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000
FXUS63 KMQT 072337
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
637 PM EST SAT DEC 7 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS DIGGING FROM NRN
CA INTO NEVADA. AT THE SFC...WRLY WINDS PREVAILED THROUGH THE UPPER
GREAT LAKES TO THE NORTH OF THE ARCTIC RIDGE BUILDING FROM THE NRN
PLAINS AND UPPER MS VALLEY TO THE SRN LAKES. VERY COLD AIR REMAINED
WITH MID AFTERNOON READINGS ONLY CLIMBING INTO THE 5F TO 15F RANGE
THROUGH MID AFTERNOON. VIS SATELLITE INDICATED BACKING WINDS OVER
WRN LAKE SUPERIOR WITH THE LES BANDS BECOMING ALIGNED FROM SW-NE.

TONIGHT...EXPECT LES BANDS INTO THE KEWEENAW TO LIFT SLOWLY
NORTHWARD THIS EVENING. EVEN THOUGH THE HIGHER RES MODELS INDICATED
PERSISTENT LOW LEVEL CONV AND LES FROM AT LEAST CMX
NORTHWARD...CONFIDENCE IS LOWER GIVEN THE SATELLITE TRENDS. SO...THE
ONGOING HEADLINES WERE RETAINED FOR NOW BUT MAY NEED TO BE LIFTED
EARLIER THAN PREVIOUSLY FCST. IF A DOMINANT BAND CAN REDEVELOP AND
BRUSH THE WRN SHORE OF THE KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS OF
3 TO 6 INCHES MAY BE POSSIBLE.

WITH A PERIOD OF FAVORABLE RADIATIONAL COOLING UNTIL LATE TONIGHT...
EXPECT MIN TEMPS NEAR LOWER END OF GUIDANCE WITH LOW TO MID TEENS
BELOW ZERO ACROSS MUCH OF THE WRN INTERIOR RANGING TO AROUND ZERO
OVER THE INTERIOR EAST. WINDS INTO THE 5 T0 10 MPH RANGE TIL LATE
TONIGHT CAUSED WIND CHILL READINGS TO DIP TO NEAR 25 BELOW...SO THE
WIND CHILL ADVISORY WAS RETAINED. THE POTENTIAL FOR INCREASING HIGH
CLOUDS LATE TONIGHT COULD CAUSE TEMPS TO LEVEL OFF A BIT OR RISE
SLIGHTLY TOWARD 12Z SUN.

SUN...ANY REMAINING LES IS EXPECTED TO LIFT TO THE NORTH OF KEWEENAW
AS WINDS BACK IN THE DEVELOPING WAA PATTERN. A BROAD AREA OF
280K-290K ISENTROPIC LIFT WILL BRING LIGHT SNOW FROM MN/WI INTO
UPPER MI DURING THE AFTERNOON. ALTHOUGH...THE VERY DRY LOW LEVELS IN
THE ARCTIC AIRMASS MAY DELAY THE ONSET OF THE PCPN...EXPECT AT LEAST
SOME LIGHT SNOW OVER THE SOUTH IN THE AFTERNOON THAT WILL SPREAD
THROUGH THE REST OF THE CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS
BY 00Z/09 WILL BE RELATIVELY LIGHT...AROUND A HALF INCH OR
LESS...MAINLY OVER THE SOUTH.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013

DEEP TROUGHING ORIENTED FROM EASTERN CANADA ACROSS THE GREAT LAKES
AND WEST TO THE SOUTHWEST CONUS IS REINFORCED THROUGHOUT THE UPCOMING
WEEK. COLD AIRMASS MAY FINALLY MAY START TO RELAX BY NEXT WEEKEND AS
FLOW ALOFT BECOMES MORE ZONAL. FLOW PATTERN THIS WEEK REMAINS ACTIVE
ACROSS THE UPPER LAKES. A COUPLE OF SYSTEMS WILL CROSS THE AREA WITH
WIDESPREAD SYSTEM SNOWS. MOST SIGNIFICANT OF THESE WILL OCCUR SUNDAY
NIGHT AS SHORTWAVE/PV ANAMOLY CROSSING NEVADA/UTAH THIS AFTN/EVENING
HEADS OUT INTO CNTRL PLAINS SUNDAY AFTN THEN LIFTS ACROSS UPPER
GREAT LAKES SUNDAY NIGHT. SLIGHT WARM AIR ADVECTION...RELATIVE
TERM IN THIS AIRMASS...OCCURS OVER SOUTH CENTRAL AND EASTERN CWA
SUNDAY EVENING WITH PVA/DEEP LAYER FORCING THROUGH REST OF NIGHT.
CROSS-SECTIONS INDICATE VERY SHALLOW FGEN FORCING BLO H9...MAINLY
SOUTH AND EAST. MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV TO RESULT
IN HEAVIER BANDED SNOW THOUGH. ENHANCEMENT TO SYSTEM SNOW MAY OCCUR
NEAR BAY OF GREEN BAY AND LK MICHIGAN WITH ESE/E WINDS IN LOW-LEVELS
WITH TEMPS AT INVERSION TOP OF H85 AROUND -10C /LK MICHIGAN WATER
TEMPS ARE AROUND +5C/. TRICK IS HOW LONG FAVORABLE WIND DIRECTION
PERSISTS AND WHETHER THERE IS TOO MUCH SHEAR IN LAKE CONVECTIVE
LAYER TO OFFSET THIS. EXPECT GENERAL 2-4" OF SYNOPTIC SNOW WITH
MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED MODEL QPF USING
SLR/S 17-19:1. BASED ON SOUNDINGS...HIGHER SLR/S SEEMED TOUGHER TO
ACHIEVE AS BULK OF LIFT WILL BE OCCURRING AT TEMPS LESS THAN -20C.
SLR/S WILL PROBABLY BE EVEN LOWER HEADING FARTHER NORTH INTO UPR
MICHIGAN...SO SNOW AMOUNTS OF AN INCH MAYBE TWO ARE EXPECTED CLOSER
TO LK SUPERIOR SHORE. ISSUED WINTER WEATHER ADVY FOR THE SYSTEM
SNOW. BASED ON SREF PLUMES AND FCST POPS...VALID TIME OF ADVY FAR
SCNTRL WILL START LATE SUNDAY AFTN AND GO THROUGH DAYBREAK ON
MONDAY. ADVY FOR ZONES TO THE EAST WILL START AND END A FEW HOURS
LATER.

LOW PRESSURE SYSTEM LIFTS TO NORTHEAST OF LK SUPERIOR BY 18Z ON
MONDAY AND THIS WILL USHER IN ANOTHER RETURN TO THE COLD AND WINDY
WEATHER THAT OCCURRED LATE THIS LAST WEEK INTO TODAY. AND YES...LAKE
EFFECT SNOWS...HEAVY AT TIMES...WILL RAMP UP AGAIN IN THE AREAS
FAVORED BY WNW-W FLOW. SO...ONCE AGAIN...KEWEEENAW PENINSULA WILL BE
IN LINE FOR HEAVY LK EFFECT SNOWS. SOUNDINGS IN WAKE OF THE LOW
PRESSURE INDICATE MOIST/UNSTABLE PROFILE TO H7 WITH SHARP CONVERGENCE
DEVELOPING ACROSS KEWEENAW BY MID MORNING MONDAY AND CONTINUING
THROUGH AT LEAST LATE EVENING ON MONDAY NIGHT. SIMILAR TO
THURSDAY...IF WESTERLY FLOW CAN PERSIST IN ONE AREA...LEADING TO
STRONG CONVERGENCE...FOOT PLUS AMOUNTS WILL BE POSSIBLE ACROSS CNTRL
HOUGHTON COUNTY... AFFECTING PAINESDALE...ATLANTIC MINE...HOUGHTON
AND HANCOCK AND POSSIBLY AS FAR NORTH AS CALUMET AND MOHAWK. LAKE
EFFECT HEADLINES ARE RUNNING THEIR COURSE CURRENTLY...SO DID NOT
WANT TO PUT UP ANOTHER LK EFFECT SNOW WATCH AT THIS TIME. WILL LET
MID SHIFT ASSESS THIS POTENTIAL. MAIN ISSUE AWAY FM THE INCREASING
LK EFFECT BY MONDAY AFTN WILL BE ANOTHER BLAST OF COLD TEMPS AND
LOWERING WIND CHILL READINGS.

DOES APPEAR THAT AS STRONGER SHORTWAVE/PRETTY DECENT AREA OF H7-H5
Q-VECTOR CONVERGENCE ARRIVES LATER MONDAY NIGHT...BLYR WINDS BACK SW
ENOUGH TO DISRUPT HEAVIER SNOW ON THE KEWEENAW. THIS MAY PROVIDE A
GOOD BREAK POINT FOR WHATEVER HEADLINE IS ISSUED FOR MONDAY AND
MONDAY EVENING...THOUGH THERE IS A CHANCE THE HEAVIER SNOW BANDS
WILL JUST MAKE INTO KEWEENAW COUNTY BEFORE STALLING OUT. TOUGH TO
SAY AT THIS POINT. SOUNDINGS ELSEHWERE INDICATE ENOUGH MOISTENING
AND LIFT TO INCREASE POPS FOR THE SYSTEM...ESPECIALLY NORTH HALF.
SNOW AMOUNTS FM THE SYSTEM WILL BE ON THE LGT SIDE...LESS THAN AN
INCH MAINLY. OTHER IMPACT FM THE SHORTWAVE WILL BE FOR TEMPS TO TRY
TO RISE SOME LATER MONDAY NIGHT AS THE WINDS INCREASE. THIS MAKES
FOR TRICKY WIND CHILL FORECAST. CURRENT FCST FOR WINDS AND TEMPS
DOES SUGGEST THAT WESTERN HALF OF CWA MAY SEE WIND CHILL CRITERIA
BE MET AT TIMES ON MONDAY NIGHT INTO TUESDAY MORNING. LAST IMPACT
FROM THE SYSTEM WILL BE TO PUSH STRONGER SFC TROUGH SOUTH ACROSS LK
SUPERIOR RESULTING IN MORE OF A NW WIND IN BLYR FOR TUESDAY/TUESDAY
NIGHT. USED LK EFFECT CLIMATOLOGY POPS TO BRING HIGHER POPS TO AREAS
FAVORED BY WNW FLOW SUCH AS ONTONAGON COUTNY AND ALSO IN THE EASTERN
CWA...MAINLY EAST OF MUNISING AND TO THE NORTH OF NEWBERRY.

IN WAKE OF THE TROUGH PASSAGE...COLDEST AIR OF WEEK POURS ACROSS
WITH H85 TEMPS DOWN TO AROUND -25C TUESDAY NIGHT INTO WEDNESDAY.
MAY HAVE MORE WIND CHILL ISSUES TUESDAY NIGHT INTO WEDNESDAY AS
INLAND TEMPS FALL BLO ZERO AND WINDS STAY UP BEHIND THE TROUGH.
COLDEST DAY OF THE WEEK FOR WEDNESDAY WITH MAX TEMPS OVER INLAND
WEST POSSIBLY STAYING AT OR BLO ZERO THE ENTIRE DAY. COLDEST NIGHT
OF THE WEEK LIKELY ON WEDNESDAY NIGHT. AS WINDS GO CALM MAY SEE MINS
LESS THAN 20 BLO ZERO.

SLIGHT WARMING TREND FOR LATE THIS WEEK...BUT STILL QUITE A BIT BLO
NORMAL FOR DAYTIME HIGHS. WEST/SOUTHWEST FLOW LK EFFECT STAYS IN
PLACE ON KEWEENAW THURSDAY BUT THEN SHOULD REORIENT TO MORE NNW-N
FLOW AREAS ON FRIDAY AS ANOTHER SFC TROUGH SWINGS ACROSS. MAY SEE
SOME SYSTEM SNOW THURSDAY NIGHT INTO FRIDAY AHEAD OF THAT TROUGH BUT
THERE ARE SOME TIMING ISSUES THERE STILL...SO WILL JUST HAVE LOW
CHANCE POPS FOR NOW. DID BUMP UP THE CONSENSUS POPS FOR THE LK
EFFECT AREAS.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 637 PM EST SAT DEC 7 2013

WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND
DIRECTION AT KIWD/KSAW WILL RESULT IN VFR CONDITIONS THRU SUN
MORNING. AT KCMX...LAKE EFFECT SNOW WILL CONTINUE THROUGH EARLY SUN
MORNING AS WINDS WILL CONTINUE TO HAVE ENOUGH OF AN ONSHORE
COMPONENT. WITH HEAVIER SNOW BANDS LIKELY REMAINING N OF KCMX...
EXPECT CONDITIONS TO VARY GENERALLY BTWN IFR AND MVFR THRU THE
NIGHT. WITH LOSS OF ONSHORE WIND COMPONENT SUN MORNING AS WINDS
BACK...CONDITIONS WILL IMPROVE TO VFR. IN THE AFTN...NEXT
DISTURBANCE WILL APPROACH FROM THE SW. EXPECT -SN AND MVFR
CONDITIONS TO SPREAD NE TO ALL TERMINALS DURING THE AFTN...BEGINNING
FIRST AT KIWD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST SAT DEC 7 2013

EXPECT BRIEF BREAK IN STRONGER WINDS OVER LK SUPERIOR LATER THIS
EVENING THROUGH SUNDAY AS PRESSURE GRADIENT WEAKENS. A LOW PRESSURE
SYSTEM MOVING ACROSS THE AREA ON SUNDAY NIGHT...BUT WINDS WILL REMAIN
LESS THAN 25 KTS. AS THE LOW MOVES OUT OF THE AREA ON MONDAY...EXPECT
THE GRADIENT TO TIGHTEN AND WEST GALES TO DEVELOP THROUGH MONDAY
NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL PASS THROUGH THE UPPER GREAT
LAKES TUESDAY INTO WEDNESDAY...POSSIBLY LEADING TO MORE GALES FROM
THE WEST TO NORTHWEST TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW WARNING UNTIL 1 AM EST SUNDAY FOR MIZ003.

  WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ SUNDAY TO 7 AM
     EST /6 AM CST/ MONDAY FOR MIZ012-013.

  LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SUNDAY FOR MIZ001.

  WIND CHILL ADVISORY UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-
     004-009>011-084.

  WINTER WEATHER ADVISORY FROM 7 PM SUNDAY TO 9 AM EST MONDAY FOR
     MIZ007-014-085.

LAKE SUPERIOR...
  GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     LSZ264>267.

  HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ THIS
     EVENING FOR LSZ162-263-264.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA