Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 111029
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
529 AM EST THU FEB 11 2016

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM EST WED FEB 10 2016

UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE IN THE ROCKIES AND A
DEEP TROUGH IN THE EASTERN U.S. THIS MORNING WITH NW UPPER FLOW OVER
THE AREA ALLOWING COLD AIR TO SPILL ACROSS THE REGION. A SHORTWAVE
OVER THE ERN U.P. THIS MORNING WILL CONTINUE TO HEAD SOUTHEAST TO
THE LOWER GREAT LAKES BY THIS EVENING AND THIS REINFORCES THE TROUGH
OVER THE ERN U.S. AND ALSO THE COLD AIR ACROSS THE REGION. ANOTHER
SHORTWAVE THEN DIGS SE FROM NRN MANITOBA ON THU INTO CENTRAL
ONTARIO. NAM SHOWS MAJORITY OF ENERGY WITH THIS NEXT SYSTEM PASSING
BY TO THE NORTH AND EAST OF THE CWA WITH DEEPER MOISTURE STAYING
NORTH OF THE AREA.

PERSISTENCE HAS BEEN THE WAY TO GO WITH THIS FORECAST AND WILL
CONTINUE TO USE THAT TO BASE THE FORECAST AROUND. INVERSION HEIGHTS
OFF NAM BUFKIT SOUNDINGS ARE AT OR BELOW 4000 FEET NOW WITH BEST
OMEGA AND LIFT EXITING THE AREA WITH THE SHORTWAVE THAT MOVED
THROUGH THIS MORNING. 950 MB CONVERGENCE STRENGTHENS OVERNIGHT OFF
TO THE WEST AND ALSO ACROSS ALGER COUNTIES...BUT DRY AIR AT THE LOW
LEVELS AND DEW POINTS BELOW ZERO NORTH AND WEST OF LAKE SUPERIOR
APPEAR TO HAVE TAKEN THEIR TOLL ON LAKE EFFECT SNOW SHOWER INTENSITY
AND COVERAGE A BIT AS LAKE EFFECT BANDS HAVE BECOME SPLOTCHY AND
REFLECTIVITIES HAVE DECREASED ON THE KMQT RADAR THIS AFTERNOON. PLAN
IS TO LET ADVISORIES GO IN THE WEST WITH THE DRY AIR CUTTING DOWN
ACCUMULATIONS AND WITH LIGHTER WINDS NOT LETTING THE SNOW BLOW AND
DRIFT AROUND AS MUCH. FOR MARQUETTE COUNTY...PLAN IS TO CANCEL
WARNING AND GO WITH ADVISORY FOR THE ERN PART OF COUNTY FOR TONIGHT
INSTEAD AS BAND WILL CONTINUE TO AFFECT THE FAR ERN COUNTY OVERNIGHT
AND KEEP WARNING UP FOR ALGER COUNTY TONIGHT. WINDS GO WESTERLY ON
THU.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 528 AM EST THU FEB 11 2016

THE MAIN STORY WILL BE THE VERY COLD CONDITIONS ALONG WITH STRONG
WINDS AND ADDITIONAL NW FLOW LES. THEN...MODELS SUGGEST THAT THE
AMPLIFIED PATTERN ALLOWING THE INTRUSION OF VERY COLD ARCTIC AIR
INTO THE NRN LAKES WILL BECOME MORE ZONAL NEXT WEEK WITH MILDER
PACIFIC AIR AND ABOVE NORMAL TEMPERATURES RETURNING TO THE REGION.

BEHIND THE CLIPPER SHRTWV AND ARCTIC FRONT...CAA WITH VERY COLD AIR
WILL PUSH INTO THE NRN LAKES. ALTHOUGH THE CORE OF THE COLDEST
ARCTIC AIR WITH 850 MB TEMPS TO AROUND -38C SLIDES TO THE NE OF THE
LAKE SUPERIOR...850 MB TEMPS IN THE -26C TO -30C RANGE ARE EXPECTED
ACROSS LAKE SUPERIOR...PROVIDING PLENTY OF INSTABILITY FOR MODERATE
TO LCLY HEAVY LES. THE HIGHER RES MODELS SUGGEST THAT THE 330-340
WINDS AND BEST LOW LEVEL CONV WILL KEEP THE STRONGEST LES BANDS EAST
OF MARQUETTE WITH POTENTIAL FOR 3 TO 5 INCH ACCUMULATIONS. A SHORTER
FETCH INTO THE WEST WITH LOWER INVERSION HEIGHTS WILL KEEP
ACCUMULATIONS MAINLY BLO ADVY CRITERIA WITH 1 TO 3 INCH
AMOUNTS...GREATEST FROM THE PORCUPINE MOUNTAINS TO TWIN LAKES.

BY FRIDAY NIGHT...THE COMBINATION OF STRENGTHENING LAKE INDUCED
TROUGHING AND LAND BREEZES WILL HELP INCREASE LOW LEVEL CONV AND
POTENTIAL FOR DOMINANT LES BANDS...LIKELY INTO WRN ALGER COUNTY
WHERE ADDITIONAL 3 TO 6 INCH AMOUNTS ARE EXPECTED. OUTSIDE THE
HEAVIER LES BANDS...A VERY SHALLOW DGZ NEAR THE SFC WILL LIMIT
SNOWFLAKE SIZE AND SLR VALUES. HOWEVER...THE SMALL FLAKES WILL BE
EFFECTIVE AT REDUCING VSBY...ESEPCIALLY WITH THE GUSTY WINDS TO 30
MPH ALONG LAKE SUPERIOR.

STEADY OR SLOWLY FALLING TEMPS TO AROUND ZERO NORTH TO 5 TO 10 SOUTH
WITH THE GUSTY NW WINDS WILL PRODUCE WIND CHILLS OF -15 TO -25 BY
LATE IN THE DAY AND MAY REACH -20 TO -30 LATE FRI NIGHT INTO EARLY
SATURDAY.

THE LES WILL SLOWLY DIMINSH SATURDAY AND END SATURDAY NIGHT AS
RIDING BUILDS INTO THE REGION AND SHIFTS TO THE EAST WITH WINDS
BECOMING SRLY. ADDITIONAL 1 TO 3 INCH AMOUNTS WILL BE POSSIBLE.

SUN...THE MODELS HAVE TRENDED WEAKER WITH THE WAA PATTERN AND
MOISTURE INFLOW SUPPORTING LIGHT SNOW INTO THE REGION. SO...ONLY
LOWER END CHANCE POPS REMAIN WITH INSIGNIFICANT SNOW ACCUMULATIONS.

MON-WED...SOME LIGHT LES MAY BE POSSIBLE BY LATE MON INTO TUE AS 850
MB TEMPS DROP BACK INTO THE -10C TO -15C RANGE. HOWEVER...ONLY
CHANCE POPS WERE MENTIONED GIVEN THE WEAK WIND FIELDS AND MARGINAL
INSTABILITY. THE GFS AND ECMWF SUGGEST THAT A STRONGER SHRTWV MOVING
OUT OF THE NRN PLAINS MAY BRING ANOTHER CHANCE OF SNOW TUE NIGHT
INTO WED BUT WITH THE HIGHER CHANCES TO THE SOUTH THROUGH WI.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1223 AM EST THU FEB 11 2016

UNDER A NW FLOW OF ARCTIC AIR ACROSS LAKE SUPERIOR...LAKE EFFECT
SNOW SHOWERS WILL CONTINUE MAINLY AT KIWD AND KCMX OVERNIGHT.
HOWEVER...INCREASINGLY DRIER FROM NORTH AND WEST OF LAKE SUPERIOR AND
WEAKENING WINDS SHOULD ONLY RESULT AT WORST MVFR VSBY RESTRICTION
AT KIWD AND KCMX OVERNIGHT UNDER MVFR CIGS. WINDS BACKING MORE
NW AT KSAW AIDED BY DEVELOPING LAND BREEZE SHOULD KEEP SHSN GENERALLY
NE OF KSAW AND CONDITIONS AT VFR. WINDS BACKING WSW BY LATE THU
MORNING WILL ALLOW CONDITIONS TO IMPROVE TO VFR AT KIWD WHILE VSBY AT
KCMX MAY LOWER TO IFR FOR A BRIEF TIME THU AFTERNOON UNDER WESTERLY
WIND FLOW. ANOTHER ARCTIC COLD FRONT APPROACHING THE WRN TAF SITES
THU EVENING WILL BRING DETERIORATING CONDITIONS LATE THU EVENING
INTO FRI MORNING FOR KIWD AND KCMX AS WINDS SHIFT BACK AROUND TO THE
NW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 320 PM EST WED FEB 10 2016

ANOTHER ROUND OF GALES ARE POSSIBLE THURSDAY NIGHT INTO FRIDAY NIGHT
ACROSS LAKE SUPERIOR AS NEXT SHOT OF COLD AIR MOVE IN AND PRESSURE
GRADIENT TIGHTENS UP AGAIN. FREEZING SPRAY WILL ALSO INCREASE WITH
THE HEAVIEST FREEZING SPRAY EXPECTED THROUGH TONIGHT AND AGAIN
THURSDAY NIGHT INTO SATURDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
     007-085.

  LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ005.

LAKE SUPERIOR...
  HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
     LSZ264>267.

  GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR
     LSZ264>266.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...JLB
AVIATION...VOSS
MARINE...07


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