Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 301943
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
343 PM EDT THU OCT 30 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 601 AM EDT THU OCT 30 2014

MAIN CONCERN FOCUSES ON POTENTIAL MODERATE LAKE EFFECT SNOW EVENT
FOR WEST AND NORTH CENTRAL UPPER MI TONIGHT INTO FRIDAY MORNING AS
VIGOROUS SHORTWAVE WEST OF HUDSON BAY DIGS SOUTH ACROSS THE UPPER
GREAT LAKES TONIGHT.

LATEST 09Z WATER VAPOR LOOP SHOWS A WEAKER SHORTWAVE MOVING SE
THROUGH ERN SD WHILE THE SHORTWAVE OF BIGGER CONCERN FOR OUR AREA IS
NOW LOCATED WEST OF HUDSON BAY. MAIN FORCING FROM SHORTWAVE OVER ERN
SD IS EXPECTED TO PASS WELL SOUTH OF THE AREA TODAY WITH ONLY WEAK
FORCING EXPECTED OVER OUR AREA FROM WEAK MID-LVL TROF OVERHEAD. AS A
RESULT EXPECT ONLY ISOLD SHRA...POSSIBLY A SNOW FLURRY THIS MORNING
ACROSS MUCH OF THE FCST AREA. FORCING WITH MODERATE TO STRONG Q-VECT
CONV WILL INCREASE THIS AFTERNOON ESPECIALLY LATE IN DAY AHEAD OF
HUDSON BAY SHORTWAVE WHICH WILL BE RAPIDLY DIVING SOUTH TOWARD THE
UPPER LAKES. COMBINATION OF FORCING AND ARRIVAL OF COLDER 8H TEMPS
OF -5 TO -6C IN WAKE OF FRONTAL PASSAGE WILL ALLOW SHRA/LAKE
ENAHNCED SHRA TO BECOME NUMEROUS OVER NW AND NCNTRL COUNTIES LATE IN
DAY AS WINDS SHIFT FM W TO NW.

TONIGHT...CONTINUED CAA IN WAKE OF FRONTAL PASSAGE WILL LOWER 8H
TEMPS TO -11C TO -12C AS NOTED ON MODELS. MODEL WET BULB ZERO
HEIGHTS AND CRITICAL 1000-850 MB THICKNESSES SUGGEST A QUICK
TRANSITION FM RAIN/SNOW MIX TO ALL SNOW BY EARLY EVENING IN
WEST...LATE EVENING CENTRAL AND EARLY OVERNIGHT EAST. MESOSCALE
MODEL AVERAGED QPF FROM .2-.4 IN WEST TO .3-.6 IN NCNTRL AND A
GENERAL 10-12/1 SNOW/WATER RATIO SHOULD YIELD 2-4 INCHES OVER THE
HIGHER TERRAIN OF WRN COUNTIES AND COULD YIELD 3 TO POSSIBLY 8
INCHES OVER THE HIGHER TERRAIN OF NCNTRL COUNTIES. MODERATE SNOW
SHOULD TAPER OFF QUICKER WEST AS FLOW BECOMES MORE ANTICYCLONIC LATE
TONIGHT BEHIND SHORTWAVE AND INVERSION HGTS BEGIN TO LOWER. THIS
SHOULD LIMIT ACCUMS IN WEST TO MARGINAL ADVISORY AMTS. FEEL MORE
CONFIDENT WITH ADVISORY AMOUNTS OVER BARAGA-MQT WHERE CYCLONIC
CONVERGENT LOW-LVL FLOW WILL LINGER LONGER AND FAVORABLE NRLY FETCH
SHOULD YIELD INLAND TOTAL SNOW AMTS SOLIDLY IN ADVISORY CATEGORY 4-7
BEFORE SNOW TAPER OFF FRI MORNING. WRN ALGER SHOULD ALSO SHOULD ALSO
SEE ADVISORY AMTS OF 4-5 INCHES ALTHOUGH SNOW WON`T LIKELY START
ACCUMULATING THERE UNTIL LATE TONIGHT. NRN DELTA COULD ALSO PUSH
ADVISORY AMTS DURING THE EVENT BUT DID NOT INCLUDE THEM IN AN
ADVISORY AT THIS TIME. HAVE ALL WEST AND NORTH CENTRAL COUNTIES
BORDERING LAKE SUPERIOR IN LAKE EFFECT SNOW ADVISORY TONIGHT INTO
FRIDAY MIDDAY.

NORTH WINDS GUSTING TO 45 MPH OR HIGHER ESPECIALLY ALONG THE LAKE
SUPERIOR SHORE MAY CAUSE SOME FLOODING OF LOW-LYING AREAS SO HAVE
ALSO ISSUED A LAKESHORE FLOOD ADVISORY LATE TONIGHT INTO EARLY
FRIDAY AFTERNOON FOR WEST AND NORTH CENTRAL UPPER MI. NORTH WINDS
GUSTING AT OR ABOVE 30 MPH JUST INLAND FM THE LAKE COULD ALSO CAUSE
SOME BLOWING OF SNOW AS WELL AND THIS IS MENTIONED IN THE WSW
STATEMENT.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM EDT THU OCT 30 2014

MAIN FCST CONCERNS IN THE MEDIUM TO EXTENDED PERIOD ARE FOCUSED ON
HOW QUICKLY LINGERING LK EFFECT SNOW WL DIMINISH ON FRI NGT AND THEN
ON POPS EARLY NEXT WEEK ACCOMPANYING NEXT SHRTWV FCST TO SHIFT E
THRU SRN CANADA. EXPECT WELL BLO NORMAL TEMPS ON FRI NGT TO RISE TO
AOA NORMAL INTO EARLY NEXT WEEK UNDER SW FLOW/UPR RDGING IN ADVANCE
OF THE SHRTWV MOVING ACROSS SRN CANADA. BUT COLDER AIR WL RETURN BY
MID WEEK AS THE SHRTWV HELPS TO CARVE OUT AN UPR TROF IN SE CANADA.

FRI NGT...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE IN ADVANCE
OF FAIRLY SHARP UPR RDG AXIS MOVING SLOWLY EWD THRU THE NRN PLAINS
IS FCST TO SHIFT SFC HI PRES RDG AXIS TO OVER CENTRAL UPR MI BY 12Z
SAT. LINGERING LES IN THE EVNG OVER MAINLY THE N WIND SN BELTS ACRS
THE NCENTRAL CWA AND E OF THE INCOMING RDG AXIS WL DIMINISH AS THE
SUBSIDENCE INVRN SINKS AOB 3K FT AGL AND THE SUB INVRN LVL MSTR
WARMS ABV -10C/THE DGZ. ALTHOUGH SOME SC/FLURRIES MIGHT LINGER THRU
MOST OF THE NGT OVER THE E HALF...ARRIVAL OF HI PRES RDG AXIS OVER
THE W WL BRING SOME CLRG TO THE WI BORDER LATER. WITH PWAT FALLING
TOWARD 0.10 INCH AND LGT WINDS...EXPECT MIN TEMPS TO FALL WELL INTO
THE TEENS IN SOME PLACES. TENDED TOWARD THE LO END OF GUIDANCE FOR
FCST TEMPS FOR THE INTERIOR W.

SAT THRU SUN...EXPECT MOSUNNY WX ON SAT WITH SFC RDG AXIS/DRY
AIRMASS SHIFTING SLOWLY E TO OVER THE SAULT BY LATE IN THE DAY.
ALTHOUGH SOME HI CLDS DRIFTING OVER THE UPR RDG AXIS MAY MOVE INTO
THE W IN THE AFTN...A GOOD DEAL OF SUNSHINE AND RETURN SLY FLOW ON
THE BACKSIDE OF THE HI THAT IS FCST TO LIFT H85 TEMPS TOWARD 2C BY
00Z SUN OVER THE W SHOULD ALLOW SFC MAX TEMPS THERE TO REBOUND INTO
THE 40S. COMBINATION OF INCRSG SLY FLOW ON THE WRN FLANK OF SLOWLY
DEPARTING RDG AXIS/COME HI CLDS WL LIMIT THE DIURNAL TEMP FALL ON
SAT NGT. THE LOWEST TEMPS TOWARD 20 WL OCCUR OVER THE INTERIOR E
CLOSER TO THE DEPARTING HI/FLATTER PRES GRADIENT AND LOWER PWAT.
DOWNSLOPE AREAS NEAR LK SUP WL SEE HIER TEMPS AOA 30. UNDER SOME HI
CLDS...TEMPS ON SUN SHOULD RISE INTO THE 40S EVERYWHERE WITH MIXING
TO H875-9. BUT GUSTY S WINDS UNDER SHARPENING PRES GRADIENT BTWN
DEPARTING HI/FALLING MSLP IN THE PLAINS ASSOCIATED WITH SHRTWV
LIFTING NEWD THRU THE NRN ROCKIES AND THE DAYTIME MIXING TAPPING
H925 WINDS FCST AS HI AS 30 KTS WL MAKE THE DAY FEEL COOLER.

SUN NGT...STEADY SSW WIND BTWN HI PRES SHIFTING INTO THE MID
ATLANTIC STATES AND LO PRES IN THE NRN PLAINS MOVING TOWARD LK
WINNIPEG IN ADVANCE OF SHRTWV LIFTING INTO SCENTRAL CANADA WL ADVECT
HIER PWAT UP TO ARND 0.75 INCH /ABOUT 150 PCT OF NORMAL/. BUT
ABSENCE OF MUCH IN THE WAY OF DYNAMIC SUPPORT WITH PASSAGE OF SHRTWV
SO FAR TO THE NW AND RELATIVE DRYNESS OF THE FCST SDNGS WARRANTS
GOING DRY FCST. WINDS/INCRSG PWAT WL LIMIT THE NOCTURNAL TEMP DROP.

MON THRU TUE NGT...AS SHRTWV/ACCOMPANYING SFC LO NEAR LK WINNIPEG ON
MON SHIFTS E INTO NW ONTARIO ON TUE...ATTENDANT COLD FNT WL SHIFT
THRU THE UPR LKS...CROSSING THE CWA ON MON NGT. ALTHOUGH THE TRACK
OF THIS DISTURBANCE TO THE N WL TAKE THE SHARPER DEEP LYR QVECTOR
CNVGC TO THE N OF UPR MI AND MOST OF THE GUIDANCE SHOWS DEEPER MSTR
ASSOCIATED WITH A SRN BRANCH DISTURBANCE REMAINING TO THE S...12HR
H5 HGT FALLS UP TO 100M OVER UPR MI JUSTIFY AT LEAST CHC POPS. THE
PTYPE WL BE RA INTO AT LEAST LATE TUE. THE MODELS THAT SHOW A MORE
AMPLIFIED TROF THEN SHOW CYC WNW FLOW ON THE SRN FLANK OF THE LO IN
ONTARIO DROPPING H85 TEMPS TOWARD -5 TO -7C TUE NGT IN THE PRESENCE
OF HIER RH THRU H7...SO SOME SN MAY MIX WITH THE RA AS THE PCPN
TRANSITIONS TOWARD A LK EFFECT MODE WITHIN THE CYC FLOW.

EXTENDED...A CLIPPER-TYPE SHRTWV IS FCST TO SWING NEAR THE UPR LKS
THE MIDDLE OF NEXT WEEK...BRINGING A CHC OF RA/SN AND SOME LK EFFECT
SN IN ITS WAKE. BUT THE SPREAD IN MODEL SCENARIOS AS FAR AS THE
TRACK/ INTENSITY OF THIS DISTURBANCE IS TOO LARGE TO DEVIATE FM A
CONSENSUS FCST.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 151 PM EDT THU OCT 30 2014

CIGS WILL REMAIN MVFR THROUGH MUCH OF THIS AFTERNOON WITH SCATTERED
RAIN SHOWERS AS AN UPPER DISTURBANCE MOVES THROUGH THE AREA.
HOWEVER...BEHIND THIS DISTURBANCE...MUCH COLDER AIR WILL GRADUALLY
FILTER INTO THE AREA. MEANWHILE...ANOTHER LOW PRESSURE SYSTEM WILL
DEVELOP SOUTHEAST OF THE AREA ALLOWING WINDS TO TURN NORTHERLY OFF
THE LAKE. THE COMBINATION OF THE COLD AIR AND NORTHERLY WINDS WILL
ALLOW LAKE ENHANCED PCPN TO DEVELOP LATE THIS AFTN AND CONTINUE
THROUGH TONIGHT. THE AIR WILL BECOME COLD ENOUGH FOR THE PCPN TO
CHANGE TO ALL SNOW BY THIS EVENING. WHEN THIS OCCURS...EXPECT VSBYS
TO DROP TO IFR. THE LOWEST VSBY OVERNIGHT IS EXPECTED AT SAW. LOOKS
LIKE THE SNOW WILL CONTINUE INTO FRI MORNING AT LEAST AND THE
NORTHERLY WINDS WILL GRADUALLY BECOME STRONGER INTO FRIDAY MORNING
WITH GUSTS ABOVE 30 KT NOT OUT OF THE QUESTION.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 342 PM EDT THU OCT 30 2014

EXPECT N TO NW GALES TO 35-45 KTS TO DEVELOP OVER LAKE SUPERIOR
TONIGHT AS A STRONG DISTURBANCE SHIFTS SE THROUGH THE UPPER LAKES
AND THE PRES GRADIENT SHARPENS BETWEEN ACCOMPANYING LO PRES OVER
LOWER MI AND HI PRES IN THE NORTHERN PLAINS. STRONG SURGE OF COLD
AIR ACROSS THE RELATIVELY WARM LAKE WATERS WILL DESTABILIZE THE
LOWER LEVELS AND ENHANCE MIXING OF STRONGER N WINDS TO THE LAKE
SURFACE. THESE WINDS WILL THEN DIMINISH W-E LATE FRI INTO SAT AS THE
HI PRES RIDGE/WEAKER GRADIENT OVERSPREAD THE LAKE W-E. ONCE THE HI
SHIFTS TO THE E AND THE PRES GRADIENT SHARPENS AGAIN TO THE E OF LO
PRES DEVELOPING IN THE NORTHERN PLAINS...LOOK FOR S WINDS UP TO
20-25 KTS TO DEVELOP AND PERSIST INTO MON. AS THE LO SHIFTS ACROSS
ONTARIO LATER ON MON INTO TUE...A COLD FRONT WILL PASS OVER LAKE
SUPERIOR...WITH WINDS VEERING TO THE W-NW UP TO 25 KTS ON TUE IN ITS
WAKE.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY FROM 8 PM EDT /7 PM CDT/ THIS EVENING
     TO NOON EDT /11 AM CDT/ FRIDAY FOR MIZ001>003-009-084.

  LAKESHORE FLOOD ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 2 PM EDT /1
     PM CDT/ FRIDAY FOR MIZ001>006-009.

  LAKE EFFECT SNOW ADVISORY FROM 8 PM THIS EVENING TO 2 PM EDT
     FRIDAY FOR MIZ004>006.

LAKE SUPERIOR...
  GALE WARNING FROM 11 PM THIS EVENING TO 2 PM EDT FRIDAY FOR
     LSZ249>251-266-267.

  GALE WARNING FROM 10 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
     LSZ243>248-264-265.

  GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 8 AM EDT
     /7 AM CDT/ FRIDAY FOR LSZ162-240>242-263.

LAKE MICHIGAN...
  GALE WARNING FROM 4 AM TO 5 PM EDT FRIDAY FOR LMZ221-248-250.

&&

$$

SHORT TERM...VOSS
LONG TERM...KC
AVIATION...JLB
MARINE...KC




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