Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 252152
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
452 PM EST TUE NOV 25 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 450 PM EST TUE NOV 25 2014

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA WITH RIDGING ALONG/JUST OFF THE W COAST...A TROF EXTENDING
FROM N OF HUDSON BAY TO TX AND A RIDGE JUST OFF THE EAST COAST.
SHORTWAVE THAT PROVIDED WIDESPREAD SYNOPTIC SNOW AS WELL AS LAKE
ENHANCED SNOW ACROSS THE FCST AREA LAST NIGHT HAS SHIFTED NE INTO
QUEBEC. UPSTREAM...NEXT SHORTWAVE IS DIVING SE INTO THE DAKOTAS. A
LESS DEFINED SHORTWAVE TROF IS FARTHER N OVER NRN PORTIONS OF
MANITOBA/SASKATCHEWAN. DRYING AIR MASS...LOWERING INVERSION AND LOW
LEVEL WINDS BECOMING MORE ANTICYCLONIC WITH SFC HIGH PRES THAT IS
NOW NOSING INTO WRN UPPER MI HAVE RESULTED IN A STEADY DIMINISHING
TREND/SHIFTING OF LINGERING LES THIS AFTN. IN FACT...OVER THE
W...THERE MAY NOT BE MUCH MORE THAN SCT FLURRIES REMAINING. LAKE
EFFECT CLOUD COVER IS ALSO DIMINISHING WITH CLR SKIES NOW BEING
NOTED AROUND KIWD. TO THE W...CLOUDS IN ADVANCE OF AFOREMENTIONED
SHORTWAVES ARE SLOWLY MOVING ACROSS NRN MN.

MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS TONIGHT...MIN
TEMPS TONIGHT WITH A PROBABLE PERIOD OF CLR/PARTLY CLOUDY SKIES IN
MANY AREAS AND THEN NEXT ROUND OF HEAVIER LES THAT WILL BEGIN TO
ENTER THE PICTURE WED AFTN AS SHORTWAVE TROF SWINGS SE TOWARD THE
UPPER LAKES.

TONIGHT...ARRIVAL OF WEAK SFC HIGH PRES RIDGE COMBINED WITH
STRENGTHENING LAND BREEZES WILL CONTINUE TO SHIFT LINGERING LES
OFFSHORE. OVER THE E...SHIFTING LES SHOULD BE OFFSHORE NO LATER THAN
AROUND MIDNIGHT. OVER THE W...ALTHOUGH THERE IS PROBABLY NOT MUCH
MORE THAN FLURRIES CURRENTLY REMAINING...NOCTURNAL COOLING AND LAND
BREEZE DEVELOPMENT RESULTING IN INCREASING CONVERGENCE SHOULD FAVOR
SOME REDEVELOPMENT OF LES DURING THE NIGHT. AMONG THE HIGH RES
MODELS...THERE IS DISAGREEMENT IN WHETHER SE MOVING SFC TROF WILL
SINK FAR ENOUGH S TO KEEP LES OVER THE KEWEENAW. AT THIS POINT...
BELIEVE SW FLOW ENHANCED BY LAND BREEZE WILL PUSH LES OFFSHORE...BUT
THERE IS ENOUGH UNCERTAINTY TO MAINTAIN SOME SCT -SHSN WORDING OVER
THE NRN PORTION OF THE KEWEENAW OVERNIGHT. AS FOR TEMPS...BASED ON
SATELLITE IMAGERY...IT LOOKS LIKE THERE WILL BE A DECENT PERIOD OF
CLEAR TO PARTLY CLOUDY SKIES TONIGHT OVER MUCH OF THE AREA. WITH
LIGHT WINDS AND PRECIPITABLE WATER 40-55PCT OF NORMAL...FAVORED THE
LOW END OF GUIDANCE. TEMPS SHOULD PLUMMET RAPIDLY THIS EVENING WHERE
SKIES ARE CLEAR...AND EXPECT TRADITIONAL COLD SPOTS TO FALL TO
AROUND -5F. HOWEVER...GIVEN THE SLOW ADVANCE OF UPSTREAM CLOUDS...
CLOUDS MAY BE SLOWER TO ARRIVE THAN CURRENTLY FCST. COMBINED WITH
FRESH SNOW COVER...COULD EASILY SEE TEMPS FALL TO -10F OR LWR IN THE
USUAL COLD SPOTS.

SHORTWAVE CURRENTLY MOVING INTO THE DAKOTAS WILL CONTINUE TO DROP SE
TOWARD THE TENNESSEE VALLEY TONIGHT/WED AND WILL HAVE NO INFLUENCE
HERE AS IT PASSES WELL S OF UPPER MI. OF CONCERN IS THE FOLLOWING
SHORTWAVE TROF WHICH WILL SWING SE AND EXTEND FROM JAMES BAY TO MN
BY 00Z THU. AS HEIGHT FALLS/MODEST DEEP LAYER FORCING PER QVECTORS
OVERSPREAD THE RELATIVELY WARM WATERS OF LAKE SUPERIOR...SFC TROF
MOVING OVER THE LAKE WILL SHARPEN UP...RESULTING IN INCREASING
CONVERGENCE AND INTENSIFYING LAKE ENHANCED SNOW ALONG/NEAR TROF.
EXPECT THIS TROF TO REACH THE KEWEENAW DURING THE MORNING AND THE W
IN THE AFTN. TROF PROBABLY WON`T REACH NCNTRL UPPER MI UNTIL
EVENING. NE ORIENTATION OF THE WINDS ACROSS THE KEWEENAW AFTER
TROF PASSAGE WON`T BE ESPECIALLY FAVORABLE FOR PERSISTENT HEAVIER
LAKE ENHANCED SNOW AFTER THE MAIN MDT/HVY SNOW BAND ALONG TROF
SHIFTS S. FARTHER S...SHARPER LOW-LEVEL CONVERGENCE AND BETTER
UPSLOPING IS EXPECTED INTO ONTONAGON/GOGEBIC COUNTIES...AND THIS IS
INDICATED IN MODEL GUIDANCE IN LOW-LEVEL OMEGA FIELDS. WIND FLOW
SUGGESTS LAKE NIPIGON PRECONDITONING WILL ALSO COME INTO PLAY OVER
THE FAR W. WITH THESE FAVORABLE CONDITIONS CONTINUING INTO THE WED
NIGHT...WILL HOIST A LAKE EFFECT SNOW ADVISORY FOR ONTONAGON/GOGEBIC
STARTING AT 20Z WED. IN GENERAL...A QUICK COUPLE OF INCHES OF SNOW
WILL PROBABLY OCCUR AS THE TROF MOVES ONSHORE OVER THE W.
ELSEWHERE...SOME -SN SHOULD GRADUALLY OVERSPREAD THE REST OF WRN
UPPER MI IN THE AFTN. TO THE E...IT APEARS WINDS WILL BACK
SUFFICIENTLY TO BRING SOME LES OFF LAKE MICHIGAN INTO THE FAR ERN
FCST AREA IN THE AFTN. WINDS ARE LIGHT/CONVERGENCE WEAK...SO NOT
EXPECTING MUCH WITH THE LES OFF LAKE MI WED (LESS THAN 1 INCH).

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EST TUE NOV 25 2014

...ACTIVE WITH FREQUENT CHANCES OF LAKE EFFECT OFF BOTH SUPERIOR AND
MICHIGAN...

BROAD TROUGHING ALOFT OVER EASTERN TWO THIRDS OF NORTH AMERICA TO
START THE LONG TERM PERIOD ON WEDNESDAY. PRIMARY SHORTWAVE AND SFC
LOW WITH SWATH OF SNOW OVER THE MID CONUS SHOULD STAY WELL TO THE
SOUTH OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. SHORTWAVE IN THE
NORTHERN STREAM SLIDES FROM SOUTHERN MANITOBA TOWARD UPPER GREAT
LAKES REGION ON WEDNESDAY AFTN. EVEN THOUGH SFC LOW WILL BE WELL TO
SOUTH...TROUGHING SFC-925MB DEVELOPS VCNTY OF LK SUPERIOR AND UPR
MICHIGAN IN RESPONSE THE NORTHERN STREAM SHORTWAVE AND SHARP TEMP
GRADIENT FM NORTHERN ONTARIO TO THE UPPER GREAT LAKES. SE/S WINDS
AHEAD OF THE SFC TROUGH AND MOISTURE TO H85 WITH H85 TEMPS OF -10C
SHOULD SUPPORT SOME LAKE EFFECT OFF NORTHERN LK MICHIGAN INTO THE
EASTERN CWA. MARGINAL INSTABILITY AND LACK OF ENHANCEMENT FACTORS
SHOULD LIMIT LES INTENSITY OVER EAST CWA MOST OF WEDNESDAY. COULD
SEE INCREASE ON WEDNESDAY EVENING WITH LITTLE CHANGE IN LOW-LEVEL
WINDS AND TEMPS BUT INCREASING MOISTURE/LIFT AS THE SHORTWAVE AND
DEEP LAYER Q-VECTOR CONVERGENCE MOVES THROUGH. LATER ON WEDNESDAY
NIGHT...WINDS BECOME W-WNW BLO H85 WHICH WILL DIMINISH THE LES FOR
THE EASTERN CWA.

MEANWHILE...EXPECT LES ON THE KEWEENAW IN WESTERLY LOW-LEVEL FLOW
ON WEDNESDAY MORNING TO SHIFT TO THE AREAS OF WESTERN UPR MICHIGAN
AND EVENTUALLY NORTH CENTRAL UPR MICHIGAN ON WEDNESDAY AFTN INTO
WEDNESDAY EVENING AS WINDS TURN NORTHERLY IN WAKE OF THE SFC TROUGH
PASSAGE. NNE WINDS H95-H85 WITH NORTH WINDS AT SFC AND TEMPS AT H85
OF -15C LEADING TO DELTA T/S NEARING 20C SUPPLEMENTED WITH LARGER
SCALE FORCING FM THE SHORTWAVE COULD RESULT IN HEAVY LES FOR FAR
WEST UPR MICHIGAN...VCNTY OF GOGEBIC COUNTY...LATE WEDNESDAY AFTN
THROUGH MUCH OF WEDNESDAY NIGHT. SIMILAR POTENTIAL FOR HIGHER
TERRAIN OF BARAGA AND MARQUETTE COUNTY WEDNESDAY NIGHT THROUGH
AROUND DAYBREAK ON THANKSGIVING MORNING. SHORTWAVE LIKELY WILL
PRODUCE WIDESPREAD LGT SNOW FOR MOST OF THE CWA AWAY FM THE LAKE
EFFECT AREAS. MOISTURE LACKING WITH H7 MIXING RATIOS AROUND 1G/KG.
THROUGH AND NAM/GFS SOUNDINGS POINT TO MAYBE 6 HOURS OF SNOW AT
IMT/ESC...SO PROBABLY LOOKING AT UP TO AN INCH OF FLUFFY SNOW FOR
AREAS AWAY FM LK SUPERIOR. WINDS UP TO 30 KTS WITHIN THE MIXED LAYER
BUT DOES NOT APPEAR TO BE ESPECIALLY WINDY...SO ALTHOUGH THERE WILL
BE SOME BLSN DOES NOT SEEM THAT WILL BE WIDESPREAD.

INTO THANKSGIVING...WILL BE IMPROVING TREND TO WEATHER AWAY FM LK
SUPERIOR...BUT EXPECT LAKE EFFECT TO PERSIST THROUGH MOST OF THE DAY
ALONG LK SUPERIOR. SOUNDINGS SHOW A CHILLY AIRMASS WITH GRADUALLY
LOWERING INVERSIONS BLO 5KFT BY 00Z FRIDAY. MAX TEMPS ONLY IN THE
LOWER TEENS WEST HALF AND AROUND 20 DEGREES EAST HALF...WELL BLO
NORMAL FOR LATE NOVEMBER AND LIKELY NEAR A RECORD LOW MAX TEMP FOR
THIS DAY. TEMPS AT TOP OF INVERSION HOVER AROUND -18C THROUGH THE
DAY WHICH WILL BE PLENTY GOOD ENOUGH FOR LAKE EFFECT WITH LK
SUPERIOR WATER TEMPS NOW AROUND 3-4C. SNOW SHOULD BE FAIRLY FLUFFY
AS MAJORITY OF CLOUD BEARING LAYER WILL BE WITHIN THE DGZ. SLR/S
COULD BE PUSHING 30:1...SO THAT FLUFF COULD ADD UP QUICKLY.
CONFIDENCE INCREASING THAT WILL NEED ANOTHER ROUND OF LAKE EFFECT
SNOW HEADLINES FOR AREAS ALONG LK SUPERIOR WEDNESDAY AFTN INTO EARLY
THURSDAY. ISOLD WARNING AMOUNTS MAY OCCUR FOR HIGHER TERRAIN AREAS
FAVORED BY NNE WINDS... BUT MOSTLY EXPECT ADVY TYPE SNOWS. NO
HEADLINES THOUGH NOW WITH CURRENT LAKE EFFECT EVENT STILL RUNNING
ITS COURSE. WILL HIGHLIGHT IN THE HWO AND WITHIN THE EWHO GRAPHICS.

ONCE THE SHORTWAVE ON THANKSGIVING CLEARS THE AREA...UPPER LEVEL
FLOW FLATTENS OUT SOME...BUT STAYS WNW COMPARED TO THE WESTERLY FLOW
MODELS INDICATED 24 HR AGO. RESULT IS TIGHT BAROCLINIC ZONE AT
925-850MB STAYS TO THE WEST AND SOUTH OF UPR MICHIGAN. THUS WHEN THE
NEXT SERIES OF SHORTWAVES AND UPPER LEVEL JET PUSH ACROSS THE
NORTHERN PLAINS...MODELS NOW SHOW BAND OF MODERATE SNOW WILL STAY
MOSTLY ALONG THE BAROCLINIC ZONE TO THE SOUTH OF UPR MICHIGAN. H7
MIXING RATIOS 3-4G/KG SUGGEST WHEREVERE THAT BAND OF SNOW DEVELOPS
IT COULD BE AT LEAST MODERATE. MAIN ISSUE OVER UPR MICHIGAN FM THAT
SYSTEM MAY BE LAKE ENHANCED SNOW OVER EASTERN CWA OFF LK MICHIGAN
DUE TO FORCING FM THE SYSTEM GLANCING THE AREA...SSW WINDS
SFC-H85...AND H85 TEMPS -10C OR LOWER. MOST IDEAL LAKE ENHANCEMENT
PERIOD FRIDAY AFTN THROUGH FRIDAY EVENING OVER SOUTHERN SCHOOLCRAFT
INTO LUCE COUNTIES. INCREASED QPF/SNOW AMOUNTS MARKEDLY. LIKELY A
HEADLINE WILL BE NEEDED FOR THOSE AREAS AT LEAST FRIDAY/FRIDAY NIGHT.

ANOTHER SHORTWAVES QUICKLY FOLLOWS FOR SATURDAY. AT THIS POINT
BETTER FORCING AND THUS QPF STAYS ALONG AND NORTH OF LK SUPERIOR.
SOME INDICATION OF AT LEAST LGT PRECIP OVER THE CWA THOUGH. WARM
LAYER H8-H9 BECOMES MORE OF AN ISSUE. ECMWF WARMER THAN GFS AND
WOULD SUGGEST MOSTLY RAIN AS PTYPE OVER MUCH OF CWA BY SATURDAY
AFTN. GFS HAS MAINLY SNOW WITH A LITTLE RAIN WORKING IN OVER SCNTRL.
COULD BE FZRA IF WARMING AT SFC IS DELAYED. BLENDED TWO SOLUTIONS
FOR NOW AND CAME UP WITH HIGHER POPS NORTH AND MOSTLY SNOW IN
MORNING TRENDING TOWARD MORE RAIN/FZRA IN AFTN. FZRA MAY BE NOT AS
LONG LASTING THOUGH...ESPECIALLY IF THE WARMER ECMWF IDEA IS CORRECT
AS SFC WARMING WOULD BE MORE THAN IS SHOWN IN THIS FORECAST. EITHER
WAY...IF THE PRECIP OCCURS...COULD BE KIND OF A MESSY DEAL.

BECOMES COLDER AGAIN /H85 TEMPS -16C TO -20C/ BEHIND THAT SYSTEM TO
CLOSE THE WEEKEND. MORE LES EXPECTED FOR NW FLOW AREAS ALONG LK
SUPERIOR INTO MONDAY. CYCLONIC FLOW LACKING THOUGH AS BROAD HIGH
PRESSURE RIDGE OVER 1035MB EXPANDS FM THE NORTHERN PLAINS TO THE
GREAT LAKES. ANTICYCLONIC FLOW SHOULD LIMIT THE LES COVERAGE AND
INTENSITY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1248 PM EST TUE NOV 25 2014

DRIER AIR AND BACKING WINDS TO THE SW WITH APPROACHING WEAK SFC HIGH
PRES RIDGE WILL RESULT IN LAKE EFFECT -SHSN ENDING AND MVFR
CONDITIONS IMPROVING TO VFR AT KIWD DURING THE MID AFTN AND AT KSAW
LATE THIS AFTN. MAY YET SEE SOME BRIEF IFR CONDITIONS AT KSAW BASED
ON RADAR IMAGERY SHOWING HEAVIER SNOW SHOWERS IN NCNTRL UPPER MI.
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT. NEXT APPROACHING
DISTURBANCE MAY BRING SOME -SN/MVFR CONDITIONS TO KIWD LATE WED
MORNING. AT KCMX...WINDS WILL PROBABLY RETAIN ENOUGH OVERWATER
COMPONENT TO MAINTAIN MVFR CONDITIONS THRU THE NIGHT EVEN THOUGH
-SHSN SHOULD END. BEFORE THE -SHSN END...THERE MAY BE A PERIOD OF
SOMEWHAT HEAVIER SNOW SHOWERS AT KCMX THIS EVENING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST TUE NOV 25 2014

PRES GRADIENT RAPIDLY WEAKENS TONIGHT WITH A WEAK SFC TROF DROPPING
SE OVER LAKE SUPERIOR. THIS WILL RESULT IN WINDS DIMINISHING TO UNDER
20KT ACROSS THE LAKE. STRONG HIGH PRES WILL THEN BUILD SE INTO THE
CANADIAN PRAIRIES WED AND INTO THE NRN PLAINS WED NIGHT. THIS WILL
PUSH THE TROF SE AND TIGHTEN THE PRES GRADIENT. AS A RESULT... WITH
THE TROF PASSAGE...EXPECT NORTHERLY WINDS TO RAMP UP TO 20-30KT FROM
NW TO SE WED/WED NIGHT. NOT OUT OF THE QUESTION THAT THERE COULD BE
SOME GALE FORCE GUSTS OVER THE CNTRL PORTION OF LAKE SUPERIOR. WINDS
WILL THEN DIMINISH TO UNDER 20KT W TO E THU/THU NIGHT AS HIGH PRES
RIDGE ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES
SAT...EXPECT INCREASING WINDS TO 15-25KT FRI/FRI NIGHT AHEAD OF
FRONT. BEHIND FRONT...NW WINDS MAY REACH 20-30KT LATE SAT/SUN.

&&

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

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

  LAKE EFFECT SNOW ADVISORY FROM 3 PM EST /2 PM CST/ WEDNESDAY TO
     10 AM EST /9 AM CST/ THURSDAY FOR MIZ002-009.

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

$$

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






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