Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 111133
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
633 AM EST THU FEB 11 2016

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM EST THU FEB 11 2016

IMPACT WEATHER: LAKE EFFECT SNOW.

SYNOPTIC PATTERN AND OBSERVATIONS:

UPPER LEVEL TROUGHING RESIDES ACROSS THE EASTERN CONUS WITH RIDGING
AND WARMTH OUT WEST. NW FLOW ALOFT IN NRN MICHIGAN FEATURES EMBEDDED
SHORTWAVES...ONE OF WHICH IS CROSSING US ATTM...HELPING TO PUSH LAKE
INDUCED TROUGHING SOUTH THROUGH NRN LOWER. THE WAVE ITSELF ISN`T
REALLY AIDING FLOW LAKE EFFECT...WITH NO ASSOCIATED MOISTURE...AND
WE CONTINUE TO BE IN A PURE LES SITUATION. VERY COLD AIR RESULTING
IN SMALLER FLAKE SIZES AND ONLY MINOR ACCUMULATIONS IN MOST AREAS.
HOWEVER...WE DO STILL HAVE A DOMINANT BAND OF SNOW WITH MODERATE TO
HEAVY SNOWFALL RATES THAT HAD SHIFTED FROM LEELANAU AND GRAND
TRAVERSE COUNTIES INTO ANTRIM AND KALKASKA COUNTIES OVER THE LAST
SEVERAL HOURS. THIS BAND OF SNOW LASTED 1 1/2 TO 2HRS IN ANY ONE
SPOT ACROSS THIS AREA...AS IT TURNED OUT TO BE MORE TRANSIENT THAN
PREVIOUSLY THOUGHT...WITH LESS TOTAL SNOWFALL. THE SOUTHWARD SINKING
LAKE INDUCED TROUGHING IS BEGINNING TO PUSH THIS SNOW BACK INTO THE
GTV BAY REGION. ANOTHER STRONGER SHORTWAVE IS SEEN DROPPING
SOUTHEAST TOWARD NRN ONTARIO.

SYNOPTIC PATTERN AND WEATHER EVOLUTION:

CURRENT BAND OF HEAVIER LAKE EFFECT WILL DROP INTO LEELANAU AND
GRAND TRAVERSE COUNTIES THROUGH DAYBREAK AND WILL LIKELY BRING A
PERIOD OF POOR VISIBILITY AND ACCUMULATING SNOWS. HAVE ALREADY
LOWERED THEM BACK INTO AN ADVISORY HOWEVER...AS THE LONG PERIOD OF
EXPECTED ACCUMULATING SNOWS JUST DIDN`T HAPPEN. WILL SEE HOW THE
RADAR PLAYS OUT OVER THE NEXT SEVERAL HOURS...WHICH SHOULD FEATURE
THE SNOW INTENSITIES FALLING OFF THROUGH THE MORNING WITH THE
PASSAGE OF THE SHORTWAVE AND SOME INFLUX OF DRIER AIR. CURRENT
ADVISORIES GO THROUGH THE MORNING...AND WILL NOT CHANGE THAT. THE
FLOW BACKS WESTERLY BY THE DAYS END AS THE AFOREMENTIONED STRONGER
SHORTWAVE FROM ONTARIO WORKS TOWARD THE GREAT LAKES. THIS WILL BRING
SOME LIGHTER SNOWS MINOR ACCUMULATIONS INTO FAR NW LOWER. FLOW MAY
BACK JUST SLIGHTLY SOUTH OF DUE WEST HEADING THROUGH EVENING...AS
HEIGHTS FALL WITH THE APPROACH OF THE WAVE. H8 TEMPS "WARM" BACK
INTO THE TEENS EXPOSING THE DGZ...AND LIFT INCREASING THROUGH THE
NIGHT WITH INCREASING CHANCES OF FOCUSING IN ON THE DGZ. WESTERLY
LAKE EFFECT SNOWS WILL PICK BACK UP IN INTENSITY ACROSS FAR NW LOWER
AND MAYBE SCRAPE THE PARADISE AREA OF CHIPPEWA COUNTY...OR REMAIN
JUST OFFSHORE BEFORE WINDS SHIFT OUT OF THE NW LATE TONIGHT. CAN
FORESEE 3-5 INCHES OF SNOW...WITH A COUPLE INCHES FALLING INTO
CHIPPEWA COUNTY LATE TONIGHT.

&&

.SHORT TERM...(FRIDAY THROUGH SATURDAY NIGHT)
ISSUED AT 321 AM EST THU FEB 11 2016

HIGH IMPACT WEATHER POTENTIAL: BRUTALLY COLD WITH MORE ACCUMULATING
LAKE SNOWS INTO THE START THE WEEKEND.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: A PATTERN VERY REMINISCENT
OF LAST FEBRUARY TO START THE WEEKEND...WITH CORRIDOR OF ONLY
MARGINALLY MODIFIED ARCTIC AIR EXPECTED TO DROP OVERHEAD FRIDAY
NIGHT INTO SATURDAY. NOW...UNLIKE LAST FEBRUARY...OVERALL BACKGROUND
PATTERN LOOKS TO BECOME MUCH MORE TRANSIENT...WITH A RAPID
DEVELOPMENT OF A MUCH MORE ZONAL APPEARANCE TO THE LONG WAVE PATTERN
BY THE END OF THE WEEKEND. THIS ENSURES POLAR VISIT WILL BE A BRIEF
ONE...WITH QUICK MODIFICATION EXPECTED TO BEGIN AS EARLY AS SUNDAY.

PRIMARY FORECAST CONCERNS/CHALLENGES: JUST HOW COLD TO GO FRIDAY
THROUGH SATURDAY NIGHT. LAKE SNOW EVOLUTION AND AMOUNTS THROUGH THE
PERIOD.

DETAILS: AN INTERESTING AND POTENTIALLY HIGH IMPACT PERIOD OF WEATHER
EXPECTED FRIDAY AS ARCTIC SHORTWAVE AND ATTENDANT FRONT CROSS THE
AREA. DEEP SLUG OF QG SUPPORT AND ENHANCED LOW LEVEL CONVERGENCE TO
ACCOMPANY THESE FEATURES...AND WHEN COMBINED WITH WHAT SHOULD BE AN
INCREASING AMOUNT OF LAKE MOISTURE CONTRIBUTION (INVERSION LEVELS
SPIKE TO AOA 10KFT...COULD POSSIBLY RESULT IN ONE INTENSE BAND OF
SNOW SHOWERS DROPPING THROUGH THE REGION. BAND SHOULD BE A TRANSIENT
ONE...BUT COULD EASILY LEAD TO A QUICK COUPLE INCHES OF SNOW AND
NEAR WHITEOUT CONDITIONS. FLOW REGIME QUICKLY SWINGS AROUND TO NORTH-
NORTHWEST AFTER FRONTAL PASSAGE...WITH A QUICK TRANSITION TO A MORE
PURE LAKE EFFECT ENVIRONMENT BY LATE FRIDAY INTO FRIDAY NIGHT. NICE
LAKE SUPERIOR CONNECTION DURING THIS PERIOD...AT LEAST PARTIALLY
MINIMIZING IMPACTS FROM THE EXTREMELY DRY LOW LEVELS AND LIKELY
ENTICING AT LEAST A FEW DOMINATE BANDS TO DEVELOP. PRIMARY IMPACT
AREAS WILL BE ALONG AND WEST OF US-131 AND ALONG AND SOUTH OF GRAND
TRAVERSE BAY (AGAIN!)...AND PERHAPS CLIPPING THE NORTHEAST LOWER
COASTLINE NORTH OF ALPENA. IN-CLOUD DENDRITIC GROWTH LAYER IS
COMPLETELY LOST AS H8 TEMPS SPIRAL DOWN TO WELL BELOW -20C...
SUPPORTING SMALL FLAKE SIZE. SIMPLE PERSISTENCE OF LAKE SNOWS AND
DOMINATE BAND POTENTIAL WILL DEFINITELY COMPENSATE SOME...LIKELY
BRINGING ANOTHER 2 T0 4 INCHES OF SNOW TO FAVORED AREAS. NOW...THOSE
SAME HARD TO ACCUMULATE SMALL FLAKES ARE REMARKABLY EFFICIENT AT
REDUCING VISIBILITY AND BEING BLOW ABOUT IN WHAT SHOULD BE SOME VERY
GUSTY WINDS. NO DOUBT TRAVEL IMPACTS WILL CONTINUE...AND COULD BE
QUITE SIGNIFICANT WHERE DOMINATE BANDS ALIGN.

CORE OF ARCTIC PLUNGE CENTERS ITSELF DIRECTLY OVERHEAD DURING THE
DAY SATURDAY. NORTH-NORTHWEST FLOW PURE LAKE EFFECT ENVIRONMENT
CONTINUES...TARGETING SAME AREAS AS FRIDAY NIGHT. SMALL FLAKE
SIZE/LOWERING INVERSIONS WILL DEFINITELY HELP THROTTLE BACK LAKE SNOW
INTENSITY AND ACCUMULATIONS...ALTHOUGH COULD EASILY SEE ANOTHER INCH
OR TWO THROUGH SIMPLE PERSISTENCE...AND A CONTINUATION OF TRAVEL
IMPACTS VIA LOW VISIBILITY. LAKE SNOW PARAMETERS REALLY TAKE A DIVE
SATURDAY NIGHT AS FLOW VEERS MORE NORTH TO NORTHEAST WITH TIME AND
LAND BREEZES BEGIN TO DOMINATE AT THE SURFACE. SO...WHILE SNOW
SHOWERS WILL CONTINUE ALONG THE IMMEDIATE SHORELINES...ANY
ADDITIONAL ACCUMULATIONS WILL BE MINIMAL.

TEMPERATURES A WHOLE OTHER STORY WITH PASSAGE OF THAT ARCTIC
FRONT...WITH CORE OF NEGATIVE MID TO UPPER 20C H8 TEMPERATURES
SETTLING OVERHEAD. SIMPLE MAGNITUDE OF CAA SUPPORTS LOWS DIPPING
SEVERAL DEGREES BELOW ZERO AWAY FROM THE BIG WATERS FRIDAY
NIGHT...AND HIGHS STRUGGLING INTO THE SINGLE DIGITS ON SATURDAY
(FULLY POSSIBLE NON-LAKE MODIFIED AREAS OF EASTERN UPPER AND THE
HIGHLANDS OF NORTHERN LOWER MIGHT EVEN FALL TO REACH THOSE NUMBERS).
OF COURSE...EXACT TEMPERATURES ONLY ONE PART OF THE EQUATION...WITH
GUSTY WINDS PRODUCING WIND CHILLS 10 TO 30 DEGREES BELOW
ZERO...COLDEST EARLY SATURDAY MORNING. COULD EASILY BE LOOKING AT
OUR FIRST WIND CHILL HEADLINE OF THIS WINTER FRIDAY NIGHT INTO
SATURDAY MORNING. STILL LOOKING AT WIDESPREAD LOWS SEVERAL DEGREES
BELOW ZERO SATURDAY NIGHT...ALTHOUGH WIND CHILL VALUES "WARM" TO
THOSE SAME NUMBERS AS WINDS GO LIGHT.

&&

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM EST THU FEB 11 2016

A PERIOD OF RATHER SUBSTANTIAL MODERATION AS COLD CORE ANOMALIES
QUICKLY MOVE EAST. HIGHS IN THE TEENS SUNDAY WARM FURTHER INTO THE
20S AND LOWER 30S MONDAY THROUGH WEDNESDAY. MUCH LOWER CONFIDENCE
ENDEAVOR FIGURING OUT ADDITIONAL SNOW CHANCES. ANY SNOW POTENTIAL
WILL BE TIED TO PASSING WAVES AS LAKE CONTRIBUTION BECOMES LOST.
GUIDANCE ALL OVER THE BOARD WITH REGARDS TO TIMING AND MAGNITUDE
OF THESE WAVES...AND EVEN IF THEY WILL IMPACT US AT ALL. ANY SORT
OF SPECIFIC TIMING/IMPACTS FAR FROM BEING FIGURED OUT...SO A
SIMPLE CONSENSUS BLEND APPROACH WILL BE UTILIZED FOR NOW...AT
LEAST ALLOWING FOR ADDITIONAL CHANCES FOR LIGHT SNOW (ESPECIALLY
SUNDAY NIGHT THROUGH WEDNESDAY).

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 628 AM EST THU FEB 11 2016

NORTH NORTHWEST FLOW LAKE EFFECT SNOW SHOWERS WILL CONTINUE
THROUGH THIS MORNING...WHILE WEAKENING. THE FLOW BACKS MORE
WESTERLY...DRIVING LIGHT SNOWS ACROSS PRIMARILY PLN THIS
AFTERNOON. THIS WESTERLY FLOW LAKE EFFECT GETS ENHANCED TONIGHT
WITH THE ARRIVAL OF AN UPSTREAM COLD FRONT AND DEEPER MOISTURE.
SNOWFALL RATES WILL INCREASE TO POSSIBLY AN INCH PER HOUR IN THE
HEAVIER SNOWS ACROSS PLN...WITH SNOWS BECOMING MORE WIDESPREAD.
CIGS/VSBYS WILL BE PRIMARILY LOW END VFR...BUT FALL TO MVFR IN
SNOW SHOWERS. ACCUMULATIONS NEAR 4 INCHES AT PLN TONIGHT.

GUSTY WINDS TO 20 KNOTS THROUGH THE PERIOD...EVEN TONIGHT AS A
TIGHTER GRADIENT ARRIVES WITH THE COLD FRONT.

&&

.MARINE...
ISSUED AT 321 AM EST THU FEB 11 2016

ADVISORY LEVEL GUSTS WILL BE COMMON ACROSS THE NEARSHORES INTO THE
WEEKEND WITH VERY COLD AND AND UNSTABLE OVERLAKE CONDITIONS.
PERIODIC LAKE EFFECT SNOWS WILL ALSO GET ENHANCED TONIGHT INTO
FRIDAY AS AN ARCTIC FRONT PLOWS THROUGH THE REGION.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     MIZ019>021-025>027-031>033.

LH...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ323-341-342-
     344>346.

LS...NONE.
&&

$$

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


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