Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 200343 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
943 PM CST WED NOV 19 2014

.UPDATE...

ADJUSTED SKIES FOR MORE CLEARING THIS EVENING THAN EARLIER
FORECAST AND ADJUSTED TEMPERATURES AND WINDS. SCATTERED TO BROKEN
CLOUDS AHEAD OF NEXT SHORT WAVE AND ON LEADING EDGE OF COLDER 925
MB TEMPS EXPECTED TO MOVE IN OVER MOST OF THE AREA AROUND/AFTER
MIDNIGHT...WITH 925 MB TEMPS ABOUT 3C COOLER BY 12Z. PREVIOUS COLD
LOWS TEMPS LOOK ON TRACK.

&&

.AVIATION/06Z TAFS/...

CLOUDS HAVE SCATTERED/CLEARED FOR A TIME...BUT EXPECT BROKEN VFR
CIGS TO RETURN OVERNIGHT WITH COLD AIR ADVECTION AND FORCING
AHEAD OF NEXT SHORT WAVE SPINNING OVER STATE. COULD SEE A FEW
FLURRIES BUT NO VSBY REDUCING SNOW SHOWERS NOR ACCUMULATIONS
EXPECTED. WINDS HAVE LOWERED A BIT BUT EXPECTED TO COME BACK UP
WITH GUSTS AROUND 25 KNOTS THURSDAY.

&&

.MARINE...

WINDS AT SHORELINE OB SITES HAVE LOWERED WITH WEST WINDS DECOUPLING
OVER COLD LAND SURFACE AND CLEARING SKIES...HOWEVER MID-LAKE BUOY
AND SHIP OBS SHOWING WINDS AT OR ABOVE CRITERIA WITH BETTER MIXING OVER
WARMER LAKE WATERS SO SMALL CRAFT ADVISORY CONTINUES.

&&

.PREV DISCUSSION... /ISSUED 335 PM CST WED NOV 19 2014/

TONIGHT AND THURSDAY...CONFIDENCE - HIGH.

AREA OF LIGHT SNOW SHOWERS WITH EMBEDDED MODERATE SNOW SHOWERS ARE
MOVING THROUGH THE AREA...IN ASSOCIATION WITH SOME MID LEVEL
FRONTOGENESIS RESPONSE FIELDS. AREA FORECAST SOUNDINGS ALSO SHOW
SHALLOW LOW LEVEL MOISTURE WITHIN DEEP DENDRITE SNOW GROWTH ZONE.
MESOSCALE MODELS NOT HANDLING THIS ACTIVITY WELL. WILL TREND HIGH
POPS FOR LIGHT SNOW SHOWERS DOWNWARD TO FLURRIES BY THE EARLY
EVENING HOURS.

AREA REMAINS IN CYCLONIC FLOW AT 500 MB TONIGHT INTO THURSDAY...WITH
A STRONG VORTICITY MAXIMUM SLIDING SOUTHWARD THROUGH THE AREA. AREA
FORECAST SOUNDINGS KEEP THE SHALLOW MOISTURE IN THE LOW LEVELS
WITHIN DENDRITE SNOW GROWTH ZONE TONIGHT INTO THURSDAY...SO KEPT
FLURRY MENTION GOING DURING THIS TIME. DRIER AIR MOVING IN ON
THURSDAY SHOULD GRADUALLY BRING PARTLY SUNNY SKIES.

A TIGHT PRESSURE GRADIENT TONIGHT AND THURSDAY WILL KEEP BRISK WEST
WINDS GOING...WITH GRADUAL COLD AIR ADVECTION. 925 MB TEMPERATURE
FIELDS SUGGEST LOWS TONIGHT INTO THE 9 TO 13 ABOVE ZERO RANGE...WITH
HIGHS THURSDAY IN THE MID TO UPPER TEENS IN MOST AREAS. WIND CHILLS
WILL DROP INTO THE SINGLE DIGITS BELOW ZERO LATER TONIGHT...AND
SINGLE DIGITS ABOVE ZERO FOR THURSDAY.

THURSDAY NIGHT THROUGH SATURDAY...CONFIDENCE - MEDIUM.

INCREASING SUBSIDENCE AND DRYING OF LOW LAYERS SHOULD END MOST OF
ANY LINGERING FLURRIES EARLY THU EVE SO WL NOT INCLUDE MENTION AT
THIS TIME.

RIDGE AXIS APPROACHING WRN CWA LATE THU NIGHT AND 925H TEMPS AROUND
-13C WL ALLOW OVERNIGHT TEMPS TO DIP WELL INTO THE SINGLE DIGITS BY
SUNRISE FRI.  FEW LOCATIONS IN THE WEST COULD BE BELOW ZERO. A QUIET
DAY EXPECTED ON FRI AS THE RIDGE AXIS SLIDES THRU WI.  SUNSHINE
SHOULD HELP TEMPS RECOVER INTO THE LOW TO MID 20S...STILL 15 TO 20
DEGREES BELOW NORMAL.

MEDIUM RANGE GUIDANCE REMAINS IN GOOD AGREEMENT ON INCREASING
SOUTHERLY WINDS ON THE BACK SIDE OF THE RETREATING HIGH PRESSURE
FRI/FRI NIGHT PULLING LOW LEVEL MOISTURE BACK INTO THE WRN
GTLAKES.  LOW LEVEL THETA-E ADVECTION MAY BRING SOME LIGHT PRECIP
INTO THE AREA LATER FRI NIGHT AND SAT.  SFC TEMPS WL NOT HAVE HAD
TIME TO RISE TO ABOVE FREEZING...AND FORECAST SOUNDINGS SHOW LITTLE
IF ANY ICE INTRODUCTION INTO THE MOISTURE LAYER.  LOW LEVEL LAYER
TEMPS AROUND -6C WHICH MAY RESULT IN REFREEZING OF THE LIQUID DROPS
TO SLEET.  ANY QPF WL BE LIGHT...BUT MAY BE ENOUGH TO CAUSE
HAZARDOUS TRAVEL CONDITIONS BY EARLY SAT.  SOUTH WINDS WL CONTINUE
TO PUMP WARMER AIR INTO SRN WI ON SAT...WARMING PAVEMENT TEMPS TO
ABV FREEZING DURING THE DAY.

SATURDAY NIGHT THROUGH WEDNESDAY...CONFIDENCE - MEDIUM.

PERSISTENT SOUTH TO SOUTHWEST LOW LEVEL FLOW AHEAD OF PHASING
NORTHERN AND SOUTHERN STREAMS WL RESULT IN CONTINUED WARMER...ABOVE
FREEZING TEMPS OVER THE WEEKEND.  PHASING OF TWO STREAMS WL CAUSE
DEEPENING LOW PRESSURE IN SOUTHERN STREAM TO TAKE A MORE NWD TRACK
FROM THE SOUTHERN MS VALLEY INTO THE SRN LAKE MI AREA SAT NIGHT THRU
SUN EVE.  PRECIPITABLE WATER VALUES WITH THIS LOW WILL INCREASE TO
AROUND 1.0 OVER SRN WI WHICH IS APPROACHING 2 STANDARD DEVIATIONS
AND THE 90TH PERCENTILE FOR MID-NOVEMBER.  MOISTURE IN PLACE OVER
COLD SFC WL LIKELY RESULT IN AREAS OF FOG DESPITE EXPECTED BOUNDARY
LAYER MIXINESS.

THIS STRONG MOISTURE ADVECTION AND TRANSPORT ASSOCIATED WITH THE
APPROACHING LOW PRESSURE SYSTEM WILL BRING RAIN TO SRN WI SUN INTO
SUN EVE.  AHEAD OF THIS STRONG SYSTEM...WL CONTINUE LOWER POPS FOR
-RA/-DZ DUE TO LINGERING WEAK ISENTROPIC OMEGA AND LINGERING LOW
LEVEL RH SAT/SAT NGT.

MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT ON THIS STRONG LOW PRESSURE
SYSTEM BRINGING THE WET CONDITIONS LATER IN THE WEEKEND.  BY THAT
TIME...PAVEMENT TEMPS SHALL HAVE WARMED ABOVE FREEZING.

DEEPENING LOW PRESSURE WL CONTINUE MOVING NORTH THROUGH THE WRN
GTLAKES SUN NIGHT AND MON.  BRISK WEST WINDS IN ITS WAKE WILL PULL
COLDER AIR INTO SRN WI SUN NIGHT.  THERE MAY BE TIME TO CHANGE THE
-RA OVER TO A MIXTURE OR -SN BEFORE ENDING OR DIMINISHING TO
FLURRIES.

REMNANTS OF SECOND NRN STREAM LOW PRESSURE WL ROTATE AROUND NRN
GTLAKES UPPER LOW EARLY NEXT WEEK AS COLD AIR SETTLES BACK INTO THE
REGION. THIS WILL RESULT IN A CHANCE FOR -SHSN MON NGT INTO TUE.
COLD WX WL THEN REMAIN ANCHORED OVER SRN WI THRU MIDWEEK.


AVIATION/00Z TAFS/...

LIGHT SNOW SHOWERS WITH SOME MODERATE SNOW SHOWERS WILL MOVE THROUGH
TAF SITES INTO THE EARLY EVENING HOURS...BEFORE TAPERING OFF TO
FLURRIES TONIGHT INTO THURSDAY MORNING. GUSTY WEST WINDS SHOULD
LIMIT ANY ACCUMULATIONS TO A DUSTING AT WORST UNTIL AROUND 00Z
THURSDAY.

THE GUSTY WINDS WILL LINGER INTO THURSDAY. CEILINGS WILL REMAIN
VFR/MVFR TONIGHT INTO THURSDAY MORNING...SCATTERING OUT DURING THE
LATE MORNING AND AFTERNOON.

MARINE...

SMALL CRAFT ADVISORY HAS BEEN EXTENDED UNTIL 09Z FRIDAY ACROSS THE
NEARSHORE WATERS OF LAKE MICHIGAN. A TIGHT PRESSURE GRADIENT ACROSS
THE AREA WILL LINGER INTO THURSDAY NIGHT...ALLOWING FOR BRISK WEST
WINDS TO 30 KNOTS AT TIMES.

HIGH WAVES WILL BE TOWARD AND OVER THE OPEN WATERS OF LAKE
MICHIGAN...DUE TO THE OFFSHORE FLOW. WINDS AND WAVES WILL SUBSIDE
AFTER 09Z FRIDAY...AS HIGH PRESSURE WORKS INTO THE REGION.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 AM CST FRIDAY FOR LMZ643>646.

&&

$$

UPDATE...REM
TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD
THURSDAY NIGHT THROUGH WEDNESDAY...MBK



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