000
FXUS63 KMKX 031702 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1102 AM CST TUE DEC 3 2013

.UPDATE...

WITH LOW PRESSURE APPROACHING FROM THE PLAINS...SOUTHERN WISCONSIN
WILL REMAIN NORTH OF THE WARM FRONT THROUGH MOST OF TONIGHT. THEN
AS THE WARM FRONT GETS INTO CENTRAL WI WED MORNING...THE SURFACE
LOW WILL BE DIRECTLY OVER SOUTHERN WI...WHICH WILL MEAN A
CONTINUED WEAK PRESSURE GRADIENT. THEREFORE...EXPANDED AND
EXTENDED THE DENSE FOG ADVISORY UNTIL NOON TOMORROW. LEFT OUT THE
COUNTIES NORTH OF MILWAUKEE AND COLUMBIA DUE TO SOME DRIER AIR
AND HIGHER WINDS...BUT CONDITIONS SEEM TO CONTINUE
DETERIORATING...SO MAY HAVE TO EXPAND IT NORTHWARD.

&&

.AVIATION/18Z TAFS/...

SOUTHERN WI WILL REMAIN ON THE NORTH SIDE OF THE WARM FRONT
THROUGH MUCH OF THE NIGHT AND THEN GET INTO A WEAK PRESSURE
GRADIENT THROUGH WEDNESDAY MORNING. THEREFORE...EXPECT DENSE FOG
WITH 1/4 TO 3/4SM VSBY AND CEILINGS BELOW 500 FEET TO PERSIST
THROUGH WEDNESDAY MORNING. THERE COULD BE BRIEF PERIODS OF
IMPROVEMENT THIS AFTERNOON AND DURING ANY LIGHT RAIN
SHOWERS...BUT TOO MUCH UNCERTAINTY TO TIME THAT CORRECTLY IN THE
TAFS.

&&

.PREV DISCUSSION... /ISSUED 327 AM CST TUE DEC 3 2013/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.

ZONAL 250 MB FLOW BECOMES SOUTHWEST AS THE UPPER JET MAX LIFTS
NORTHEAST FROM THE BASE OF THE WEST COAST TROUGH AND INCREASES
THIS AFTERNOON AND TONIGHT. WEAK UPPER DIVERGENCE TODAY AND
TONIGHT.

500 MB TROUGH WILL EXIT TO THE NORTHEAST EARLY THIS MORNING
ENDING MUCH OF THE MEASURABLE PRECIPITATION. 850/700 MB WARM AIR
ADVECTION CONTINUES TODAY AND TONIGHT. WEAK 700 MB UPWARD MOTION
TODAY INCREASES A LITTLE THIS EVENING AS THE SOUTHWEST 850/700 MB
WINDS INCREASE TO 35/43 KNOTS RESPECTIVELY...BEFORE LIFTING
NORTHEAST LATE TONIGHT. THE UPWARD MOTION AND MOISTURE CONVERGENCE
DECREASES LATE TONIGHT AS THE LOW LEVEL WIND MAX LIFTS NORTHEAST.

ANY RAIN SNOW MIX WILL BECOME RAIN AS THE MEASURABLE
PRECIPITATION LIFTS NORTHEAST EARLY THIS MORNING. THERE COULD BE
DRIZZLE AS THE 3 TO 8 THSD LEVELS DRY OUT A LITTLE PER MODEL
SOUNDINGS. THEN ANOTHER ROUND OF RAIN IS EXPECTED ACROSS SOUTHERN
WISCONSIN DURING THE AFTERNOON AND EVENING. APPEARS THE LOW LEVELS
REMAIN SATURATED...SO THE STRATUS WILL CONTINUE.

SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM TO HIGH.

NAM/GFS/ECMWF MODELS ARE QUICKER AND FURTHER NORTH WITH THE
SURFACE LOW MOVEMENT NORTHEAST THROUGH THE REGION THAN THE
CANADIAN ON WEDNESDAY. NAM/GFS HAS THE SURFACE LOW NORTHEAST OF
WISCONSIN BY 00Z THURSDAY...WITH THE ECMWF OVER WEST CENTRAL
WISCONSIN...WHILE THE CANADIAN IS OVER FAR SOUTHWESTERN
WISCONSIN. WARM AIR ADVECTION CONTINUES OVER THE AREA BEFORE THE
LOW PUSHES THROUGH THE REGION...THEN COLD AIR ADVECTION KICKS IN
AS THE LOW MOVES TO THE NORTHEAST. AGAIN...TIMING IS FASTER WITH
THIS TRANSITION ON NAM/GFS/ECMWF VERSUS SLOWER CANADIAN.

FOR NOW...WILL USE A BLEND OF THESE MODELS IN THE FORECAST. 500MB
VORTICITY MAXIMUM SLIDES NORTHEAST THROUGH THE REGION...CLIPPING
THE NORTHWEST HALF OF THE FORECAST AREA LATER ON WEDNESDAY. AREA
FORECAST SOUNDINGS ARE SHOWING A FAIR AMOUNT OF DRY AIR ABOVE
850MB ON THE NAM WEDNESDAY...WITH THE AIR COLUMN MOIST ON THE GFS.
AREA OF LOW LEVEL FRONTOGENESIS RESPONSE SHIFTS THROUGH THE AREA
LATER WEDNESDAY WITH THE COLD FRONT. GIVEN SOME UNCERTAINTY
HERE...WILL CONTINUE WITH MIDDLE RANGE POPS WEDNESDAY INTO
WEDNESDAY NIGHT...WITH A RAIN TO SNOW TRANSITION WEDNESDAY NIGHT.

COLD AIR ADVECTION WILL CONTINUE WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT ACROSS THE REGION...AS A CANADIAN HIGH MOVES INTO THE
NORTHERN PLAINS REGION. THIS WILL DRY OUT THE AIR COLUMN ACROSS
THE REGION...WITH SOME STRATOCUMULUS CLOUDS AT TIMES. 925MB
TEMPERATURE TRENDS SUGGEST TEMPERATURES WILL NOT RISE MUCH
THURSDAY...BEFORE DROPPING INTO THE 8 TO 16 DEGREE RANGE NORTHWEST
TO SOUTHEAST THURSDAY NIGHT. WIND CHILLS IN THE SINGLE DIGITS ARE
EXPECTED AS WELL.

LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS
MEDIUM.

GFS/ECMWF ARE IN FAIR AGREEMENT FRIDAY INTO SATURDAY. THEY BRING
THE CANADIAN HIGH EAST ACROSS THE REGION FRIDAY THROUGH
SATURDAY...BEFORE SHIFTING EAST OF THE REGION SATURDAY NIGHT. THE
HIGH WILL BRING QUIET WEATHER BUT COLD TEMPERATURES TO THE REGION.

THE GFS AND ECMWF THEN DIFFER QUITE A BIT WITH THE LOW TRACKING
NORTHEAST THROUGH THE REGION LATER SUNDAY INTO SUNDAY NIGHT. THE
ECMWF TAKES THE LOW FURTHER NORTH THAN THE GFS...BRINGING IT FROM
THE CENTRAL PLAINS TO NORTHERN LOWER MICHIGAN BY 12Z MONDAY...THEN
TO THE NORTHEAST MONDAY. THIS TRACK BRINGS A SWATH OF QPF IN THE
FORM OF LIGHT TO MODERATE SNOW...WITH SEVERAL INCHES OF
ACCUMULATION POSSIBLE.

THE GFS KEEPS THE LOW WELL SOUTHEAST OF THE REGION DURING THIS
TIME...WITH PERHAPS A FRONTOGENETIC BAND CLIPPING THE AREA SUNDAY
NIGHT WITH LIGHT QPF AND LIGHT SNOW. THE COLD AIR IS THEN
REINFORCED ACROSS THE AREA MONDAY ON BOTH MODELS.

FOR NOW...WILL USE THE CONSENSUS POPS AND TEMPERATURES FOR THE
SUNDAY INTO MONDAY PERIOD. THIS PERIOD WILL NEED TO BE WATCHED
IN LATER FORECASTS FOR ACCUMULATING SNOW...ESPECIALLY IF THE
MODELS TREND MORE TO THE ECMWF. STAY TUNED.

AVIATION/12Z TAFS/...

EXPECT IFR/LIFR WITH STRATUS. SOME DRIZZLE THIS MORNING THEN
LIGHT RAIN SPREADING NORTHEAST AGAIN THIS AFTERNOON AND EVENING AS
A WARM FRONT APPROACHES.

MARINE...

A SMALL CRAFT ADVISORY IS IN EFFECT AS BRISK SOUTHEAST WINDS
CONTINUE EXCEPT FOR AREAS SOUTH OF WIND POINT WHEN WINDS/WAVES
WILL SUBSIDE A LITTLE THIS AFTERNOON. EXPECT WAVES TO SUBSIDE AS
WINDS BECOME OFFSHORE...SOMETIME WEDNESDAY MORNING. A STRONG COLD
FRONT WILL THEN SWEEP EAST ACROSS LAKE MICHIGAN ON WED. BRISK AND
GUSTY WEST NORTHWEST FLOW WILL THEN PREVAIL THE REMAINDER OF THE
WEEK. A SMALL CRAFT ADVISORY WILL BE NEEDED BEHIND THE FRONT.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ056-057-
     062>072.

LM...SMALL CRAFT ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR LMZ645-
     646.

     SMALL CRAFT ADVISORY UNTIL NOON CST WEDNESDAY FOR LMZ643-644.

&&

$$

UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
WEDNESDAY THROUGH MONDAY...WOOD