Winter Storm in Michigan, January 12, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
625 AM EST TUE JAN 12 2016

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 325 AM EST TUE JAN 12 2016

IMPACT WEATHER: MODERATE TO HEAVY ACCUMULATING SNOW IN THE GTV BAY
REGION WITH 1-2"/HR SNOWFALL RATES. MORE ACCUMULATING SNOW TONIGHT.

SYNOPTIC PATTERN AND OBSERVATIONS:

STRONG SHORTWAVE AND DEEPENING SFC LOW PRESSURE WERE WORKING THROUGH
THE MIDDLE OF LAKE MICHIGAN EARLY THIS MORNING. STRONG DEEP LAYER
FORCING AND LIGHT SYNOPTIC SNOWS HAVE OVERSPREAD NRN LOWER. WINDS
HAVE BACKED SE ON THE NRN END OF THE SFC LOW ACROSS NRN LOWER
MICHIGAN...AND HAVE SHOVED SW FLOW LAKE EFFECT OUT OVER MID LAKE.
THIS SNOW HAS BEEN INTENSIFYING ALONG THE LOW LEVEL CONVERGENCE AXIS
AND MOISTURE/SYNOPTIC SNOW FEED. WINDS ON THE SRN PERIPHERY OF THE
SFC LOW...DOWN ACROSS SRN LAKE MICHIGAN HAD SWITCHED OUT OF THE SW
EARLIER...AND HAD PUSHED A MONSTER BAND OF SNOW INTO SW LOWER
MICHIGAN. ACROSS NRN LAKE MICHIGAN...IT'S BECOME APPARENT THAT A
MESOLOW HAS DEVELOPED SW OF BEAVER ISLAND...WHERE THERE HAS BEEN
LITTLE MOVEMENT IN THE SNOW BAND. RATHER QUIET UPSTREAM...WITH A
VERY WEAK WAVE ALOFT RUNNING SE THROUGH MANITOBA WITH LITTLE
FORCING.

SYNOPTIC PATTERN AND WEATHER EVOLUTION:

SFC LOW PRESSURE.AND DEEP FORCING WILL CROSS THE THUMB AROUND
DAYBREAK...WITH THE LOW LEVEL CONVERGENCE AXIS OVER MID LAKE GETTING
DRAWN DOWN THROUGH THE GRAND TRAVERSE BAY REGION BETWEEN 5AM AND
11AM. HARD TO TELL EXACTLY WHERE THE BEST LOW LEVEL CONVERGENCE WILL
BE MAXIMIZED...AND HOW LONG IT PERSISTS THROUGH DAYBREAK. LATEST
THOUGHT IS CONVERGENCE WILL LINGER LONGEST SOMEWHERE ACROSS LEELANAU
AND MAYBE INTO WESTERN GRAND TRAVERSE COUNTY...WITH A PIVOT POINT
THERE SOMEWHERE. THE MESOLOW WOULD THEN TRACK THROUGH THERE AS NW
WINDS INCREASE/DEVELOP. THE INTENSE SNOW BAND IS VERY NARROW...BUT
IF THAT BAND CONTINUE ACROSS THE SAME AREA...THIS COULD BE THE
HEAVIEST SNOW. WITH THE DELAYED TIMING OF HEAVIER SNOWFALL
RATES...WILL CUT BACK ON SNOWFALL THROUGH DAYBREAK.

AS THE SFC LOW CONTINUES OFF TO THE EAST...1000-850MB WINDS SETTLE
IN OUT OF THE NNW/NW FOR THE MORNING...BUT THEN START BACKING
THROUGH THE REMAINDER OF THE DAY. THIS WILL FAN OUT THE SNOWS ACROSS
NW LOWER AND EASTERN UPPER...WITH INCREASING WINDS GRADUALLY
THROWING SNOWS FURTHER INLAND. THE FANNING IS NOT GOOD FOR HEAVY
SNOWFALL AMOUNTS...AND PLUS WE LOSE SOME OF THE CYCLONIC CONVERGENCE
THROUGH THE DAY. NOW WE DO HAVE OTHER INCREDIBLE LAKE EFFECT
PARAMETERS...WITH INVERSION HEIGHTS THROUGH EARLY AFTERNOON NEAR
10KFT AND MAXIMUM LIFT STILL EXPECTED TO POUND THE DGZ THROUGH THE
ENTIRE DAY. MAX LIFT WILL BE THIS MORNING ACROSS THE GTV BAY REGION
WHERE RATES COULD BE AS HIGH AS 1-2"/HR. FORCING/LIFT SLOWLY WEAKENS
WITH TIME AS BANDS SLIDE NORTH. MAYBE A LITTLE LEARY ABOUT LOWERING
OVERALL SNOWFALL AMOUNTS...BUT DO BELIEVE THAT PULLING DOWN AMOUNTS
A COUPLE OF INCHES THROUGH THE DAY IN THE WARNING AREA MAY BE THE
RIGHT CALL. THIS REMAINS A DECENT ENOUGH EVENT TO BE IN A WARNING
HOWEVER...ESPECIALLY WITH SOME BLOWING SNOW ISSUES AS WINDS INCREASE
THROUGH THE DAY. AMOUNTS ACROSS EASTERN UPPER WILL BE LESS. SNOWS
THERE DO NOT KICK IN UNTIL LATE MORNING...AS FLOW WILL BE NORTH
EARLY ON. LOOKING AT 1-2 INCHES...LOCALLY 3".

TONIGHT...WINDS BACK FROM NW TO WEST THROUGH THE NIGHT AND WEAKEN.
INVERSION HEIGHTS COME DOWN TO 5KFT...BUT WHAT LIFT THERE IS...IS
STILL PEGGING THE DGZ FOR FLUFFIER/STACKIER SNOWFLAKES. DESPITE
WEAKENING LAKE EFFECT PARAMETERS...DECENT SNOW AMOUNTS ARE EXPECTED
AND WILL RAISE AMOUNTS AN INCH OR SO ACROSS NW LOWER NORTH OF M-72
TO A GENERAL 1-3 INCHES...HIGHEST IN THE HIGHER TERRAIN OF NRN
LOWER. ACROSS EASTERN UPPER...1-4 FOCUSED IN CHIPPEWA COUNTY...AND
WILL HAVE TO WATCH FOR A LATE NIGHT COLD AIR DRAINAGE SCENARIO WITH
BUBBLE HIGH DEVELOPMENT IN ONTARIO. MAY BE QUITE SHALLOW AND DOESN'T
AFFECT THE BANDS WHICH WILL CONTINUE LIFTING NORTH.

CHILLY COLD WITH HIGHS IN THE TEENS/LOW 20S AND LOWS IN THE SINGLE
DIGITS TO 10-15 DOWNWIND OF THE LAKES.

&&

.SHORT TERM...(WEDNESDAY THROUGH THURSDAY NIGHT)
ISSUED AT 325 AM EST TUE JAN 12 2016

HIGH IMPACT WEATHER: LAKE EFFECT REGIME THROUGH THE NEXT FEW
PERIODS.

FORECAST CHALLENGE:  WIND FLOW PATTERNS CHANGING SO THAT THE LES IS
NOT IN ONE SPOT THROUGH THE PERIODS.

(1/13)WEDNESDAY...ADJUSTED THE FORECAST GRIDS A BIT AS THE WINDS
SHIFT THROUGH THE DAY, BUT ONLY BY ABOUT 20 DEGREES OR SO. ADD TO
THAT ANY MOISTURE THAT WE MAY LOSE AROUND 18Z, THAT THE MOISTURE
INCREASE TO BETTER THAN 80% IN THE 850-700 MB LAYER BY 00Z, USING
THE HIRES GUIDANCE AS A GUIDE FOR THE BANDS, WOULD AGREE THAT WITH
THE W TO WSW BANDING THAT THERE SHOULD BE SOME LONG BANDS EMANATING
FROM AROUND LITTLE TRAVERSE BAY AND ON INTO LAKE HURON. ALL THE OF
THE MODELS ALSO SHOW THAT THE BANDS IN LAKE SUPERIOR SHOULD BE W
BANDS, THAT MAY OR MAY NOT AFFECT WHITEFISH POINT. AT NIGHT, THE
WINDS REMAIN W THROUGH 06Z, BUT LOOK LIKE UPSTREAM THE WNW WINDS
WILL BE MOVING IN AFTER THAT. BY 12Z, THE GFS AND ECMWF ARE WNW WITH
THE FLOW AT 1000-850 MB THE NAM IS WEST WITH THE WARM FRONT MOVING
INTO THE FORECAST AREA. 850 MB TEMPERATURES BY 12Z ARE -8C IN MID
LAKE MICHIGAN WATER TEMPERATURES MID LAKE ARE BETWEEN 5 AND 6 C SO
WE WILL BE AT OR ABOVE THE MAGIC INSTABILITY NUMBER (13C). SO THERE
WILL BE SOME LAKE ENHANCEMENT THE QUESTION WILL AGAIN BE A WIND
DIRECTION ISSUE. SO WILL HAVE A FEW INCHES NEAR LAKE MICHIGAN, WITH
MUCH LESS INLAND AS THE WARM FRONT MOVES IN WITH ITS LIGHT SNOW.

(1/14)THURSDAY...THE WARM FRONT MOVES NORTH THROUGH N LOWER. WILL
EXPECT THAT THE CHANCE FOR SNOW COULD BE HIGHER, BUT THAT THE SNOW
AMOUNTS WILL BE LIGHT AS THE BEST FORCING WILL BE PROBABLY WEST OF
THE FORECAST AREA UNTIL LATE IN THE DAY AS THE SFC TROUGH BEGINS TO
PUSH INTO S LOWER, AND THE RRQ OF THE 500 MB JET MOVES OVER THE
FORECAST AREA. THERE WILL PROBABLY BE SOME LAKE ENHANCEMENT AGAIN AS
THE NORTHERN PART OF LAKES MICHIGAN AND HURON HAVE THE 850 MB
TEMPERATURES TO SUPPORT 13C OR BETTER INSTABILITY, BUT WE ARE LOSING
THAT ABILITY IN THE MID PART OF THE LAKES WITH THE -4C LINE
APPROACHING LDM, IN THE WEST, AND BAX IN THE EAST. WE ARE RIGHT ON
THE LINE, LITERALLY, WITH WHETHER WE WILL SEE ANY RAIN OR FREEZING
RAIN TO MIX IN BEFORE 12Z AS THE MODEL SOUNDINGS SHOW A FAINT
POSSIBILITY ALONG THE M-55 CORRIDOR. PROBABLY ABOUT A 30% CONFIDENCE
LEVEL AT THIS POINT SINCE THE MODELS ARE SO CLOSE. SO WILL MENTION
THIS IN THE HWOAPX FOR THURSDAY NIGHT INTO FRIDAY MORNING PERIOD.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 325 AM EST TUE JAN 12 2016

EXTENDED (FRIDAY THROUGH MONDAY)...INITIALLY, WE START OUT A FEW
DEGREES ABOVE NORMAL AS THE LOW MOVES OUT OF THE SOUTHERN PLAINS ON
THURSDAY AND INTO THE OHIO VALLEY ON FRIDAY. MODELS HAVE FLIPPED ON
THE SOLUTIONS WITH THE GFS WHERE THE ECMWF WAS YESTERDAY, AND THE
00Z ECMWF NOW BRINGING THE NORTHERN BRANCH FEATURE THROUGH STRONGER
AND ACROSS MICHIGAN. SO WHAT DOES THIS MEAN? THAT WITH THE ECMWF
THERE COULD BE SOME RAIN POSSIBLE AS THE WARMER AIR GET FARTHER
NORTH THAN THE GFS. HOWEVER, BY SATURDAY WE ARE AGAIN IN THE 500 MB
TROUGH AND BELOW NORMAL AGAIN FOR THE END OF THE EXTENDED. HOWEVER,
THERE IS HOPE FOR THOSE WHO WANT THAT MILD WINTER BACK AS THE ANALOGS
ARE HINTING AT AROUND NORMAL TEMPERATURES IN THE 6-10 AND 8-14 DAY
PERIODS. IS THE PATTERN GOING TO CHANGE AGAIN? MAYBE...

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 617 AM EST TUE JAN 12 2016

SFC LOW PRESSURE WAS TRACKING TOWARD THE THUMB WITH LIGHT SNOWS
WRAPPING AROUND ITS NRN/WSTRN PERIPHERY INTO ALL AIRPORTS. LAKE
EFFECT SNOW AND EVEN A MESOLOW (MAYBE ANOTHER?) OUT OVER MID LAKE
WILL FINALLY WORK INTO THE GTV BAY REGION THROUGH THIS MORNING. A
MORE SETTLED FLOW OUT OF THE NNW/NW DEVELOPS LATER THIS MORNING
(BRINGING LAKE EFFECT SNOWS TO APN). SNOWFALL RATES AT MBL/TVC
1-2"/HR STILL EXPECTED WITH SNOW RATIOS AROUND 20:1. WINDS BACK
MORE WNW THROUGH THE DAY AND THEN WEST OVERNIGHT (PEGGING MORE SO
PLN) WITH SNOWS GRADUALLY BECOMING LESS INTENSE OVER THE ENTIRE
TIME. TOTAL SNOWFALL THROUGH TODAY AT TVC/MBL...4-8". PLN THROUGH
TONIGHT 3-4". APN AROUND 2".

CONDITIONS WILL PRIMARILY BE MVFR...BUT DEFINITE PERIODIC IFR/LIFR
CONDITIONS IN SNOW BANDS...ESPECIALLY TVC/MBL THIS MORNING.

&&

.MARINE...
ISSUED AT 325 AM EST TUE JAN 12 2016

ADVISORY LEVEL WINDS WILL BE COMMON ACROSS THE NEARSHORE WATERS
MOVING THROUGH THE DAY...AS SFC LOW PRESSURE EXITS EAST OF
US...AND A TIGHTER PRESSURE GRADIENT SWINGS ACROSS US. LOW END
GALES ARE EXPECTED ACROSS THE NW LOWER NEARSHORE WATERS TODAY...AS
WELL AS AROUND PRESQUE ISLE LATER THIS AFTERNOON INTO THIS
EVENING. WINDS ARE BORDERLINE ADVISORY LEVEL IN SEVERAL NEARSHORE
WATERS THROUGH WEDNESDAY EVENING...AS OVERLAKE INSTABILITY REMAINS
HIGH.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ020-025-
     026-031-032.

     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ015-
     021-027-033.

LH...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR LHZ346.

     SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR LHZ345-349.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 1 AM EST WEDNESDAY FOR
     LHZ347-348.

LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR LMZ323-341-342.

     GALE WARNING FROM 11 AM THIS MORNING TO 7 PM EST THIS EVENING
     FOR LMZ344>346.

LS...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR LSZ322.

     SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR LSZ321.

&&

NEAR TERM...DICKSON
SHORT TERM...JSL
LONG TERM...JSL
AVIATION...DICKSON
MARINE...DICKSON

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GAYLORD MI
347 AM EST TUE JAN 12 2016

LHZ345>349-LMZ323-341-342-344>346-LSZ321-322-MIZ008-015>036-041-
042-130900-
STRAITS OF MACKINAC WITHIN 5NM OF MACKINAC BRIDGE INCLUDING
MACKINAC ISLAND-ST IGNACE TO FALSE DETOUR CHANNEL-
5NM EAST OF MACKINAC BRIDGE TO PRESQUE ISLE LIGHT MI INCLUDING
BOIS BLANC ISLAND-
PRESQUE ISLE LIGHT TO STURGEON PT MI INCLUDING THUNDER BAY
NATIONAL MARINE SANCTUARY-STURGEON POINT TO ALABASTER MI-
GRAND TRAVERSE BAY SOUTH OF A LINE GRAND TRAVERSE LIGHT TO
NORWOOD MI-SEUL CHOIX POINT TO 5NM WEST OF MACKINAC BRIDGE-
NORWOOD MI TO 5NM WEST OF MACKINAC BRIDGE INCLUDING LITTLE
TRAVERSE BAY-SLEEPING BEAR POINT TO GRAND TRAVERSE LIGHT MI-
POINT BETSIE TO SLEEPING BEAR POINT MI-
MANISTEE TO POINT BETSIE MI-
WHITEFISH BAY (U.S. PORTION)/WHITEFISH POINT TO POINT IROQUOIS MI-
ST. MARYS RIVER POINT IROQUOIS TO E. POTAGANNISSING BAY-CHIPPEWA-
MACKINAC-EMMET-CHEBOYGAN-PRESQUE ISLE-CHARLEVOIX-LEELANAU-ANTRIM-
OTSEGO-MONTMORENCY-ALPENA-BENZIE-GRAND TRAVERSE-KALKASKA-CRAWFORD-
OSCODA-ALCONA-MANISTEE-WEXFORD-MISSAUKEE-ROSCOMMON-OGEMAW-IOSCO-
GLADWIN-ARENAC-
347 AM EST TUE JAN 12 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN LOWER MICHIGAN...
EASTERN UPPER MICHIGAN...AND ADJACENT NEARSHORE WATERS OF LAKE
MICHIGAN...LAKE HURON AND LAKE SUPERIOR.

.DAY ONE...TODAY AND TONIGHT.

MODERATE TO HEAVY SNOWFALL AND BLOWING SNOW WILL PERIODICALLY
IMPACT THE GRAND TRAVERSE BAY REGION TODAY. PLEASE SEE THE WINTER
STORM WARNING FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

EXPECT ADDITIONAL ACCUMULATING LAKE EFFECT SNOW IN THE FAVORED
SNOWBELTS THROUGH THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT ANY SNOW ACCUMULATIONS TO THE
NATIONAL WEATHER SERVICE. REPORTS MAY BE MADE ONE OF THREE WAYS:

ONLINE:   WEATHER.GOV/GAYLORD

FACEBOOK: FACEBOOK.COM/NWSGAYLORD

TWITTER:  TWITTER.COM/NWSGAYLORD

&&

FOR MORE INFORMATION VISIT WEATHER.GOV/GAYLORD.

SMD