Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 200900
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
300 AM CST THU NOV 20 2014

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

A BROAD 250 MB UPPER TROUGH EXTENDS ACROSS THE GREAT LAKES THIS
MORNING THAT MOVES OFF TOWARD NEW ENGLAND TONIGHT...WITH A
NORTHWEST FLOW ACROSS SOUTHERN WISCONSIN.

LITTLE IN THE WAY OF UPPER DIVERGENCE TODAY. A MID LEVEL 500 MB
SHORTWAVE WILL DROP SOUTHEAST ACROSS CENTRAL WISCONSIN IN THE
CYCLONIC FLOW THIS MORNING AND EARLY AFTERNOON.  ONLY WEAK 700 MB
UPWARD MOTION WITH THE SHORTWAVE. THEN DOWNWARD MOTION TONIGHT.

AREA FORECAST SOUNDINGS KEEP THE SHALLOW MOISTURE IN THE LOW LEVELS
WITHIN DENDRITE SNOW GROWTH ZONE INTO THE AFTERNOON...SO KEPT
FLURRY MENTION GOING DURING THIS TIME...ESPECIALLY NORTH AREAS
CLOSER TO THE SHORTWAVE.  NO ACCUMULATIONS EXPECTED.

THE PRESSURE GRADIENT WILL KEEP BRISK WEST WINDS GOING...WITH
GRADUAL COLD AIR ADVECTION. 925 MB TEMPERATURE FIELDS SUGGEST HIGHS
IN THE MID TO UPPER TEENS IN MOST AREAS. WIND CHILLS SHOULD BE
IN THE SINGLE DIGITS ABOVE ZERO TODAY.

A SURFACE RIDGE AXIS MOVES ACROSS SOUTHERN WISCONSIN TONIGHT.  THE
CLEARING SKIES...AND DIMINISHING WINDS WILL DROP TEMPERATURES INTO
THE SINGLE DIGITS MOST AREAS.

.FRIDAY - CONFIDENCE...HIGH
SURFACE HIGH EXPECTED TO SHIFT INTO THE OHIO VALLEY WITH
PRONOUNCED 925/850 WAA RETURN FLOW SETTING UP. MID LEVEL FLOW
BECOMES ANTICYCLONIC WITH UPSTREAM SHORTWAVE STAYING TO THE WEST.
925 TEMPS MODERATE TO -2C TO -4. EXPECT TEMPS TO NUDGE INTO THE
MID 20S. MOISTURE FEED LIKELY TO RESULT IN WIDESPREAD STRATUS
DEVELOPMENT AND THIS IS REFLECTED WELL IN THE 925/850 RH PANELS.
AT THIS TIME THIS ALSO STAYS TO OUR WEST DURING FRIDAY.

.FRIDAY NIGHT AND SATURDAY MORNING - CONFIDENCE...MEDIUM
EXPECTING SKIES TO QUICKLY CLOUD OVER AS STRATUS ADVECTS
NORTHEAST INTO SRN WI. THE WARM/MOIST ADVECTION REGIME WILL LIKELY
RESULT IN A NON- DIURNAL TEMP PROFILE WITH COLDEST TEMPS OBSERVED
IN THE EARLY EVENING BEFORE CLOUDS AND WARM PUSH STRENGTHENS
FURTHER. INFLUENCE OF QUICK HITTING SHORTWAVE ARRIVES AFTER 6Z.
MOISTURE PROFILE IS SHALLOW WITH VERY LITTLE RH IN THE DENDRIDIC
GROWTH ZONE. PRONOUNCED WARM LAYER WITH LINGERING COLDER SURFACE
TEMPS SUGGESTS KEEPING SOME LIGHT ZR OR ZL IN PLACE. QPF AMOUNTS
ARE MEAGER.

.SATURDAY AFTERNOON THROUGH SATURDAY NIGHT - CONFIDENCE...MEDIUM
MILDER AIRMASS PROGGD TO BE IN PLACE WITH 850/925 TEMPS WELL
ABOVE ZERO CELSIUS. BROAD WAA/MOIST ADVECTION PERSISTS THOUGH
BETTER FORCING/BAROCLINICITY LIFTS NORTH AND INTERACTS WITH A
NORTHERN STREAM WAVE LIFTING NORTHEAST. QPF AMOUNTS ONLY A FEW
HUNDREDTHS AND MORE OVER THE SOUTHEAST CWA. DEBATED ON GOING DRY
ALL TOGETHER IN THE NW CWA BUT TOO CLOSE OF A CALL BUT WENT SLIGHT
CHANCE THERE. MUCH OF CWA SHOULD REACH THE LOW/MID 40S. EXPECT
SOME FOG DEVELOPMENT ESPECIALLY GETTING INTO SATURDAY NIGHT AS LOW
LEVEL FLOW BECOMES MORE SSE AND ON THE LIGHTER SIDE. AIRMASS
LIKELY QUITE MOIST IN THE LOW LEVELS. ANOTHER WING OF WAA PRECIP
WRAPS INTO THE AREA LATER IN THE NIGHT AHEAD OF EVOLVING CENTRAL
PLAINS LOW PRESSURE.

.SUNDAY AND MONDAY - CONFIDENCE...MEDIUM
PRIMARY SURGE OF RAIN ARRIVES WITH POTENT STRONGLY NEGATIVELY
TILTED SHORTWAVE FROM SOUTHERN PLAINS. CYCLOGENESIS INCREASES WITH
TIME TO A 981MB LOW IN NRN IL BY THE END OF THE DAY. DECENT
AGREEMENT ON THE HEAVIEST RAINFALL FOR SUNDAY AFTERNOON INTO THE
EARLY EVENING HOURS. THE SURFACE LOW LIFTS NORTHEAST WITH COLDER
AIR AND MID LEVEL DRY SLOT WRAPING IN AROUND THE LOW SUNDAY NIGHT
INTO MONDAY. 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.

.TUESDAY - CONFIDENCE...MEDIUM
LINGERING CYCLONIC FLOW AND LOW LEVEL TROUGHINESSS SUGGESTS
KEEPING CHCY POPS GOING PER SUPERBLEND. GFS HAS COME AROUND TO
SHOWING AT LEAST SOME MEASURABLE QPF WITH THIS PATTERN SO EXPECT
SHSN ACTIVITY WHICH MAY EVENTUALLY NECESSITATE A BOOST IN THE
POPS.

.TUESDAY NIGHT AND WEDNESDAY - CONFIDENCE...LOW
WEAK RIDGING PROGGD TO SETTLE IN FOR TUESDAY NIGHT. THEN TIMING
DIFFERENCES ARISE WITH THE ECMWF A BIT MORE QUICK WITH DEVELOPING
WAA BAND OF LIGHT SNOW ON WEDNESDAY. THE GFS DOES NOT BRING THIS
UNTIL WEDNESDAY NIGHT. SUPERBLEND BROUGHT POP INTO WESTERN CWA BUT
PER COLLAB WITH SURROUNDING OFFICES GOING DRY FOR NOW BUT IF THE
QUICKER TRENDS OF THE ECMWF BECOME PERSISTENT THE POP WILL BE
NEEDED.

&&

.AVIATION/12Z TAFS/...EXPECT SCATTERED TO BROKEN MVFR CIGS TO RETURN
TODAY...ESPECIALLY IN AREAS NORTH OF MADISON TO KENOSHA AS A MID
LEVEL SHORTWAVE MOVES ACROSS EAST CENTRAL WISCONSIN. SHOULD SEE A
FEW SNOW SHOWERS/FLURRIES WITH BRIEF MVFR VSBYS. NO SNOW ACCUMULATIONS
EXPECTED. WINDS HAVE LOWERED A BIT BUT EXPECTED TO COME BACK UP WITH
GUSTS AROUND 25 KNOTS LATER THIS MORNING.

A SURFACE RIDGE AXIS MOVES ACROSS SOUTHERN WISCONSIN TONIGHT WITH
CLEARING SKIES...AND DIMINISHING WINDS.

&&

.MARINE...WINDS AT SHORELINE SITES HAVE LOWERED WITH WEST WINDS
DECOUPLED A BIT OVER THE COLD LAND SURFACE...HOWEVER MID-LAKE
BUOY SHOWING WINDS ABOVE CRITERIA WITH BETTER MIXING OVER WARMER
LAKE WATERS SO SMALL CRAFT ADVISORY CONTINUES. SHORELINE WINDS
EXPECTED TO REACH SMALL CRAFT ADVISORIES LATER THIS MORNING AND
AFTERNOON.

A SURFACE RIDGE AXIS MOVES ACROSS SOUTHERN WISCONSIN TONIGHT WITH
DIMINISHING WINDS.

&&

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

&&

$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
FRIDAY THROUGH WEDNESDAY...COLLAR



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