Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 272041
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
341 PM EST SAT DEC 27 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 339 PM EST SAT DEC 27 2014

THE SHORTWAVE AND LOW THAT BROUGHT THE SNOW TO UPPER MICHIGAN TODAY
IS NOW LOCATED JUST TO THE EAST OF THE SOO AND IS QUICKLY LIFTING TO
THE NORTHEAST. THIS QUICK DEPARTURE AND ARRIVAL OF DRIER AIR AND NVA
BEHIND THE SHORTWAVE HAS LED TO THE SNOW QUICKLY DIMINISHING FROM
WEST TO EAST THROUGH THIS AFTERNOON. LIGHT SNOW IS STILL FALLING
OVER THE EASTERN U.P. AND THERE AREA SOME SCATTERED LAKE ENHANCED
SNOW SHOWERS AFFECTING THE NORTH CENTRAL U.P. EXPECT BOTH THE
SYNOPTIC AND LAKE ENHANCED SNOW SHOWERS TO CONTINUE TO DIMINISH
OVER THE NEXT FEW HOURS. TAKING A QUICK LOOK BACK AT THIS
OVERACHIEVING SYSTEM ACROSS BOTH WISCONSIN AND THE U.P....MANY
LOCATIONS ACROSS NORTHERN WISCONSIN AND CENTRAL/EASTERN UPPER
MICHIGAN SAW SNOWFALL AMOUNTS IN THE 4-8 INCH RANGE. BUT OVER
SOUTHERN MENOMINEE COUNTY...A POCKET OF WARM AIR PUSHED FARTHER
NORTH THAN EXPECTED AND LED TO PRIMARY RAIN AND NO SNOW
ACCUMULATION IN THE CITY OF MENOMINEE. BUT HEADING 40 MILES TO THE
NORTH IN HERMANSVILLE THEY RECEIVED 7.5 INCHES OF SNOW. THE MAIN
CULPRIT SEEMS TO BE THE UNDER-PERFORMANCE OF THE MODELS WITH QPF
AMOUNTS AND LOCATION. IN FACT...LOOKING BACK AT THE LAST 4 RUNS OF
THE SREF NOT ONE HAD LIQUID EQUIVALENT VALUES REACHING VALUES THAT
WE RECEIVED HERE AT OUR OFFICE. A QUICK LOOK AT SOME OF THE OTHER
SITES ACROSS THE AREA SHOWS A SIMILAR TREND.

BACK TO THE FORECAST. BEHIND THIS LOW...EXPECT QUIET CONDITIONS THIS
EVENING AS THAT POCKET OF DRIER AIR CONTINUES TO MOVE ACROSS UPPER
MICHIGAN AND A WEAK SURFACE RIDGE NOSES NORTHEAST INTO THE AREA.
THIS WILL LEAD TO A BRIEF PERIOD OF SCATTERED CLOUDS ACROSS THE AREA
DURING THE EVENING...BEFORE A SECONDARY TROUGH SWEEPS ACROSS WESTERN
LAKE SUPERIOR OVERNIGHT TONIGHT AND THE REST OF THE CWA ON SUNDAY.
THIS SECONDARY TROUGH WILL USHER IN MUCH COLDER AIR (850MB TEMPS
FALLING TO -18C ON SUNDAY) WHICH WILL REMAIN THROUGH MUCH OF NEXT
WEEK. AS THE TROUGH MOVES THROUGH THE WESTERN LAKE OVERNIGHT AND THE
COLDER AIR SURGES IN...EXPECT LAKE EFFECT PRECIPITATION TO QUICKLY
DEVELOP IN THE WEST-NORTHWEST WIND FAVORED LOCATIONS OF
NORTHWESTERN UPPER MICHIGAN (GENERALLY NORTHERN HOUGHTON AND
KEWEENAW COUNTIES). IN ADDITION...A SHORTWAVE MOVING EAST THROUGH
NORTHERN ONTARIO WILL BRUSH NORTHERN LAKE SUPERIOR AND THE
KEWEENAW...POTENTIALLY ADDING SOME LARGER SCALE FORCING. AS THAT
COLDER AIR MOVES IN...INVERSION HEIGHTS OVER THE KEWEENAW PENINSULA
WILL RISE TO 9-10KFT AND LEAD TO MUCH OF THE CLOUD LAYER BEING
WITHING THE DGZ. ALL OF THAT IS SUPPORTIVE OF A PERIOD OF MODERATE
SNOW IN THE KEWEENAW AFTER MIDNIGHT TONIGHT...ESPECIALLY WITH THE
INDICATIONS OF SOME ENHANCED CONVERGENCE RIGHT AHEAD OF THE SURFACE
TROUGH DROPPING ACROSS WESTERN LAKE SUPERIOR. THERE IS SOME
CONCERN ON THE WIND DIRECTIONS...AS THERE ARE SUBTLE VARIATIONS IN
THE AMOUNT OF WESTERLY COMPONENT. THAT WESTERLY WINDS IS AN
IMPORTANT FACTOR FOR THAT AREA...AS IT CAN QUICKLY INCREASE THE
FETCH BY AROUND 20 MILES. SINCE THE TREND IN THE MODELS RECENTLY IS
FOR MORE OF A WESTERN WIND DIRECTION INITIALLY BEFORE SWITCHING MORE
WEST-NORTHWEST...WILL FOLLOW THAT IDEA FOR THE OVERNIGHT PERIOD AND
FOCUS THE HEAVIEST SNOWFALL OVER NORTHERN HOUGHTON COUNTY. WHERE
THE HEAVIEST CONVERGENT BAND OF SNOW OCCURS...THERE WILL LIKELY BE
A FEW TO SEVERAL HOUR PERIOD OF AN INCH AN HOUR OF FLUFFY SNOWFALL.
THUS...HAVE 1 TO ALMOST 4 INCHES OF SNOW OVER NORTHERN HOUGHTON
COUNTY FOR THE OVERNIGHT HOURS. THEN AS THE TROUGH SWEEPS SOUTHEAST
ACROSS THE REST OF THE AREA ON SUNDAY...EXPECT THE WINDS TO
TRANSITION TO MORE OF A NORTHWESTERLY WIND DIRECTION AND WILL FOCUS
THE POPS IN THOSE FAVORED LOCATIONS. OVER THE WEST...THE DEPARTURE
OF THE TROUGH WILL LOWER INVERSION HEIGHTS TOWARDS 5-6KFT BUT STILL
KEEP MUCH OF THE CLOUD WITHIN THE DGZ. SO EXPECT THE INTENSITY TO
DIMINISH...BUT STILL SHOULD SEE SOME FLUFFY ACCUMULATIONS OF 1 TO
4 INCHES OVER MUCH OF THE WESTERN HIGHER TERRAIN LOCATIONS. WITH
THE FORECASTED SNOWFALL AMOUNTS...HAVE ISSUED LAKE EFFECT SNOW
ADVISORY FOR NORTHERN HOUGHTON TO COVER THE MODERATE LAKE EFFECT
OVERNIGHT TONIGHT INTO SUNDAY MORNING.

MEANWHILE OVER THE EAST THE ARRIVAL OF THE COLDER AIR AND BETTER
MOISTURE WILL BE DELAYED TOWARDS THE MORNING HOURS AND THEN WILL
INCREASE POPS FAIRLY QUICKLY DURING THAT PERIOD. FIRST ALONG THE
LAKE SUPERIOR SHORELINE EAST OF MUNISING WITH THE WEST-NORTHWEST
WIND AND THEN TRANSITION TO NORTHWESTERLY WIND FAVORED AREAS BY
EARLY EVENING. OVERALL...SNOWFALL AMOUNTS OVER THE EAST DURING THE
DAY ON SUNDAY WILL BE IN THE 1 TO 3 INCH RANGE.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 458 AM EST SAT DEC 27 2014

WILL START OUT 12Z SUNDAY WITH A COLD FRONT DRAPED ACROSS THE FAR W
CWA. THIS WILL BE THE FOCUS FOR LIGHT TO POTENTIALLY MODERATE SNOW
SHOWERS FROM AROUND ONTONAGON UP THROUGH THE KEWEENAW PENINSULA. AS
NOTED IN THE PREVIOUS DISCUSSION...A LES ADVISORY BY BE NEEDED FOR
ONTONAGON AND HOUGHTON COUNTIES. CURRENTLY FORECASTING 3-5IN OF NEW
SNOW IN THIS AREA OVERNIGHT THROUGH SUNDAY EVENING. WILL HOLD OFF ON
ISSUING ANYTHING AS ONTONAGON AND S HOUGHTON HAVE BEEN INCLUDED IN
THE INITIAL WINTER WX ADVISORY FOR TODAY.

WITH COOLER AIR SLIDING IN...LOOK FOR SNOW RATIOS TO BE ON THE
INCREASE...RANGING FROM AROUND 20-23:1 THROUGH MUCH OF THIS PERIOD.
THE SFC TROUGH WILL SLOWLY EXIT AS STRONG AND COLD HIGH PRESSURE
PUSHES FROM FAR NW CANADA SUNDAY TO BRITISH COLUMBIA/ALBERTA ON
MONDAY...WITH A SIZABLE RIDGE EXTENDING INTO THE UPPER GREAT LAKES.

THE LOWERING INVERSION HEIGHTS /AROUND 850MB AT IWD/ WILL START TO
BECOME A CONCERN FOR MODERATE/HEAVY SNOWFALL DEVELOPMENT FROM 00Z
MONDAY ON ACROSS THE CWA. STILL EXPECTING 12HR SNOW TOTALS OF 1-3IN
WHERE THE BEST CONVERGENCE DEVELOPS WITH PLENTY OF MOISTURE STILL
STUCK IN OUR STEADY NW FLOW INTO TUESDAY.

THE COLDEST AIR LOOKS TO SWING IN TUESDAY NIGHT...ON THE ORDER OF
-21 TO -24C. IF WINDS BECOME MORE WESTERLY AND THE INTERIOR W HALF
CLEARS OUT...THIS COULD BE A VERY CHILLY NIGHT. CURRENTLY CALLING
FOR -5 TO -10F LOWS BY DAYBREAK WEDNESDAY UNDER A PARTLY CLOUDY SKY.

THERE MAY BE A BRIEF REPRISE FROM THE STEADY NW TO WNW WINDS
WEDNESDAY INTO WEDNESDAY NIGHT. POPS/WX MAY NEED TO BE DIMINISHED
FROM THE CURRENT FCST FOR WEDNESDAY NIGHT IF THIS TREND HOLDS UP.
THERE IS PLENTY OF DISCREPANCIES BETWEEN THE AVAILABLE GUIDANCE AT
THIS POINT...VARYING FROM -20C 850MB AIR OVERHEAD ON GUSTY NW WINDS
/UP TO 40KTS AT 850MB/ FROM THE 27/00Z GFS...AND MORE W-WSW WINDS
WITH -12C 850MB TEMPERATURES OFF THE 26/12Z ECMWF. WILL KEEP GOING
WITH A GENERAL BLEND BETWEEN THE CONSENSUS AND OUR PREVIOUS FORECAST
BEYOND THIS POINT GIVEN THE MODERATE TO LOWER CONFIDENCE.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM EST SAT DEC 27 2014

THE SYSTEM LEADING TO THE MODERATE SNOW ACROSS MUCH OF UPPER
MICHIGAN WILL BE QUICKLY LIFTING NORTHEAST AND OUT OF THE AREA OVER
THE NEXT COUPLE OF HOURS. HAVE ALREADY SEEN VISIBILITIES COMING UP
AT KIWD AS THE BACK EDGE OF THE SNOW IS DEPARTING. THAT WEST TO
EAST DIMINISHING TREND WILL CONTINUE AT ALL THREE SITES AND EXPECT
WINDS TO BACK TO THE WEST-NORTHWEST INTO THE EVENING. THIS SHOULD
LEAD TO A TREND TOWARDS VFR AT KIWD/KSAW...BUT KCMX MAY TRY TO HOLD
ONTO HIGH END MVFR THIS EVENING WITH SOME LAKE ENHANCED CLOUDS.

FOCUS THEN TURNS TO A SECOND TROUGH THAT WILL DROP ACROSS WESTERN
LAKE SUPERIOR LATE TONIGHT AND UPPER MICHIGAN ON SUNDAY. JUST AHEAD
OF THIS TROUGH...EXPECT LAKE EFFECT SNOW TO DEVELOP IN THE WESTERLY
WINDS AND AFFECT KCMX SHORTLY AFTER MIDNIGHT. THIS WILL LEAD TO A
PERIOD OF MODERATE SNOWFALL AND HAVE BROUGHT VSBYS BELOW ALTERNATE
LANDING MINS. ONCE THE TROUGH MOVES THROUGH...CONDITIONS WILL
BECOME LESS FAVORABLE AT KCMX AS WINDS TURN TO THE NORTHWEST BUT
BRING A BETTER OPPORTUNITY FOR SNOW AT KIWD. AT KSAW...EXPECT THE
VFR CONDITIONS TO REMAIN THROUGH MUCH OF THE MORNING...BUT BLOWOFF
FROM THE UPSTREAM LAKE EFFECT WILL LIKELY BRING SOME LIGHT SNOW
SHOWERS AND BORDERLINE MVFR/VFR CEILINGS AROUND NOON ON SUNDAY.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 PM EST SAT DEC 27 2014

A LOW JUST TO THE EAST OF THE SOO WILL QUICKLY LIFT TO THE
NORTHEAST THIS EVENING. IMMEDIATELY BEHIND THE LOW...THERE WILL BE
A PERIOD OF NORTH TO NORTHWEST WINDS OF 20 TO 30KTS OVER THE
EASTERN LAKE. BUT THEN A WEAK RIDGE WILL SLIDE OVER THE AREA AND
BACK WINDS TO THE WEST UP TO 20KTS. A SECONDARY SURFACE TROUGH
SWEEPING SOUTHEAST ACROSS LAKE SUPERIOR LATE TONIGHT THROUGH SUNDAY
MORNING WILL LEAD TO AN INCREASE IN THE NORTHWEST WINDS WITH GUSTS
TO 25KTS AND MAYBE EVEN 30KTS OVER EASTERN LAKE SUPERIOR. THE
NORTHWESTERLY WINDS OF 15-25KTS WILL REMAIN THROUGH THE FIRST PART
OF THE UPCOMING WORK WEEK AS THE UPPER GREAT LAKES REGION IS
BETWEEN A HIGH IN THE NORTHERN/CENTRAL PLAINS AND A LOW OVER
NORTHERN QUEBEC. THIS LOW WILL ROTATE A TROUGH SOUTHEAST ACROSS THE
UPPER GREAT LAKES REGION WEDNESDAY INTO THURSDAY. THE TIGHTENING OF
THE PRESSURE GRADIENT AHEAD OF THIS TROUGH WILL LEAD TO WESTERLY
GALES OF 35-40KTS WEDNESDAY INTO WEDNESDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
     007-014-085.

  WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON
     FOR MIZ004-005-010>013.

  LAKE EFFECT SNOW ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM EST
     SUNDAY FOR MIZ003.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...KF
AVIATION...SRF
MARINE...SRF






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