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000
FXUS63 KAPX 041106
AFDAPX

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

.SYNOPSIS...
ISSUED AT 423 AM EST WED DEC 4 2013

LOW PRESSURE ORGANIZING ACROSS THE WESTERN LAKES WILL BRING A SURGE
OF WARMER AIR NORTH ALONG WITH IT...CHANGING LINGERING MIXED
PRECIPITATION TO RAIN FROM SOUTH TO NORTH TODAY. ANY LINGERING
SHOWERS WILL CHANGE BACK OVER TO SNOW THURSDAY...AS A COLD FRONT
BLASTS THROUGH THE REGION. ARCTIC AIR WILL SETTLE INTO THE AREA BY
FRIDAY AND INTO THIS WEEKEND...WITH LAKE EFFECT SNOW SHOWERS FOR
EASTERN UPPER AND NORTHWEST LOWER MICHIGAN. MORE COLD AIR AND
ADDITIONAL SNOW CHANCES ARE EXPECTED TO CONTINUE RIGHT INTO NEXT
WORK WEEK.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 423 AM EST WED DEC 4 2013

HIGH IMPACT WEATHER POTENTIAL: CONTINUED SLICK TRAVEL THROUGH TODAY
ESPECIALLY OVER INTERIOR PORTIONS OF NORTHERN LOWER MICHIGAN WHERE
SOME PATCHY FREEZING DRIZZLE MAY PERSIST THIS MORNING. ADDITIONAL
FREEZING RAIN POTENTIAL RETURNS THIS EVENING OVER EASTERN UPPER
FOR A 3-6 HOUR PERIOD.

PATTERN SUMMARY: PATTERN AMPLIFICATION UNDERWAY ACROSS THE CONUS AS
OF THIS WRITING AS EARLY MORNING WATER VAPOR IMAGERY REVEALS
IMPRESSIVE TROUGH CARVING OUT ALONG THE WEST COAST AS CHILLY AIR
SPILLS DOWN THE NORTHWESTERN QUARTER OF THE CONUS. SUBSEQUENT
DOWNSTREAM RIDGE DEVELOPMENT ALSO UNDERWAY WITH HEIGHTS BUILDING
ACROSS THE GREAT LAKES REGION. LOOKING DOWN TO THE SURFACE REVEALS
LOW PRESSURE TAKING SHAPE NEAR THE OKLAHOMA PANHANDLE WITH
INVERTED TROUGH AND ASSOCIATED QUASI- STATIONARY BOUNDARY
STRETCHING NORTH AND EAST TOWARDS SOUTHERN LAKE MICHIGAN...BEFORE
IT MEANDERS EAST AND SOUTH ALONG THE SOUTHERN EDGE OF THE LAKES.
THIS LOW PRESSURE SYSTEM WILL BE THE FOCUS OF THE SHORT TERM
FORECAST AS IT MOVES NORTHEAST AND STRENGTHENS...PROMISING A
BRIEF WARMUP ABOVE FREEZING ACROSS NORTHERN MICHIGAN WITH A TRACK
JUST WEST OF THE AREA.

MODEL TRENDS: MODELS HAVE CONVERGED TOWARDS THE ECWMF/GGEM/UKMET
IDEA OF THE PAST FEW DAYS AS EXPECTED...WITH A MODEL CONSENSUS
SERVING AS A GOOD STARTING POINT FOR THIS FORECAST.

THROUGH DAYBREAK: TRACKING AN EXPANDING AREA OF LIGHT RADAR RETURNS
THAT PUSHED EAST FROM WISCONSIN INTO NORTHWEST LOWER OVER THE PAST
HOUR.  THIS IS ASSOCIATED WITH A WEAK MID LEVEL VORTICITY LOBE
INTERACTING WITH ONGOING WARM ADVECTION. WITH AN EVOLUTION TOWARDS
BUILDING HEIGHTS OVER THE GREAT LAKES THIS MORNING...NOT EXPECTING
THIS FEATURE TO PACK MUCH OF A PUNCH...BUT IT WILL LIKELY RENEW
SOME LIGHT SNOW/MIX FOR AREAS M-32 TO M-72 THROUGH DAYBREAK.

WITH BONA-FIDE PRECIPITATION COMPLETE AND ANY VERY LIGHT ICING
FALLING ON SNOW-COVERED ROADS...SEE NO REASON TO CONTINUE ADVISORY
THROUGH 6AM AND WILL CANCEL WITH THIS ISSUANCE. THIS IS ALSO
SUPPORTED BY TEMPERATURES QUICKLY REACHING THE FREEZING MARK
ACROSS NORTHERN LOWER. STILL...THERE WILL BE SOME REMAINING SLICK
TRAVEL THIS MORNING FROM THE OVERNIGHT SNOWS...AND WILL CONTINUE
MENTION IN THE HWO AND MORNING HAZARDOUS WEATHER BRIEFING.

TODAY: NORTHERN MICHIGAN WILL BE IN SOMEWHAT OF A NO MAN/S LAND
THROUGH MUCH OF THE DAY TODAY AS HEIGHTS BUILD AND THE FLOW ALOFT
BACKS AHEAD OF OUR MORE SUBSTANTIAL LOW PRESSURE SYSTEM.  SURFACE
WARM FRONT WILL STRUGGLE TO MAKE MUCH PROGRESS NORTH TODAY WITH LOW
PRESSURE STILL WELL TO OUR SOUTH AND WEST UNABLE TO GIVE A
SUBSTANTIAL-ENOUGH PUSH.  MOISTURE ALOFT ALSO THINS FOR A TIME
BEFORE RAPIDLY FILLING IN TOWARDS EVENING.  GIVEN MODEL PROFILES
SUGGESTING VERY LIMITED DEPTH TO LOW LEVEL MOISTURE AFTER
AFOREMENTIONED WAVE PASSES OVERHEAD EARLY...DON/T SEE MUCH TO FORCE
PRECIPITATION DURING THE DAY...WITH CHANCES REALLY RESTRICTED TO THE
H8 WARM FRONT /OVER EASTERN UPPER/ AND THE DEVELOPING LOW LEVEL
JET-INDUCED PRECIPITATION TOWARDS EVENING. THUS...FOR THE BALANCE
OF THE DAY WILL CARRY LOW CHANCE POPS FOR A LIGHT RAIN/SNOW
SHOWER.

PTYPE:  FROM M-68 SOUTH...WILL TAILOR WEATHER BASED ON SURFACE
TEMPERATURES...WITH LIGHT RAIN NEAR THE COASTS...AND LIGHT FREEZING
RAIN INLAND. WHILE CHANCES FOR PRECIPITATION DWINDLE DURING THE
DAY...ANY DAYTIME PRECIPITATION SOUTH OF THE BRIDGE SHOULD FALL AS
PLAIN RAIN.  AS PRECIPITATION REDEVELOPS LATE THIS AFTERNOON...THERE
IS THE POTENTIAL FOR A PERIOD OF FREEZING RAIN OVER EASTERN UPPER
WHERE SURFACE TEMPS WILL LIKELY STILL BE BELOW FREEZING AS WARM
ADVECTION ABOVE THIS LEVEL QUICKLY ALLOWS A SNOWFLAKE-MELTING WARM
NOSE /+3-4C/ TO DEVELOP ALOFT.  DEPENDING ON TIMING AND PRECIPITATION
INTENSITY...MAY HAVE TO WATCH FOR A SNEAKY ADVISORY SCENARIO.  WILL
MENTION THIS POTENTIAL IN THE MORNING HAZARDOUS WEATHER OUTLOOK.

TEMPERATURES: WILL STEADILY RISE TODAY UNDER WARM ADVECTION...BUT
GIVEN SLOW MOVEMENT OF SURFACE WARM FRONT...THIS RISE WILL NOT BE
SPECTACULAR. CONSENSUS BRINGS NORTHERN LOWER TOWARDS 40 BY
EVENING...WITH EASTERN UPPER STUCK NEAR THE FREEZING MARK.

TONIGHT: NOW WELL-AGREED UPON CONSENSUS LOW TRACK BRINGS SURFACE LOW
FROM CENTRAL WISCONSIN THIS EVENING TO NORTH OF LAKE SUPERIOR BY
DAYBREAK THURSDAY.  THIS WILL HELP DRIVE A FINAL BAND OF THETAE
ADVECTION AS SURFACE WARM FRONT RIDES NORTH TOWARDS THE STRAITS
OVERNIGHT IN THE PRESENCE OF AN INCREASINGLY MOIST AIRMASS /PWATS
NEARING 1"/  THIS SHOULD BRING A ROUND OF PRIMARILY LIQUID
PRECIPITATION TO NORTHERN MICHIGAN /WITH ANY FREEZING RAIN
TRANSITIONING TO RAIN OVER EASTERN UPPER/. PROGRESSIVE NATURE TO
SYSTEM AND OUR POSITION ON IT/S WARM SIDE SUGGEST QPF WILL NOT GET
TOO OUT OF CONTROL WITH VALUES REMAINING AT OR BELOW 0.5" CWA-
WIDE. SURFACE COLD FRONT PUSHES THROUGH THE REGION AFTER MIDNIGHT
WITH AN IMPRESSIVE SURGE OF DRY AIR...WHICH SHOULD BRING A QUICK
END TO RAINFALL.

TEMPERATURES: INITIALLY WILL BE WARMING AHEAD OF COLD FRONT...BUT
WHAT COULD BE A RATHER WARM OVERNIGHT LOW WILL BE SOMEWHAT HINDERED
BY FRONTAL PASSAGE BEFORE 12Z...WHICH SHOULD ALLOW FOR TEMPERATURES
TO RAPIDLY FALL BACK TOWARDS THE FREEZING MARK /PARTICULARLY WEST
OF INTERSTATE 75/ BY DAYBREAK.  MID/UPPER 30S OVER THE COAST OF
NORTHEAST LOWER.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 423 AM EST WED DEC 4 2013

LONG RANGE PERIOD NO DOUBT DOMINATED BY COLD WEATHER...WITH TRENDS
CLEARLY SUPPORTING TEMPERATURES DROPPING TO WELL BELOW NORMAL VALUES
(AND THAT`S SAYING ALOT IN DECEMBER) BY FRIDAY AND SATURDAY...WITH
PERHAPS AN EVEN COLDER SHOT OF AIR BY TUESDAY OF NEXT WEEK. LONG
WAVE PATTERN CLEARLY SUPPORTIVE OF SUCH PLEASANTRIES...WITH
ANOMALOUSLY STRONG UPPER LEVEL RIDGING BUILDING NORTH ACROSS THE
EASTERN PACIFIC AND UP THROUGH ALASKA (AND EVENTUALLY BEYOND).
DOWNSTREAM RESPONSE ALREADY WELL UNDERWAY...WITH DIGGING TROUGH
CARVING ITS WAY THROUGH THE INTERMOUNTAIN WEST. ABOVE ABOUT A
TEXTBOOK EXAMPLE OF HOW TO UNLEASH UNSEASONABLY COLD ARCTIC AIR INTO
THE LOWER 48...A FACT ALREADY MADE WELL EVIDENT BY SINGLE DIGIT
TEMPERATURES THROUGH MONTANA AND NORTH DAKOTA. NO SHORTAGE OF EVEN
COLDER AIR ACROSS NORTHWEST CANADA...WHERE LATE EVENING TEMPERATURES
ARE IN THE DOUBLE DIGITS BELOW ZERO. THIS AIRMASS WILL BE FORCED
SOUTH OVER THE COMING DAYS...SETTING ITS SIGHTS ON THE NORTHERN
PLAINS AND EVENTUALLY OUR NECK OF THE WOODS. REALLY COLD ANOMALIES
LOOK TO REMAIN UPSTREAM THROUGH THIS WEEKEND... HOWEVER...WITH LACK
OF DOWNSTREAM NORTH ATLANTIC BLOCKING ALLOWING TEMPERED SOUTHEAST
RIDGING TO CONTINUE...GIVING US A MORE "GLANCING" BLOW FROM THE TRUE
ARCTIC AIR. SAME CANNOT BE SAID HEADING INTO THE MID WEEK PORTIONS
OF NEXT WEEK...WITH GOOD GUIDANCE SUPPORT FOR UPSTREAM BLOCKING TO
BREAK DOWN...ALL THE WHILE STRONG ENERGY DIVES SOUTH THROUGH
INCREASING TRANSIENT CENTRAL NOAM TROUGHING. THIS COULD OPEN THE
DOOR FOR THE TRUE ARCTIC BLAST...WITH SOME OF THE MID RANGE GUIDANCE
SHOWING HIGHS JUST ACROSS THE BIG POND REMAINING SEVERAL DEGREES
BELOW ZERO (YUP...THAT IS HIGH TEMPERATURES) AND ONLY THROUGH THE
GOOD GRACE OF LAKE MICHIGAN DO WE LOOK TO REMAIN ON THE POSITIVE
SIDE OF ZERO. THAT ARCTIC BLAST MAY BE KICKED OFF BY A DESCENT
LITTLE SNOW EVENT TO END THIS WEEKEND ON INTO MONDAY. COMBINE ALL
THE ABOVE WITH MULTI-PERIOD LAKE EFFECT SNOW POTENTIAL...AND ONE CAN
SEE FORECAST CHALLENGES ARE MANY HEADING THROUGH THE NEXT SEVEN DAYS.

STEP-DOWN PROCESS TO THIS COLDER WEATHER WILL BE UNDERWAY TO START
THE EXTENDED...WITH PASSAGE OF SECONDARY COLD FRONT BEHIND DEPARTING
ONTARIO LOW PRESSURE THURSDAY MORNING. TEMPERATURES LIKELY TO FALL
THROUGH THE DAY...REACHING LOWER AND MIDDLE 20 VALUES BY LATE
AFTERNOON AND EARLY EVENING. DRY SLOT ACCOMPANIES THE FRONTAL
PASSAGE...AND ESSENTIALLY LOOKS TO REMAIN STEADFAST RIGHT THROUGH
EARLY FRIDAY EVENING. TEMPERATURES DEFINITELY TREND COLD ENOUGH TO
ENTICE A GOOD LAKE RESPONSE...WITH H8 TEMPERATURES THURSDAY NIGHT
INTO FRIDAY IN THE NEGATIVE MID AND UPPER TEENS. WHILE DELTA T/S
WILL BE GREAT...OTHER THERMODYNAMIC PROPERTIES NOT SO MUCH SO...WITH
PERUSAL OF CROSS SECTIONS AND MODEL DERIVED SOUNDINGS SHOWING RAPID
LOSS OF ANY MOISTURE ABOVE PALTRY H8 INVERSION LEVEL. KINEMATICS NOT
SPECTACULAR EITHER...WITH PRIMARILY WEST WINDS KEEPING MOST LAKE
SUPERIOR ACTIVITY OFFSHORE OF EASTERN UPPER...WHILE ALSO ALLOWING
LOW LEVEL DRY AIR TO CONTINUOUSLY FILTER ACROSS NORTHERN LAKE
MICHIGAN. SO...DESPITE VERY COLD TEMPERATURES...WITH HIGHS FRIDAY
LIKELY STUCK IN THE TEENS AND LOWER 20S...JUST NOT EXPECTING THIS TO
BE A BIG LAKE EFFECT EVENT. LITTLE DOUBT SOME SNOW SHOWERS WILL
OCCUR...AND SIMPLE PERSISTENCE MIGHT ALLOW WEST FLOW AREAS TO PICK
UP A FEW INCHES THROUGH THIS PERIOD. UPTICK IN MOISTURE/INVERSION
HEIGHTS EXPECTED OVERNIGHT FRIDAY INTO EARLY SATURDAY...AND THINKING
THIS IS WHEN THINGS COULD GET A LITTLE BIT MORE INTERESTING. H8
TEMPERATURES RIGHT AT ABOUT THE UPPER (COLDER) LIMITS OF THE
DGZ...SUPPORTING AT LEAST DECENT SNOW/LIQUID RATIOS. WOULD NOT BE
SURPRISED TO SEE AN ADVISORY TYPE SNOW EVENT FOR YOUR TRADITIONAL
LAKE SNOW BELTS OF CHARLEVOIX...ANTRIM... AND OTSEGO COUNTIES. WINDS
MAY VEER JUST ENOUGH TO IMPACT THE FAR NORTHWEST REACHES OF CHIPPEWA
COUNTY BY SATURDAY MORNING. THIS COULD POTENTIALLY BRING A BAND OF
SNOW INTO AREAS AROUND PARADISE. SOMETHING TO WATCH...AS SNOWFALL
RATES WITH THIS BAND MAY BE RATHER IMPRESSIVE GIVEN EXCELLENT FETCH
LENGTH AND MUCH BETTER SYNOPTIC MOISTURE SUPPORT. LAKE PROCESSES
EXPECTED TO WIND DOWN LATER SATURDAY AND SATURDAY NIGHT AS HIGH
PRESSURE DRIFTS OVERHEAD. GONNA BE COLD REGARDLESS...BUT IF SOME
CLEARING IS REALIZED SATURDAY NIGHT...WITH ARCTIC HIGH DIRECTLY
OVERHEAD...FORECAST READINGS IN THE SINGLE DIGITS MAY BE A GOOD 5 OR
MORE DEGREES TOO "WARM" FOR SOME LOCATIONS.

MID-RANGE GUIDANCE TRENDS WELL ONBOARD FOR ENERGY PINWHEELING OUT OF
WESTERN TROUGH TO DRUM UP AN AREA OF LOW PRESSURE OVER THE SOUTHERN
PLAINS LATER SUNDAY...ROCKETING IT NORTHEAST THROUGH THE GREAT LAKES
SUNDAY NIGHT INTO THE START OF MONDAY. ACTUAL TREND HAS BEEN FOR A
FURTHER WEST SOLUTION...PERHAPS EVEN CUTTING OVER OR JUST TO OUR
WEST. NOW...NORMALLY...THIS WOULD RAISE ALL KINDA PRECIP TYPE
CONCERNS. DON`T SEE THAT HAPPENING THIS TIME...HOWEVER...WITH
WEEKEND ARCTIC AIRMASS SIMPLY REFUSING TO COMPLETELY DISLODGE. SNOW
SHOULD BE IT...AND LOW ORIGIN OVER THE SOUTHERN PLAINS USUALLY MEANS
ALOT OF IT. DON`T SEE THAT HAPPENING EITHER...WITH DEEPEST GULF OF
MEXICO MOISTURE LOCKED WELL TO THE SOUTHEAST OF THE LOW ALONG
STATIONARY SURFACE TROUGH. DISCONNECT LOOKS TO BE LARGE ENOUGH TO
KEEP SNOW AMOUNTS FROM GETTING TOO OUT OF HAND...WITH JUST A COUPLE
INCHES EXPECTED PER EARLY PROGS. BIGGER STORY WITH THIS SYSTEM MAY
BE WHAT COMES BEHIND IT...WITH TRENDS SUPPORTING H8 TEMPERATURES
FALLING INTO THE LOWER (MIDDLE?) NEGATIVE 20S CELSIUS. LONG WAY OUT
TO GET TOO EXCITED...BUT INTERESTING TO SEE CLIMO-INFLUENCED (AT
THIS RANGE) GFS MEX AND EXPERIMENTAL ECMWF MOS GUIDANCE SHOWING
HIGHS TUESDAY IN THE SINGLE DIGITS AND LOWER TEENS. CONDITIONS LOOK
IDEAL FOR AN EXCELLENT LAKE RESPONSE...ALTHOUGH SUCH COLD
TEMPERATURES LIKELY TO RESULT IN PIXIE DUST TYPE SNOWS...EXCELLENT
AT REDUCING VISIBILITIES...BUT NO SO MUCH AT ACCUMULATING. PLENTY OF
TIME FOR CHANGES...BUT DEFINITELY SOME INTERESTING WEATHER TO
MONITOR.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 605 AM EST WED DEC 4 2013

SUMMARY: LOW PRESSURE WILL MOVE INTO THE WESTERN GREAT LAKES REGION
THROUGH TONIGHT...WITH CONTINUED POOR FLYING CONDITIONS THROUGH THE
PERIOD AS SOME DAYTIME DRIZZLE/FOG GIVE WAY TO A ROUND OF RAINFALL
THIS EVENING.

RESTRICTIONS: IFR ALL SITES THROUGH MOST IF NOT ALL OF THE FIRST 18
HOURS OF THE FORECAST.  THIS IS DUE PRIMARILY TO LOW CIGS...BUT
DURING THE DAY...EXPECT FOG TO THICKEN...WITH SOME POTENTIAL THAT
LIFR VSBYS MAY DEVELOP FOR A TIME.  CONFIDENCE IS LOW IN THIS
OUTCOME.  RAIN WILL DEVELOP THIS EVENING WITH IFR CONDITIONS /DUE TO
CIGS/ CONTINUING THROUGH MIDNIGHT BEFORE IMPROVEMENT TO MVFR DURING
THE LAST 6 HOURS OF THE TAF AS RAIN ENDS AND DRIER AIR ARRIVES
BEHIND THE DEPARTING COLD FRONT.

ICING: PLN ONLY SITE STILL BELOW FREEZING...WITH FREEZING DRIZZLE
POSSIBLE /BUT SNOW MORE LIKELY/ THROUGH 15Z BEFORE PRECIPITATION
ENDS.  BEYOND THIS...EVENING AND OVERNIGHT PRECIPITATION WEDNESDAY
NIGHT WILL TAKE THE FORM OF RAIN AT ALL TERMINALS.

WINDS: EASTERLY WINDS 10KTS WILL VEER SOMEWHAT SOUTHEASTERLY THIS
EVENING BEFORE SHIFTING SOUTHWESTERLY AND STRENGTHENING TO 12G20KTS
AFTER MIDNIGHT WITH COLD FRONTAL PASSAGE.

LLWS: SOUTHERLY WINDS AT 2KFT WILL INCREASE TO 30-40KTS THIS
AFTERNOON AND STRENGTHEN TO 40-50KTS THIS EVENING AND TONIGHT FROM
THE SOUTHWEST...PROMOTING A PERIOD OF LLWS AT ALL TERMINALS.  LLWS
WILL BEGIN TO ABATE AFTER COLD FRONTAL PASSAGE WITH DEEP MIXING
ELIMINATING ANY RESIDUAL SHEAR LAYERS.

&&

.MARINE...
ISSUED AT 423 AM EST WED DEC 4 2013

SUMMARY: LOW PRESSURE TAKING SHAPE OVER THE SOUTHERN PLAINS WILL
LIFT THROUGH THE WESTERN GREAT LAKES TONIGHT WITH AN ASSOCIATED
STRONG COLD FRONT PASSING THROUGH THE REGION.  HIGH PRESSURE WILL
BRING QUIETER CONDITIONS TO THE REGION BY THIS WEEKEND.

HEADLINES: MARGINAL SMALL CRAFT CONDITIONS WILL CONTINUE UNDER
EASTERLY FLOW THROUGH TODAY WITH WIDESPREAD SMALL CRAFTS CERTAINLY
NEEDED LATER TONIGHT THROUGH AT LEAST EARLY FRIDAY AS WINDS SHIFT
SOUTHWESTERLY AND STRENGTHEN TONIGHT/THURSDAY BEFORE GRADUALLY
VEERING WESTERLY AND WEAKENING THROUGH EARLY FRIDAY.

A PERIOD OF GALE FORCE WINDS IS CERTAINLY POSSIBLE ON THURSDAY
ESPECIALLY ALONG THE COAST OF NORTHWEST LOWER AND THROUGH THE
STRAITS...AND THEREFORE WILL ISSUE A GALE WATCH FOR THIS AREA IN
COORDINATION WITH LOT.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
     LHZ345>349.
LM...GALE WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING FOR LMZ342-
     344>346.
     SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR LMZ341-
     342.
LS...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR LSZ321.

&&

$$

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