Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 300949
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
549 AM EDT THU OCT 30 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 548 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. AS A RESULT HAVE ALL WEST AND NORTH CENTRAL
COUNTIES BORDERING LAKE SUPERIOR IN LAKE EFFECT SNOW ADVISORY TONIGHT
INTO FRIDAY MIDDAY.

NORTH WINDS GUSTING TO 30 MPH OR HIGHER ESPECIALLY ALONG THE LAKE
SUPERIOR SHORE COULD ALSO CAUSE SOME BLOWING OF SNOW AND REDUCED
VSBY ALTHOUGH WET NATURE OF SNOW SHOULD LIMIT BLOWING.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 429 AM EDT THU OCT 30 2014

NAM SHOWS A DEEP TROUGH OVER THE UPPER GREAT LAKES 12Z FRI WITH A
STRONG 500 MB RIDGE OVER THE ROCKIES. THE TROUGH DIGS INTO THE
EASTERN U.S. ON FRI WHILE THE RIDGE MOVES INTO THE PLAINS. THE RIDGE
THEN REMAINS IN THE PLAINS THROUGH SAT NIGHT WITH THE DEEP TROUGH
MOVING TO THE ERN SEABOARD.

DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST THIS PERIOD.
TEMPERATURES SEEMED REASONABLE AND LEFT THEM ALONE. NAM AND GFS SHOW
850MB TEMPERATURES DOWN TO -10C TO -12C 12Z FRI WARMING TO -2C TO
-6C BY 12Z SAT AND WITH LAKE SUPERIOR TEMPERATURES FROM 6C TO
8C...THIS IS ENOUGH ON FRI AND FRI EVENING TO GET LAKE EFFECT SNOW
SHOWERS. NORTHERLY LAKE EFFECT SNOW BELTS WILL SEE UP TO 2 INCHES OF
SNOW ON FRIDAY. SFC HIGH PRESSURE WILL BUILD IN QUICKLY AND LAKE
EFFECT SNOW SHOWERS LOOK TO HANG ON INTO FRI NIGHT WITH SLOWLY
DIMINISHING POPS FRI AND FRI NIGHT. SAT AND SAT NIGHT LOOK DRY FOR
NOW WITH FURTHER MODIFICATION IN THE AIRMASS AND TEMPERATURES
WARMING ENOUGH TO GET RID OF LAKE EFFECT CLOUDS...SO SHOULD SEE
DECREASING CLOUDS SAT AND SAT NIGHT.

IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE
WESTERN U.S. AND A RIDGE OVER THE CENTRAL U.S. 12Z SUN. THE RIDGE
MOVES TO THE LOWER GREAT LAKES ON MON. THE TROUGH PUSHES INTO THE
UPPER GREAT LAKES LATE MON INTO TUE MORNING. MORE UPPER TROUGHING
COMES IN FOR WED. IT WILL START OFF DRY FOR SUN AND SUN NIGHT AND
THEN WET THROUGH WED WITH THE BEST CHANCE FOR PCPN MON NIGHT AND
TUE. TEMPERATURES WILL STAY NEAR NORMAL THIS FORECAST PERIOD.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1256 AM EDT THU OCT 30 2014

CIGS WILL GENERALLY REMAIN MVFR OVERNIGHT. SCATTERED RAIN SHOWERS
WILL MOVE INTO THE AREA LATER TONIGHT INTO THU MORNING AS AN UPPER
DISTURBANCE MOVES THROUGH THE AREA...BUT CIGS/VSBYS SHOULD REMAIN
MVFR. 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 EFFECT PCPN TO DEVELOP LATE THU AFTN
AND CONTINUE INTO THU NIGHT. THE AIR WILL BECOME COLD ENOUGH FOR THE
PCPN TO CHANGE TO ALL SNOW. WHEN THIS OCCURS /MOST LIKELY AFTER 03Z
FRI/...EXPECT VSBYS TO DROP TO IFR FOR AT LEAST SAW AND POSSIBLY
IWD AND CMX. 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 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EDT THU OCT 30 2014

A WEAK LOW PRESSURE SYSTEM MOVING ACROSS UPPER MICHIGAN THURSDAY
AFTERNOON WILL STRENGTHEN AS IT MOVES SOUTHEAST THROUGH THE REST OF
THE GREAT LAKES TONIGHT INTO FRIDAY. THAT LOW...IN COMBINATION WITH
A STRONG HIGH IN CENTRAL CANADA AND THE NORTHERN PLAINS WILL LEAD TO
STRONG NORTHERLY FLOW ACROSS LAKE SUPERIOR. AT THE PRESENT
TIME...EXPECT GALES UP TO 45KTS TONIGHT INTO FRIDAY MORNING AND WILL
UPGRADE TO A GALE WARNING FOR ALL OF LAKE SUPERIOR. THE GALES WILL
COME TO AN END ON FRIDAY AFTERNOON AS THE HIGH PRESSURE RIDGE BUILDS
OVER THE AREA. THIS WILL LEAD TO WINDS DIMINISHING BELOW 20KTS ON
FRIDAY NIGHT AND CONTINUING INTO SATURDAY EVENING. AS THE HIGH
DEPARTS AND ANOTHER LOW DEVELOPS IN THE NORTHERN PLAINS...SOUTHERLY
FLOW WILL DEVELOP OVER LAKE SUPERIOR ON SATURDAY NIGHT (WINDS UP TO
25KTS) AND CONTINUE INTO MONDAY.
&&

.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...07
AVIATION...MRD
MARINE...07






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