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000
FXUS63 KMQT 041734
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1234 PM EST WED DEC 4 2013

.UPDATE...
ISSUED AT 947 AM EST WED DEC 4 2013

WARM AIR COMING IN FROM THE SOUTH PRETTY QUICK. 12Z RAOB FM KGRB
INDICATED WARM LAYER WITH +2C TEMPS H9-H85. 12Z NAM/RUC13 WERE A BIT
COOLER THAN THAT THOUGH. H9-H85 WARM AIR ADVECTION IS PLOWING NORTH
AS SHORTWAVE OVR SW MN IS ALLOWING H85 LOW TO PUSH TOWARD NORTHWEST
WI. UPDATED FCST TO BRING IN FREEZING RAIN/SLEET QUICKER. DO THINK
THAT WITH UPSLOPE EAST FLOW INTO NCNTRL CWA...SNOW/SLEET WILL TRY
TO HANG ON LONGER. HEAVIEST SNOW TOTALS TODAY IN THE FAR WEST AND
ACROSS KEWEENAW AS THIS IS WHERE STRONGEST/PERSISTENT LIFT OCCURS IN
PVA AREA/DIVERGENCE ALOFT AHEAD OF SHORTWAVE MOVING OUT OF MINNESOTA.
WILL KEEP ADVY HEADLINES AS IS SINCE SO FAR THIS MORNING SNOW HAS
NOT FALLEN TOO HEAVY...BUT WILL MONITOR FOR POSSIBLE UPGRADE LATER
ON. GOING ADVY LOOKS FINE ELSEWHERE...DUE TO MIX OF SNOW/SLEET/FZRA.
FARTHER EAST...WILL PUT AN SPS OUT DUE TO BATCH OF LGT SNOW TO START
MIXING WITH LGT FREEZING RAIN/RAIN BY LATER AFTN. NOT MUCH PRECIP
WILL OCCUR IN THE EAST THOUGH...PROHIBITING THE NEED FOR ISSUING AN
ADVY.
&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 542 AM EST WED DEC 4 2013

CONTINUED WINTER WEATHER ADVISORY THROUGH TONIGHT FOR CENTRAL
AND WESTERN PORTIONS OF THE CWA.

RADAR AND SURFACE OBSERVATIONS ARE INDICATING ONLY LIGHT SNOW
OCCURRING OVER THE U.P. WITH HEAVIER SNOWFALL BEGINNING TO DEVELOP
OVER NORTHWESTERN WI AND SHIFT SLOWLY NORTHEASTWARD. THIS TREND IS
EXPECTED TO CONTINUE WITH THE SNOW REACHING THE WESTERN U.P. BY 12Z.
THIS IS ALSO THE LOCATION THAT DEPICTS THE TALLER...MUCH COLDER
CLOUD TOPS ON IR IMAGERY. THE WV IMAGERY SHOWS A SHORTWAVE LIFTING
NORTHEASTWARD INTO EASTERN SD/NE...WITH A CONTINUOUS STREAM OF
MOISTURE NORTHWARD INTO THE UPPER GREAT LAKES REGION.

TODAY...MODELS ARE IN BETTER AGREEMENT WITH THE PLACEMENT OF THE
SURFACE LOW OVER NORTH CENTRAL MO THIS MORNING. THE LOW WILL LIFT
NORTH AND EASTWARD THROUGH 12Z WHILE SHIFTING A WARM FRONT
STRETCHING JUST SOUTH OF THE UPPER PENINSULA...NORTHWARD. AHEAD OF
THIS WARM FRONT SNOW IS EXPECTED TO SPREAD ACROSS MUCH OF THE U.P.
BETWEEN 12Z/04 AND 18Z/04. THIS SNOWFALL WILL BREAK OUT ON
ISENTROPIC ASCENT PUSHING INTO THE AREA ON THE NOSE OF WARM AIR
ADVECTING INTO THE REGION. THIS CAN BE SEEN BY ANALYZING
MOISTURE...MOISTURE TRANSPORT AND PRESSURE THE 295K ISOSURFACE. THE
SURFACE LOW WILL CONTINUE NORTHWARD...REACHING SOUTHWESTERN WI BY
18Z WED...AS THE WARM FRONT LIFTS FARTHER NORTHWARD TO ROUGHLY THE
LAKE SUPERIOR SHORELINE. AS THIS HAPPENS A WEDGE OF WARM AIR WILL
MAKE ITS WAY INTO MAINLY THE CENTRAL AND EASTERN HALF OF THE UPPER
PENINSULA. BY 18Z...SOUNDINGS INDICATE THAT POINTS EAST OF A LINE
FROM MARQUETTE SOUTHWESTWARD TO NEAR IRON MOUNTAIN WILL BEGIN THE
TRANSITION TO SLEET AND SNOW INITIALLY BEFORE TRANSITIONING TO A MIX
OF FREEZING RAIN...SLEET AND SNOW. BY 21Z THE WARMER LAYER BEGINS TO
THICKEN UP ON CONTINUED WAA BEHIND THE WARM FRONT AND AREAS ALONG
AND EAST OF THE MARQUETTE TO IRON MOUNTAIN LINE MAY BEGIN TO MIX
WITH OR CHANGE TO PERIODS OF RAIN. AREAS WEST OF THE IRON MOUNTAIN
TO MARQUETTE LINE WILL LIKELY REMAIN SNOW THROUGH 18Z...BUT A MIX OF
SNOW...SLEET AND FREEZING RAIN WILL MAKE ITS WAY INTO THOSE AREAS AS
WELL BY 21Z. THIS IS MAIN REASON THAT THE WESTERN HALF OF THE UPPER
PENINSULA WILL SEE A BIT HIGHER SNOWFALL TOTALS THAN CENTRAL
LOCATION. ANOTHER REASON THAT THE HIGHER TOTALS ARE FARTHER WEST IS
THE POTENTIAL FOR AN FGEN BAND TO DEVELOP...HOWEVER THIS CURRENTLY
PROGGED TO REMAIN OVER WESTERN LAKE SUPERIOR JUST TO THE WEST OF THE
U.P. IF THIS BAND SHIFTS A BIT EAST...SNOWFALL TOTAL COULD POSSIBLY
BE ENHANCED...PROVIDED THE MIXED PRECIP DOESNT BECOME A LARGE
FACTOR. ICE ACCUMULATIONS ARE EXPECTED TO REMAIN FAIRLY LIGHT WITH
MOST LOCATIONS SEEING LESS THAN ONE TENTH OF AN INCH. PROFILES HAVE
BEEN FAIRLY SIMILAR AMONG THE MODELS WITH THE 00Z NAM PULLING THE
NOSE OF WARMER AIR A BIT FARTHER WEST.

TONIGHT...THE LOW IS EXPECTED TO BE DIRECTLY OVER THE CENTRAL U.P.
BY 00Z AND OVER LAKE SUPERIOR BY 06Z/05. AS THE LOW MOVES OVERHEAD
THE BETTER PRECIPITATION CHANCES WILL SHIFT SLOWLY TO THE NORTH WITH
PRECIPITATION CHANCES LINGERING OVER THE NORTHERN HALF OF THE CWA
THROUGH 06Z. AS THE LOW SHIFTS THROUGH...CAA KICKS IN ON THE BACK
SIDE OF THE SYSTEM AND ANY REMAINING MIXED PRECIPITATION WILL
TRANSITION RAPIDLY TO SNOW FROM WEST TO EAST ACROSS THE AREA. SNOW
ACCUMULATIONS WILL BE GREATEST DURING THE EVENING HOURS...ESPECIALLY
OVER THE WESTERN HALF OF THE UPPER PENINSULA WHERE AN ADDITIONAL 1
TO 3 INCHES OF SNOW MAY OCCUR. 24 HOURS STORM TOTALS OVER THE
WESTERN U.P. MAY APPROACH 8 INCHES...ESPECIALLY NEAR THE IWD TO CMX
AREAS. BEYOND 06Z THE LOW SHIFTS FARTHER NORTH AND EASTWARD ALLOWING
FOR ONLY VERY LIGHT WRAP AROUND SNOW SHOWERS. UP TO 1 INCH OF
ADDITIONAL SNOWFALL IS POSSIBLE OVERNIGHT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 507 AM EST WED DEC 4 2013

MAIN FCST CONCERNS IN THE LONG TERM INCLUDE TEMPS/LES MAINLY IN THE
W-NW SN BELTS AND THE POTENTIAL FOR ANOTHER LARGER SCALE SN EVENT
EARLY NEXT WEEK. OVERALL TEMPS WL RUN WELL BLO NORMAL MOST OF THE
LONGER TERM WITH ARCTIC HI PRES DOMINATING. THE COLDEST AIRMASS OF
THE SEASON IS LIKELY TO INVADE THE UPR LKS IN THE WAKE OF THE LO
PRES SYSTEM THAT MIGHT BRING THE WDSPRD SN LATE SUN INTO MON.

THU...STRONG LLVL W FLOW IN THE WAKE OF LO PRES SHIFTING NEWD THRU
ONTARIO WL DRAW MUCH COLDER AIR INTO THE UPR LKS. IN FACT...THE
COLDEST GUIDANCE SHOWS H85 TEMPS APRCHG -20C OVER THE WRN CWA BY 00Z
FRI. THE ARRIVAL OF VIGOROUS DEEP LYR QVECTOR DVGC RESULTING FM THIS
INTENSE CAD AND DNVA/MID LVL DRYING WL SUPPRESS ANY LARGE SCALE
PCPN. BUT LES WL DVLP IN THE SN BELTS FAVORED BY THE LLVL W
FLOW...PRIMARILY OVER THE KEWEENAW. SOME MODEL FCST SDNGS SHOW A
PERIOD WHERE THE SHARPER OMEGA WITHIN THE MOIST LYR IS FAVORABLY
ALIGNED WITHIN THE DGZ TO CAUSE A RELATIVELY HI SN/WATER RATIO. SO
ADVYS FOR LES MAY BE NECESSARY FOR THE KEWEENAW. WITH WNW H925 WINDS
UP TO 35-40 KTS AND VIGOROUS CAD THAT WL CAUSE CONSIDERABLE LLVL
DESTABILIZATION...WINDS AT EXPOSED LOCATIONS ESPECIALLY OVER THE
KEWEENAW MAY ALSO APRCH ADVY CRITERIA. ALTHOUGH THESE STRONG WINDS
WL BREAK UP THE DENDRITIC SN FLAKES AND REDUCE THE OTRW FVRBL
SN/WATER RATIOS...THE RESULTING BLSN FM THE SMALLER FLAKES WL
EFFECTIVELY REDUCE VSBY. WITH THE ARCTIC AIR INVASION... TEMPS ARE
LIKELY TO FALL THRU THE DAY.

THU NGT INTO SAT...AS THE LO TO THE NE DRIFTS SLOWLY INTO QUEBEC AND
ARCTIC HI PRES SLIDES FM WRN CANADA INTO THE NRN PLAINS...THE STEADY
FLOW OF VERY COLD AIR IS PROGGED TO SLOWLY VEER MORE TO THE WNW AND
DIMINISH WITH TIME AS H85 TEMPS FALL SLOWLY TO -18C OVER THE E AND
-20C OR -21C OVER THE W BY SAT. THIS TYPICAL WINTER WX REGIME WL
FAVOR NEARLY CONTINUOUS LES IN THE FAVORED SN BELTS. A SHRTWV
TRACKING EWD THRU SRN ONTARIO/NRN LK SUP ON FRI NGT AND ACCOMPANYING
DEEPER MSTR MAY RESULT IN SOME ENHANCEMENT TO THE LES. ALTHOUGH THE
WINDS/BLSN WL BE DIMINISHING GRDLY...EXPECT LES/WINTER WX ADVYS TO
BE IN PLACE FOR THE FAVORED LES BELTS WITH FAVORABLE ALIGNMENT OF
THE LLVL OMEGA WITHIN THE DGZ. WENT HIER THAN MODEL CONSENSUS POPS
FOR LES IN THE FAVORED SN BELTS...USING CLIMATOLOGRY GRIDS TO
EVALUATE THE POPS. AS THE LLVL WINDS DIMINISH...LAND BREEZE CNVGC
MAY PLAY A MORE IMPORTANT ROLE IN ENHANCING THE LES BANDS IN SOME
PLACES...WITH AT LEAST LOCALLY HEAVIER SN FALL APRCHG WARNING
CRITERIA. SN/WATER RATIOS WL ALSO LIKELY BE FVRBL FOR LARGER FLAKES
AS THE FLAKE FRACTURING DIMINISHES. AWAY FM THE FAVORED SN
BELTS...THE WX DURING THIS TIME WL BE VERY COLD BUT DRY. SUB ZERO
MIN TEMPS WITH DAYTIME TEMPS STRUGGLING TO RISE ABV 10F WL THE RULE
OVER THE INTERIOR W HALF WITHIN THE LESS MODIFIED ARCTIC AIR.

SAT NGT/SUN...THE SLOW EWD PUSH OF THE ARCTIC HI CENTER FM THE NRN
PLAINS INTO THE GREAT LKS/SLOWLY BACKING WINDS TO WSW ON SUN WL
CAUSE THE LES TO DIMINISH. DEPENDING ON HOW QUICKLY WAD CLDS SPILL
INTO THE UPR LKS ON SUN TO THE E OF A DEEPENING TROF IN THE
PLAINS...TEMPS AT SOME PLACES OVER THE INTERIOR ON EARLY SUN MRNG
MAY FALL INTO THE TEENS BLO ZERO WITH LGT WINDS UNDER THE ARRIVING
SFC HI CENTER.

EXTENDED...NEXT LARGER SCALE PCPN EPISODE IS LIKELY TO ARRIVE ON SUN
NGT INTO EARLY MON. SOME OF THE LONGER TERM MODELS ARE SHOWING A
PHASING OF THE ARCTIC/POLAR BRANCHES WITH A DEEPER SFC LO TRACKING
THRU THE WCENTRAL GREAT LKS. IF THIS SCENARIO WERE TO VERIFY...A
WDSPRD ADVY SN WL BE PSBL OVER MUCH OF THE CWA. BUT SOME OF THE
GUIDANCE HINTS AT LESS PHASING/A WEAKER SFC LO THAT WOULD CAUSE JUST
A COUPLE OF INCHES. IN THE WAKE OF THIS LO MOVING INTO ONTARIO ON
MON...THE COLDEST AIRMASS OF THE SEASON WITH H85 TEMPS AS LO AS -25
TO -28C WL INVADE THE UPR LKS. NEXT TUE LOOKS PARTICULARLY COLD WITH
A SHARP PRES GRADIENT/NW FLOW THAT MIGHT CAUSE WIND CHILLS TO FALL
TO ADVY LVL. TENDED HIER THAN MODEL CONSENSUS FOR LES POPS IN THE
FAVORED SN BELTS FOR MON THRU TUE.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1234 PM EST WED DEC 4 2013

A LOW PRESSURE SYSTEM WILL KEEP PRECIP AT THE TAF SITES INTO
TONIGHT. WARM AIR MOVING INTO THE REGION WILL SWITCH SNOW THIS
MORNING TO RAIN AND FREEZING RAIN AT TIMES INTO EARLY TONIGHT...MOST
LIKELY AT SAW AND MORE LIKELY TO STAY A WINTRY MIX AT IWD AND CMX.
LOTS OF DIFFICULTY FORECASTING EXACT CHANGE OVER TIMES...SO PUT BEST
GUESS INTO TAFS. PRECIP WILL CHANGE BACK TO SNOW TONIGHT AS COLD AIR
COMES IN BEHIND A COLD FRONT...WHILE PRECIP TRANSITIONS FROM AREA
WIDE PRECIP TO LAKE EFFECT SNOW...FAVORING IWD AND ESPECIALLY CMX
INTO THURSDAY. USED CONSENSUS GUIDANCE FOR CIGS/VIS AND MORE
CLIMATOLOGY FOR LAKE EFFECT SNOW LATE IN THE PERIOD.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 AM EST WED DEC 4 2013

GALE WARNINGS ARE IN EFFECT FOR THE WEST HALF OF LAKE SUPERIOR FROM
EARLY THIS MORNING INTO THU NIGHT. GALE WARNINGS ARE IN EFFECT FOR
THE EAST HALF THU AND THU NIGHT.

AS DEEPENING LO PRES OVER THE SCENTRAL PLAINS MOVES TO THE N TODAY
AND THRU UPPER MI TONIGHT...EXPECT E GALES TO PERSIST OVER THE W
HALF...WHERE THE TERRAIN SURROUNDING THE OPEN WATERS ENHANCES THIS
FLOW. A FLATTER GRADIENT NEAR THE CENTER OF THE LO MAY CAUSE WINDS
IN THIS AREA TO DIMINISH A BIT TONIGHT. BUT ONCE THE
INTENSIFYING LO MOVES INTO ONTARIO ON THU...A W GALE WILL DEVELOP
OVER ALL OF LK SUP. EVEN THOUGH THE GALES MAY DIMINISH TEMPORARILY
TONIGHT...OPTED TO MAINTAIN THE GOING GALE WARNINGS FOR THE W HALF
FOR THE ENTIRE PERIOD. THESE W GALES WILL GRADUALLY WEAKEN BY FRI AS
THE LOW MOVES FARTHER TO THE N. THE WINDS WILL THEN SLOWLY DIMINISH
WITH WITH THE CLOSER APPROACH OF ARCTIC HI PRES FROM THE PLAINS ON
SUN. EXPECT WIDESPREAD FREEZING SPRAY ON THU THRU SAT WITH THE GUSTY
WINDS...HI WAVES AND ARCTIC CHILL.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ THURSDAY
     FOR MIZ002-004-005-009>011-084.

  WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR MIZ001-003.

LAKE SUPERIOR...
  GALE WARNING FROM 6 AM THURSDAY TO 4 AM EST FRIDAY FOR
     LSZ265>267.

  GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ263-264.

  GALE WARNING FROM 8 AM TO 7 PM EST THURSDAY FOR LSZ247-248-250-
     251.

  GALE WARNING FROM 5 AM EST /4 AM CST/ TO 7 PM EST /6 PM CST/
     THURSDAY FOR LSZ241>245.

  GALE WARNING UNTIL 10 PM EST /9 PM CST/ THURSDAY FOR LSZ162.

LAKE MICHIGAN...
NONE.
&&

$$

UPDATE...JLA
SHORT TERM...KEC
LONG TERM...KC
AVIATION...TITUS
MARINE...KC