Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 311530 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1030 AM CDT FRI OCT 31 2014

.UPDATE...

THE PEAK WINDS MADE THEIR WAY DOWN THE LAKESHORE COUNTIES FROM 8 AM
THROUGH 10 AM ON THE BACK SIDE OF THE POTENT UPPER LEVEL SHORTWAVE.
THIS LAST PUSH OF LOW/MID LEVEL FORCING IS BRINGING LIGHT SNOW TO
THE LAKESHORE COUNTIES THROUGH LATE MORNING AS WELL. T

HE WINDS WILL REMAIN VERY STRONG JUST ABOVE THE GROUND THROUGH MID
AFTERNOON. RAP AND NAM SOUNDINGS SHOW WINDS OF 40 MPH AT 1000 FEET
ABOVE GROUND THROUGH EARLY AFTERNOON. WE WILL BE MIXING UP TO 2000
TO 3000 FT THIS AFTERNOON... SO WIND GUSTS WILL BE QUITE HIGH
EVERYWHERE. THE WIND ADVISORY IN EFFECT FOR THE EASTERN TWO TIERS OF
COUNTIES FOR SUSTAINED WINDS OF 30 MPH OR GUSTS TO 45 MPH CRITERIA
THROUGH 6 PM STILL LOOKS REASONABLE.

&&

.AVIATION/18Z TAFS/...

THE ONSET OF HIGHEST WINDS OCCURRED THIS MORNING FROM 8 TO 10 AM AS
THE LAST BURST OF ENERGY TREKKED DOWN THE LAKESHORE IN THE WAKE OF
STRONG UPPER LEVEL LOW PRESSURE. LIGHT SNOW ACCOMPANIED THIS
FEATURE. WINDS AND GUSTS WILL REMAIN AT THESE HIGH LEVELS THROUGH AT
LEAST MID AFTERNOON WITH HIGHEST WINDS IN THE EASTERN COUNTIES OF
SOUTHERN WI. WINDS WILL GRADUALLY WEAKEN AT MADISON TONIGHT...BUT
REMAIN GUSTY AT THE EASTERN SITES.

CEILINGS ARE GENERALLY VFR WITH A FEW POCKETS OF MVFR. EXPECT DRIER
AIR TO SPREAD INTO THE REGION WITH MOSTLY CLEAR SKIES TONIGHT AS
HIGH PRESSURE APPROACHES. AN EXCEPTION WILL BE AT KENOSHA AND SOUTH
OF MILWAUKEE...WHERE LAKE EFFECT CLOUDS AND SCATTERED LIGHT
RAIN/SNOW SHOWERS WILL LINGER THROUGH TONIGHT AND POSSIBLY SATURDAY
MORNING. MVFR CEILINGS WITH ANOTHER 0.1 INCHES OF SNOWFALL ON GRASSY
AREAS IS POSSIBLE AT KENOSHA.

&&

.PREV DISCUSSION... /ISSUED 358 AM CDT FRI OCT 31 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.

FIRST ISSUE ARE THE MODERATE SNOW SHOWERS THAT WILL SHIFT EAST
SOUTHEAST THROUGH THE AREA THROUGH AROUND 13Z THIS MORNING. THIS
AREA IS LOCATED FROM NEAR VOLK FIELD EAST TO NEAR GREEN BAY INTO
SOUTHERN DOOR COUNTY. THESE WERE BEING DRIVEN BY A STRONG 500 MB
SHORTWAVE TROUGH MOVING THROUGH. MOST MESOSCALE MODELS TAKE THESE
SNOW SHOWERS SOUTHEAST THROUGH THE AREA BY 13Z.

AREA FORECAST SOUNDINGS FROM RAP/HRRR/NAM/GFS SHOWING LOW LEVEL
SATURATION WITHIN DENDRITE GROWTH ZONE...SO MODERATE INTENSITY
SHOULD PERSIST. A QUICK 0.1 OR 0.2 INCHES OF SNOWFALL ON GRASSY
AREAS ARE POSSIBLE AS THEY MOVE THROUGH. ROADS SHOULD JUST REMAIN
WET...AS ROAD TEMPERATURES REMAIN ABOVE FREEZING. THESE WILL HAVE AN
EFFECT ON THE MORNING COMMUTE ACROSS THE AREA...BUT SHOULD BE ABLE
TO HANDLE WITH NOWCASTS/SPECIAL WEATHER STATEMENTS.

NEXT ISSUE WILL BE WINDY CONDITIONS EXPECTED TODAY INTO THIS
EVENING. A STRONG PRESSURE GRADIENT WILL CONTINUE TO DEVELOP INTO
THE MORNING HOURS ACROSS THE AREA...ASSOCIATED WITH STRONG COLD AIR
ADVECTION PUSH BEHIND LOW PRESSURE TO THE EAST. THIS WILL ALLOW
STRONG NORTH WINDS TO LINGER TODAY ACROSS THE AREA.

AREA FORECAST SOUNDINGS SHOWING SUSTAINED WINDS AROUND 25 KNOTS AND
GUSTS TO 40 TO 45 KNOTS ACROSS THE EASTERN COUNTIES...SOMEWHAT LOWER
TO THE WEST. THUS...WIND ADVISORY CONTINUES FROM 12Z TO 23Z TODAY IN
THE EAST. THE PRESSURE GRADIENT WILL RELAX TONIGHT FROM WEST TO
EAST...ALLOWING WINDS TO GRADUALLY WEAKEN IN THE WEST. EASTERN AREAS
WILL REMAIN GUSTY THROUGH THE EVENING...SLOWLY WEAKENING LATER IN
THE NIGHT.

LAST ISSUE IS THE SYNOPTIC/MESOSCALE MODELS SHOWING LIGHT LAKE
EFFECT RAIN/SNOW SHOWERS LINGERING SOUTH OF MILWAUKEE NEAR THE LAKE
THROUGH TODAY...WITH LIGHT SNOW SHOWERS TONIGHT. ONSHORE LOW LEVEL
FLOW WITH VERY FAVORABLE DELTA T VALUES LINGER DURING THIS TIME.
SNOWFALL ON GRASSY AREAS MAY REACH 0.1 TO 0.2 INCHES IN THIS AREA.

925 MB TEMPERATURE FIELDS FROM MODELS SUGGEST HIGHS WILL STRUGGLE TO
GET OUT OF THE 30S IN MOST AREAS TODAY...WITHIN STRONG COLD AIR
ADVECTION REGIME. LOWS TONIGHT SHOULD DROP INTO THE 20S
INLAND...AROUND 30 LAKESIDE. WIND CHILLS WILL BE IN THE 20S
TODAY...AND THE TEENS TONIGHT.

SATURDAY - CONFIDENCE...MEDIUM
LOW LEVEL NE FLOW WITH CHILLY 850 TEMPS SUGGEST FAVORABLE ENOUGH
DELTA T TO RETAIN THE SMALL CHANCES OF LIGHT PRECIP IN THE FAR SE
CORNER TO START THE DAY. MODELS SHOW THE SHRINKING BAND OVER THE
LAKE WITH THE WESTERN EDGE CLIPPING AREAS FROM MILWAUKEE AND ON
SOUTH. UPPER TROUGH PULLS FURTHER EAST WHILE MID LEVEL RIDGE AXIS
REMAINS IN THE PLAINS. SURFACE/850 HIGH RIDGE AXES SHIFTING INTO
ERN WI BY DAYS END. THIS WILL HELP MODIFY THE LOW LEVEL THERMAL
TROUGH WITH 850 TEMPS TRYING TO GET ABOVE ZERO CELSIUS.

SUNDAY - CONFIDENCE...MEDIUM
SURFACE/850 HIGHS SHIFT INTO THE EASTERN U.S. WHILE MID LEVEL
RIDGE AXIS NUDGES UP ACROSS WRN WI. SOUTHERLY RETURN FLOW KICKS IN
WITH DRY AIRMASS CONTINUING. 925 TEMPS BUMP UPWARDS A BIT THROUGH
THE SINGLE DIGITS ABOVE ZERO CELSIUS. SO WARMER THAN SATURDAY WITH
MOST HIGHS REACHING AT LEAST THE UPPER 40S WITH SOME LOW 50S.

MONDAY AND TUESDAY - CONFIDENCE...LOW
MID LEVEL RIDGE AXIS SHIFTS INTO THE EASTERN LAKES AS 500 FLOW
TURNS MORE SOUTHWEST. SURFACE FRONT SLOWLY APPROACHES FROM THE
PLAINS. APPEARS 850 JET DOES INCREASE MOISTURE INTO SRN WI. THE
GFS IS MORE AGGRESSIVE WITH THIS ON MONDAY WHILE THE 12Z ECMWF
SHOWS MORE OF A DELAY UNTIL MONDAY NIGHT. THE GFS MAINTAINS THE
LOWER LOOK OF THE SURFACE FRONT KEEPING PRECIP GOING INTO TUESDAY
MORNING WHILE THE ECMWF SHOWS JUST SOME LIGHT LINGERING RAIN IN
THE FAR SOUTHEAST TUESDAY MORNING. SO STILL SOME TIMING
DIFFERENCES TO WORK OUT SO WILL NOT DEVIATE MUCH FROM THE
SUPERBLEND POPS.

WEDNESDAY - CONFIDENCE...MEDIUM
QUICK MOVING PATTERN CONTINUES AS STRONGER 500 FLOW PERSISTS AND
MODELS IN PRETTY GOOD AGREEMENT IN RACING YET ANOTHER SHORTWAVE
ACROSS THE AREA THIS PERIOD. SURFACE LOW WELL NORTH AND MUCH OF
THE QPF IS ALSO NORTH. OUR NORTHERN CWA IS A CLOSE CALL SO HAVE
KEPT SOME SMALL POPS THERE BUT WENT DRY IN SOUTH PER COLLABORATION
WITH SURROUNDING OFFICES.

THURSDAY - CONFIDENCE...MEDIUM
COLD ADVECTION PATTERN LINGERS FROM WEDNESDAY NIGHT WITH NW
WINDS. HOWEVER SURFACE HIGH BUILDS IN WITH TIME RESULTING IN
LIGHTER WINDS WITH TIME THOUGH A CHILLY DAY IS EXPECTED WITH 925
TEMPS JUST A SMIDGE ABOVE ZERO CELSIUS.

AVIATION/12Z TAFS/...

BANDS OF MODERATE SNOW SHOWERS WILL SLIDE SOUTH SOUTHEAST ACROSS TAF
SITES BETWEEN 09Z AND 13Z THIS MORNING. A QUICK 0.1 OR 0.2 INCHES OF
SNOWFALL IS POSSIBLE ON GRASSY AREAS...BUT THE RUNWAYS SHOULD REMAIN
ABOVE FREEZING AND BE JUST WET. VISIBILITIES MAY DROP TO 1/2 MILE AT
TIMES...PREVAILING 1 TO 2 MILES...AROUND OR BELOW ALTERNATE
MINIMUMS. CEILINGS SHOULD DROP INTO MVFR CATEGORY AS WELL...LASTING
INTO THE MIDDLE MORNING HOURS.

MVFR CLOUDS WILL BECOME VFR AND GRADUALLY MIX OUT AS THE DAY GOES
ON...WITH MOSTLY CLEAR SKIES TONIGHT...AS HIGH PRESSURE APPROACHES.
AN EXCEPTION WILL BE AT KENOSHA AND SOUTH OF MILWAUKEE...WHERE LAKE
EFFECT CLOUDS AND SCATTERED LIGHT RAIN/SNOW SHOWERS WILL LINGER
TODAY...WITH SCATTERED LIGHT SNOW SHOWERS TONIGHT. MVFR CEILINGS
WITH ANOTHER 0.1 INCHES OF SNOWFALL ON GRASSY AREAS IS POSSIBLE AT
KENOSHA.

STRONG WINDS TODAY WILL BE NORTHERLY IN THE 20 TO 25 KNOT
RANGE...HIGHEST AT THE EASTERN SITES. GUSTS UP TO 33 KNOTS AT
MADISON...TO AROUND 40 KNOTS AT THE EASTERN SITES...ARE EXPECTED AS
WELL. THESE WINDS WILL GRADUALLY WEAKEN AT MADISON TONIGHT...BUT
REMAIN GUSTY AT THE EASTERN SITES.

MARINE...

GALE WARNING REMAINS IN EFFECT UNTIL 06Z SATURDAY ACROSS THE
NEARSHORE WATERS OF LAKE MICHIGAN. A STRONG PRESSURE GRADIENT BEHIND
LOW PRESSURE TO THE EAST WILL ALLOW FOR STRONG NORTH WINDS TO OCCUR
TODAY INTO THIS EVENING. FREQUENT GUSTS OF 35 TO 45 KNOTS ARE
EXPECTED. HIGH WAVES OF 10 TO 15 FEET ARE POSSIBLE DURING THIS TIME.

NORTH WIND GUSTS WILL FALL BELOW 35 KNOTS AFTER 06Z SATURDAY...BUT
REMAIN IN THE 25 TO 30 KNOT RANGE UNTIL AROUND 15Z SATURDAY. WAVES
WILL SLOWLY SUBSIDE BELOW 4 FEET BY SATURDAY EVENING. THUS...A SMALL
CRAFT ADVISORY WILL BE NEEDED AFTER THE GALE WARNING EXPIRES INTO
SATURDAY EVENING.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR WIZ051-052-059-060-
     065-066-070>072.

LM...GALE WARNING UNTIL 1 AM CDT SATURDAY FOR LMZ643>646.

&&

$$

UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...WOOD
SATURDAY THROUGH THURSDAY...COLLAR



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