000
FXUS63 KAPX 291635
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1135 AM EST THU JAN 29 2015

.UPDATE...
ISSUED AT 1135 AM EST THU JAN 29 2015

14Z SURFACE ANALYSIS SHOWS OCCLUDED 1006MB LOW ALONG THE MICHIGAN/
INDIANA BORDER...WITH AN INVERTED TROUGH EXTENDING NORTH UP THE LONG
AXIS OF LAKE MICHIGAN.  SECONDARY COLD FRONT STRETCHES ACROSS LAKE
SUPERIOR/WESTERN UPPER MICHIGAN/NORTHWEST WISCONSIN.  WATER VAPOR
IMAGERY SHOWS A COUPLE WELL-DEFINED VORTICITY CENTERS OVER CENTRAL
INDIANA AND CENTRAL IOWA RESPECTIVELY.  SHORT WAVE TROUGH OVER
INDIANA AND ITS ATTENDANT SURFACE LOW/INVERTED TROUGH HELPING DRIVE
SNOWFALL ACROSS THE FORECAST AREA THIS MORNING...ALONG WITH SOME
FRONTOGENESIS/WEAK STATIC STABILITY AROUND 700MB HELPING FOCUS AN
EARLIER SNOW BURST OVER NORTHERN LOWER (GETTING REPORTS OF 4-6+
INCHES LOCALLY).  A SECOND NARROW BAND OF SNOW LIES RIGHT ALONG/
AHEAD OF THE INVERTED TROUGH AXIS.  SOME LOW LEVEL FRONTOGENESIS
OCCURRING ALONG SECONDARY COLD FRONTAL ZONE.

BACK EDGE OF THE SYNOPTIC SNOW WILL CONTINUE TO SWEEP ACROSS
NORTHERN LOWER THIS AFTERNOON...SHOULD EXIT FAR SOUTHEAST PORTION OF
THE FORECAST AREA TOWARD 21Z.  STRONGER COLD ADVECTION ARRIVES
DURING MID/LATE AFTERNOON WHICH SHOULD GIN UP SOME LAKE CONVECTION
IN NORTH-NORTHWEST LOW LEVEL FLOW...THOUGH PRIOR TO THAT MOIST LOW
LAYERS AND MODESTLY STEEP LAPSE RATES COULD ALLOW FOR SOME FREEZING
DRIZZLE/FLURRIES ESPECIALLY IN THE HIGHER TERRAIN WITH MARGINAL
CLOUD LAYER TEMPERATURES FOR ICE NUCLEATION.  LIGHT WINDS WILL BEGIN
TO RAMP UP DURING THE MID/LATE AFTERNOON AS WELL.

WILL LET ADVISORY DROP OFF WITH FORECAST ISSUANCE.

UPDATE ISSUED AT 617 AM EST THU JAN 29 2015

QUICK UPDATE FOR BAND OF MODERATE SNOW DEVELOPING IN A BAND OF
FGEN FROM LEELANAU COUNTY THROUGH TVC...GAYLORD AND OVER TOWARD
ROGERS CITY AND ALPENA. INCREASED SNOW AMOUNTS TO 2-3 INCHES OF
SNOW THROUGH THE MORNING.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 342 AM EST THU JAN 29 2015

...STRONG WINDS DEVELOPING THIS AFTERNOON AND EVENING...

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...SHALLOW MID LEVEL RIDGING AND LOW LEVEL WARMING
FROM YESTERDAY IS SHUNTING OFF TO THE EAST...WHILE NEXT UPPER LEVEL
TROUGH IS ADVANCING INTO THE GREAT LAKES. THIS TROUGH HAS TWO
EMBEDDED AND WELL DEFINED SHORTWAVES AND ASSOCIATED SFC LOWS. ONE IS
CROSSING THE MID MISSISSIPPI VALLEY WHILE THE OTHER IS CROSSING INTO
FAR WESTERN LAKE SUPERIOR. STRONG DEEP LAYER WAA IS ALREADY
OCCURRING OVERHEAD WITH 50-60KT LLJ..AS WELL AS A POCKET OF UPPER
DIVERGENCE ASSOCIATED WITH A DOUBLE JET STRUCTURE ALOFT...AND RADAR
HINTS AT SOME FGEN ALOFT. THIS FORCING IS TRYING HARD TO SATURATE
ATMOSPHERE...BUT THUS FAR...WE STILL HAVE A FAIRLY DRY SUB 750MB
LAYER...AND ONLY SOME LIGHT SNOWS HAVE BEEN ABLE TO REACH GROUND
(ALTHOUGH EXPANDING). THE BETTER ECHOES WERE LIFTING INTO EASTERN
UPPER...WHILE ANOTHER POCKET OF SNOW IS LIFTING OUT OF NE LOWER
(ASSOCIATED WITH BETTER LOWER LEVEL MOISTURE) TOWARD SW LOWER
MICHIGAN.

FURTHER NORTH...MUCH COLDER AIR IS SEEN BACK BEHIND THE NRN SFC
LOW...WITH TEMPERATURES IN THE TEENS AND SINGLE DIGITS. THERE`S A LOT
GOING ON...WITH LITTLE IN THE WAY OF SNOW RIGHT NOW...BUT IT`S
TRYING.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

ALL OF THE FORCING DISCUSSED ABOVE WILL CONTINUE TO INVADE NRN
MICHIGAN THROUGH DAYBREAK...WITH SOME BETTER LOW LEVEL MOISTURE
TRYING TO BE LIFTED UP INTO THE REGION. SNOWS ARE EXPECTED TO
CONTINUE EXPANDING OVER THIS TIME PERIOD. ALL OF THE UPPER LEVEL
FORCING WILL EXIT THROUGH THE MORNING HOWEVER...AS THE SFC LOWS
ARRIVE. A TERTIARY SHORTWAVE ALOFT THEN RACES SE IN STRONG FLOW
ALOFT. THIS WILL HELP FORCE THE LOW LEVEL COLD AIR THROUGH US DURING
THE AFTERNOON AND EVENING. THIS ALSO TIGHTENS UP THE LOW LEVEL
BAROCLINICITY..AND THERE ARE ADDITIONAL HINTS OF LOW LEVEL FGEN.
REALLY QUITE THE MESSY FORCING/PATTERN OUT THERE...AND SNOWS WILL BE
BASICALLY DEVELOPING OVERHEAD FOR THIS "EVENT". UPDATES TO THE
FORECAST WILL HAVE TO BE MADE WHILE WATCHING RADAR THROUGH
DAYBREAK...BUT FEELING IS THAT THE SNOWFALL FORECAST MAY BE A TAD
TOO HIGH AT THIS PARTICULAR TIME. THE POCKET OF SNOW SHOULD EXPAND
AND LIFT TOWARD NE LOWER...WHILE ADDITIONAL SNOWS CONTINUE TO
DEVELOP ALONG SFC TROUGH AXIS/COLD FRONT FROM THE NRN SFC LOW
THROUGH THE MORNING. THE POSSIBLE ENHANCED LOW LEVEL FGEN IS LIKELY
TO BRING A BAND OF SNOW ALONG THAT COLD FRONT...INTO THE REGION
LATER THIS MORNING AND EARLY AFTERNOON.

AM THINKING OF A GENERAL 1-2" WITH PORTIONS OF NE LOWER POSSIBLY
SEEING 3"...AND MORE TRACE MOUNTS CLOSER TO THE MANISTEE AREA.

LATE THIS AFTERNOON AND HEADING INTO TONIGHT...NNW WINDS INCREASE
AND BECOME RATHER GUSTY...ESPECIALLY NEAR THE LAKE MICHIGAN
SHORELINE...DOWNWIND OF LESS ICE COVERAGE AND GREATER INSTABILITY.
H8 TEMPERATURES CRASH INTO THE TEENS BELOW ZERO...AND WHILE MOISTURE
WILL BE MORE SCANT THAN ANYTHING...LIGHT LAKE EFFECT SNOW SHOWERS
WILL DEVELOP. ADDITIONAL ACCUMULATIONS WILL BE LIGHT/MINIMAL.
INVERSION HEIGHTS AVERAGING 4000-4500 FEET...COLDER THAN OPTIMAL
TEMPS AND AND A RELATIVELY DRY NEAR SFC LAYER. THIS TO LEAD TO MAYBE
AND INCH ACROSS THE GTV BAY...A HALF INCH OR LESS ACROSS EASTERN
UPPER...ESPECIALLY WESTERN SECTIONS FOR GREATER FETCH AND LESS ICE
COVER. THESE AMOUNTS ARE ALSO LIKELY SCRAPING ROGERS CITY/ALPENA
AREAS WHERE THERE IS MORE OPEN WATER.

CURRENT MILDER TEMPERATURES WILL FALL LATER THIS MORNING NORTH...AND
THIS AFTERNOON ACROSS NRN LOWER. THESE TEMPERATURES WILL CONTINUE TO
FALL THROUGH THE NIGHT...REACHING MAINLY SINGLE DIGITS ABOVE
AND BELOW ZERO.

&&

.SHORT TERM...(FRIDAY THROUGH SATURDAY NIGHT)
ISSUED AT 342 AM EST THU JAN 29 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING TOO MAJOR FOR THE FINAL DAYS
OF JANUARY. GUSTY NORTH WINDS AND SOME BLOWING SNOW POTENTIAL FRIDAY
MORNING...WITH OTHERWISE MAINLY JUST LIGHT LAKE INDUCED SNOW
SHOWERS.

A FAMILIAR PATTERN FOR SURE THIS WINTER...FEATURING BRIEF INTRUSIONS
OF DEEPER UPPER TROUGHING AND ASSOCIATED QUITE CHILLY CONDITIONS
INTO THE GREAT LAKES...FOLLOWED BY A QUICK RECOVERY IN ADVANCE OF
THE NEXT APPROACHING WEAK NORTHERN STREAM SHORTWAVE. INDEED THAT
LOOKS TO BE THE SETUP THROUGH THE FIRST HALF OF THE WEEKEND...WITH A
QUICK ROUND OF ROBUST UPPER TROUGHING INTO FRIDAY...FOLLOWED QUICKLY
BY RISING HEIGHTS LATE IN THE DAY AND INTO FRIDAY NIGHT...AHEAD OF
OUR NEXT WEAK AND MOISTURE-STARVED SHORTWAVE SLATED TO ARRIVE
SOMETIME ON SATURDAY...COMPLETE WITH ANOTHER COLD FRONT PASSAGE TO
USHER IN OUR NEXT ROUND OF MODIFIED ARCTIC AIR INTO THE EARLY WORK
WEEK PERIOD. SHEW...THAT WAS A MOUTH-FULL.

FROM A SENSIBLE WEATHER PERSPECTIVE...NOTHING OVERLY DRAMATIC BY
VERY LATE JANUARY STANDARDS...WITH THE INCOMING AIRMASS ON FRIDAY
MORE THAN PLENTY COLD TO SUPPORT A LAKE RESPONSE...BUT WITH THE
DEPTH MOISTURE SEVERELY LACKING. THAT WON`T MATTER ALL THAT MUCH AS
THE SUB-850MB AIRMASS IS IN THE "SWEET SPOT" FOR DENDRITIC GROWTH IN
THE -15C TO -19C RANGE AND LAKE-INDUCED OMEGA NICELY BISECTS THAT
REGION. HOWEVER...INCREASINGLY ANTICYCLONIC AND LIGHT FLOW THROUGH
THE DAY WON`T EXACTLY HELP THE CAUSE...WITH INITIAL 340-ISH DEGREE
FLOW BECOMING RATHER DISORGANIZED AFTER 18-21Z AS THE LOW LEVEL FLOW
STARTS TO BACK WHILE ALSO DECREASING TO LESS THAN 5 KNOTS. AS
SUCH...WHILE IT WILL CERTAINLY SNOW FOR THE FAVORED FLOW REGIMES...
AMOUNTS SHOULD REMAIN WELL IN CHECK...WITH PERHAPS AN INCH (WORST
CASE SCENARIO: 2 INCHES) OF FLUFF THROUGH THE DAY ON FRIDAY.
CONTINUED TIGHT GRADIENT FIRST THING FRIDAY MORNING SHOULD CONTINUE
THE RISK FOR SOME AREAS OF DRIFTING SNOW...MAINLY OPEN AREAS OF
COURSE. IN ADDITION...TEMPS SHOULD BASICALLY GO NOWHERE THROUGH THE
DAY...PROBABLY STUCK JUST ABOVE ZERO EASTERN CHIPPEWA/MACKINAC
COUNTIES BUT RANGING THROUGH THE MID TEENS SOUTHWEST COUNTIES WHERE
NORTH FLOW WON`T BE ABLE TO "DRAIN" ARCTIC AIR FROM ONTARIO AS
EFFECTIVELY.

BACKING FLOW AND SLOWLY WARMING THERMAL PROFILES FRIDAY NIGHT INTO
EARLY SATURDAY SHOULD HELP SPREAD CLOUDS AND PROBABLY SOME LIGHT
SNOW SHOWERS/FLURRIES BACK INLAND...AS WE AWAIT OUR NEXT CLIPPER
SYSTEM SET TO ARRIVE LATER IN THE DAY. THIS SYSTEM LOOKS LESS THAN
IMPRESSIVE AND IS REALLY JUST A GLORIFIED COLD FRONT PASSAGE.
STILL...INTERACTION OF SHALLOW COLD ADVECTION JUST BEHIND THE
BOUNDARY WILL LIKELY BE ENOUGH TO DRIVE ANOTHER ROUND OF MAINLY
LIGHT SNOW SHOWERS ACROSS MANY AREAS INTO THE AFTERNOON AND EARLY
EVENING. PONDERED THE INTRODUCTION OF SOME FREEZING DRIZZLE DURING
THIS PERIOD AS WELL...AS WE SEE SHALLOW ARCTIC AIR UNDERCUT AN
OVERALL "WARMER" CLOUD DECK JUST BARELY SUPPORTIVE OF ICE.
HOWEVER...THE AMBIENT AIRMASS ALONE APPEARS JUST COLD ENOUGH TO
SUPPORT MOSTLY ICE-PRODUCING CLOUDS...SO MAYBE WE END UP WITH JUST
SOME LIGHT SNOW OR EVEN (WAIT FOR IT - EVERYONE`S FAVORITE WORD)
"SNIZZLE" INTO EARLY EVENING. AFTER THAT...NOT MUCH INTO SATURDAY
NIGHT AS LOW LEVEL RIDGING AGAIN FOLDS IN FROM ONTARIO...BUT WILL BE
WATCHING OUR NEXT POTENTIAL SYSTEM UNFOLDING JUST UPSTREAM (MORE ON
THAT BELOW).

&&

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 342 AM EST THU JAN 29 2015

PLENTY OF UNCERTAINTY AS WE HEAD INTO THE SUNDAY/MONDAY TIME
FRAME...AND IT ALL HINGES ON JUST HOW MUCH AMPLIFICATION WE CAN GET
WITH A STRONGER NORTHERN STREAM WAVE DIVING THROUGH THE EASTERN
ROCKIES AND ATTEMPTING TO INTERACT WITH STRONGER SOUTHERN STREAM
ENERGY MEANDERING OVER THE DESERT SOUTHWEST. VARIOUS MODEL SOLUTIONS
OFF A WIDE RANGE OF POTENTIAL OUTCOMES...WITH THE 29/00Z NAM AND
28/12Z GGEM CERTAINLY THE MOST AMPED SOLUTIONS...WHILE THE GFS AND
ECMWF CONTINUE TO DOWNPLAY THAT INTERACTION...THOUGH EVEN THESE
MODELS HAVE A TIMES HINTED AT A MORE AMPLIFIED SOLUTION THE PAST FEW
DAYS. CONFIDENCE REMAINS QUITE LOW AS TO THE OUTCOME...BUT BASED ON
HISTORY THIS WINTER AND THE MORE DOMINANT NORTHERN STREAM TO
DATE...MY GUT FEELING IS ON A MORE SOUTHERLY/SUPPRESSED SOLUTION
WORKING OUT...WHICH WOULD SEVERELY LIMIT THE THREAT FOR ANY SYNOPTIC
SNOW THIS FAR NORTH. THIS IDEA IS ALSO TIED TO THE STRENGTH OF
SOUTHERN CANADA HIGH PRESSURE SYSTEMS THIS WINTER...WHICH WILL
LIKELY ACT TO DRIVE A WEDGE OF DRY AIR ACROSS NORTHERN MICHIGAN...
THUS FURTHER LIMITING OUR SNOW RISK. WITH THAT SAID...CERTAINLY THIS
BEARS WATCHING OVER THE NEXT FEW DAYS AS THINGS CAN CHANGE...AND
OFTEN HAVE CHANGED DRASTICALLY THIS SEASON.

OTHERWISE...LOOKS LIKE ANOTHER ROUND OF MODIFIED ARCTIC AIR AND
NORTHERLY FLOW LAKE EFFECT IS IN THE WORKS INTO MIDWEEK...WITH TEMPS
WELL BELOW NORMAL AND SEVERAL CHANCES FOR INLAND AREAS TO DIP BELOW
ZERO AT NIGHT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 617 AM EST THU JAN 29 2015

...TVC AND APN WITH A PERIOD OF MODERATE SNOW THIS MORNING...

SFC LOW PRESSURE DRIFTING ACROSS THE REGION TODAY WITH MOST AREAS
SEEING LIGHT SNOW AMOUNTS. HOWEVER...A BAND OF STRONGER LIFT AND
HEAVIER SNOWS HAS DEVELOPED FROM TVC TO APN. AM EXPECTING HALF
INCH TO ONE INCH PER HOUR SNOWS INTERMITTENTLY THROUGH 15-16Z AND
2 TO 3 INCHES OF SNOW. MOST ALL FORCING WILL BE GONE BY AFTERNOON
WITH ONLY SOME POTENTIAL VERY LIGHT REMNANT SNOWS. WINDS WILL ALSO
BECOME STRONG AND GUSTY LATE THIS AFTERNOON AND THIS EVENING AFTER
THE PASSAGE OF A COLD FRONT.

GRADIENT WILL SLACKEN ACROSS APN OVER THE NEXT FEW HOURS WITH WINDS
BEING VARIABLE OF 5 KTS OR LESS FOR ALL AIRPORTS PRIOR TO THE
FRONTAL PASSAGE. WINDS WILL EVENTUALLY GUST TO 25-35 KNOTS
(HIGHEST NEAR MBL) LATE THIS AFTERNOON AND THIS EVENING BEFORE A
SLIGHT DROP OFF IS EXPECTED OVERNIGHT.


&&

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

$$

UPDATE...JPB
NEAR TERM...SMD
SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...SMD