Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 272140
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
440 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 NIGHT THROUGH SATURDAY)
ISSUED AT 439 PM EST SAT DEC 27 2014

THE START OF A SIGNIFICANT PATTERN CHANGE IS NOW GETTING UNDERWAY
ACROSS NAMERICA AS A RIDGE IS BUILDING N THRU ALASKA. OVER THE NEXT
SEVERAL DAYS...THE RIDGE WILL CONTINUE TO BUILD INTO ALASKA/WRN
CANADA. TODAYS 00Z GFS ENSEMBLE MEAN STILL SHOWS 500MB HEIGHT
ANOMALIES PEAKING AT 2.5 STANDARD DEVIATIONS ABOVE THE LONG TERM
LATE DEC AVG MON THRU EARLY WED OVER FAR WRN CANADA. OF COURSE...THE
DOWNSTREAM RESPONSE WILL BE A DEVELOPING CNTRL/ERN NAMERICA TROF.
THIS AMPLIFIED PATTERN WILL ALLOW THE BUILDUP AND EXPANSION OF
ARCTIC AIR ACROSS CANADA THAT WILL SPILL S INTO THE CONUS...SIMILAR
TO THE PATTERN OBSERVED MOST OF LAST WINTER AND LAST MONTH. SO...
AFTER AN EXTENDED PERIOD OF MOSTLY ABOVE NORMAL TEMPS OVER THE LAST
2+ WEEKS...A BLO NORMAL TEMP REGIME WILL DOMINATE NEXT WEEK ACROSS
THE UPPER LAKES. AT THIS TIME...IT DOES NOT APPEAR THAT THIS IS A
PATTERN THAT WILL LOCK IN. WHILE THE GFS/ECMWF HIGH RES RUNS
MAINTAIN A COLD PATTERN THRU DAY 10...FARTHER OUT TO DAY 16...
MAJORITY OF GEM ENSEMBLES INDICATE DAMPLIFICATION AND A TREND BACK
TOWARD NORMAL TEMPS BY MID JAN. CFSV2 RUNS GO FURTHER TO BRING A
RETURN OF A WARM PATTERN/ABOVE NORMAL TEMPS FOR MID/LATE JAN. WE`LL
SEE. AS FOR PCPN...PCPN POTENTIAL NEXT WEEK WILL BE CONFINED MOSTLY
TO THE LAKE EFFECT SNOW BELTS NEAR LAKE SUPERIOR AS COLD NW FLOW
PREVAILS. THERE ARE STILL SOME HINTS IN GFS/ECMWF RUNS THAT A WINTER
STORM COULD WIND UP AND TRACK FROM THE SRN PLAINS TO THE GREAT
LAKES/OHIO VALLEY EARLY NEXT WEEKEND...BUT GEM ENSEMBLES STILL FAIL
TO GENERATE ANYTHING SIGNIFICANT...THOUGH A FEW RUNS ARE NOW SHOWING
A SFC LOW LIFTING NE INTO THE GREAT LAKES. AT THIS POINT...SEEMS
LIKE A LOW PROBABILITY OF SOMETHING SIGNIFICANT PCPN-WISE AFFECTING
THE UPPER LAKES...BUT IT WILL CONTINUE TO BE SOMETHING TO MONITOR IN
THE COMING DAYS.

BEGINNING SUN NIGHT THRU TUE...INCREASINGLY COLDER AIR FLOWS INTO
THE UPPER LAKES WITH 850MB TEMPS FALLING FROM AROUND -18C SUN
EVENING TO AROUND -20C MON AND TO AROUND -22C TUE. THIS WILL BE
REFLECTED IN SFC TEMPS FALLING TO BLO NORMAL VALUES FOR LATE DEC.
MAX TEMPS IN THE TEENS WILL BE COMMON ON MON WITH SINGLE
DIGITS/TEENS THE RULE ON TUE. AT NIGHT...EXPECT SUBZERO TEMPS IN THE
INTERIOR AWAY FROM LAKE EFFECT CLOUDS/SNOW. TUE NIGHT WILL PROBABLY
BE COLDEST WITH SOME INTERIOR W HALF COLD SPOTS SLIPPING TO -10F OR
LWR. WITH SUCH COLD AIR...EXPECT NMRS SNOW SHOWERS IN THE SNOW BELTS
FAVORED BY NW WINDS. NAM/GFS FCST SOUNDINGS SHOW INVERSIONS AT
4-5KFT...SO LES WILL OVERALL BE ON THE LIGHT SIDE (1-4IN/12HRS).
THRU THE PERIOD...WHERE FETCH ACROSS THE LAKE IS LONGEST...ALLOWING
MOST LAKE MODERATION...DGZ WILL DOMINATE THE CONVECTIVE LAYER. THIS
MAY ALLOW FOR SOME ADVY LEVEL SNOW ACCUMULATIONS...IN PARTICULAR
WHERE LONGER FETCH AND LOCALIZED ENHANCED CONVERGENCE WORK TOGETHER.
A COUPLE OF SHORTWAVES ARE FCST TO SWING THRU THE UPPER LAKES...A
VERY WEAK ONE ON MON AND A STRONGER ONE ON TUE. AS WAS THE CASE THE
LAST 2 DAYS...MODELS INDICATE THAT THE ONE ON TUE WILL LIKELY HAVE
SOME IMPACT ON INCREASING MOISTURE DEPTH/RAISING INVERSION HEIGHTS.
SO...EXPECT SOME INCREASE IN LES COVERAGE/INTENSITY FOR A TIME ON
TUE.

ON NEW YEARS EVE DAY...LOW-LEVEL WINDS WILL BACK TO THE WSW OR EVEN
SW IN RESPONSE TO THE NEXT SHORTWAVE TROF SWINGING SE THRU MANITOBA
INTO NRN ONTARIO. THIS WILL CAUSE LES TO SHIFT. HOWEVER...UP AT
850MB...WINDS REMAIN OUT OF THE W. SO...LES WILL LIKELY CONTINUE TO
AFFECT THE KEWEENAW PENINSULA. TIGHTENING PRES GRADIENT BTWN HIGH
PRES OVER THE CNTRL/SRN PLAINS AND LOW PRES OVER HUDSON BAY WILL
RESULT IN INCREASING SFC WINDS...ESPECIALLY OVER THE EXPOSED
KEWEENAW WHERE 950MB WINDS ARE FCST AT AROUND 40KT. BLSN MAY BECOME
AN ISSUE THERE ON NEW YEARS EVE...ESPECIALLY IF SHSN COVERAGE
REMAINS NMRS OR GREATER.

NEXT ARCTIC COLD FRONT SHOULD THEN SWEEP ACROSS THE AREA EARLY ON
NEW YEARS DAY...ENHANCING LES AND PROBABLY BRINGING AT LEAST SOME
-SHSN TO THE REMAINDER OF THE AREA.

LES WILL CONTINUE ON INTO FRI UNDER COLD AIR MASS...BUT UNCERTAINTY
IN WIND DIRECTION INCREASES AS IT APPEARS WINDS MAY BEGIN TO BACK IN
RESPONSE TO PRES FALLS SPREADING OUT OVER THE PLAINS. ON INTO SAT...
MUCH WILL DEPEND ON EVOLUTION OF THE CLOSED LOW THAT WILL BE OVER
THE SW STATES MIDWEEK. THE 12Z GFS REMAINS ON THE NW SIDE OF MEDIUM
RANGE GUIDANCE IN TAKING THAT ENERGY FARTHER N AND W INTO THE GREAT
LAKES REGION. AS STATED EARLIER...IT APPEARS TO BE A LOW PROBABILITY
FOR THAT SYSTEM TO TRACK FAR ENOUGH N AND W TO HAVE MUCH IMPACT ON
THE UPPER LAKES. ENSEMBLE MEANS INDICATE AN INVERTED TROF PUSHING
INTO THE AREA WHICH WOULD SUGGEST A PERIOD OF AT LEAST -SN IS
POSSIBLE AT SOME POINT FRI INTO SAT...FOLLOWED BY ANOTHER SURGE OF
ARCTIC AIR.
&&

.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.

  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...ROLFSON
AVIATION...SRF
MARINE...SRF






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