Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 281015
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
515 AM EST SUN DEC 28 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST SUN DEC 28 2014

TODAY...A SHORTWAVE AS NOTED ON WATER VAPOR IMAGERY MOVING E ACROSS
NRN MN AND ONTARIO WILL HELP PROPEL A SFC TROUGH/COLD FRONT ACROSS
LAKE SUPERIOR AND UPPER MI TODAY. A CONVERGENT WNW LOW-LVL FLOW
ALONG THIS TROUGH/COLD FRONT WILL PROVIDE THE FOCUS FOR SOME
MODERATE LAKE EFFECT SNOW SHOWERS OVER PORTIONS OF NW UPPER MI
THROUGH THIS MORNING AS 850 MB TEMPS FALL TO -18 TO -20C AS NOTED ON
MODELS. INVERSION HGTS OFF KCMX NAM BUFR SNDGS INDICATE INVERSION
HEIGHTS OVER THE KEWEENAW PENINSULA FM 7-8KFT WITH THE CLOUD LAYER
FIRMLY PLACED WITHIN THE DGZ. ALL THESE FACTORS SHOULD SUPPORT
MODERATE LAKE EFFECT SNOW ACROSS NRN HOUGHTON AND NE ONTONAGON
COUNTIES AST LEAST THROUGH THIS MORNING. SEVERAL HOURS OF INCH PER
HR FLUFFY LAKE EFFECT SNOWFALL COULD LEAD TO 3-6 INCHES INTO THE
AFTERNOON HOURS ACROSS NRN HOUGHTON AND NE ONTONAGON COUNTIES. THUS
WILL KEEP ADVISORY GOING FOR THESE COUNTIES THROUGH LATE AFTERNOON
HOURS. AS THE TROUGH MOVES ACROSS THE FCST AREA...EXPECT WINDS TO
SHIFT FROM WNW TO MORE NW DIRECTION SO WILL CONTINUE TO FOCUS HIGHER
POPS INTO NW SNOWBELTS BY LATE MORNING INTO AFTERNOON. INVERSION
HEIGHTS WILL LOWER QUICKLY TO 4-5KFT IN THE WAKE OF TROUGH/FRONTAL
PASSAGE BUT SOUNDING STILL INDICATE CLOUD WITHIN THE DGZ. SO
ALTHOUGH LES INTENSITY WL DIMINISH...COULD STILL SEE SOME FLUFFY
ACCUMULATIONS OF 1 TO 2 INCHES OVER MUCH OF THE WESTERN HIGHER
TERRAIN LOCATIONS THIS AFTERNOON.

OVER THE EAST...THE LATER ARRIVAL OF THE COLDER AIR AND BETTER
MOISTURE WITH WINDS SHIFTING NW WILL WARRANT CATEGORICAL POPS BY
LATE MORNING/EARLY AFTERNOON OVER ALGER...NRN SCHOOLCRAFT AND LUCE
COUNTIES. OVERALL...SNOWFALL AMOUNTS OVER THE EAST TODAY SHOULD BE
GENERALLY IN 1 TO 3 INCH RANGE.

TONIGHT...MODELS HAVE 850MB TEMPS FALLING TO AROUND -20C BY LATE
TONIGHT AS INVERSIONS REMAIN FM 4-5 KFT. BUT AGAIN WITH DGZ FIRMLY
PLACED WITHIN CLOUD LAYER...EXPECT ANOTHER 1-3 INCHES OF FLUFFY LES
ACCUMULATION FOR NW SNOW BELTS OF WEST AND EASTERN UPPER MI. NOT OUT
OF THE QUESTION THAT A FEW LOCATIONS MAY SEE LOCALLY HIGHER SNOW
AMOUNTS APPROACHING 4 INCHES. WITH COLD AIRMASS IN PLACE AND PARTIAL
CLEARING POSSIBLE FAR INLAND FROM LAKE SUPERIOR...MIN TEMPS COULD
DIP AT OR BELOW ZERO OVER WESTERN INTERIOR PORTIONS OF
CWA...ESPECIALLY ALONG THE WI BORDER.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 431 AM EST SUN DEC 28 2014

THIS PERIOD WILL BE MARKED BY COLD CONDITIONS WITH PERSISTENT LES.

ON MONDAY THE LONGWAVE TROUGH WILL ENCOMPASS ALL BUT FL...STRETCHING
FROM FAR N CANADA THROUGH QUEBEC...AND A SECONDARY LOW ACROSS THE
PACIFIC NW. LOOK FOR PERSISTENT NW FLOW ALOFT WITH SEVERAL SMALL
DISTURBANCES KEEPING OFF AND ON LES GOING OVER W UPPER MI...AND
MAINLY E OF MUNISING ALONG LAKE SUPERIOR.

THE FIRST OF MANY SHORTWAVES WILL BE IMPACTING OUR LOCAL WEATHER
MONDAY...PUSHING ACROSS MN AND N MN MONDAY AFTERNOON...AND SINKING
ACROSS UPPER MI LATE MONDAY AFTERNOON-MONDAY NIGHT. DURING THIS TIME
850MB TEMPS WILL ALSO DROP A COUPLE OF DEGREES C TOO FROM AN
AVERAGE -18 TO -20.

KEEPING THE THEME GOING...THE BACK EDGE OF THE 500MB TROUGH WILL
TIGHTEN TO OUR NW ON TUESDAY IN RESPONSE TO THE N CANADIAN TROUGH
SINKING/EXTENDING ACROSS E HUDSON BAY. THIS SHOULD BASICALLY ACT TO
DOUBLE THE AMOUNT OF SNOW PLACES FAVORED BY THE NW WINDS...LIKE CMX
WOULD HAVE OTHERWISE RECEIVED EVERY 6HRS. 850MB TEMPS WILL COOL
ANOTHER COUPLE DEGREES C TO AROUND -22 BY 00Z WEDNESDAY. IT WILL BE
A COLD DAY /SINGLE DIGITS TO MID TEENS/...FOLLOWED BY A COLD NIGHT.
WITH SOME CLEARING IS ANTICIPATED S CENTRAL AND ALONG THE WI BORDER
AS SFC WINDS BECOME MORE OUT OF THE W AND SW...-10C IS WELL WITHIN
REACH.

BRIEF WAA IS ANTICIPATED WEDNESDAY /NEW YEAR/S EVE/...WITH SNOW
SHOWERS PUSHING OFF MUCH OF THE S SHORES OF LAKE SUPERIOR ON WSW
WINDS. 850MB TEMPS SHOULD RISE TO AROUND -17C...OR EVEN WARMER
AROUND -14C OFF THE 28/00Z GFS. THERE REMAINS SOME DISCREPANCIES ON
THE TRACK/INTENSITY OF A SHORTWAVE THAT THE 27/00Z ECMWF HAS DIGGING
ACROSS S LOWER MI BY 00Z THURSDAY...RESULTING IN MORE CLOUD
COVER/LES SNOW AND COOLER CONDITIONS. THE GFS IS NOT TOO
IMPRESSIVE...KEEPING MUCH OF THE ACTIVITY N OF THE CWA. WILL GO WITH
A BLENDED/CONSENSUS SOLUTION FOR WEDNESDAY/WEDNESDAY NIGHT. BOTH THE
GFS AND ECMWF INDICATE 45-60KT 850MB WINDS WEDNESDAY INTO EARLY
THURSDAY...STRONGEST 18Z WEDNESDAY-12Z THURSDAY. OTHER THAN STRONG
WINDS ACROSS LAKE SUPERIOR AND PORTIONS OF THE MORE EXPOSED KEWEENAW
PENINSULA...IT IS UNKNOWN HOW MUCH OF THAT WILL BE ABLE TO MAKE IT
TO THE SFC. ALSO DURING THIS TIME THE 500MB LOW OVER THE PACIFIC NW
WILL HAVE SUNK ACROSS S CANADA...AND THE N LOW WILL HAVE SLID ACROSS
MUCH OF HUDSON BAY.

FRIDAY INTO SATURDAY LOOK A BIT MORE INTERESTING. THE GFS INDICATES
THAT WE LOSE THE STRONG INVERSION THAT/S BASICALLY BEEN SET UP
800-850MB....AND PLENTY OF MOISTURE IN A BROAD DGZ STRETCHING FROM
NEARLY 900-600MB. WILL BE INTERESTING TO WATCH THE EVOLUTION OF THIS
SYSTEM...WITH THE 500MB LOW IN THE SW PUSHING ACROSS THE S PLAINS
AND NUDGING A SFC LOW UP THE MS VALLEY...TO AROUND CENTRAL/S LOWER
MI BY 18Z SATURDAY...THEN RAPIDLY DEEPENING ACROSS S ONTARIO AND
QUEBEC SATURDAY NIGHT. THE 28/00Z HAS COME IN STRONGER AND FARTHER E
WITH THE LOW COMPARED TO THE GFS. INCREASED POPS A BUT FRIDAY NIGHT
GIVEN THE SOMEWHAT DECENT AGREEMENT...WITH FEW SIGNIFICANT CHANGES
OTHERWISE.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1231 AM EST SUN DEC 28 2014

A TROUGH DROPPING ACROSS WESTERN LAKE SUPERIOR OVERNIGHT
INTO SUNDAY WILL BRING AN INCREASE IN LES OVER MAINLY THE KEWEENAW.
JUST AHEAD OF THIS TROUGH...EXPECT LAKE EFFECT SNOW TO DEVELOP WITH
THE WESTERLY FLOW BTWN 06Z-08Z. THIS MAY LEAD TO A PERIOD OF
MODERATE SNOWFALL...SO 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 RESIDUAL CLOUDS/PCPN 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 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST SUN DEC 28 2014

A SURFACE TROUGH SWEEPING SOUTHEAST ACROSS LAKE SUPERIOR THIS
MORNING WILL LEAD TO AN INCREASE IN THE NORTHWEST WINDS WITH GUSTS
TO 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 NE CANADA. 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 THU MORNING. WINDS WILL DIMINISH BLO GALES THU
AFTERNOON AS HIGH PRESSURE BUILDS IN FM THE WEST AND THE PRES
GRADIENT BEGINS TO WEAKEN ACROSS THE AREA.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
     MIZ002-003.

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

$$

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





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