Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 262048
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
348 PM EST WED NOV 26 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 610 AM EST WED NOV 26 2014

...MODERATE TO HEAVY LAKE EFFECT FOR NORTH FLOW AREAS TONIGHT...

RAOBS AND WV/IR SATELLITE LOOP INDICATE WESTERN CONUS RIDGE AND
CENTRAL AND EASTERN CONUS TROUGH. TWO MAIN JET CORES...A STRONG
NEAR 200 KT H3 JET RACING SW-NE FROM SOUTHEAST UNITED STATES TO
QUEBEC AND ANOTHER 150 KT H3 JET DIVING NW-SE INTO THE SOUTHERN
PLAINS. LEAD JET IS SUPPORTING THE STRONG SYSTEM MOVING UP THE
EASTERN SEABOARD WHILE PLAINS JET IS SUPPORTING COMPACT LOW
PRESSURE SYSTEM NEAR OMAHA NEB PRODUCING SWATH OF PRECIP FM MN
INTO MO. FARTHER NORTH...SHORTWAVE WORKING ALONG IN NORTHERN STREAM
PUSHING INTO NORTHWEST ONTARIO IS RESULING IN SWATH OF LGT SNOW
NORTHERN MN INTO NORTHERN LK SUPERIOR. ANOTHER TWO SHORTWAVES WITHIN
THE NORTHERN STREAM ARE OVER DROPPING SE OVER SASKATCHEWAN AND
MANITOBA AND ALSO OVER NORTHERN MANITOBA. THOUGH LOW PRESSURE SYSTEM
OVR PLAINS STAYS SOUTH OF HERE...WEAK TROUGH IS EXTENDING TO THE
NORTHEAST OF IT WILL AFFECT WEATHER OVER UPR MICHIGAN TODAY. OTHER
MAIN SFC FEATURE IS ARCTIC HIGH PRESSURE EXPANDING ACROSS CANADIAN
PRAIRIE PROVINCES AND NOSING A RIDGE OVER NORTHWEST ONTARIO TO NORTH
OF LK SUPERIOR AND ALSO INTO NORTHERN PLAINS.

WEAK GRADIENT OVER UPR MICHIGAN AND SOME AREAS OF CLEAR SKIES HAS
ALLOWED TEMPS TO FALL TO AROUND 10 BLO OVER INTERIOR SECTIONS OF
CNTRL AND EAST CWA THIS MORNING. QUIET OVER THE AREA AS LAKE EFFECT
CLOUDS ARE NORTH OF KEWEENAW THANKS TO SW WINDS AHEAD OF TROUGH SET
UP OVER WESTERN LK SUPERIOR. WEAK SRLY FLOW IS BRINGING LOW CLOUDS
INTO LK MICHIGAN ZONES AND OVER PARTS OF EAST CWA.

LATER TODAY...EXPECT THE TROUGH OVER WESTERN LK SUPERIOR TO SINK
SLOWLY OVER KEWEENAW AND FAR WEST CWA THIS AFTN...PROBABLY NOT UNTIL
AFTER 21Z AT KIWD. THIS WILL OCCUR AS DEEPER LAYER MOISTURE/FORCING
SPREADS OVER WESTERN UPR MICHIGAN AS THE TWO SHORTWAVES UPSTREAM IN
CANADA AND THE ONE JUST TO THE WEST OF HERE MOVE ACROSS. SOUNDINGS
INDICATE SHALLOW LAYER UP TO H9 FOR FAVORABLE WIND TRAJECTORIES FOR
LES OVER WESTERN CWA THIS AFTN. BY 00Z OVER FAR WEST CWA...NNE WINDS
TO H9 WITH TEMPS NEAR -15C SUPPORT LAKE ENHANCED SNOW AS THE BETTER
LARGE SCALE FORCING CROSSES. SLR/S INCREASE TO 20:1 AS MOST LIFT IS
WITHIN DGZ. ENOUGH INSTABILITY AND SHARP CONVERGENCE DEVELOPING WITH
LARGER SCALE FORCING ALONG WITH AFFECTS FM SHORTWAVE WILL SUPPORT
PERIOD OF HEAVIER SNOW IN THE EVENING FAR WEST...FROM IWD TO WHITE
PINE/PORCUPINE MTS. ADDITIONALLY...ONCE THE SHORTWAVES EXITS BY
MIDNIGHT...SOUNDINGS SHOW ALL OF LAKE CONVECTIVE LAYER IS WITHIN
DGZ. SLR/S MAY REACH 30:1 AS WINDS ARE ALSO DIMINISHING AT THAT
TIME. HIGH SLR/S COULD ALLOW FOR GOOD TACK ON SNOW LATER TONIGHT.
DUE TO THE HEAVY SNOW IN THE EVENING AND THE POTENTIAL FOR A LOT OF
FLUFFY SNOW OVERNIGHT INTO EARLY THANKSGIVING DAY...SETUP SEEMED
GOOD ENOUGH TO UPGRADE TO LAKE EFFECT WARNING FOR GOGEBIC/ONTONAGON.
ONLY MARGINAL SNOW AMOUNTS OVER THE KEWEENAW BUT WITH A PERIOD OF
STRONG GUSTY WINDS TO 30 MPH BEHIND THE TROUGH THIS EVENING AND THE
FLUFFY SNOW ISSUED A LAKE EFFECT ADVY TO COVER THE SNOW AND BLSN ON
A BUSIER THAN NORMAL TRAVEL DAY AHEAD OF THANKSGIVING.

TROUGH SINKS INTO NCNTRL UPR MICHIGAN THIS EVENING AND THAT BRINGS
AT LEAST A PERIOD OF HEAVIER LES INTO BARAGA AND NORTHERN MARQUETTE
COUTNIES. SIMILAR TO FAR WEST CWA...SUFFICIENT INSTABIILTY AND
UPSLOPE NNE FLOW SUPPORTED SNOW AMOUNTS UP TO 6 INCHES OVER BARAGA
COUNTY AND PUT OUT AN ADVY FOR TONIGHT TO COVER THAT. HEAVIEST SNOW
EXPECTED FOR L`ANSE AREA AND ESPECIALLY OVER THE FAVORED HIGHER
TERRAIN OF EASTERN BARAGA COUNTY. CONTINUED THE ADVISORY FOR
MARQUETTE COUNTY THAT WAS ISSUED ON TUESDAY AFTN...BUT WITH THE
SHARPER LOW-LEVEL UPSLOPE FLOW AND SINCE THE TROUGH CONVERGENCE WILL
BE SYNCED UP WITH THE SHORTWAVE...SETUP SEEMED GOOD FOR LAKE
ENHANCEMENT IN THE EVENING...ESPECIALLY OVER THE HIGHER TERRAIN FROM
THE HURON MTS TO NEGAUNEE AND POSSIBLY ALONG THE SHORE AT MARQUETTE.
NNE WINDS DO BECOME NNW-NW FAIRLY QUICK OVERNIGHT TONIGHT AND THE
SHORTWAVE WILL BE EXITING AT THAT TIME AS WELL. THOUGHT THE
POTENTIAL FOR PERSISTENT HEAVIER SNOW WOULD BE TOO LOW TO DO ANY
KIND OF UPGRADE TO MARQUETTE EVEN THOUGH IT SHOULD SNOW AROUND
INCH/HOUR RATES IN THE EVENING. WILD CARD FOR MARQUETTE COUNTY IS
THE STRONGER NRLY WINDS/BLSN. COULD SEE GUSTS TO AROUND 30 MPH VCNTY
OF MARQUETTE AND HARVEY LATE TONIGHT AND WITH THE FLUFFY SNOW...THAT
COULD BE BIG VSBY REDUCER INTO THANKSGIVING MORNING. WILL LET LATER
SHIFTS DECIDE ON NEED FOR UPGRADE THOUGH. SETUP FOR MARQUETTE IS
SIMILAR FOR ALGER. TROUGH JUST ARRIVES LATER TONIGHT AND HEAVIER LES
LINGERS INTO THANKSGIVING LONGER. HEAVIEST SNOW FOCUSES MAINLY OVER
WESTERN SNOW BELTS OF THE COUNTY.

FINALLY...SOUTH FLOW LES STILL EXPECTED OFF LK MICHIGAN MAINLY
AFFECTING FAR EAST CWA. CONVERGENCE APPEARS TOO WEAK TO SUPPORT
ANYTHING MORE THAN LIGHT SNOW ACCUMS INTO TONIGHT WITH PERHAPS UP TO
A FEW INCHES. LACK OF STRONG WINDS THOUGH WILL CURTAIL BLSN
ISSUES...SO DID NOT SEE NEED FOR ANY HEADLINE FOR SCHOOLCRAFT OR
LUCE COUNTIES. INLAND AREAS WILL ALSO SEE SOME SNOW...BUT AMOUNTS
WILL BE LESS THAN 1 INCH DUE TO LIMITED OVERALL MOISTURE WITH THE
SYSTEM MOVING THROUGH THIS EVENING.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM EST WED NOV 26 2014

THU NIGHT...THE LINGERING LES WILL DIMINISH AS THE SFC RIDGE AXIS
SLIDES THROUGH THE WRN LAKES AND LOW LEVEL WINDS BACK TO THE SW.
WITH LIGHT WINDS AND A PERIOD OF CLEARING OVER THE INTERIOR WEST
DURING THE EVENING...TEMPS WILL DROP QUICKLY TO MINS BELOW GUIDANCE
BEFORE RECOVERING OVERNIGHT AS CLOUDS MOVE IN. MODELS WERE
CONSISTENT IN BRINGING POTENTIAL FOR SOME LIGHT SNOW INTO THE WEST
LATE WITH THE DEVELOPING WAA PATTERN.

FRI...SNOW IS EXPECTED TO SPREAD ACROSS THE REGION WITH FAVORABLE
MOISTURE ADVECTION AND ISENTROPIC LIFT THROUGH THE 850-700 MB
FRONTAL ZONE. 3 G/KG MOISTURE AVAILABLE IN THE 285K-295K LAYER
DURING THE PERIOD OF STRONGEST LIFT IS CONSISTENT WITH POTENTIAL FOR
2 TO 4 INCHES OF SNOW WITH MODELS CONSENSUS QPF OF 0.10 TO 0.20
INCHES AND SLR VALUES FROM AROUND 15/1-20/1. THERE IS STILL SOME
UNCERTAINTY WHERE THE BAND OF HEAVIER SNOW WILL DEVELOP AS THE 12Z
NAM BRINGS GREATER AMOUNTS OF PCPN INTO SRN UPPER MI COMPARED TO THE
GFS AND ECMWF. THERE WILL ALSO BE THE POTENTIAL FOR A BAND OF LAKE
ENHANCED SNOW OFF OF LAKE MI THAT COULD SPREAD EASTWARD FROM NEAR
THE GARDEN PENINSULA INTO LUCE COUNTY. SINCE THE STRONGEST LOW
LEVEL CONV IS EXPECTED TO MOVE STEADILY TO THE EAST...SNOW AMOUNTS
IN ANY ONE LOCATION SHOULD BE LIMITED. HOWEVER...CONFIDENCE IS LOWER
FOR THE POSITION/STRENGTH OF THIS FEATURE THAT COULD ADD SEVERAL
INCHES TO THE SNOW TOTALS.

FRI NIGHT INTO SAT...SFC LOW PRES IS FCST TO SPREAD FROM THE NRN
PLAINS TO THE UPPER MS VALLEY WITH CONTINUED WAA BRINGING
SUBSTANTIAL 850 MB WARMING. NAM/GFS 285-295K ISENTROPIC PROGS
SUGGEST THAT THE STRONGEST LIFT AND DEEPEST MOISTURE WILL REMAIN
ACROSS LAKE SUPERIOR AND FAR NRN UPPER MI. WITH A PROMINENT 850-700
MB DRY LAYER DEVELOPING TO THE SOUTH...FREEZING DRIZZLE WILL BE
POSSIBLE ALONG WITH SOME LIGHT SNOW OR FLURRIES AS ICE NUCLEI BECOME
MORE SCARCE. ANY PCPN AMOUNTS ARE EXPECTED TO BE LIGHT WITH
ONLY A FEW HUNDREDTHS OF AN INCH AT MOST. THERE MAY ALSO BE ENOUGH
900-700 MB WARMING INTO THE AREA OF DEEPER MOISTURE FOR SOME
FZRA.

SAT NIGHT AND SUN...LOW PRES LIFTING NE TOWARD JAMES BAY SAT NIGHT
WILL DRAG A COLD FRONT THROUGH THE NRN LAKES WITH MUCH COLDER AIR
MOVING IN ON NW WINDS. WITH 850 MB TEMPS FALLING TO NEAR -18C...LES
WILL BE LIKELY FOR NW WIND SNOW BELTS. A LIMITING FACTOR FOR HEAVIER
SNOW WILL BE SUBSTANTIAL 850-700 MB DRYING WITH BACKING AND
INCREASING ACYC LOW LEVEL WINDS FROM LATE SUN INTO SUN NIGHT.

MON-WED...THE GFS/GEFS AND ECMWF WERE IN REASONABLE AGREEMENT WITH
THE PATTERN INTO NEXT WEEK WITH HIGH PRES BUILDING INTO THE REGION
MON INTO MON NIGHT BRINGING DIMINISHING LES. ANOTHER MID LEVEL AND
SFC TROUGH MOVING THROUGH TUE INTO TUE NIGHT COULD BRING SOME LIGHT
SNOW TO THE AREA. THE MODELS HAVE TRENDED TOWARD KEEPING COLDER
ACROSS REGION THAT WOULD KEEP ANY PCPN AS SNOW WITH MAX TEMPS
RECOVERING INTO THE MID 20S TO AROUND 30 BY TUE AND WED.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1245 PM EST WED NOV 26 2014

DISTURBANCE AND ASSOCIATED SFC TROF WILL SWING ACROSS UPPER MI THIS
AFTN/EVENING. INCREASING LAKE ENHANCED SNOW WILL AFFECT ALL
TERMINALS AS THE TROF PUSHES ACROSS THE AREA...BEGINNING LATEST AT
KSAW. AT KIWD/KCMX...IFR CONDITIONS ARE EXPECTED TO BECOME THE
PREVAILING CONDITION THIS AFTN...THOUGH SOME LIFR WILL OCCUR AS
WELL. WIND FLOW THIS EVENING WILL FAVOR KIWD FOR HEAVIEST
SNOW/LOWEST CONDITIONS...AND LIFR WILL LIKELY PREVAIL THERE THIS
EVENING WHILE KCMX REMAINS IFR. LOWERING INVERSION/DRYING AIR MASS
WILL RESULT IN DIMINISHING LAKE EFFECT SNOW LATER IN THE PERIOD...
ALLOWING IMPOVEMENT TO VFR. AT KSAW...VFR CONDITIONS WILL PREVAIL
THIS AFTN. WITH TROF PASSAGE...EXPECT CONDITIONS TO FALL TO IFR LATE
THIS EVENING ALONG WITH PERIODS OF LIFR. AS WINDS BEGIN TO BACK LATE
TONIGHT AND ESPECIALLY THU MORNING...LAKE EFFECT SNOW WILL SHIFT
MOSTLY E OF KSAW...ALLOWING IMPROVEMENT TO MVFR.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EST WED NOV 26 2014

A SFC TROUGH WILL SLIDE SOUTH OVER LAKE SUPERIOR TONIGHT.
BEHIND THE TROUGH...EXPECT NORTHERLY WINDS TO 30 KTS. WINDS WILL
THEN DIMINISH TO UNDER 20 KT W TO E THU/THU NIGHT AS HIGH PRES RIDGE
ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES SAT
NIGHT...EXPECT INCREASING S/SW WINDS TO 15-25KT FRI INTO SAT AHEAD
OF FRONT. BEHIND THE FRONT...NW WINDS MAY REACH 20-30KT LATE SAT
NIGHT AND SUN AND INCREASE TO GALES BY SUN NIGHT INTO MON.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
     THURSDAY FOR MIZ006.

  LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
     THURSDAY FOR MIZ004.

  LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
     THURSDAY FOR MIZ005.

  LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY FOR
     MIZ002-009.

  LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ001-003.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

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







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