Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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000
FXUS63 KMKX 011044 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
544 AM CDT WED APR 1 2015

.TODAY...FORECAST CONFIDENCE HIGH

500 MB RIDGE AXIS WILL BE CENTERED OVER STATE AT 18Z TODAY AHEAD OF
SHORT WAVE TROUGH DIGGING INTO THE NORTHERN PLAINS BY LATE THIS
AFTERNOON. SURFACE RIDGE IS SLOWLY SHIFTING EAST WITH GUSTY WINDS
DEVELOPING IN TIGHTENING GRADIENT AHEAD OF SURFACE LOW THAT DEEPENS
AS IT TRACKS THROUGH THE NORTHERN PLAINS/CANADIAN PRAIRIE PROVINCES
THEN CONSOLIDATES OVER EASTERN MANITOBA TONIGHT.

WARM ADVECTION BRINGS 925 MB TEMPS UP TO +16C IN THE WEST AND 15C IN
THE EAST BY 00Z. THIS YIELDS HIGHS IN THE LOWER 70S FAR WEST...AND
MID 60S IN CENTRAL SECTIONS WITH ONSHORE SERLY WINDS HOLDING HIGHS
IN THE 45 TO 50 DEGREE RANGE FAR EAST TO AROUND 60 IN THE KETTLE
MORAINE. IF MIXING UP TO 40+ KT WINDS AROUND 900 MB ON THE FORECAST
SOUNDINGS OCCURS LATE IN THE AFTERNOON WEST...IT COULD BRING A FEW
GUSTS CLOSE TO WIND ADVISORY CRITERIA. WILL HAVE TO BE MONITORED.

.TONIGHT...FORECAST CONFIDENCE HIGH

ALL MODELS ARE BRINGING PCPN INTO THE WRN CWA BETWEEN 00Z AND 06Z
WITH A LEAD IMPULSE...WITH THE GFS FARTHEST EAST WITH QPF...THEN
BRING STRONGER SHORT WAVE ACROSS THURSDAY MORNING.

STRONG WARM AIR ADVECTION ON STRONG LOW-LEVEL JET WILL KEEP
CONVECTION ELEVATED TONIGHT WITH STEEP LAPSE RATES ABOVE 800 MB.
HOWEVER ELEVATED CAPE DOES NOT INCREASE UNTIL 03Z AND AFTER WITH
BETTER 850-700 MB MOISTURE ADVECTION AHEAD OF THE MID-LEVEL TROUGH.
WILL TRIM BACK BEGINNING OF QPF UNTIL BETTER ELEVATED CAPE COMES
INTO FORECAST AREA. NOT EXPECTING ANY SEVERE WITH DEVELOPING
INVERSION PREVENTING MUCH INTRUSION OF STRONG WINDS ALOFT DOWN TO
THE SURFACE. COULD NOT RULE OUT A FEW HAIL STONES. SPC DAY 1 OUTLOOK
HAS KEPT MARGINAL RISK OF SEVERE BACK TO THE WEST...JUST CLIPPING
THE FAR WEST-CENTRAL PORTION OF THE STATE.

NOT MUCH OF A DROP OFF IN TEMPS TONIGHT WITH OCCLUDED FRONT/SURFACE
TROUGH CENTERED OVER CWA AT 12Z THURSDAY.

.THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM

THE COLD FRONT WILL CLEAR THE SOUTHEAST FORECAST AREA BY LATE THURSDAY
MORNING. SHOWERS CAN BE EXPECTED AS THE FRONT MOVES THROUGH.
SEEING A LITTLE ELEVATED INSTABILITY LINGERING THURSDAY MORNING...SO
KEPT THUNDER MENTION GOING.

HAVE SOME LOW POPS IN THE SOUTH FRIDAY...AS THE ECMWF AND CANADIAN
CLIP THE SOUTHEAST WITH SOME PRECIP. THE GFS AND NAM REMAIN FARTHER
SOUTH AND DRY FOR THIS PERIOD.

TEMPS WILL BE COOLER...BUT STILL ABOVE NORMAL THURSDAY. BELOW
NORMAL TEMPS ARE THEN EXPECTED FRIDAY.

.SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...LOW

SHOULD BE DRY SATURDAY...WITH SOUTHERN WISCONSIN SITTING BETWEEN
HIGH PRESSURE TO THE SOUTH AND A PASSING LOW TO THE NORTH. COULD
THEN SEE SOME PRECIP AT TIMES FROM SATURDAY NIGHT INTO MONDAY...AS
A SERIES OF SYSTEMS MOVE THROUGH A MAINLY STALLED FRONTAL ZONE.
THERE REMAINS A BIT OF UNCERTAINTY WITH THIS PORTION OF THE
FORECAST DUE TO SIGNIFICANT MODEL DIFFERENCES IN FRONTAL PLACEMENT
AND THUS TEMPS AND PRECIP CHANCES. IF THE FRONT SNEAKS FARTHER
NORTH AS IN THE GFS...WOULD EXPECT MUCH MILDER TEMPS AND A BETTER
CHANCE FOR THUNDER. THE SOUTHERN ECMWF WOULD RESULT IN PERSISTENT
WINDS OFF THE LAKE...COOLER TEMPS...AND LESS INSTABILITY.
CONTINUED THE DOWN THE MIDDLE APPROACH BETWEEN THE VARIOUS MODEL
SOLUTIONS FOR NOW.

.FIRE WEATHER...

AFTERNOON WINDS AND LOWER DEW POINTS HELPING TO PUSH CONDITIONS TO
NEAR-CRITICAL LEVELS TODAY. HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
ARE MARGINAL AND TEMPERATURES AND FUEL MOISTURE LEVELS WILL BE BELOW
WARNING CRITERIA SO WILL HANDLE MENTION IN FIRE WEATHER DISCUSSION
AND HWO FOR NOW. OFFICES TO THE WEST WILL BE CLOSER TO HEADLINE
LEVELS WITH STRONGER WINDS...HIGHER TEMPERATURES AND LOWER RELATIVE
HUMIDITY LEVELS.

.AVIATION/12Z TAFS/...

VFR CONDITIONS THROUGH THE DAY INTO TONIGHT...THOUGH GUSTY WINDS
WILL DEVELOP THROUGH THE DAY WITH APPROACHING LOW PRESSURE FROM
THE NORTHERN PLAINS. LOW-LEVEL WIND SHEAR KICKS IN THIS EVENING AS
STRONG SOUTH TO SOUTHWEST WINDS OVER A LOW-LEVEL INVERSION REACH
45 TO 50 KNOTS WITH SURFACE WINDS AROUND 15 KTS.

A WEAK COLD FRONT/SURFACE TROUGH EXTENDING SOUTH INTO THE STATE
FROM THE LOW AS IT CROSSES SOUTHERN CANADA WILL BE THE FOCUS FOR
SHOWERS AND ELEVATED THUNDERSTORMS...MAINLY AFTER 03Z AT KMSN AND
AFTER 06Z AT EASTERN TAF SITES. LOOK FOR MVFR CIGS AND VSBYS WITH
THE SHOWERS AND STORMS FOR THE END OF THE FORECAST PERIOD.

.MARINE...ISSUED A SMALL CRAFT ADVISORY FROM EARLY THIS EVENING
THROUGH MID-MORNING THURSDAY. STRENGTHENING SOUTHEAST TO SOUTH
WINDS IN TIGHTENING PRESSURE GRADIENT BETWEEN DEPARTING RIDGE OF
HIGH PRESSURE AND DEEPENING LOW PRESSURE OVER THE NORTHERN PLAINS
WILL REACH SMALL CRAFT LEVELS BY 00Z AND CONTINUE INTO THURSDAY
MORNING. LOW-LEVEL INVERSION OVER THE COOL WATERS OF THE LAKE
PREVENTING EVEN STRONGER WINDS FROM MIXING DOWN. WAVES WILL BUILD
AS WELL WITH THE HIGHER WAVES NORTH OF MILWAUKEE. WINDS SHIFT
SOUTHWEST THEN SOUTH WITH WEAK COLD FRONT/SURFACE TROUGH PASSAGE
EARLY THURSDAY MORNING...WITH WAVE HEIGHTS FALLING BELOW CRITERIA
BY MID-MORNING.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM CDT
     THURSDAY FOR LMZ643>646.

&&

$$

TODAY/TONIGHT AND AVIATION/MARINE...REM
THURSDAY THROUGH TUESDAY...DDV



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