Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 181813 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1213 PM CST TUE NOV 18 2014

.UPDATE...

STRATOCUMULUS CLOUDS ARE EXPECTED TO CONTINUE TO DEVELOP AND
SPREAD EASTWARD ACROSS THE AREA THIS AFTERNOON. AREA FORECAST
SOUNDINGS SUPPORT THIS DEVELOPMENT WITH STEEP LOW LEVEL LAPSE
RATES AND ENOUGH LOW LEVEL MOISTURE. GUSTY WEST WINDS WILL ALSO
CONTINUE WITH ROBUST MIXING IN THE LOW LEVELS.

925 MB TEMPERATURESS SUGGEST HIGHS TOPPING OUT ONLY IN THE MIDDLE
TO UPPER TEENS...HIGHEST IN THE FAR EASTERN COUNTIES.

&&

.AVIATION/18Z TAFS/...

MVFR CEILINGS SHOULD GRADUALLY BECOME VFR BY SUNSET ACROSS TAF
SITES...WITH STRATOCUMULUS CLOUDS DEVELOPING AND SPREADING ACROSS
THE AREA. THESE VFR CEILINGS SHOULD LINGER THIS EVENING AND LATER
TONIGHT. GUSTY WEST WINDS ARE EXPECTED TO CONTINUE THIS AFTERNOON
AND EVENING...WITH SOME GUSTS TO 25 KNOTS. WINDS WILL WEAKEN AFTER
MIDNIGHT TONIGHT...AS WEAK LOW PRESSURE MOVES TOWARD THE AREA.

EXPECT AN AREA OF LIGHT SNOW TO SPREAD EAST ACROSS TAF SITES
BETWEEN 11Z TO 16Z AT MADISON...AND 12Z TO 17Z AT THE EASTERN
SITES. VISIBILITIES SHOULD DROP TO NEAR 1 MILE OR NEAR ALTERNATE
MINIMUMS DURING THIS TIME...WITH CEILINGS MVFR TO PERHAPS IFR
CATEGORY. FLUFFY SNOW ACCUMULATIONS OF 1/2 TO 1 INCH ARE
POSSIBLE...WITH 0.1 TO 0.2 INCH RATES PER HOUR.

SHOULD SEE VFR CONDITIONS RETURN BY THE AFTERNOON HOURS ON
WEDNESDAY...WITH GUSTY WEST WINDS AS WELL. MAY SEE A LITTLE
BLOWING AND DRIFING SNOW...BUT VISIBILITIES SHOULD REMAIN VFR
CATEGORY.

&&

.MARINE...

SMALL CRAFT ADVISORY CONTINUES UNTIL 06Z WEDNESDAY ACROSS THE
NEARSHORE WATERS OF LAKE MICHIGAN. GUSTY WEST WINDS WILL CONTINUE
THIS AFTERNOON AND EVENING...WITHIN A TIGHT PRESSURE GRADIENT AND
ROBUST LOW LEVEL MIXING. GUSTS TO 25 KNOTS ARE EXPECTED DURING
THIS TIME.

THE PRESSURE GRADIENT AND SUBSEQUENT WINDS WILL WEAKEN BY LATER
TONIGHT INTO WEDNESDAY MORNING...AS WEAK LOW PRESSURE MOVES
THROUGH THE AREA. HIGH WAVES WILL BE TOWARD AND OVER THE OPEN
WATERS WITH THE OFFSHORE FLOW.

GUSTY WEST WINDS ARE EXPECTED AGAIN WEDNESDAY AFTERNOON AND INTO
THURSDAY...AS ANOTHER TIGHT PRESSURE GRADIENT DEVELOPS BEHIND THE
DEPARTING LOW. COULD SEE GUSTS TO 30 KNOTS AT TIMES. HIGH WAVES
WOULD BE TOWARD AND OVER THE OPEN WATERS WITH THE OFFSHORE FLOW. A
SMALL CRAFT ADVISORY WILL BE NEEDED DURING THIS PERIOD.

&&

.PREV DISCUSSION... /ISSUED 310 AM CST TUE NOV 18 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH

THE 250 MB UPPER TROUGH AXIS ACROSS WISCONSIN WILL MOVE EAST ACROSS
THE UPPER GREAT LAKES. LITTLE IN THE WAY OF UPPER DIVERGENCE. A MID
LEVEL 500 MB SHORTWAVE WILL DROP SOUTHEAST ACROSS SOUTHERN WISCONSIN
THIS MORNING. A SECOND WEAK SHORTWAVE ENTERS SOUTHERN WISCONSIN
AROUND SUNRISE WEDNESDAY.  LITTLE IN THE WAY OF UPWARD MOTION WITH
THE FIRST SHORTWAVE....WHILE 700 MB UPWARD MOTION INCREASES LATE
TONIGHT AS THE 700 MB LAYER SATURATES. ISENTROPIC ANALYSIS SHOWS
CONDENSATION PRESSURE DEFICITS FALL TO LESS THAN 10 MB IN THE 830
TO 620 MB LAYER...BUT ONLY FOR A BRIEF TIME.

MAY BE A FEW FLURRIES WITH THE INITIAL SHORTWAVE THIS MORNING...AND
WILL HAVE LESS THAN AN INCH OF SNOW ACCUMULATION LATE TONIGHT.
LIGHT ACCUMULATIONS SHOULD BEGIN VERY LATE IN THE SOUTHEAST.

THE VERY COLD AIRMASS WILL CONTINUE TODAY WITH A GRADUAL MODERATION
LATE TONIGHT AS THE SURFACE TROUGH APPROACHES.  THE DEVELOPING LIGHT
SOUTHEAST FLOW OFF LAKE MICHIGAN SHOULD ALSO HELP TEMPERATURE TO
RISE LAKE IN THE FAR EAST.

WEDNESDAY - CONFIDENCE...MEDIUM
PRIMARY SHORTWAVE OF CONCERN WILL SHIFT EAST OF THE AREA DURING
THE MORNING. EXPECT SOME LIGHT ACCUMULATIONS IN THE MORNING...SOME
AREAS UP TO AN INCH IN THE EAST. NAM QPF AMOUNTS ARE HIGHER WITH
THE ECMWF AND GFS SHOWING LIGHTER QPF. WITH THE TROUGH STILL
COMING THROUGH DURING THE MORNING HAVE LEANED TOWARDS THE WPC/NAM
IDEA. 850 TROUGH/COLD FRONT ALSO SHIFTS EAST DURING THE AFTERNOON.
STRONGLY CYCLONIC FLOW TAKES SHAPE INTO WEDNESDAY NIGHT WITH
RENEWED COLD ADVECTION SETTING UP LATER IN THE AFTERNOON INTO THE
EVENING IN THE WAKE OF THE LOW LEVEL FRONT.

THURSDAY - CONFIDENCE...MEDIUM
SURFACE HIGH WILL APPROACH. HOWEVER INFLUENCE OF THE COLD TROUGH
WILL PERSIST. 925 TEMPS OF -12 TO -14C WITH 925 WINDS RUNNING 20
TO 30 KNOTS ALL DAY...SO BLUSTERY CONDITIONS PERSIST. PRESSURE
GRADIENT WILL EASE LATER IN THE DAY.

FRIDAY - CONFIDENCE...MEDIUM
SOME MODIFICATION GETS UNDERWAY WITH SURFACE HIGH TO THE EAST AND
MORE OF A SOUTHERLY FLOW SETTING UP. 850 WAA REALLY RAMPS UP. THE
MOISTURE SURGE REMAINS TO OUR SOUTH. HOWEVER 925 TEMPS REALLY
MODIFY QUITE A BIT RISING QUITE A BIT THROUGH THE NEGATIVE SINGLE
DIGITS CELSIUS. UPTICK IN 925/850 RH NOTED FOR THE AFTERNOON
HOURS.

FRIDAY NIGHT - CONFIDENCE...LOW
MAIN FORECAST CHALLENGE WILL BE PRECIPITATION TYPE WITH ARRIVING
MOISTURE SURGE. PRECIP AMOUNTS LOOK FAIRLY LIGHT. 850 TEMPS WILL
BE ABOVE ZERO CELSIUS. HOWEVER LOW LEVELS MAY BE SLOWER TO WARM
ABOVE THE FREEZING MARK...SO SOME CONCERN FOR A LIGHT MESSY
MIXTURE UNTIL TEMPS MODIFY.

SATURDAY AND SUNDAY - CONFIDENCE...MEDIUM
MILDER AIRMASS PROGGD TO BE IN PLACE WITH 850/925 TEMPS WELL
ABOVE ZERO CELSIUS. PRECIPITATION THIS PERIOD IN THE FORM OF
RAIN. AS WE MOVE INTO SATURDAY NIGHT AND SUNDAY A SURFACE LOW IS
PROGGD TO TAKE SHAPE AND SWING UP TOWARDS THE WESTERN GREAT LAKES.
SO HAVE LIKELY POPS FOR RAIN ON SUNDAY. AT THIS TIME THE ECMWF IS
SHOWING A BETTER DEVELOPED LOW TRACKING TO NEAR SRN LAKE MI BY 00Z
MON.

SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM
THE SURFACE LOW LIFTS NORTHEAST WITH COLDER AIR WRAPPING IN
AROUND THE LOW. SO EXPECT SOME CHANGEOVER TO OCCUR AS THE
PROFILE/COLUMN COOLS. LOW LEVEL TROUGH AND UPPER CYCLONIC FLOW
WILL KEEP SNOW SHOWER CHANCES GOING MONDAY WITH SOME LIGHT
ACCUMULATION POSSIBLE.

AVIATION/12Z TAFS/...POCKETS OF MVFR CIGS AND VERY LIGHT SNOW
SHOWERS/FLURRIES EARLY THIS MORNING...THEN MAINLY VFR CONDITIONS THROUGH
THIS EVENING. MVFR CIGS/VSBYS SHOULD DROP TO IFR LATE TONIGHT AS A
TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST.

MARINE...BUOYS INDICATING SMALL CRAFT ADVISORY LEVEL SUSTAINED WINDS
AND/OR GUSTS IN SPITE OF NOCTURNAL LOWERING OVER LAND. THE TIGHT GRADIENT
LINGERS THROUGH MOST OF TODAY...THEN SLOWLY EASING AS A WEAK RIDGE
AXIS REACHING THE LAKE SHORE BY MIDNIGHT CST TONIGHT. CURRENT ADVISORY
TIMING LOOKS GOOD.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.

&&

$$

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



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