Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 310207
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1007 PM EDT THU OCT 30 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 424 PM EDT THU OCT 30 2014

WV IMAGERY AND RUC ANALYSIS INDICATED A STRONG SHORTWAVE TROUGH OVER
NW ONTARIO(N OF KINL) DIVING TO THE SE TOWARD WRN LAKE SUPERIOR. THE
SHRTWV SUPPORTED SCT/NMRS RAIN SHOWERS OVER NE MN AND SOME SNOW
SHOWERS OVER FAR NRN MN AND ADJOINING PORTIONS OF ONTARIO WHERE
VISIBILIITES HAD DROPPED AOB 1SM. A WEAK SHRTWV THROUGH CNTRL UPPER
MI ALSO WAS BRINGING SOME SCT LIGHT RAIN SHOWERS THROUGH NRN UPPER
MI. STRONG NRLY WINDS HAVE DEVELOPED INTO NRN MN BETWEEN 1015MB LOW
PRES OVER CNTRL UPPE R MI AND A 1036 MB HIGH OVER SASK INTO WRN
MANITOBA. WINDS WERE GUSTING INTO THE 30-35 KNOT RANGE INTO NW MN
WITH THE PRES RISE ASSOCIATED WITH THE FRONT/TROUGH.

TONIGHT...EXPECT THE PCPN COVERAGE TO INCREASE THIS EVENING FROM
WEST TO EAST AS THE ONTARIO SHRTWV MOVES INTO THE AREA. WET-BULB
ZERO HEIGHTS AND UPSTREAM OBS SUGGEST THAT THE RAIN WILL QUICKLY
CHANGE OVER TO SNOW THIS EVENING AS THE COLDER AIR MOVES IN BEHIND
THE COLD FRONT. THE COMBINATION OF STRONG 700-300 MB QVECTOR
CONV...850 MB TEMPS DROPPING INTO THE -8C TO -10C RANGE BY 06Z AND
TO -12C BY 12Z (LAKE WATER TEMPS NEAR 7C) AND STRONG CYCLONIC NRLY
WINDS WILL RESULT IN A PERIOD OF MODERATE TO BRIEFLY HEAVY LAKE
ENHANCED SNOW...MAINLY BTWN 03Z-09Z. ALTHOUGH SLR VALUES INTO THE
10/1-15/1 RANGE ARE EXPECTED ALONG WITH QPF IN THE 0.25 TO 0.50 INCH
RANGE...THERE IS LINGERING UNCERTAINTY WITH HOW MUCH SNOW WILL
ACCUMULATE OVER THE WARMER GROUND AND ROAD SURFACES THAT WERE STILL
NEAR 40F. LOCATIONS FAVORED BY THE STRONG UPSLOPE
FLOW IN WEST AND N CNTRL UPPER WILL SEE THE GREATEST SNOWFALL RATES
WITH ACCUMULATIONS IN THE 2 TO 4 INCH RANGE WEST AND POSSIBLY 3 TO 6
INCHES N CNTRL. A LATER CHANGEVER TO SNOW AND GREATER MARINE
INFLUENCE WILL LIMIT ACCUMULATIONS CLOSER TO THE SHORE TO AN INCH OR
TWO. OVER THE SOUTH...ACCUMULATIONS AROUND AN INCH ARE ALSO POSSIBLE.

GUSTY WINDS INTO THE 30 TO 40 MPH RANGE WILL ALSO DEVELOP AS THE
STRONG ISALLOBARIC WIND COMPONENT MOVES THROUGH BTWN 03Z-09Z WITH A
FST 5 MB 3 HOUR PRES RISE AND A VERY TIGHT GRADIENT DEVELOPS TOWARD
DAYBREAK. THE COMBINATION OF THE WINDS AND WAVES MAY LEAD TO SOME
MINOR LAKESHORE FLOODING.

FRIDAY...EXPECT THE SNOWFALL INTENSITY TO DIMINISH DURING THE
MORNING AS STRONG QVECTOR DIV AND SUBSIDENCE TAKE OVER WITH
INVERSION HEIGHTS FALLING TO AROUND 5K FT. IN ADDITION MORE ACYC
FLOW MOVES INTO THE WEST AS THE SFC RIDGE APPROACHES.
HOWEVER...INSTABILITY OVER THE LAKE COMBINED WITH THE UPSLOPE FLOW
WILL KEEP LES GOING THROUGH MUCH OF THE DAY ESPECIALLY OVER THE
HIGHER TERRAIN IN N CNTRL UPPER WITH LOWER AMOUNTS OF ONLY AN INCH
OR TWO. TEMPS WILL STRUGGLE INTO THE LOWER 30S.

.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 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 1008 PM EDT THU OCT 30 2014

FIRST WIDESPREAD WINTER EVENT OF THE SEASON HAS BEGUN. WINDS ARE
QUICKLY COMING UP W-E...AS COOLER AIR SWITCHED RAIN TO SNOW. VIS
ALREADY DOWN TO 3/4SM AT CMX WITH GUSTS NEARING 25KTS. EXPECT VIS TO
FLUCTUATE FROM 3/4 TO 3SM THROUGH 10Z...AFTER WHICH WE WILL BEGIN TO
EXPERIENCE SOME IMPROVEMENTS AS HIGH PRESSURE NEARS FROM THE W. VFR
CEILINGS AND VIS SHOULD RETURN TO ALL 3 SITES BY MID AFTERNOON AT
IWD AND CMX.
&&

.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 UNTIL 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 UNTIL 2 PM EDT FRIDAY FOR MIZ004>006.

LAKE SUPERIOR...
  GALE WARNING UNTIL 2 PM EDT FRIDAY FOR LSZ249>251-266-267.

  GALE WARNING UNTIL 11 AM EDT FRIDAY FOR LSZ243>248-264-265.

  GALE WARNING UNTIL 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...JLB
LONG TERM...KC
AVIATION...KF
MARINE...KC






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