Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 110523
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1223 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...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM EST WED FEB 10 2016

MAIN STORY WILL BE THE EXPECTED ARCTIC AIR MASS PUSHING ACROSS THE
UPPER GREAT LAKES FRIDAY AND SATURDAY...WITH ASSOCIATED LAKE EFFECT
SNOW AND GUSTY NORTH TO NORTHWEST WINDS PRODUCING HAZARDOUS
CONDITIONS ALONG LAKE SUPERIOR.

THURSDAY NIGHT...WEAK LOW-LEVEL RIDGING WILL BE EXITING TO THE SE AS
A MID-LEVEL LOW PIVOTS OVER JAMES BAY. AN ASSOCIATED TROUGH AXIS
WILL QUICKLY DIVE SE ACROSS THE CWA THURSDAY NIGHT INTO FRIDAY
MORNING. A PERIOD OF WNW LOW-LEVEL FLOW THURSDAY EVENING AND EARLY
OVERNIGHT WILL LIKELY FOCUS A MODERATE LES BAND FROM GRAND MARAIS TO
WHITEFISH POINT.

FRIDAY INTO SATURDAY...LOW-LEVEL WINDS WILL VEER BEHIND THE
TROUGH...REFOCUSING LES ACTIVITY TO NW FAVORED SNOW BELTS BY THE
AFTERNOON. FOR THE EAST...SEVERAL TRANSIENT BANDS WILL LIKELY BE THE
REGIME FOR MOST OF THE DAY AS THE WIND FIELD ADJUSTS BEHIND THE
TROUGH...SO AM NOT EXPECTING ANY SIGNIFICANT SNOWFALL FOR ANY GIVEN
LOCATION. HOWEVER...BY THE LATE AFTERNOON...A DEVELOPING LAKE
INDUCED TROUGH OVER EASTERN LAKE SUPERIOR WILL BEGIN TO ENHANCE LOW-
LEVEL CONVERGENCE OVER THE CENTRAL LAKE...RESULTING IN AN OVERALL
TREND TOWARD A DOMINANT BAND WITH WEAKER SATELLITE BANDS. CURRENT
THINKING IS THAT THE DOMINANT BAND WILL SETTLE OVER WESTERN ALGER
COUNTY AND EXTREME NE MARQUETTE COUNTY WITH EVEN MORE LOW-LEVEL
CONVERGENCE FROM A WEAK LAND BREEZE COMPONENT TO THE LOW-LEVEL WINDS.
ACROSS THE WESTERN CWA...LOW-LEVEL CONVERGENCE IS A BIT LOWER AND
FETCH A BIT SHORTER...SO SNOW AMOUNTS SHOULD GENERALLY REMAIN UNDER
ADVISORY CRITERIA. THE ONE EXCEPTION MAY BE AN ENHANCED BAND OFF THE
BAYFIELD PENINSULA INTO THE PORCUPINE MOUNTAINS.

THE SW EDGE OF AN IMPRESSIVE CORE OF -36 TO -38C 850 HPA TEMPS WILL
BEGIN TO BRUSH CWA ON FRIDAY...USHERING IN WHAT WILL LIKELY BE THE
COLDEST AIR SO FAR THIS SEASON. MOST LOCATIONS WILL SEE HIGHS IN THE
MORNING...WITH TEMPS FALLING TO ZERO OR BELOW FOR ALL BUT THE SOUTH-
CENTRAL AND IMMEDIATE LAKE SUPERIOR SHORE. WINDS WILL ALSO BE
INCREASING AS A STRONG 1044HPA SFC HIGH BUILDING ACROSS THE NORTHERN
PLAINS BEGINS TO IMPINGE ON THE LINGERING LAKE-INDUCED TROUGH.

AT THIS TIME...LES ADVISORY CONDITIONS APPEAR LIKELY FOR AT LEAST
ALGER COUNTY FRIDAY INTO SATURDAY DUE TO THE COMBINATION OF
WINDS...SNOW AMOUNTS...AND WIND CHILLS. THE COLD AIR WILL SUPPORT
RELATIVELY LOW SNOW-TO-LIQUID RATIOS /15-17 TO 1/ FOR LES...SO VERY
LOW VISIBILITY WILL BE THE BIGGEST CONCERN. FREQUENT WHITE OUT
CONDITIONS WILL BE POSSIBLE...ESPECIALLY ALONG THE LAKE SUPERIOR
SHORE BETWEEN MARQUETTE AND MUNISING. HOWEVER...WINDS ARE EXPECTED
TO STAY WELL BELOW BLIZZARD CRITERIA OF 35MPH. ELSEWHERE...WIND
CHILL ADVISORIES WILL BE POSSIBLE FRIDAY NIGHT AS WIND CHILLS REACH
-25F FOR MUCH OF THE CWA OVERNIGHT.

THE SUNDAY-WEDNESDAY TIME PERIOD LOOKS TO BE FAIRLY QUIET COMPARED
TO THE PAST FEW DAYS...AS THE SURFACE HIGH OVER THE AREA SAT NIGHT
INTO SUNDAY SHIFTS EAST. FIRST OF ALL...IT LOOKS LIKE SAT NIGHT WILL
BE VERY COLD WITH THE ARCTIC HIGH PRES OVERHEAD. GUIDANCE ALREADY
SHOWING -10 ACROSS THE INTERIOR...AND WILL LIKELY SEE -15 TO -20F IN
THE NORMALLY COLDER SPOTS DUE TO CLEARING SKIES AND LIGHT WINDS. AS
THE HIGH SHIFTS EAST...GRADUAL WARM ADVECTION WILL TAKE PLACE ACROSS
THE UPPER GREAT LAKES SUN NIGHT INTO MON AHEAD OF A WEAK UPPER
DISTURBANCE. COULD BE SOME LIGHT SNOW ASSOCIATED WITH THIS
SYSTEM...BUT NOT ANYTHING SIGNIFICANT. SOME LIGHT LES POSSIBLE ON
TUESDAY INTO WED WITH WEAK NORTHERLY FLOW...BUT GIVEN THE LACK OF
SIGNIFICANT UPPER FORCING DO NOT THINK THERE WILL BE ANYTHING
SIGNIFICANT. OVERALL...TEMPS WILL START OUT SAT NIGHT INTO SUNDAY
WELL BELOW NORMAL. HOWEVER...BY WEDNESDAY TEMPS WILL BE NEAR OR
PERHAPS SLIGHTLY ABOVE NORMAL WITH RISING HEIGHTS.
&&

.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 AM EST THIS MORNING FOR MIZ005.

  LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ006.

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

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KLUBER/MRD
AVIATION...VOSS
MARINE...07


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