Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 180445
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1145 PM EST MON NOV 17 2014

.SYNOPSIS...
ISSUED AT 405 PM EST MON NOV 17 2014

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...(TONIGHT)
ISSUED AT 1022 PM EST MON NOV 17 2014

PERSISTENT WESTERLY FLOW LAKE EFFECT SNOW BANDS STREAMING INTO THE
TIP OF THEM MITT HAVE DISORGANIZED A BIT AND SHIFTED SOUTH INTO
ANTRIM AND OTSEGO COUNTIES IN RESPONSE TO A SLIGHT SHIFT IN WINDS
VIA THE PASSAGE OF A WEAK SURFACE TROUGH AHEAD OF THE MAIN
TROUGH. BANDING WILL LIKELY REMAIN A BIT DISORGANIZED FOR THE
REMAINDER OF THE NIGHT UNTIL LOW LEVEL WINDS SETTLE INTO A MORE
STEADY W/NW FLOW ON TUESDAY BEHIND THE MAIN SURFACE FEATURE. IN
THE MEANTIME...CURRENT HEADLINES ARE DOING WELL...ESPECIALLY THE
WARNINGS AS HEAVIEST SNOW CONTINUES TO TARGET FAR NRN/NW LWR
MICHIGAN COUNTIES EVEN WITH THE SLIGHT SHIFT IN LOW LEVEL WINDS.
NO MAJOR CHANGES NEEDED FOR NOW...ALL HEADLINES WILL CONTINUE
UNCHANGED INTO THE OVERNIGHT.

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 405 PM EST MON NOV 17 2014

...SNOWIN` AND BLOWIN` COMING UP...

HIGH IMPACT WEATHER POTENTIAL: HEAVY LAKE SNOWS WITH CONSIDERABLE
BLOWING/DRIFTING TUESDAY INTO TUESDAY EVENING...WIDESPREAD MOSTLY
LIGHT SYNOPTIC SNOW WEDNESDAY...THEN ANOTHER ROUND OF SIGNIFICANT
LAKE EFFECT SNOWFALL FOR THURSDAY/THURSDAY NIGHT.

PATTERN SYNOPSIS/FORECAST: DEEP LONG WAVE TROUGH HAS OVERTAKEN THE
EASTERN TWO-THIRDS OF NORTH AMERICA...WITH 500MB HEIGHTS A SOLID 3-4
STANDARD DEVIATION BELOW THE MEAN CENTERED OVER THE MIDWEST THIS
MORNING WITH EQUALLY ANOMALOUS RIDGING EXTENDING INTO ALASKA AND THE
CANADIAN TERRITORIES.  THIS IS ALLOWING CROSS-POLAR FLOW TO DUMP
COLD AIR INTO THE MEAN TROUGH POSITION.  SHORT WAVE TROUGH IS
LIFTING UP THE FRONT SIDE OF THE LONG WAVE TROUGH ACROSS THE OHIO
VALLEY...ANOTHER DISTURBANCE WAS EMERGING FROM ABOVE THE ARCTIC
CIRCLE WITH SEVERAL WEAKER WAVES ROTATING THROUGH THE MEAN TROUGH
POSITION.  AT THE SURFACE... LOW PRESSURE WAS SPINNING AWAY NORTH OF
LAKE SUPERIOR WITH A TRAILING COLD FRONT HEADING TOWARD THE LOWER
GREAT LAKES...SURFACE HIGH PRESSURE ENCOMPASSES MUCH OF THE WESTERN
HALF OF THE COUNTRY.  IN BETWEEN THESE FEATURES COLD AIR IS SPILLING
SOUTHWARD ACROSS THE PLAINS/MIDWEST AND ADVECTING INTO THE UPPER
GREAT LAKES.

LONG WAVE TROUGH DOESN`T MOVE MUCH THROUGH MIDWEEK...REINFORCED BY
ARCTIC SHORT WAVE TROUGH DIGGING INTO IT.  THIS PIECE OF ENERGY WILL
EVENTUALLY SWING THROUGH THE BASE OF THE TROUGH AND ACROSS THE STATE
IN THE WEDNESDAY TIME FRAME.  EVENTUALLY...HEIGHT FALLS FROM THE
PACIFIC MUSCLE INTO THE GREAT BASIN/ROCKIES THIS WEEKEND...WHICH
BENDS THE FLOW BACK TOWARD SOMETHING MORE ZONAL/PACIFIC ORIENTED FOR
THE WEEKEND...BUT MAY ALSO SET US UP FOR UNSETTLED WEATHER FOR THE
START OF THANKSGIVING WEEK.  IN THE NEAR TERM...CORE OF THE COLDEST
AIR ALOFT WILL COME ACROSS THE UPPER LAKES TUESDAY (500MB
TEMPERATURES -42C/VERY UNUSUAL EVEN BY MID NOVEMBER STANDARDS)...
WHICH WILL BE FOLLOWED BY ARCTIC ORIGIN SHORT WAVE TROUGH WEDNESDAY
NIGHT/THURSDAY...AND POSSIBLY FOLLOWED BY ANOTHER PIECE OF ENERGY
FOR FRIDAY THOUGH THERE IS SOME UNCERTAINTY WITH THAT SCENARIO.
SURFACE LOW NORTH OF LAKE SUPERIOR PULLS AWAY THIS EVENING...WITH
COLD CYCLONIC FLOW ACROSS THE UPPER GREAT LAKES INTO TUESDAY.  WEAK
SURFACE RIDGE MOVES INTO MICHIGAN TUESDAY NIGHT/EARLY WEDNESDAY WITH
BACKS LOW LEVEL FLOW TO THE WEST THEN SOUTHWEST BY WEDNESDAY ALONG
WITH INCREASING WARM ADVECTION AND A LEAD SHORT WAVE TROUGH AHEAD OF
THE MAIN ARCTIC SHORT WAVE TROUGH.  COLD FRONT WITH ARCTIC ENERGY
PUSHES ACROSS THE AREA IN THE WEDNESDAY NIGHT TIME FRAME...SWINGING
WINDS BACK AROUND TO THE NORTHWEST FOR THURSDAY.

PRIMARY FORECAST CONCERNS (NEAR TERM): PLENTY.  SIGNIFICANT LAKE
EFFECT SNOW AND ATTENDANT IMPACTS TUESDAY/TUESDAY NIGHT...THEN MORE
WIDESPREAD SNOW/POSSIBLE ENHANCEMENT AHEAD OF ARCTIC SHORT WAVE
WEDNESDAY...THEN RETURN TO LAKE EFFECT SNOWS FOR THURSDAY.

NEAR TERM (TUESDAY/WEDNESDAY/THURSDAY): SNOW SHOWERS EXPECTED TO BE
GOING HOT AND HEAVY TO START TUESDAY MORNING...MULTI-BAND CONVECTION
THOUGH WITH A FEW DOMINANT BANDS LIKELY EMBEDDED OVER WESTERN
PORTIONS CHIPPEWA/MACKINAC COUNTIES...PROBABLY SOUTH OF THE STRAITS
WITH LONGEST EFFECTIVE FETCH OFF LAKE SUPERIOR (A LIKELY MIDPOINT
FOR A LAKE NIPIGON ORIGIN BAND THAT CONTINUES ON INTO GEORGIAN
BAY)...AND PERHAPS ANOTHER IN THE VICINITY OF THE M-32 CORRIDOR.
AFOREMENTIONED COLD 500MB TEMPERATURES WILL LEAD TO DEEP LAKE
INDUCED CONVECTIVE BOUNDARY LAYERS (INVERSION HEIGHTS NEAR
500MB)...SO EXPECT SNOWFALL RATES OF 1-2IN/HR WITHIN HEAVIER BANDS.
INITIAL MORE FOCUSED SNOWFALL ACROSS EASTERN UPPER LIKELY ACROSS
WESTERN CHIPPEWA/MACKINAC COUNTIES MOSTLY WEST OF THE I-75 CORRIDOR
BEFORE SHIFTING EAST DURING THE DAY.  THINK BANDS WILL REMAIN PRETTY
ORGANIZED AND NOT UNDERGO MUCH DISRUPTION DUE TO DEVELOPMENT OF
TERRESTRIAL INSTABILITY...AND WINDS WILL LIKELY REMAIN MORE STEADY
STATE FOR THE MOST PART ACROSS NORTHERN LOWER (270-280 DEGREES).
SOME SYNOPTIC LIFT AS WELL ACROSS NORTHERN PORTIONS OF THE FORECAST
AREA WON`T HURT THE CAUSE (SOME MID LEVEL "SEEDER-FEEDER" ACTION
POSSIBLE?).  OVERALL...LIKE THE IDEA OF AROUND A FOOT OF SNOW ACROSS
THE HIGHER TERRAIN OR NORTHERN LOWER AROUND PARTS OF CHARLEVOIX/
ANTRIM/OTSEGO/MONTMORENCY COUNTIES DURING THE DAY TUESDAY...WITH 4-8
INCHES ACROSS EASTERN UPPER AND TIP OF THE MITT COUNTIES...ALONG M-
72 2-4 INCHES AS WELL AS WEST OF I-75...AND LITTLE ACCUMULATION OVER
SOUTHEAST PORTIONS OF THE FORECAST AREA.  SIGNIFICANT BLOWING AND
DRIFTING ALSO EXPECTED TO BE A PROBLEM...SUSTAINED WINDS 20-25MPH
EXPECTED WITH GUSTS 30-40MPH WILL LIKELY RESULT IN NEAR WHITEOUT
CONDITIONS.  WILL MAKE A COUPLE SMALL ADJUSTMENTS TO GOING
HEADLINES...WILL EXPAND WINTER STORM WARNING INTO MONTMORENCY AND
PRESQUE ISLE COUNTIES WITH THE EXPECTATION THAT HEAVIER SNOW WILL
GET THAT FAR EAST...AND WILL ADD MACKINAC/ALPENA/OSCODA COUNTIES TO
THE ADVISORY AREA.

A COUPLE STRONG BANDS TO START TUESDAY EVENING...ONE ACROSS NORTHERN
CHIPPEWA COUNTY OFF WHITEFISH BAY AND A SECOND IN THE M-32/M-68
VICINITY.  LOW LEVEL WINDS WILL START BACKING TO SOUTHWEST TUESDAY
EVENING...WHICH WILL PUSH THESE BANDS NORTHWARD.  OF MORE IMPACT
WILL BE THE NORTHERN LOWER BAND AS IT PUSHES INTO THE TIP OF THE
MITT AND TOWARD THE STRAITS REGION.  SO A MOVING SNOW BAND SHOULD
DUMP LESS SNOWFALL OVER A PARTICULAR AREA THOUGH STILL THINK SEVERAL
INCHES ALONG AND NORTH OF THE M-32 CORRIDOR THROUGH THE EARLY
MORNING HOURS REASONABLE.  FOR THIS REASON WILL STRETCH THE WARNING
FOR THE M-32 COUNTIES TIL MIDNIGHT WEDNESDAY...AND THE TIP OF THE
MITT COUNTIES UNTIL 5AM.  ONSET OF WARM ADVECTION AND A NARROW AREA
OF DOWNWARD QG FORCING WILL SEE INVERSION HEIGHTS BEGIN TO FALL
THOUGH WILL STILL BE DECENT THROUGH THE STRAITS VICINITY.  SO
OUTSIDE OF THE BAND MOVING THROUGH FAR NORTHERN LOWER EXPECT AN
OVERALL DECREASE IN SNOWFALL INTENSITY.

COMBINATION OF A LEAD SHORT WAVE TROUGH AND WARM ADVECTION WITH
BACKING LOW LEVEL FLOW EXPECTED TO SPREAD SYNOPTIC SNOWFALL ACROSS
THE FORECAST AREA WEDNESDAY MORNING.  WINDS BECOMING SOUTH WILL
ALLOW FOR LAKE ENHANCEMENT OFF LAKE MICHIGAN...LIKELY A HEAVIER BAND
OF PRECIPITATION DEVELOPING ALONG A COLD FRONT EXPECTED TO MOVE INTO
LOWER MICHIGAN DURING THE AFTERNOON.  OVERALL NOT EXPECTED A LOT OF
SNOWFALL WITH THIS WITH THE CONCERN AREA FOR THE COUNTIES RINGING
THE EASTERN SIDE OF LAKE MICHIGAN FOR ENHANCEMENT POTENTIAL...
GENERALLY 1-2 INCHES WITH 2-4 INCHES FOR THE LAKE MICHIGAN COUNTIES.
SNOW WILL BEGIN TO TRANSITION BACK TO LAKE EFFECT WEDNESDAY NIGHT
WITH COLD FRONT PASSAGE...ALLOWING WINDS TO SHIFT BACK TO A MORE
WESTERLY DIRECTION.  INVERSION HEIGHTS ALSO EXPECTED TO CLIMB BACK
ABOVE 700MB WITH FAVORABLE SYNOPTIC FORCING AS ARCTIC SHORT WAVE
TROUGH ARRIVES.  SO WILL START GETTING THE SNOW AMOUNTS CRANKED UP
AGAIN (ON THE ORDER TO 3-5 INCHES FOR THE WEST/NORTHWEST FAVORED SNOW
BELTS FOR EASTERN UPPER/NORTHWEST LOWER) BUT NOT GOING OVERBOARD
WITH THIS YET.  PLENTY TO DEAL WITH ON THE FRONT END OF THIS
EVENT...WILL WORRY ABOUT DETAILS AND PUTTING MORE THOUGHT INTO THE
BACK END AS WE GET CLOSER.

WINDS MAY COME AROUND A BIT MORE NORTHWESTERLY THURSDAY...BUT LOOKS
LIKE A GOOD SET UP FOR SNOWFALL AS INVERSION HEIGHTS CREEP UP TOWARD
650-600MB.  WILL LIKELY NEED ANOTHER ROUND OF HEADLINES FOR THIS
PORTION OF THE EVENT WITH MORE SNOWIN` AND BLOWIN`...BUT AGAIN WILL
DEAL WITH THE NEARER TERM PERIODS FIRST.  PLENTY OF FODDER FOR THE
HAZARDOUS WEATHER OUTLOOK.

JPB

EXTENDED RANGE (FRIDAY THROUGH MONDAY):

MODELS TEND TO BE IN FAIRLY GOOD AGREEMENT WITH THURSDAY NIGHT INTO
FRIDAY MORNING HAVING THE POTENTIAL TO BE PRODUCING LAKE EFFECT SNOW
SHOWERS BEHIND THE DEPARTING COLD FRONT...MENTIONED IN PREVIOUS TIME
PERIOD...AS 850MB TEMPERATURES DROP TO -14 TO -18C TO PRODUCE DELTA
T/S IN THE MID 20S...AMPLE MOISTURE...AND WEST-NORTHWEST TO
NORTHWESTERLY 925MB WINDS STILL IN THE 20 TO 30KT RANGE OVERHEAD.
LIGHT TO MODERATE ACCUMULATIONS ARE POSSIBLE DURING THURSDAY NIGHT
INTO FRIDAY MORNING/EARLY AFTERNOON TIME FRAME. HIGH PRESSURE WITH
DRIER AIR AND INCREASING HEIGHTS/850MB TEMPERATURES WILL MOVE INTO
THE GREAT LAKES REGION BEGINNING LATE FRIDAY MORNING TO LATE FRIDAY
AFTERNOON PUTTING AN END TO ANY CHANCES OF LAKE EFFECT
SNOW...HOPEFULLY SETTING THE STAGE FOR A BIT WARMER WEEKEND WITH A
BREAK IN PRECIPITATION FOR THE FIRST HALF OF SATURDAY AHEAD OF THE
NEXT STORM SYSTEM THAT WILL DEVELOP OVER THE CENTRAL PLAINS LATE
SATURDAY NIGHT AND BEGIN IT/S APPROACH TO THE GREAT LAKES REGION.
CONFIDENCE IN THE TRACK OF THIS FORECAST STORM SYSTEM IS LOW AT THIS
TIME. THE TEMPERATURES AND TYPE OF PRECIPITATION NORTHERN MICHIGAN
WILL SEE SATURDAY NIGHT INTO MONDAY WILL DEPEND GREATLY ON THE EXACT
TRACK OF THIS STORM SYSTEM. THIS STORM... ONCE AGAIN... HAS THE
POTENTIAL TO PUT OUT A LOT OF PRECIPITATION...WE JUST HAVE TO WAIT
TO SEE WHAT FORM...FROZEN OR LIQUID...IT WILL TAKE.

TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FRIDAY...ONLY REACHING
INTO THE LOW 20S DURING THE AFTERNOON HOURS...BUT HAS THE POTENTIAL
TO FINALLY REACH FREEZING SATURDAY AND INTO THE UPPER 30S TO EVEN
NEAR 40 BOTH SUNDAY AND MONDAY. LOW TEMPERATURES FRIDAY AND SATURDAY
MORNING WILL DROP TO THE LOW TEENS AND THEN SUNDAY AND MONDAY ONLY
DOWN TO THE UPPER 20S TO NEAR FREEZING. ONCE AGAIN...TEMPERATURES
SATURDAY THROUGH MONDAY VARY GREATLY DEPENDING ON THE EXACT TRACK
THE STORM SYSTEM TAKES.

TJL

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1145 PM EST MON NOV 17 2014

A SHARP TROUGH WILL SWING THRU NRN MICHIGAN LATE TONIGHT INTO
TUESDAY...SERVING TO ENHANCE LOW LEVEL CONVERGENCE AND THUS
ONGOING LAKE EFFECT SNOW SHOWERS. IN ADDITION...W/NW WINDS WILL
STRENGTHEN AS THIS TROUGH SLIDES THRU...RESULTING IN SIGNIFICANT
BLOWING AND DRIFTING SNOW. MAINLY IFR CONDITIONS ARE EXPECTED AT
ALL NRN LWR MICHIGAN TAF SITES THRU TUESDAY EVENING DUE TO THE
COMBINATION OF FALLING AND BLOWING SNOW. WINDS WILL GUST TO 20 T0
30 KTS LATER TONIGHT AND TUESDAY...WITH SOME HIGHER GUSTS
POSSIBLE ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE.

&&

.MARINE...
ISSUED AT 405 PM EST MON NOV 17 2014

GALE WARNINGS WILL BE NEEDED AROUND NORTHERN LOWER NEARSHORE ZONES
TONIGHT INTO TOMORROW...WITH WINDS DIMINISHING AND BACK AROUND TO
THE SOUTHWEST/SOUTH OVERNIGHT TUESDAY INTO WEDNESDAY MORNING.  WINDS
WILL COME AROUND TO THE SOUTH/SOUTHEAST DURING THE DAY WEDNESDAY...
THEN SHIFT BACK AGAIN TO THE WEST WEDNESDAY NIGHT INTO THURSDAY AND
INCREASE AGAIN TO AT LEAST SMALL CRAFT ADVISORY LEVELS.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ020-
     024>029-031>033.

     WINTER STORM WARNING UNTIL MIDNIGHT EST TUESDAY NIGHT FOR
     MIZ021>023.

     WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TUESDAY NIGHT FOR
     MIZ008.

     WINTER WEATHER ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ015.

     WINTER STORM WARNING UNTIL 5 AM EST WEDNESDAY FOR MIZ016>019.

LH...GALE WARNING FROM 4 AM TO 7 PM EST TUESDAY FOR LHZ345-347>349.

     SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR LHZ346.

LM...GALE WARNING UNTIL 7 PM EST TUESDAY FOR LMZ323-341-342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR LSZ321-322.

&&

$$

SYNOPSIS...TJL
SHORT TERM...MLR
LONG TERM...JPB/TJL
AVIATION...MLR
MARINE...JPB



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