Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 280301
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1001 PM EST THU NOV 27 2014

.SYNOPSIS...
ISSUED AT 636 PM EST THU NOV 27 2014

A CHILLY THANKSGIVING NIGHT IS AHEAD WITH SCATTERED LAKE EFFECT SNOW
SHOWERS FOR THE TRADITIONAL LAKE EFFECT BELTS. A PERIOD OF MORE
WIDESPREAD SNOW IS EXPECTED FRIDAY INTO FRIDAY NIGHT BEFORE MILD
CONDITIONS LOOK TO ARRIVE SATURDAY AND SUNDAY OUT AHEAD OF YET
ANOTHER SHOT OF COLD AIR THAT IS DUE IN EARLY NEXT WEEK.

&&

.UPDATE...
ISSUED AT 959 PM EST THU NOV 27 2014

NW FLOW LAKE EFFECT SNOW CONTINUES IN BOTH PENINSULAS THIS
THANKSGIVING EVENING. A COUPLE OF DOMINANT BANDS HAVE EMERGED
WITH LOSS OF HEATING. ONE IS IMPACTING CENTRAL KALKASKA CO...THE
OTHER REDUCED THE VSBY AT KINROSS BELOW 1SM FOR A FULL HOUR. BOTH
BANDS HAVE BEEN/ARE CAPABLE TO PRODUCING QUICK 1-2 INCH LOCAL
ACCUMS...AND THE FORECAST HAS BEEN UPDATED ACCORDINGLY.

WITH A PROMINENT RIDGE OF HIGH PRESSURE SITTING JUST W OF LAKE
MI...WE SHOULD SEE SOME BACKING OF THE LOW LEVEL FLOW AT ANY
MOMENT. SOME SUBTLE SIGNS IN SW SECTIONS THAT THIS IS
UNDERWAY...WITH SURFACE WINDS BACKING AT THE FRANKFORT AWOS...AND
BANDS TRANSLATING EASTWARD JUST A TOUCH IN LEELANAU CO OVER THE
LAST 30-40MIN. AS THIS OCCURS...LES-IMPACTED AREAS WILL SHIFT FROM
NW FLOW TO WSW FLOW BY DAYBREAK. CURRENT GRIDS ACCOUNT FOR THIS
IDEA...BUT WILL FILL IN SOME OF THE DETAILS. LES INTENSITY WILL
LESSEN AS RIDGING/ANTICYCLONIC 1000-850MB FLOW ARRIVES...BUT POPS
SHOULD STILL REMAIN ON THE HIGH SIDE EVEN AS THE SNOWBELTS SHIFT.

MIN TEMPS ARE REASONABLE...AS CLOUD COVER IS RELATIVELY EXTENSIVE
AND IS KEEPING TEMPS FROM PLUNGING. CLOSEST THING TO AN EXCEPTION
TO THE ABOVE IS THE SAULT...DOWN TO 9F...BUT THE BACKING WINDS
WILL THROW CLOUDS BACK INTO THE SAULT IN FAIRLY SHORT ORDER.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 359 PM EST THU NOV 27 2014

...COLD...WITH SOME LINGERING LIGHT SNOW SHOWERS...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/CURRENT CONDITIONS: NEXT SHOT OF MODIFIED ARCTIC
AIR WELL ESTABLISHED ACROSS THE NORTHERN LAKES THIS
AFTERNOON...COURTESY OF DEPARTING NORTHERN STREAM SHORTWAVE TROUGH
AND LARGE HIGH PRESSURE BUILDING INTO THE MISSISSIPPI VALLEY . H8
TEMPERATURES DOWN INTO THE NEGATIVE MID AND UPPER TEENS...PLENTY
COLD ENOUGH TO DRIVE NW FLOW LAKE EFFECT SNOW SHOWERS INTO BOTH
PENINSULAS. DESPITE SUCH IMPRESSIVE OFF THE DECK COLD
TEMPERATURES...INTENSITY OF LAKE SNOWS SUBSTANTIALLY LIMITED BY A
RAPIDLY FALLING INVERSION AND QUICK EXIT OF ANY SYNOPTIC MOISTURE
CONTRIBUTION. LAKE MODIFICATION HELPING QUITE A BIT WITH SURFACE
TEMPERATURES...WITH CURRENT TEENS AND 20S ACROSS OUR AREA SEVERAL
DEGREES WARMER THAN THE SINGLE DIGIT READINGS FOUND ACROSS NORTHWEST
WISCONSIN AND MINNESOTA.

PRIMARY FORECAST CHALLENGES/CONCERNS: LAKE EFFECT SNOW AND
TEMPERATURE TRENDS.

DETAILS: PATTERN REMAINS PROGRESSIVE TONIGHT...WITH MID LEVEL
HEIGHTS BEGINNING THE REBOUND PROCESS...ALL THE WHILE SURFACE HIGH
PRESSURE BUILDS OVERHEAD AND INTO THE OHIO VALLEY BY SUNRISE FRIDAY.
INITIAL NORTHWEST FLOW STEADILY BACKS LATER TONIGHT...BECOMING LIGHT
SOUTHWEST BY MORNING. TEMPERATURES REMAIN PLENTY COLD ENOUGH TO
CONTINUE TO ENTICE A LAKE RESPONSE...ALTHOUGH CRASHING INVERSIONS
AND COMPLETE LACK OF ANY LARGE SCALE MOISTURE CONTRIBUTION WILL
CONTINUE TO SIGNIFICANTLY THROTTLE BACK ON INTENSITY LEVELS. DON`T
EXPECT LAKE SNOWS TO END...HOWEVER...AND WILL SIMPLY FOLLOW LOW
LEVEL WIND FIELDS FOR HIGHEST POP PLACEMENT. DESPITE SUB H8 LEVEL
INVERSION...LAKE INDUCED CBL/MOISTURE LOOKS TO REMAIN IN PRIME
DGZ...SUPPORTING GOOD "FLUFF" FACTOR AND SOME MINIMAL
ACCUMULATIONS (PERHAPS AN INCH OR TWO) ACROSS FAVORED AREAS OF
NORTHWEST LOWER AND EASTERN UPPER MICHIGAN.

LOW TEMPERATURES TONIGHT DIRECTLY TIED TO CLOUD TRENDS. THINKING
AREAS AWAY FROM THE LAKE BELTS WILL SEE AT LEAST SOME PARTIALLY
CLEARING. GIVEN JUST HOW COLD THIS ARMS IS...THINKING ANY
CLEARING WILL ALLOW TEMPERATURES TO TANK...WITH WIDESPREAD SINGLE
DIGITS AND LOWER TEENS ACROSS INTERIOR REGIONS. IF CLEARING IS
MORE THAN EXPECTED...EVEN THESE TEMPERATURES WILL BE SEVERAL
DEGREES TOO "WARM".

.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 359 PM EST THU NOV 27 2014

...SNOW FRIDAY/MIXED PRECIPITATION POSSIBLE SATURDAY THEN COLDER...

HIGH IMPACT WEATHER POTENTIAL: WIDESPREAD LIGHT SNOW DEVELOPING
FRIDAY INTO FRIDAY EVENING...CHANCE FOR MIXED PRECIPITATION
SATURDAY...TURNING COLDER SUNDAY.

PATTERN SYNOPSIS/FORECAST: SPLIT LONG WAVE TROUGH ACROSS EASTERN
NORTH AMERICA...MUCH OF THE NORTHERN BRANCH ENERGY WAS OVER THE HIGH
LATITUDES OF CENTRAL CANADA...WHILE SOUTHERN STREAM ENERGY MOVES OFF
THE SOUTHEASTERN COAST.  LOW AMPLITUDE SHORT WAVE RIDGING WAS MOVING
THROUGH THE WESTERN MOUNTAINS...WITH ANOTHER SPLIT POSITIVE TILT
SHORT WAVE TROUGH OVER THE EASTERN PACIFIC.  AT THE SURFACE...EAST
COAST STORM NOW LIFTING INTO NOVA SCOTIA...WITH ANOTHER WAVE OF LOW
PRESSURE OVER THE CAROLINAS ASSOCIATED WITH ABOVE MENTIONED SOUTHERN
BRANCH ENERGY.  COLD SURFACE HIGH PRESSURE SPANS THE NATION`S MID-
SECTION (SUB-ZERO TEMPERATURES THROUGH LATE MORNING EXTENDED DOWN
INTO SOUTHERN IOWA).

WESTERN RIDGING WILL EVENTUALLY ALLOW THE LARGE SCALE PATTERN TO
FLATTEN ACROSS THE U.S...WITH ZONAL FLOW ACROSS THE COUNTRY HEADING
INTO THE WEEKEND AS THE SPLIT PACIFIC SHORT WAVE TROUGH IMPACTS THE
WEST COAST.  NORTHERN BRANCH ENERGY WITHIN THIS SPLIT THEN EXPECTED
TO TAKE OVER WITH HEIGHT FALLS SPREADING ACROSS THE NORTHERN/CENTRAL
PLAINS AND UPPER MIDWEST BY THE END OF THE WEEKEND...AND INTO THE
UPPER GREAT LAKES IN THE MONDAY TIME FRAME.  IN THE NEAR TERM...
HEIGHT RISES SPREAD ACROSS THE UPPER LAKES FRIDAY IN RESPONSE TO
WARM ADVECTION...AND SETTING THE STAGE FOR ZONAL FLOW THIS WEEKEND.
UPSTREAM HIGH PRESSURE CROSSES THE STATE TONIGHT WITH SOUTHERLY
BOUNDARY LAYER FLOW DEVELOPING FRIDAY.  JET STREAK CROSSING THE
ROCKIES EXPECTED TO SPIN LOW PRESSURE UP OVER THE NORTHERN HIGH
PLAINS FRIDAY...WHICH TRACKS INTO NORTHERN ONTARIO SATURDAY WHILE
PULLING AN ARCTIC FRONT INTO THE NORTHERN PLAINS/UPPER MIDWEST.
WILL BE DEALING WITH THIS COLD FRONT SUNDAY.

PRIMARY FORECAST CONCERNS (NEAR TERM): WARM ADVECTION SNOW SPREADING
ACROSS NORTHERN MICHIGAN DURING THE DAY FRIDAY...AND POTENTIAL FOR
SOME SNOWFALL ENHANCEMENT OFF LAKE MICHIGAN.  WARMING TEMPERATURES
AND INCREASING DEW POINTS WITH POTENTIAL FOR ADVECTION FOG/STRATUS
DEVELOPING ESPECIALLY SATURDAY NIGHT.  COLD FRONT PASSAGE IMPACTS
FOR SUNDAY.

NEAR TERM (FRIDAY/SATURDAY/SUNDAY): SURFACE THROUGH MID LEVEL
RIDGING WILL BE MOVING EAST OF MICHIGAN FRIDAY MORNING...WHICH WILL
ALLOW FOR A STRONGER PUSH OF WARM AIR TO DEVELOP.  COMBINATION OF
MID/HIGH LEVEL WARM ADVECTION CLOUDS AND RESIDUAL LAKE INDUCED
STRATOCUMULUS WILL BE AROUND TO START THE DAY.  WEDGE OF DRY AIR IN
BETWEEN WILL GRADUALLY SATURATE THROUGH THE MORNING/EARLY
AFTERNOON...AS ISENTROPIC ASCENT IS AIDED BY ARRIVAL OF AN ELONGATED
POTENTIAL VORTICITY ANOMALY (TIMING MAY BE A LITTLE SLOWER THAN
EARLIER ANTICIPATED)...WITH AN INCREASING SIGNAL FOR LOW/MID LEVEL
FRONTOGENETIC FORCING DURING THE AFTERNOON INTO NORTHWEST LOWER.  SO
ANTICIPATE BETTER SNOWFALL "INTENSITY" WILL BE DURING THE SECOND
HALF OF THE DAY AND INTO FRIDAY EVENING.  BACKING LOW LEVEL FLOW TO
SOUTH-SOUTHWEST DURING THE AFTERNOON WILL STILL PLENTY OF (ALBEIT
RELATIVELY SHALLOW) LAKE INDUCED INSTABILITY MAY FOCUS A NARROW BAND
OF HIGHER INTENSITY SNOWFALL INTO WESTERN MACKINAC COUNTY (PERHAPS
STARTING IN WESTERN EMMET COUNTY).  SHIFTING WINDS WILL SPREAD THIS
LAKE RESPONSE OUT...SO NOT EXPECTING ANY ONE AREA TO GET HIT HARD
UNLESS WINDS CAN LOCK IN.  SNOW EXPECTED TO TAPER OFF OVERNIGHT
SATURDAY WITH MID LEVEL DRYING BEHIND THE PV ANOMALY...BUT MOIST LOW
LAYERS MAY LEAD TO SOME FLURRIES/FREEZING DRIZZLE.  OVERALL SNOW
AMOUNTS EXPECTED TO BE ON THE LIGHT SIDE...1-3 INCHES THROUGH
MIDNIGHT...SOME LOCALLY HIGHER AMOUNTS POSSIBLE OVER WESTERN
MACKINAC COUNTY AND PERHAPS IN THE VICINITY OF THE M-55 CORRIDOR
DEPENDING ON HOW THE FRONTOGENETIC RESPONSE EVOLVES.

ANOTHER PUSH OF DEEPER SATURATION ON SATURDAY WILL BRING ANOTHER
CHANCE FOR MEASURABLE PRECIPITATION...THOUGH DEEP LAYER WARMING WILL
BEGIN TO BRING PRECIP TYPE ISSUES INTO THE EQUATION.  BEST CHANCE
FOR PRECIPITATION AT THIS POINT LOOKS TO BE ACROSS EASTERN
UPPER...WHERE FROZEN PRECIPITATION SHOULD PREDOMINATE INTO THE
AFTERNOON BEFORE ANY CHANCE TO MIX WITH OR CHANGE TO LIQUID (THOUGH
BY THIS TIME MID LEVELS MAY BEGIN TO DRY OUT AGAIN).  ACROSS
NORTHERN LOWER WILL BE TRICKIER WITH THE POSSIBILITY OF ENOUGH
WARMING ALOFT TO ALLOW FOR LIQUID PRECIPITATION BUT WITH MARGINAL
SURFACE TEMPERATURES ESPECIALLY ACROSS THE HIGHER TERRAIN.  SO THE
POTENTIAL EXISTS FOR A PERIOD OF FREEZING RAIN EARLY ON...WILL
MENTION A MIX OF SNOW/RAIN/FREEZING RAIN TO COVER THIS ACROSS NORTH
CENTRAL/NORTHEAST LOWER.  SATURDAY NIGHT LOOKS CLOUDY AND PERHAPS
FOGGY AS WELL WITH ADVECTION FOG A POSSIBILITY WITH INCREASING LOW
LEVEL DEW POINTS OVER SNOW COVER.

ARCTIC COLD FRONT POISED TO CROSS NORTHERN MICHIGAN ON SUNDAY...WILL
CONTINUE WITH THE FOG AHEAD OF THE FRONT UNTIL IT PASSES...WITH THE
POSSIBILITY OF A BAND OF SNOW BEHIND IT OR AT THE VERY LEAST
SHOULD SEE INCREASING SNOW SHOWERS DEVELOP OFF LAKE SUPERIOR AND
EVENTUALLY LAKE MICHIGAN AS LOW LEVEL TEMPERATURES CRATER
DOWNWARD.

EXTENDED RANGE (SUNDAY NIGHT THROUGH THURSDAY): SUNDAY NIGHT
THROUGH MONDAY: THE PASSAGE OF A COLD FRONT SUNDAY WILL LEAD TO
STRONG COLD AIR ADVECTION AND SUBSTANTIALLY COOLER AIR MOVING INTO
THE REGION SUNDAY NIGHT. DESPITE A LACK OF MOISTURE...LOOKS TO BE
A DECENT CHANCE OF NORTH-NORTHWEST FLOW LAKE EFFECT INTO MONDAY
MORNING BEFORE MOISTURE REALLY STARTS TO WANE. NOT EXPECTING
ANYTHING TOO WILD IN TERMS OF ACCUMULATION.

MONDAY NIGHT THROUGH THURSDAY: SURFACE HIGH PRESSURE CONTINUES TO
BUILD INTO THE REGION...EFFECTIVELY BRINGING ANY LINGERING LAKE
EFFECT TO AN END MONDAY NIGHT. AFTER WHAT COULD BE A VERY COLD
MONDAY NIGHT...A BRIEF MODERATION IN TEMPERATURES IS POSSIBLE ON
TUESDAY BEFORE ANOTHER FRONT SWINGS THROUGH AND BRINGS SNOW
SHOWERS AND ANOTHER SHOT OF COLD AIR FOR TUESDAY NIGHT/WEDNESDAY.
EXPECTING SOME FORM OF LAKE EFFECT TO RESUME LATE WEDNESDAY AND
PERHAPS INTO THURSDAY AS NORTHWEST FLOW RETURNS...ALTHOUGH FAIRLY
LOW CONFIDENCE AS MODEL SPREAD GROWS FAIRLY LARGE FAR OUT.

GILLEN

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 640 PM EST THU NOV 27 2014

MVFR AT TIMES THIS EVENING NEAR LAKE MI. IFR DEVELOPING IN -SN
FRIDAY.

NW-FLOW LAKE EFFECT CLOUDS/-SHSN CONTINUE IN NORTHERN MI.
OCCASIONAL MVFR CIGS/VSBYS POSSIBLE IN -SHSN STREAMING OFF OF
NORTHERN LAKE MI. HIGH PRESSURE WILL PASS SOUTH OF THE REGION LATE
TONIGHT...HELPING TO DIMINISH -SHSN. AS THE HIGH MOVES EAST...-SN
WILL DEVELOP FROM W TO E DURING THE DAY ON FRIDAY. EXPECT IFR
VSBYS TO PREVAIL ONCE THE -SN ARRIVES.

NW WINDS WILL GO LIGHT THIS EVENING...AND BACK TO THE SOUTH BY
FRIDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 359 PM EST THU NOV 27 2014

SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR MOST NEARSHORE ZONES
THIS EVENING...WITH WINDS EXPECTED TO DIMINISH OVERNIGHT AS HIGH
PRESSURE RIDGE SLIDES ACROSS MICHIGAN. WINDS WILL BACK AROUND TO
THE SOUTH/SOUTHWEST FOR FRIDAY AND INCREASE...COULD REQUIRE SOME
SMALL CRAFT ADVISORIES ESPECIALLY ON LAKE MICHIGAN.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST FRIDAY FOR LHZ347>349.

LM...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LMZ323-342-
     344>346.

LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LSZ321.

&&

$$

UPDATE...JAZ
SYNOPSIS...MG
SHORT TERM...MSB
LONG TERM...JPB/GILLEN
AVIATION...JAZ
MARINE...JPB



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