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000
FXUS63 KMKX 202043
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
243 PM CST FRI DEC 20 2013

.REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM
DECIDED TO EXTEND FREEZING RAIN ADVISORY UNTIL 6 PM TO COVER RUSH HOUR.
STILL SEEING RETURNS ON 88-D MOVING NORTHEAST FROM IOWA. LOW PRESSURE
CONTINUES TO MOVE ENE FROM CNTRL IL. 850 MILLIBAR COLD AIR ADVECTION
INCREASES A BIT AS SLIGHTLY COLDER AIR WRAPS IN BEHIND THE DEPARTING LOW.
CLOUD COVER NOT GOING ANYWHERE SO NOT EXPECTING A BIG DROPOFF IN TEMPS.

.SATURDAY - CONFIDENCE...MEDIUM
QUIET START WITH WEAK RIDGING. ISENTROPIC UPGLIDE GETS UNDERWAY IN
THE AFTERNOON WITH SOME QPF MOVING INTO THE FAR SE DURING THE
AFTERNOON. PRECIP TYPE A QUESTION MARK. DEGREE OF WARM SURGE AHEAD
OF THE STORM STILL A LITTLE UNCERTAIN. WILL ACKNOWLEDGE THE NAM AND
BRING IN A LITTLE MIX ON THE LEADING OF THE PRECIPITATION.

.SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS HIGH.

THE WINTER STORM WATCH IS BEING UPGRADED TO A WINTER STORM
WARNING. THANKFULLY...OUR 12Z MODEL SUITE HASN/T GIVEN US ANY
SERIOUS CURVE BALLS WITH RESPECT TO STORM TRACK...TIMING...
SNOWFALL AMOUNTS. THE NAM DID MAKE A BIT OF JUMP NORTH AND
CRANKED UP THE PRECIP AMOUNTS...ESPECIALLY IN THE HEAVY SNOW BAND
OVER THE MIDDLE OF THE FORECAST AREA. THESE AMOUNTS LOOK HIGH
COMPARED TO THE CONSENSUS OF THE OTHER MODELS. THE WARMER NAM
WOULD BRING RAIN TO RACINE/KENOSHA AND SOME SLEET/RAIN/SNOW TO
MILWAUKEE DURING THE EVENING ON SATURDAY...BEFORE CHANGING OVER TO
SNOW. THE OTHER MODELS ARE GENERALLY COLDER...KEEPING ANY MIX TO
OUR SOUTH. SINCE THE NAM IS LOOKING LIKE AN OUTLIER...WILL FOLLOW
THE CONSENSUS. OUR FRIENDS IN THE SOUTHEAST ARE WELL AWARE OF THIS
USUAL UNCERTAINTY AND OFTEN GET RIPPED OFF FROM THE HIGHER SNOW
AMOUNTS DUE TO WARM AIR. IT/S A POTENTIAL...BUT NOT A VERY HIGH
ONE AT THIS POINT.

THE SYNOPTICS HAVEN/T CHANGED. WE HAVE AN UNUSUALLY STRONG UPPER
LEVEL JET OVER THE GREAT LAKES THAT WILL TRIGGER RAPID
DEEPENING/CYCLOGENESIS OF THE SFC LOW AS IT LIFTS INTO THE CENTRAL
GREAT LAKES SATURDAY NIGHT. SOME ANOMALY DATA STILL INDICATES THIS
JET STRENGTH IS WITHIN THE 90TH PERCENTILE WITH RESPECT TO A 30
YEAR CLIMATE PERIOD FOR THIS TIME OF YEAR OVER THE GREAT LAKES.
IMPRESSIVE. THE HEAT/MOISTURE ON THE EAST SIDE OF THE LOW IS
SIMILARLY OFF THE CHARTS. MOISTURE IS NOT A PROBLEM WITH THIS
SYSTEM.

THERE IS SOME HINT WE COULD SEE SOME THUNDER WITH LAPSE RATES
GETTING STEEP UP THERE AROUND 6-500MB. NOT ENOUGH TO INCLUDE IT AT
THIS TIME...BUT CAN/T RULE IT OUT BETWEEN MIDNIGHT AND SUNRISE
SUNDAY. THAT WILL BE OUR PEAK SNOWFALL RATE FOR SURE.

THE AXIS OF THE HEAVIEST SNOW IS STILL EXPECTED TO RUN FROM
SHEBOYGAN TO JEFFERSON/MADISON TO JANESVILLE/MONROE WITH PEAK
ACCUMS AROUND 9 INCHES. THE SOUTHEAST IS LOOKING CLOSER TO 6
INCHES AS WELL AS AREAS AROUND THE DELLS. TEMPERATURES WILL
GENERALLY BE IN THE 20S...SO THIS SHOULD GENERALLY BE A DRY SNOW.
THE EXCEPTION MIGHT BE IN THE SOUTHEAST WHERE WARMER TEMPS COULD
MAKE THE SNOW A LITTLE WETTER/HEAVY.

THE SNOW WILL SPREAD IN QUICKLY SATURDAY EVENING...THEN TAPER OFF
FROM SOUTHWEST TO NORTHEAST DURING SUNDAY MORNING...AFTER
SUNRISE.

OF COURSE...WE ARE STILL A DAY OR TWO AWAY...SO THINGS ALWAYS HAVE
THE POTENTIAL TO CHANGE...WEATHER IS FUNNY THAT WAY.

.SUNDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE IS HIGH.

COLD ADVECTION CLOUDS AND LIGHT SNOW WILL LIKELY CONTINUE. TEMPS
SUNDAY NIGHT WILL LIKELY DROP INTO THE SINGLE DIGITS MOST PLACES
WITH RECOVERY ON MONDAY ONLY MAKING IT INTO THE TEENS.

.TUESDAY AND CHRISTMAS DAYS...FORECAST CONFIDENCE IS MEDIUM.

A WEAK SYSTEM IS FORECAST TO MOVE ACROSS THE NRN TIER OF THE U.S.
DURING THIS TIME FRAME. THIS SHOULD ONLY BRING A SMALL CHANCE OF
LIGHT SNOW TUESDAY INTO WEDNESDAY MORNING. TEMPERATURES WILL STAY
ON THE COLD SIDE.

&&

.AVIATION/00Z TAFS/...MAIN ISSUE WILL BE LIGHT ICING INTO THE EARLY
EVENING HOURS. WILL KEEP CIGS AT IFR LEVELS THIS FORECAST PERIOD.
QUIETER CONDITIONS TAKE HOLD LATER TONIGHT INTO SATURDAY WITH BRIEF
RIDGING. WINTER STORM STILL ON TRACK FOR SATURDAY NIGHT INTO SUNDAY.
LEADING EDGE OF PRECIPITATION ARRIVING INTO THE FAR SOUTHEAST CORNER
OF THE STATE MAY START OFF MIXY SATURDAY AFTERNOON INTO THE EVENING
HOURS BEFORE BECOMING WIDESPREAD SNOW...HEAVY AT TIMES...FROM
LATER SATURDAY EVENING THROUGH SUNDAY MORNING.

&&

.MARINE...SUSTAINED NORTHEAST WINDS WILL KEEP WAVES UP A BIT LONGER
THOUGH GUSTINESS HAS ABATED SOME. SO WILL MAINTAIN SMALL CRAFT
ADVISORY THROUGH 6 PM. ANOTHER SMALL CRAFT WILL BE NEEDED WITH THE
GUSTY WINDS ASSOCIATED WITH THE APPROACHING WINTER STORM. WINDS WILL BE
STRONGEST SATURDAY NIGHT INTO SUNDAY...STARTING OFF NORTHEAST SAT
NGT AND THEN TRANSITIONING NORTHERLY SUNDAY MORNING AND EVENTUALLY
NORTHWEST SUNDAY AFTERNOON.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZING RAIN ADVISORY UNTIL 6 PM CST THIS EVENING FOR
     WIZ056>060-062>072.

     WINTER STORM WARNING FROM 6 PM SATURDAY TO 6 PM CST SUNDAY FOR
     WIZ046-047-051-052-056>060-062>072.

LM...WINTER STORM WARNING FROM 6 PM SATURDAY TO 6 PM CST SUNDAY FOR
     LMZ643.

     SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR LMZ643>646.

&&

$$

TONIGHT/SATURDAY AND AVIATION/MARINE...COLLAR
SATURDAY NIGHT THROUGH FRIDAY...DAVIS