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000
FXUS63 KMQT 042101
AFDMQT

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

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 400 PM EST WED DEC 4 2013

20Z SFC CHART INDICATES ELONGATED SFC TROUGH FROM WCNTRL WI INTO
NORTHEAST IA WITH MSLP OF 998MB. WV AND RUC FCST SHOWS SHORTWAVE
PUSHING ACROSS SOUTHERN MINNESOTA. WAVE IS EXPECTED TO LIFT TOWARD
NORTHWEST WI WHILE DEEPENING OVERNIGHT. WARM AIR ADVECTION IN FULL
SWING AHEAD OF MAINLY 850MB LOW LIFTING INTO NW WISCONSIN. RUC13 AND
NAM12 HAVE DONE NICE JOB WITH THE WARM LAYER AT H9-H85 TODAY AND
BOTH SHOW H85 TEMPS OVER 2C REACHING NORTH OF ALL CWA BY 00Z.
SOUNDINGS OVER US CURRENTLY WOULD SUGGEST MAINLY FZRA BUT LINGERING
COLD POCKET NEAR SFC /TEMPS STILL IN MID-UPR 20S/ IS ALLOWING SLEET
TO HANG ON LONGER. CURRENTLY SNOW IS STILL FALLING OVER KEWEENAW
PENINSULA BUT IS EVEN STARTING TO MIX WITH FREEZING RAIN AND SLEET
OVER PORTIONS OF WESTERN UPR MICHIGAN. PLAN FOR EVENING IS THAT
MIXED FREEZING RAIN/SLEET/SNOW WILL CHANGE TO MAINLY FREEZING RAIN
AND SLEET WHILE MOSTLY FREEZING RAIN OR EVEN JUST RAIN OCCURS FOR
CNTRL CWA...ESPECIALLY CLOSER TO LK MICHIGAN SHORE. IF HEAVIER
PRECIP WAS EXPECTED OVR CNTRL THIS EVENING...ICING COULD BE BIGGER
ISSUE. RIGHT NOW...APPEARS THAT HEAVIER PRECIP IS GOING TO OCCUR IN
STRIPE FROM SOUTHERN MINNESOTA TOWARD WESTERN LK SUPERIOR IN AREAS
OF STRONGEST PVA/DIVERGENCE ALOFT JUST AHEAD OF TRACK OF SHORTWAVE.
GIVEN TREND TO MORE FZRA THOUGH...INCREASED ICE ACCUMS OVER INTERIOR
WEST AND CNTRL TO 0.10-0.20 INCHES THROUGH THE EVENING.

AS MID-LEVEL DRYING IN THE H7-H6 LAYER ARRIVES 03Z-06Z OVER THE
SOUTH AND AFTER 06Z IN THE NORTH...EXPECT WINTRY MIX OF PRECIP TO
TAPER OFF TO MORE OF A DRIZZLE/FREEZING DRIZZLE. ACTUALLY HEADLINES
SO FAR ARE WORKING OUT PRETTY WELL. DID HAVE TO GO WITH MORE SLEET
AND FREEZING RAIN AS WARM AIR WORKED IN QUICKER...BUT OVERALL IDEA
OF WINTRY MIX IS COVERED WITH GOING WINTER WEATHER ADVY. TIMING FOR
ENDING OF ADVY SEEMS GOOD AS WELL. ONLY POSSIBLE TROUBLE SPOTS WILL
IN THE INTERIOR CNTRL AND EAST THIS EVENING DUE TO ICING IF HEAVIER
PRECIP ENDS UP BLOSSOMING TO THE EAST OF PRIMARY SHORTWAVE. SOME
SHORT TERM HIGHER-RES MODELS INDICATE EXPANSION OF PRECIP OVER
SCNTRL THIS EVENING...BUT RADAR TRENDS UPSTREAM NOT REALLY SHOWING
THIS. IF SFC TEMPS STAY BLO FREEZING THAT AREA WILL NEED TO BE
WATCHED FOR POSSIBLE ADVY.

NOW ONTO LATE TONIGHT AND THURSDAY. MAIN ISSUE SEEMS TO BE LK EFFECT
AND BLOWING SNOW ON THE KEWEENAW. WEST WINDS MAY GUST OVER 40 MPH AT
TIMES LEADING TO THE BLSN/POOR VISIBILITY...PROBABLY 1/4-1/2SM AT
TIMES OVER PORTIONS OF THE KEWEENAW. LARGER SCALE FORCING BECOMES
NEGATIVE BUT THERE IS A LOT OF LINGERING MOISTURE BLO H8 WITH
COOLING AT INVERSION TOP TO -16C OR SO BY MIDDAY. GIVEN LK SUPERIOR
WATER TEMPS AROUND 3-4C THIS GIVES MORE THAN SUFFICIENT OVER-WATER
INSTABILITY FOR AT LEAST MODERATE LK EFFECT SNOW SHOWERS. WSW WINDS
OVER LAND WITH MORE OF A WESTERLY WIND OVER LK SUPERIOR INDICATES
STRONGER CONVERGENCE AREA SETS UP ACROSS KEWEENAW. SNOW AMOUNTS WILL
BE HELD DOWN SOME BY LOWER SLR/S AS THERE IS A LOT OF FRACTURING OF
SNOWFLAKES DUE TO THE STRONG WINDS. EXPECT ADVY LEVEL SNOWS OF 3-5"
OR 4-7" WITH A LOT OF WIND/BLSN. WILL ISSUE A SEPARATE LAKE EFFECT
SNOW ADVY FOR LATE TONIGHT THROUGH THURSDAY...GOING INTO PLACE RIGHT
WHEN THE CURRENT WINTER WEATHER ADVY FOR THE MESSY MIX OF SNOW/SLEET
AND FREEZING RAIN DIMINISHES.

AND FINALLY FOR LATE TONIGHT INTO THURSDAY...AWAY FM THE
KEWEENAW...MAIN ISSUE WILL BE COLD AIR PUSHING IN FM THE WEST.
ALREADY SEEING THIS ARCTIC AIR POURING ACROSS THE DAKOTAS THIS AFTN.
EXPECT SLOWLY FALLING TEMPERATURES THROUGH THE DAY AS THE COLD WORKS
EAST...WITH READINGS LIKELY INTO THE UPPER SINGLE DIGITS BY EVENING
OVER THE FAR WEST CWA. THIS COLDER AIR WILL ALSO FREEZE ANY
LINGERING SLUSH AND WATER IS ON THE ROADS AND SIDEWALKS...WHICH
COULD RESULT IN TOUGHER TRAVEL CONDITIONS IN SPOTS.

.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 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 317 PM EST WED DEC 4 2013

LOW PRESSURE OVER WISCONSIN WILL DEEPEN ACROSS CENTRAL AND EASTERN
LAKE SUPERIOR OVERNIGHT...AND EXIT NORTHEAST ACROSS JAMES BAY WHILE
FURTHER DEEPENING THURSDAY NIGHT. THE PERIOD OF STRONG WINDS WILL
CONTINUE THROUGH THURSDAY NIGHT...WITH OUR INITIAL E TO NE WINDS
/GALES TO 35KTS OVER W LAKE SUPERIOR/ BECOMING OUT OF THE S AND SW
FOR ALL BUT FAR W LAKE SUPERIOR OVERNIGHT...BEFORE W GALES OF 35 TO
40 KNOTS START UP THURSDAY MORNING THROUGH THURSDAY NIGHT.

A STRONG ARCTIC HIGH PRESSURE SYSTEM OVER WESTERN CANADA ON THURSDAY
WILL SLIDE ACROSS THE NORTHERN PLAINS ON SATURDAY...AND ACROSS THE
GREAT LAKES SUNDAY. THE HIGH WILL EXIT ACROSS THE NEW ENGLAND STATES
WHILE WEAKENING SLIGHTLY ON MONDAY. EXPECT LOW PRESSURE OVER THE
LOWER MISSISSIPPI VALLEY SUNDAY TO DEEPEN AND SURGE NORTHWARD ACROSS
LAKE HURON LATE SUNDAY NIGHT INTO MONDAY. W TO NW GALES TO 35KTS
WILL BE POSSIBLE AGAIN MONDAY THROUGH TUESDAY.
&&

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

  LAKE EFFECT SNOW ADVISORY FROM 4 AM TO 7 PM EST THURSDAY FOR
     MIZ001-003.

  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.
&&

$$

SHORT TERM...JLA
LONG TERM...KC
AVIATION...TITUS
MARINE...KF