Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 171132
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
632 AM EST MON NOV 17 2014

.SYNOPSIS...
ISSUED AT 331 AM EST MON NOV 17 2014

LOW PRESSURE PASSING TO OUR NORTH TODAY...WILL USHER IN ANOTHER
SURGE OF COLD AIR. LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN SOME
PLACES TODAY...BUT HEAVY SNOW IS EXPECTED TONIGHT AND TUESDAY IN
SOME OF THE CLASSIC SNOWBELTS. ANOTHER SYSTEM WILL BRING LIGHT SNOW
TO THE REGION WEDNESDAY...AND MORE LAKE EFFECT SNOW WILL FOLLOW
BEHIND IT. HOWEVER...TEMPERATURES WILL BECOME MILDER DURING THE
UPCOMING WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 331 AM EST MON NOV 17 2014

...SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED LATER TODAY THROUGH
TUESDAY...

HIGH IMPACT WEATHER POTENTIAL: LOCALIZED VERY HEAVY LAKE EFFECT
SNOW. AREAS OF BLOWING SNOW AND NEAR WHITEOUT CONDITIONS POSSIBLE
TONIGHT.

PATTERN SYNOPSIS/CURRENT CONDITIONS: KINDA STATING THE OBVIOUS...BUT
MID-WINTER LIKE PATTERN WELL ESTABLISHED ACROSS THE NORTHERN LAKES.
REASON FOR SUCH IS ONE ANOMALOUSLY DEEP MERIDIONAL FLOW
REGIME...CONSISTING OF FULL LENGTH WESTERN NOAM RIDGING AND JUST AS
IMPRESSIVE TROUGHING EXTENDING THROUGH THE CENTRAL PLAINS INTO THE
WESTERN LAKES. MOST IMPRESSIVE COLD SURGE YET TIED TO WAVE OF ARCTIC
ORIGIN DIVING INTO SOUTHWEST ONTARIO AND INTO MINNESOTA (-20C H8
TEMPERATURES PER LATEST RAP ANALYSIS!). SURFACE COLD FRONT RUNNING
WELL AHEAD OF THIS WAVE...ALREADY PUSHING INTO NORTHWEST MICHIGAN AT
THIS EARLY HOUR. AREA OUT AHEAD OF THIS FRONT PLENTY COLD ENOUGH TO
CONTINUE TO ENTICE A SIGNIFICANT LAKE RESPONSE (A PRETTY RARE FEAT
TO HAVE SUCH COLD PRE-FRONTAL AIR DURING MID NOVEMBER). MAIN SHOW
TONIGHT HAS BEEN DIRECTED INTO PARTS OF EASTERN UPPER MICHIGAN..
WHERE NO DOUBT SEVERAL INCHES OF ACCUMULATION HAVE ALREADY OCCURRED.
SOMEWHAT LIGHTER MORE NUISANCE TYPE SNOWS IMPACTING NORTHER
LOWER...ALTHOUGH SOME EMBEDDED HEAVIER LAKE ENHANCED SNOWS WERE
NOTED...ESPECIALLY ACROSS PARTS OF EMMET COUNTY. SIMPLY NO END IN
SIGHT...WITH CURRENT UPSTREAM WAVE SET TO AMPLIFY OVERHEAD LATER
TODAY AND TONIGHT...FORCING A SHIFTING OF THE WINDS TO MORE W/NW AND
PUTTING THE MORE TRADITIONAL LAKE EFFECT AREAS UNDER THE GUN FOR A
HIGH IMPACT WINTER WEATHER EVENT.

PRIMARY FORECAST CONCERNS/CHALLENGES: MULTIPLE! INITIAL FOCUS ON
ONGOING SW FLOW LAKE EFFECT AND ASSOCIATED HEADLINES THIS MORNING.
OVERNIGHT FOCUS ON MUCH MORE WIDESPREAD LAKE SNOW EVENT...INCLUDING
AMOUNTS AND HEADLINE MANAGEMENT CONCERNS.

DETAILS: NOT PRETTY! FIRST OFF...ONGOING SW FLOW LAKE SNOWS SHOULD
STEADILY DECLINE IN INTENSITY SHORTLY AFTER 09Z AS WINDS BEGIN TO
SLOWLY VEER AND BRIEF CORRIDOR OF UPSTREAM DRIER AIR OVERSPEADS THE
LAKES. CURRENT HEADLINES RUN THROUGH 15Z...WHICH OFFERS SOME
FLEXIBILITY IF BANDS SHOULD PERSIST LONGER THAN ANTICIPATED (NEVER
SEEN THAN BEFORE :)). NO OFFICIAL REPORTS JUST YET...BUT BASED OFF
MACKINAC BRIDGE WEB CAMS AND SOME INFORMATION GLEANED FROM CALLING
ST. IGNACE...GOTTA FEELING WE WILL BE DEALING WITH SOME IMPRESSIVE
SNOWFALL TOTALS UP IN THE STRAITS AREA BEFORE ALL IS SAID AND DONE
THIS MORNING. ELSEWHERE...JUST SOME LIGHTER SNOWS EXPECTED AS THE
COLD FRONT PUSHES EAST...EXITING STAGE RIGHT BY MID-MORNING.

WITH PART ONE DONE...ALL FOCUS SHIFTS TO WHAT INCREASINGLY LOOKS
LIKE A VERY SIGNIFICANT AND PROLONGED LAKE EFFECT EVENT FOR THE MORE
TRADITIONAL SNOW BELTS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN.
CURRENT SOUTHWEST ONTARIO WAVE CONTINUES TO DIG...SLOWLY CROSSING
THE NORTHERN LAKES THROUGH THE OVERNIGHT. DESPITE MAIN CORE OF
ATTENDANT CAA ACTUALLY PASSING US BY TO THE SOUTH...INSTABILITY
RAMPS UP IMPRESSIVELY LATE TODAY THROUGH THE OVERNIGHT...WITH NEAR
EXTREME DELTA T/S COLLOCATED WITH DEEP SYNOPTIC MOISTURE SUPPORT AND
ESSENTIALLY ALL LOSS OF AN INVERSION. CYCLONIC FLOW IS IMPRESSIVE...
SUGGESTING ENHANCED CONVERGENCE TARGETING NORTHWEST LOWER MICHIGAN.
LOW LEVEL FLOW IS SLIGHTLY MORE BACKED IN RECENT GUIDANCE
RUNS...WELL SUPPORTED BY WHAT SHOULD BE STRENGTHENING LAKE DRIVEN
SURFACE TROUGH DEVELOPMENT. AFTER A BRIEF BREAK THIS AFTERNOON...
EXPECT SNOWS TO GET GOING IN EARNEST THIS EVENING...WITH INITIAL
FOCUS IN FAVORED WEST FLOW AREAS...WITH A SLIGHT SOUTHWARD TREND
EXPECTED DURING THE OVERNIGHT TOWARD THE M-32 CORRIDOR. SNOWFALL
AMOUNTS COULD BE QUITE IMPRESSIVE...WITH STRONG OMEGA CENTERED RIGHT
IN PRIME DGZ RIGHT THROUGH THE OVERNIGHT. DESPITE SOME FRAGMENTATION
OF FLAKES FROM VERY GUSTY WINDS (MORE ON THE WINDS TO
FOLLOW)...EXPECT SNOW TO LIQUID RATIOS TO PUSH 20 TO 1...PERHAPS
EVEN HIGHER IF STRONG LOW LEVEL CONVERGENCE UNDER BANDS HELP
SLACKING THE WIND FIELDS. SLIGHT SOUTHWARD DRIFT LOOKS TO BE THE
ONLY THING FROM PREVENTING SNOW AMOUNTS FROM GETTING TOO OUT OF
HAND. STILL...COULD EASILY SEE PARTS OF
CHARLEVOIX/ANTRIM/OTSEGO/EMMET/CHEBOYGAN COUNTIES EXCEEDING 8 INCHES
BY MORNING...WITH THE HIGHEST AMOUNTS JUST DOWNWIND OF LITTLE
TRAVERSE BAY. ANY SLOWER DRIFT OF BANDS THAN CURRENTLY ANTICIPATED
WILL RESULT IN LOCALLY HIGHER AMOUNTS. FURTHER SOUTH...COMPLETE LACK
OF A LAKE SUPERIOR CONNECTION REALLY SHORTENS THE EFFECTIVE FETCH
LENGTH. SO...DESPITE EXCELLENT INSTABILITY...JUST NOT SEEING THE
OPPORTUNITY FOR A WHOLE LOT OF ACCUMULATION ALONG AND SOUTH OF THE M-
72 CORRIDOR. HOWEVER...GUSTY WINDS OF 20 TO 30 MPH WILL MAKE FOR
SOME NASTY CONDITIONS...CREATING AREAS OF BLOWING AND DRIFTING SNOW
AND BRIEF PERIODS OF VERY LOW VISIBILITIES.

OFF LAKE SUPERIOR: INITIAL FOCUS THIS EVENING LOOKS TO REMAIN WEST
OF WHITEFISH POINT...REALLY TARGETING AREAS OVER NEAR MUNISING AND
SENEY. WINDS BEGIN TO SHIFT MORE W/NW LATE...BRINGING ACCUMULATING
SNOW BANDS INTO NORTHWEST CHIPPEWA COUNTY. LATER START AND SIGNALS
FOR BEST LOW LEVEL CONVERGENCE TO REMAIN OFF TO THE WEST SUGGESTS
LOWER SNOW TOTALS THAN THOSE TO THE SOUTH...WITH 2 TO 4 INCHES
EXPECTED BY MORNING. STRONG WINDS WILL PUSH BANDS FURTHER INLAND
THAN WHAT IS NORMAL...PERHAPS EVEN BRINGING PARTS OF NORTHWEST
MACKINAC COUNTY SEVERAL INCHES BY MORNING.

MORE SNOW WILL FALL IN ALL THE ABOVE AREAS TOMORROW...WITH SEVERAL
MORE INCHES EXPECTED (SEE LONG TERM SECTION BELOW).

HEADLINES: FOR NORTHERN LOWER...GIVEN GUSTY WINDS AND WHAT COULD BE
WIDESPREAD BLOWING SNOW EVEN OUTSIDE THE BETTER SNOW BANDS...HAVE
DECIDED TO FORGO THE SPECIFIC LAKE EFFECT HEADLINES FOR MORE GENERIC
WINTER WEATHER HEADLINES. HIGHEST SNOW TOTAL AREA MENTIONED EARLIER
WILL BE UPGRADED TO A WINTER STORM WARNING...STARTING AT 00Z THIS
EVENING RUNNING RIGHT THROUGH TUESDAY. WINTER WEATHER ADVISORIES
SHOULD DO FOR AREAS SOUTH OF M-72...AS WELL AS PARTS OF NORTHEAST
LOWER AS STRONG WINDS HELP PUSH WEAKENING BANDS FAR INLAND.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 AM EST MON NOV 17 2014

HIGH IMPACT WEATHER POTENTIAL...PLENTY OF SNOW AND COLD DURING THE
WORK WEEK. HEAVY LAKE EFFECT SNOW IN WNW/NW FLOW TUESDAY. SOME
POTENTIAL FOR HEAVY LAKE EFFECT SNOW WED NIGHT TO THU NIGHT.

TUESDAY...UPPER LOW WILL EJECT FROM NORTH OF LAKE HURON INTO EASTERN
QUEBEC. ONE TRAILING SHORTWAVE WILL CROSS CENTRAL LOWER MI IN THE
AFTERNOON...ANOTHER WEAK WAVE WILL DIG TOWARD EASTERN SUPERIOR. A
980MB SURFACE LOW STARTS THE MORNING IN CENTRAL QUEBEC...AND WILL
ADVANCE NE. SUBSTANTIAL TROFFING LINGERS ACROSS THE AREA EARLY IN
THE MORNING...THIS RELAXES AS THE UPPER LOW PULLS OUT...BUT LAKE-
INDUCED TROFFING REMAINS EVIDENT THRU THE DAY.

1000-850MB WINDS REMAIN STEADY-STATE IN THE MORNING...WNW INTO
NORTHERN LOWER AND NW INTO EASTERN UPPER. WINDS WILL BACK SOME
DURING THE AFTERNOON...BY EARLY EVENING WE WILL SEE A W FETCH INTO
NORTHERN LOWER AND WNW INTO EASTERN UPPER. PLENTY OF DEEP
MOISTURE...HIGH INVERSION HEIGHTS (TO NEARLY 500MB)...AND DELTA T/S
NEAR 20C SHOULD ENSURE RAMPAGING LAKE EFFECT SNOW IN THE MORNING
HOURS. IN THE AFTERNOON...THE INVERSION LOWERS TOWARD 700MB WITH
DRYING ALOFT. THAT WILL REDUCE SNOW INTENSITY SOMEWHAT...BUT BY AND
LARGE PARAMETERS AND STILL VERY FAVORABLE.

AS IS THE CASE FOR TONIGHT...THE LOW-LEVEL FLOW IS A LITTLE BACKED
COMPARED TO PREVIOUS RUNS. IN NORTHERN LOWER...THIS REQUIRES
ADJUSTING THE MAX SNOW TOTALS NORTHWARD SLIGHTLY.
CHARLEVOIX/ANTRIM/OTSEGO ARE THE MAIN ONES UNDER THE GUN...BUT THE
FETCH NOW SUPPORTS MORE SNOW IN SOUTHERN EMMET/CHEBOYGAN THAN IT
DOES IN NORTHERN KALKASKA/CRAWFORD. 5-9 INCHES STILL LIKES A GOOD
FORECAST FOR THE DAY IN THE HARDEST-HIT LOCALES...CENTERED ON
ELMIRA. 1-4 INCHES WORKS ELSEWHERE IN NW LOWER...WHERE THE FETCH IS
MUCH SHORTER AND HAS NO CONNECTION TO SUPERIOR.

IN EASTERN UPPER...THE BACKED FLOW OPENS UP MORE OF CHIPPEWA...BUT
SHOULD STILL KEEP THE STRONGEST BANDS WEST OF THE SAULT. BUT THINGS
ARE LOOKING CONSIDERABLY MORE FAVORABLE UP THERE...AND WILL INCREASE
WESTERN CHIP AND FAR NW MACK INTO THE 3-5 INCH RANGE.

MAX TEMPS WILL BE MAINLY IN THE 20S. HOWEVER...IN THE HIGH TERRAIN
IN THE SOUTH...WHERE MARINE MODIFICATION WILL BE SMALLER DUE TO THE
SHORTER FETCH...SOME PLACES (LIKE CAD) WILL LIKELY NOT ESCAPE THE
TEENS. (HARD TO BELIEVE IT/S ONLY MID-NOVEMBER.)

TUE NIGHT/WED...NOT MUCH REST FOR THE SNOW-WEARY. CLIPPER SHORTWAVE
WILL ADVANCE INTO THE WESTERN LAKES ON WED. ASSOCIATED SURFACE LOW
WILL ADVANCE FROM THE UPPER MS VALLEY TO NORTHERN LOWER MI ON WED.
LOW LEVEL FLOW WILL BACK TO THE SW TUE NIGHT...WITH MOISTENING
OVERNIGHT. SOME POTENTIAL FOR SOME SNEAKY 1-3 INCH ACCUMS OVER THE
TIP OF NORTHERN LOWER TUE EVENING. SYNOPTIC -SN MIGHT SNEAK INTO SW
SECTIONS LATE TUE NIGHT...BUT THE BULK OF THE THAT WILL WAIT UNTIL
WED. BY THEN...A SOUTH 1000-850MB FETCH SHOULD KEEP MOST OF THE LAKE-
INDUCED NONSENSE AT BAY...OTHER THAN ALONG THE SOUTH SHORE OF UPPER
MI (AND IT IS UNCERTAIN WHETHER SYNOPTIC PRECIP WILL MAKE IT THAT
FAR NORTH). THIS SYSTEM DOES NOT LOOK LIKE A MAJOR PROBLEM...1-2
INCHES...ESPECIALLY SOUTH OF M-32. MIN TEMPS TEENS TO PERHAPS HIGH
SINGLE DIGITS (YIKES). MAX TEMPS 20S.

REST OF THE FORECAST...POST-CLIPPER LAKE EFFECT SNOW WILL OCCUR WED
NIGHT INTO THU NIGHT...AIDED BY ANOTHER CLIPPER SHORTWAVE DROPPING
IN FROM THE NW. THE SET-UP FOR HEAVY SNOW LOOKS BETTER IN EASTERN
UPPER IN THIS EVENT...AS DEEPER MOISTURE WILL LINGER LONGER THERE VS
MID-LEVEL DRY AIR TRYING TO ENTRAIN INTO THE SOUTHER/CENTRAL LAKES.
REGARDLESS...LAKE EFFECT SHSN WILL AGAIN BE FAIRLY WIDESPREAD IN
BOTH PENINSULAS.

THOUGH THE MODELS TEND TO BE TOO FAST TO BREAK PATTERNS DOWN...ALL
MODELS HAVE THE CURRENT ONE FALL APART AFTER THIS LAST CLIPPER.
500MB FLOW BECOMES CONSIDERABLY MORE ZONAL...AND MORE SEASONABLE AIR
WILL FINALLY GET A CHANCE TO MOVE INTO THE REGION...ESPECIALLY BY
THE TAIL END OF THE WEEKEND. A SOUTHERN STREAM SYSTEM MOVING INTO
THE CENTRAL STATES WILL AMPLIFY WARM ADVECTION...AND INCREASE PRECIP
CHANCES BY SUNDAY. THIS ACTUALLY LOOKS TO BE MOSTLY RAIN.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EST MON NOV 17 2014

VFR TO MVFR AT APN...MVFR TO IFR ELSEWHERE IN LAKE EFFECT
CLOUDS/SHSN.

LOW PRESSURE ALONG THE NORTH SHORE OF SUPERIOR WILL MOVE EAST
TODAY...BRINGING ANOTHER SHOT OF COLD AIR TO THE REGION. LAKE
EFFECT SHSN TODAY WILL BECOME LESS ORGANIZED DUE TO VARYING WINDS
AND DRYING ALOFT. HOWEVER...SHSN WILL RAMP UP TONIGHT IN THE
SNOWBELTS OF FAR NORTHERN LOWER MICHIGAN...BETWEEN PLN AND GOV.
WILL HAVE VARYING CONDITIONS TODAY...TENDING TO MVFR NEAR LAKE MI
AND VFR AT APN. TONIGHT..LAKE MI TAF SITES WILL BE MAINLY IFR
(LIFR LATE AT PLN)...WHILE APN BECOMES MVFR.

WINDS WILL VEER W TODAY...STAY W AND INCREASE/BECOME GUSTY
TONIGHT.

&&

.MARINE...
ISSUED AT 331 AM EST MON NOV 17 2014

STRONG SURGE OF CAA AND INCREASINGLY SHARP PRESSURE
GRADIENT WILL BRING VERY GUSTY WINDS BY LATER TODAY RIGHT THROUGH
TUESDAY. GREATEST IMPACT EXPECTED ACROSS NORTHERN LAKE
MICHIGAN...WHERE GALE FORCE WEST WINDS ARE EXPECTED TO DEVELOP
QUICKLY THIS EVENING. SCA CONDITIONS EXPECTED ELSEWHERE...ALTHOUGH
WILL NEED TO BE ON THE LOOKOUT FOR SOME GALE GUSTS ALONG THE
NORTHEAST LOWER COASTLINE. WINDS ARE EXPECTED TO SUBSIDE LATE
TUESDAY...AND ESPECIALLY TUESDAY NIGHT.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR MIZ018-020-023-025>028-031>033.

     WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY
     FOR MIZ016-017-019-021-022.

     LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     MIZ008-016.

     WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ008.

     LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THIS MORNING FOR MIZ015.

LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR LMZ341.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR
     LMZ323-342-344>346.

LS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST TUESDAY
     FOR LSZ321-322.

&&

$$

SYNOPSIS...JAZ
SHORT TERM...MSB
LONG TERM...JAZ
AVIATION...JAZ
MARINE...MSB



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