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000
FXUS63 KAPX 010327
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1027 PM EST SAT FEB 28 2015

.UPDATE...
ISSUED AT 1027 PM EST SAT FEB 28 2015

HIGH CLOUDS CONTINUE TO INCREASE AND THICKEN ACROSS SRN SECTIONS
OF OUR CWA LATE THIS EVENING...BUT THE NRN EDGE OF THE MID CLOUD
SHIELD IS FAST APPROACHING AS THE STRONG MID MISSISSIPPI VALLEY
WAVE TRACKS NORTH OF THE OHIO VALLEY. AS LOW AND MID LEVEL
MOISTURE CONTINUES TO PUSH NORTHWARD THRU LWR MICHIGAN
OVERNIGHT...AREAS OF LIGHT SNOW WILL BEGIN TO SPREAD INTO
LOCATIONS ALONG AND WEST OF US-131. SYNOPTIC SNOWFALL WILL
CERTAINLY BE ENHANCED BY LIMITED OVER-LAKE INSTABILITY...AS LOW
LEVEL SW FLOW TARGETS THIS ENHANCEMENT INTO THIS AREA. ANY NEW
SNOW ACCUMULATIONS WILL BE MINOR OVERNIGHT...GENERALLY AN INCH OR
LESS.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 331 PM EST SAT FEB 28 2015

ANOTHER GEM OF A LATE WINTER DAY ACROSS NORTHERN MICHIGAN
TODAY...FEATURING NEARLY WALL TO WALL SUNSHINE ACROSS THE STATE AS
LOW LEVEL RIDGING WORKING INTO THE NORTHEAST CONUS MAINTAINS ITS
INFLUENCE ON OUR AREA. TEMPS ARE EVEN COOPERATING FOR ONCE...WITH
HIGHS "SOARING" THROUGH THE 20S - STILL ABOUT 10 DEGREES BELOW
AVERAGE FOR THE FINAL DAY OF FEBRUARY BUT CERTAINLY MUCH MORE
ACCEPTABLE THAN THAT RECENT NONSENSE OF PROLONGED ARCTIC COLD.
UPSTREAM FROM US AT THE MOMENT LIES A RATHER STRUNG-OUT MESS OF
VORTICITY CENTERS WORKING ACROSS THE MID MISSISSIPPI VALLEY...WITH
ASSOCIATED STRONGER PACIFIC JET ENERGY CUTTING THE LOWER 48 IN HALF.
NOT SURPRISINGLY...AS ONE WOULD EXPECT IN SUCH A SETUP...THAT JET
SORT OF MIMICS A NORTH-SOUTH DELINEATION OF WARM VERSUS COLD
AIR...WITH AN AXIS OF ENHANCED FRONTOGENESIS ALONG THIS INTERFACE
EXPECTED TO HELP ELONGATE AN AXIS OF PRECIP ALONG AND SOUTH OF THE
I-80 CORRIDOR OVERNIGHT.

WHILE THAT IS ALL WELL AND GOOD...WHAT DOES THAT MEAN FOR NORTHERN
MICHIGAN? HONESTLY NOT MUCH AS JUST ABOUT ALL OF THE BETTER FORCING
HEADS TO OUR SOUTH...WHILE A RATHER WEAK VORT MAX IS PROGGED TO
DRIFT ACROSS SOUTHERN PARTS OF THE STATE OVERNIGHT. PERSISTENT MID
LEVEL WARM ADVECTION ASCENT SHOULD SPREAD THICKENING CLOUDS NORTH
ACROSS MUCH OF THE AREA TONIGHT...PROBABLY ACTING TO ENHANCE A
LITTLE BIT OF SOUTHWEST FLOW LIGHT SNOW/SNOW SHOWERS ON A MODEST
SOUTHWEST FLOW REGIME. GIVEN THE MAGNITUDE OF DRY AIR OVER MUCH OF
THE AREA...JUST DON`T THINK SNOWS WILL MAKE MUCH INLAND OR NORTHWARD
PROGRESS...AS WE ARE ALSO FIGHTING WIDESPREAD ICE NORTH OF BENZIE
COUNTY...ESPECIALLY TOWARD THE STRAITS. THE ONE EXCEPTION TO THAT
MAY BE AREAS FROM TRAVERSE CITY TO CADILLAC WHERE SOME SNOW SHOWERS
WILL PROBABLY GET PUNTED EASTWARD AFTER 09Z...BUT WITH NO MORE THAN
AN INCH EXPECTED TO FALL FOR ANY ONE SPOT...AND LIKELY MUCH LESS
THAN THAT.

TEMPERATURES ARE VERY TRICKY AS WE HOLD ONTO SURFACE RIDGING THROUGH
06Z...AND THERE WILL BE A PERIOD OF CONTINUED CLEAR SKIES UP THROUGH
MIDNIGHT OR SO. FULLY EXPECT MANY SHELTERED AREAS TO DECOUPLE FOR A
TIME...LEADING TO A QUICK DROP AND THE POSSIBILITY THAT SOME SPOTS
MAY WELL BRIEFLY DIP BELOW 0...BEFORE RISING LATER AS CLOUDS
THICKEN. AFTER THE PAST FEW WEEKS...DON`T THINK A BRIEF PERIOD OF
NEAR ZERO IS ALL THAT BIG OF A DEAL.

&&

.SHORT TERM...(SUNDAY THROUGH TUESDAY)
ISSUED AT 331 PM EST SAT FEB 28 2015

...OCCASIONAL SNOW CHANCES SUNDAY/BETTER SNOW POSSIBILITIES
TUESDAY...

HIGH IMPACT WEATHER POTENTIAL: POTENTIAL ADVISORY LEVEL SNOWFALL
ACCUMULATION TUESDAY.

PATTERN SYNOPSIS/FORECAST: BROAD LONG WAVE TROUGH ENCOMPASSES NORTH
AMERICA...WITH SPLIT FLOW DEVELOPING ACROSS THE WEST WITH A "BLOCKY"
LOOK TO THE SOUTHERN BRANCH ACROSS THE PACIFIC AND INTO THE GREAT
BASIN (OVERALL NEGATIVE PACIFIC TELECONNECTIONS BEAR THIS OUT).
SOUTHERN BRANCH TROUGHING WILL SAG ACROSS CALIFORNIA THIS WEEKEND
WHILE NORTHERN BRANCH HEIGHT FALLS SPREAD ACROSS THE UPPER MIDWEST
AND INTO THE GREAT LAKES.  EASTERN PACIFIC/ALASKA RIDGING WILL HOLD
FAST INTO NEXT WEEK...WITH MORE TROUGHING SETTING UP ACROSS WESTERN
NORTH AMERICA AND HIGHER HEIGHTS AND SOUTHWESTERLY FLOW ALOFT ACROSS
THE EASTERN HALF OF NORTH AMERICA FOR MIDWEEK.  TROUGH AXIS WILL
THEN SLIDE INTO EASTERN NORTH AMERICA IN THE THURSDAY TIME FRAME.

NORTHERN BRANCH ENERGY SHOWS UP NICELY ON WATER VAPOR IMAGERY THIS
AFTERNOON...WITH A NICE BAROCLINIC LEAF FEATURE ACROSS SOUTHERN
MANITOBA/NORTH DAKOTA/MONTANA...AND A SECOND PIECE OF ENERGY
EMERGING FROM ABOVE THE ARCTIC CIRCLE INTO THE NORTHERN PRAIRIE
PROVINCES.  HEIGHT FALLS WITH THIS LATTER PIECE OF SHORT WAVE ENERGY
WILL ROTATE THROUGH THE UPPER MIDWEST/GREAT LAKES SUNDAY NIGHT INTO
EARLY MONDAY...WITH SHORT WAVE RIDGING/STRONG HEIGHT RISES
(+14DM/12H) MONDAY AFTERNOON/EVENING.  HIGH PRESSURE OVER THE MID
ATLANTIC/NORTHEAST THIS AFTERNOON ALLOWING FOR WARM ADVECTION TO
SPREAD INTO THE MIDWEST/OHIO VALLEY AND EVENTUALLY INTO THE GREAT
LAKES TONIGHT.  ANOTHER COLD FRONT WILL CROSS THE FORECAST AREA
SUNDAY NIGHT...SWINGING WINDS BACK AROUND NORTHWEST AND ANOTHER PUSH
OF COLD AIR FOR MONDAY.  HIGH PRESSURE BUILDS INTO MICHIGAN MONDAY
NIGHT...BUT GIVES WAY QUICKLY TUESDAY WITH ANOTHER ROUND OF
SOUTHERLY WINDS/WARM ADVECTION AND PERHAPS A MORE FOCUSED SNOW
THREAT FOR MICHIGAN TUESDAY INTO TUESDAY NIGHT.

PRIMARY FORECAST CONCERNS: SNOW CHANCES SUNDAY/SUNDAY NIGHT...AND
BETTER LOOKING SNOW THREAT FOR TUESDAY.

SUNDAY...PRIMARY FOCUS FOR SYNOPTIC WARM ADVECTION SNOWS SUNDAY
MORNING WILL PROBABLY BE SOUTH OF THE FORECAST AREA...THOUGH SOME
MOISTURE IN THE 850-700MB LAYER EARLY ON MAY SQUEEZE OUT SOME LIGHT
SNOW SHOWERS/FLURRIES PARTICULARLY ACROSS NORTHEAST LOWER.
INCREASING LOW LEVEL MOISTURE ACROSS THE OPEN PART OF LAKE MICHIGAN
LIKELY TO INCREASE LAKE CONVECTION INTO AREAS DOWNWIND OF A
SOUTHWEST TRAJECTORY OFF THE LAKE.  LATE IN THE DAY INTO SUNDAY
EVENING...NORTHERN BRANCH HEIGHT FALLS SPREAD ACROSS THE UPPER
LAKES...WHICH MAY BRING ANOTHER CHANCE FOR SOME SYNOPTICALLY DRIVEN
LIGHT SNOW MAINLY ACROSS NORTHERN LOWER. BUT OVERALL LOOKS PRETTY
DISORGANIZED AND OUTSIDE OF THE POTENTIAL LAKE EFFECT AREAS WILL BE
PRETTY GENERIC WITH POPS AS MANY AREAS MAY NOT SEE MUCH DURING THE
DAY SUNDAY.  NEXT COLD FRONT CROSSING OVER THE LAKES MAY BRING A
BAND OF CONVECTIVE SNOW SHOWERS ACROSS THE FORECAST AREA SUNDAY
EVENING AND INTO THE EARLY MORNING HOURS MONDAY...FOLLOWED BY SOME
NORTHWEST FLOW LAKE BANDS DEVELOPING AS WINDS VEER BEHIND THE COLD
FRONT.  BUT WITH AS MUCH ICE AS THERE IS OUT ON LAKES MICHIGAN/
SUPERIOR CAN`T IMAGINE ANY OF THIS WOULD AMOUNT TO MUCH.

MONDAY...RISING SURFACE PRESSURE/HEIGHTS ALOFT SIGNAL A QUIET DAY
FOR MONDAY...WITH JUST THE USUAL LITANY OF NUISANCE "MESOSCALE CLOUD
ISSUES IN A SYNOPTIC SCALE TIME FRAME" THAT DRIVES FORECASTERS TO
KANSAS AFTER ENOUGH YEARS UP HERE.  HIGH PRESSURE SLIDES ACROSS
LOWER MICHIGAN MONDAY EVENING...WITH CLEARING SKIES AND AN INITIALLY
FLAT PRESSURE GRADIENT ANOTHER CHILLY NIGHT IS IN STORE.  WINDS WILL
LIKELY PICK UP OVERNIGHT OVER EASTERN UPPER/NORTHWEST LOWER...AND
CLOUDS WILL SPREAD IN AND THICKEN FROM THE SOUTHWEST...SO WE`LL SEE
HOW COLD WE CAN EVENTUALLY GET BUT SINGLE DIGITS ABOVE AND BELOW
ZERO IS PROBABLY A GOOD START.

TUESDAY...EXPECT SNOW TO SPREAD ACROSS NORTHERN MICHIGAN TUESDAY
MORNING (HEDGING SLOWER THAN WOULD BE IMPLIED BY THE GFS).  UNLIKE
SUNDAY`S "EVENT"...STRONGER FORCING EXPECTED ACROSS MICHIGAN AIDED
BY JET FORCING AND A BETTER PUSH OF MOISTURE INTO THE UPPER LAKES
(FORECAST PRECIPITABLE WATER VALUES ABOVE 0.50 INCH).  DEFINITELY
POTENTIAL THERE FOR 0.25+ INCH QPF AMOUNTS DURING THE DAY
TUESDAY...WITH WARMING TEMPERATURES LIKELY LEADING TO LOWERING
SNOWFALL RATIOS (AROUND 15:1 ON AVERAGE...LIKELY SOME GRADIENT FROM
NORTH TO SOUTH).  SO FIRST GUESS SNOWFALL AMOUNTS WILL BE 3-5 INCHES
AREAWIDE...AND WILL ADJUST GOING FORWARD.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 331 PM EST SAT FEB 28 2015

AT THE START OF THE PERIOD...LOW PRESSURE CENTERED OVER SOUTHERN
MICHIGAN WILL CONTINUE TO SLIDE NORTHEASTWARD INTO SOUTHERN ONTARIO.
AS IT DOES SO...TUESDAY`S SYNOPTIC SNOW WILL GRADUALLY COME TO AN
END FROM WEST TO EAST ACROSS THE CWA TUESDAY NIGHT INTO VERY EARLY
WEDNESDAY. COULD SEE A FEW LINGERING SNOW SHOWERS ACROSS PARTS OF
THE AREA WEDNESDAY INTO WEDNESDAY NIGHT AS A SECONDARY WEAK UPPER-
LEVEL WAVE MOVES OVERHEAD...BUT BY ALL MEANS DOESN`T LOOK TO ADD UP
TO MUCH (IF ANY) ADDITIONAL SNOW ACCUMULATION. ANOTHER SHOT OF
CHILLY AIR IS EXPECTED TO PUSH INTO THE NRN GREAT LAKES...WITH
THURSDAY LOOKING LIKE ANOTHER POTENTIALLY CHILLY DAY AS HIGHS STAY
STUCK IN THE LOW TEENS (WEDNESDAY NIGHT LOWS IN THE SINGLE DIGITS
BELOW ZERO). THE COLD AIR WON`T LAST LONG THROUGH AS A RATHER
PROGRESSIVE PATTERN AIDS IN MODERATING TEMPS FOR FRIDAY INTO THE
WEEKEND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 613 PM EST SAT FEB 28 2015

SOLID VFR CONDITIONS WILL CONTINUE THIS EVENING FOR ALL NRN LWR
MICHIGAN TAF SITES. CONDITIONS WILL DETERIORATE TO MVFR/IFR LATE
TONIGHT AND SUNDAY AS THE NRN EDGE OF A LIGHT SNOW SHIELD SLIPS
BOTH TVC AND MBL AS LOW PRESSURE TRACKS JUST NORTH OF THE OHIO
VALLEY. SOME LAKE ENHANCEMENT WILL LEND SUPPORT AND MOISTURE TO
THIS AREA OF SNOW...ALSO TARGETING TVC AND MBL FOR THE BEST
CHANCES OF SNOW AND LOWEST CONDITIONS. LLWS WILL DEVELOP LATER
THIS EVENING AND WILL CONTINUE INTO SUNDAY MORNING AS THE BOUNDARY
LAYER DECOUPLES AND SW WINDS JUST OFF THE DECK STRENGTHEN NORTH OF
THE LOW. S/SW SURFACE WINDS BELOW 10 KTS TONIGHT INTO EARLY SUNDAY
WILL INCREASE TO AROUND 10 KTS BY MIDDAY SUNDAY...WITH A FEW
HIGHER GUSTS POSSIBLE.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...MLR
NEAR TERM...LAWRENCE
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...MLR