Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 282311
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
611 PM EST WED JAN 28 2015

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.

PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.

COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EST WED JAN 28 2015

A SHORTWAVE TROUGH WILL BE OVER THE CWA AT 00Z FRI...WITH MOST OF
THE ASSOCIATED FORCING E OF THE CWA BY THAT TIME. NW-NNW LOW LEVEL
WINDS AND 850MB TEMPS AS LOW AS -22C WILL KEEP SNOW GOING IN THE NW-
NNW WINDS SNOWBELTS THU NIGHT...BUT A SFC RIDGE PUSHING THROUGH ON
FRI WILL LEAD TO A DIMINISHING TREND IN THE LES AS WINDS BECOME ANTI-
CYCLONIC. WINDS TURN SWLY BY FRI NIGHT BEHIND THE TROUGH AND AHEAD
OF A CLIPPER SHORTWAVE/SFC TROUGH THAT WILL MOVE THROUGH LATE FRI
NIGHT/EARLY SAT. NW WIND LES WILL RAMP UP ALONG AND BEHIND THE
TROUGH AS 850MB WINDS AS LOW AS -30C SWEEP ACROSS THE AREA. TEMPS
LOOK TO MODERATE SOME MON INTO TUE AS A RIDGE MOVES THROUGH...WITH
ANOTHER COLD BLAST SHOWN BY MODELS TOWARD THE MIDDLE OF NEXT WEEK.

OVER THE NEXT WEEK THE NW WINDS SNOWBELTS MAINLY E OF MARQUETTE WILL
SEE THE MOST SNOWFALL...WITH PROLONGED LIGHT TO MODERATE SNOWFALL.
WITH THE VERY COLD AIRMASS... GROWTH WILL BE ADVERSELY
IMPACTED...WITH SMALL SNOW FLAKES EFFICIENT AT REDUCING VIS THE
PREDOMINANT CONDITION.

COLD TEMPS ARE A CERTAINTY...ESPECIALLY SUN AND MON WHEN HIGHS WILL
NOT MAKE IT OUT OF THE SINGLE DIGITS ABOVE ZERO IN MOST LOCATIONS.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 611 PM EST WED JAN 28 2015

MVFR CIGS WILL REACH KSAW THIS EVENING. AT KIWD...DOWNSLOPE WIND
COMPONENT SHOULD PREVENT THE LOWER CLOUDS IN NRN WI FROM REACHING
THE TERMINAL. DISTURBANCE APPROACHING TONIGHT WILL BRING SOME
-SN/DETERIORATING CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR
WITH A FEW HRS OF LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST WED JAN 28 2015

AHEAD OF AN APPROACHING LOW PRES TROF...S WINDS OF 20-30KT ARE
EXPECTED OVER ERN LAKE SUPERIOR TONIGHT. AS IS TYPICAL FOR SOUTHERLY
WINDS...WINDS WILL BE LIGHTER OVER THE W. THE TROF WILL PASS ACROSS
THE LAKE THU MORNING. BEHIND IT...N TO NW WINDS WILL INCREASE TO 20-
30KT OVER WRN LAKE SUPERIOR. OVER THE CNTRL AND ERN LAKE...WINDS
WILL INCREASE TO GALE FORCE (GUSTS TO AROUND 40KT) FOR THU AFTN AND
NIGHT. COMBINATION OF MUCH COLDER AIR/STRONG WINDS AND BUILDING
WAVES WILL LEAD TO HVY FREEZING SPRAY THU AFTN UNTIL EARLY FRI
MORNING WHEN WINDS/WAVES DIMINISH WITH THE CLOSER APPROACH OF
CANADIAN HIGH PRES. AFTER A PERIOD OF LIGHTER WINDS MOSTLY UNDER
20KT FRI AFTN/NIGHT...WINDS WILL INCREASE AGAIN TO 20-30KT
SAT...ESPECIALLY SAT AFTN/NIGHT...IN THE WAKE OF A LOW PRES TROUGH.
GALES MAY OCCUR OVER PORTIONS OF CNTRL LAKE SUPERIOR. WINDS SHOULD
DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MON.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 7 AM EST
     FRIDAY FOR LSZ264-266-267.

  GALE WARNING FROM 1 PM THURSDAY TO 4 AM EST FRIDAY FOR LSZ267.

  GALE WARNING FROM 10 AM THURSDAY TO 4 AM EST FRIDAY FOR LSZ265-
     266.

  GALE WARNING FROM 7 AM THURSDAY TO 1 AM EST FRIDAY FOR LSZ263-
     264.

  HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 1 AM EST
     FRIDAY FOR LSZ263.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON



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