INTO THE END OF THE WEEKEND INTO THE START OF
NEXT WORK WEEK...WITH AT LEAST SOME POTENTIAL FOR RELOADING WESTERN
TROUGH TO SEND LOW PRESSURE UP THROUGH THE GREAT LAKES SUNDAY NIGHT
AND MONDAY. IN NO HURRY TO SHOW THIS KIND OF SPECIFICITY JUST
YET...AND WILL SIMPLY USE A MODEL CONSENSUS BLEND FEATURING
MAINTENANCE OF INHERITED CHANCE SNOW WORDING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1237 PM EST TUE DEC 3 2013

SUMMARY...THE STORM SYSTEM MOVING OUT OF THE PLAINS IS BRINGING
SNOW TO N MICHIGAN. THIS IS THE INITIAL SHOT OF PRECIPITATION,
WHICH HAS BEEN IN THE FORM OF SNOW. MORE LIGHT SNOW LOOKS LIKELY
TONIGHT, BUT WILL TURN TO RAIN SOMETIME AFTER 09Z THURS.

WHILE THE VSBY AND CIGS HAVE BEEN BOUNCING AROUND FROM VFR TO IFR
AND BACK, IFR CONDITIONS ARE EXPECTED OVERNIGHT WITH FOG, AND
THURS WITH RAIN AND FOG AS THE WARM AIR PUSHES INTO THE REGION.
THERE MAY BE BRIEF PERIOD OF FZRA AT THE TVC/APN/PLN THURSDAY
MORNING BUT THE LATEST GUIDANCE SEEMS TO BE DOWN PLAYING THE
POTENTIAL SO WILL HAVE MINIMAL MENTION IN THE TAFS.

&&

.MARINE...
ISSUED AT 325 AM EST TUE DEC 3 2013

SUMMARY: LOW PRESSURE WILL GRADUALLY TAKE SHAPE OVER THE SOUTHERN
PLAINS AND LIFT NORTHEAST INTO THE GREAT LAKES REGION...BRINGING
STRENGTHENING WINDS TO THE GREAT LAKES WATERS FOR THE SECOND HALF OF
THE WEEK.

HEADLINES: EASTERLY WINDS WILL STRENGTHEN TODAY WITH MARGINAL SMALL
CRAFT CONDITIONS SPREADING TO MOST NEARSHORE ZONES BY TONIGHT.
AFTER ANOTHER LULL IN THE WINDS ON WEDNESDAY...WINDS WILL SHIFT
WESTERLY WEDNESDAY NIGHT INTO THURSDAY WITH SMALL CRAFT CONDITIONS
LIKELY AND A FEW GALE FORCE GUSTS POSSIBLE OVER LAKE MICHIGAN.
GUSTY WINDS WILL CONTINUE THROUGH FRIDAY BEFORE WINDS DIMINISH.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LHZ346-348-
     349.
     SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LHZ345-347.
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...JL
SYNOPSIS...MB
SHORT TERM...ARNOTT
LONG TERM...MB
AVIATION...JL
MARINE...ARNOTT