River Flood Watch 9, NWS Milwaukee, WI

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1035 AM CDT MON APR 8 2013

.UPDATE...RAIN WILL WIND DOWN OVER THE NEXT COUPLE HOURS...EXITING
THE NORTHEAST BY EARLY AFTERNOON. ALREADY SEEING SOME BREAKS IN
THE CLOUDS OVER THE SOUTHWEST...SO DECREASING CLOUDS THIS
AFTERNOON STILL SEEMS REASONABLE. EXPECTING A GOOD SPREAD IN HIGH
TEMPS THIS AFTERNOON...AS THE SOUTHWEST MAY SNEAK INTO THE
60S...WHILE THE FAR NORTHEAST WILL LIKELY REMAIN STUCK IN THE 40S.

&&

.AVIATION/18Z TAFS/...RAIN WILL WIND DOWN OVER THE NEXT COUPLE
HOURS...EXITING THE NORTHEAST BY EARLY AFTERNOON. CONDITIONS WILL
IMPROVE AS THE RAIN DEPARTS...THOUGH SOME LOW CIGS STILL LINGERING
WEST INTO IOWA. DAYTIME HEATING MAY HELP TO SCATTER SOME OF
STRATUS DECK...AS WELL AS RAISE CLOUD BASES. DO EXPECT SOME
SUNSHINE IN AT LEAST THE WEST...AND ALREADY SEEING THIS ON
SATELLITE. COULD SEE A BRIEF RETURN TO VFR IN SOME
LOCATIONS...MOST LIKELY IN THE WEST.

THE NEXT APPROACHING SYSTEM WILL MOVE IN QUICKLY TONIGHT...SO
SHOULD GET SOCKED RIGHT BACK INTO THE LOW CLOUDS. MORE RAIN WITH
MAYBE A LITTLE THUNDER EXPECTED TO MOVE IN TO THE SOUTHWEST LATE
TONIGHT...THEN ACROSS THE AREA THROUGH TUESDAY MORNING...LINGERING
INTO THE AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 406 AM CDT MON APR 8 2013/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.

MODELS IN MUCH BETTER AGREEMENT WITH RELATIVELY BRIEF BUT INTENSE
PERIOD OF RAIN WITH POTENT SHORT WAVE QUICKLY CROSSING THE REGION
IN ZONAL FLOW THIS MORNING. STILL SEEING TWO QPF MAXES...ONE TO
THE NORTH AND ANOTHER TO THE SOUTH...WHICH MODELS HAVE SHIFTED
MORE INTO THE SRN CWA THAN 24 HOURS AGO.

WILL TIME MAIN AREA OF PCPN ACROSS CWA WITH LAYER Q-VECTOR
CONVERGENCE MAXIMA....WITH LIFT AIDED BY STRENGTHENING UPPER LEVEL
DIVERGENCE OVER SRN WI/NRN IL AROUND 12Z. IN ADDITION...RIGHT
ENTRANCE REGION OF JET STREAK OVER NRN LK MI COUPLES WITH LEFT
EXIT REGION OF JET STREAK DRIVING THE SHORT WAVE...AS IT TRACKS
EAST FROM NRN MO/SRN IA TO NE IL/NW IN BY 18Z.

LAPSE RATES OF 7 TO 8C/KM BETWEEN 850 MB AND 650 MB WILL LEAD TO
SOME ELEVATED CAPE AND POTENTIAL FOR ISOLATED THUNDER. 700 MB
OMEGA CLEARS THE REGION BY 18Z WITH SUBSIDENCE AND MID LEVEL
DRYING. WILL CONTINUE SLIGHT CHANCE POPS INTO THE AFTERNOON THOUGH
AS LOW-LEVEL FRONTOGENESIS AND SOME CONVERGENCE LINGERS OVER
REGION WITH SURFACE TO 850 MB BAROCLINIC ZONES. GFS PRODUCES A FEW
HUNDREDTHS OF AN INCH OF QPF THIS AFTERNOON. SHARP CONTRAST WITH
HIGH TEMPS TODAY ON EITHER SIDE OF THE STATIONARY BOUNDARY...WITH
MID 60S IN THE SOUTHWEST...BUT ONLY MID 40S IN THE NORTHEAST.

NEUTRAL TEMP ADVECTION INTO THE EVENING...WITH WAA AND MID LEVEL
MOISTENING BETWEEN 06Z AND 12Z TUE AS FLOW BACKS AHEAD OF
DEEPENING WESTERN TROUGH THAT CLOSES OFF OVER THE 4-CORNERS REGION
BY 12Z TUESDAY. THIS WILL HOLD TEMPS UP...ESPECIALLY IN THE
SOUTHWEST CWA...WITH INCREASING POPS FROM SW TO NE...WITH RAIN
BECOMING LIKELY IN THE SW BY 12Z TUE.

TUESDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO
HIGH.

SHORT TERM MODELS ARE COMING INTO BETTER AGREEMENT WITH SYSTEM
MOVING THROUGH THE REGION DURING THIS PERIOD. FOLLOWED THE
GFS/ECMWF TRENDS VERSUS THE NORTHERLY TRACK OF THE NAM. GFS/ECMWF
SHOW LOW PRESSURE MOVING FROM THE SOUTHERN HIGH PLAINS AT 12Z
TUESDAY TO EAST CENTRAL/NORTHEAST MISSOURI AT 12Z WEDNESDAY. IT
MOVES TO EAST CENTRAL ILLINOIS/WEST CENTRAL INDIANA AT 12Z
THURSDAY...THEN WELL EAST OF THE AREA BY 12Z FRIDAY. SOUTHWEST
FLOW AT 500MB LINGERS TUESDAY INTO WEDNESDAY NIGHT...BEFORE 500MB
LOW SHIFTS NORTHEAST INTO THE REGION THURSDAY...BEFORE OPENING AND
SLIDING OFF TO THE EAST THURSDAY NIGHT.

FOR THE TUESDAY THROUGH WEDNESDAY PERIOD...SURFACE WARM FRONT
WILL SLOWLY RETREAT SOUTHWARD ACROSS NORTHERN ILLINOIS AS THE
SURFACE LOW APPROACHES. FOCUSED WARM AIR ADVECTION AND CONVERGENCE
AT 850MB...COMBINED WITH 850MB TO 700MB FRONTOGENESIS
RESPONSE...SHOULD BRING ROUNDS OF MODERATE RAIN SHOWERS DURING
THIS TIME. AREA FORECAST SOUNDINGS FROM GFS DOES SHOW WEAK
INSTABILITY...SO KEPT SLIGHT CHANCES FOR THUNDER GOING.

QPF TOTALS OF AROUND 1.75 INCHES IN THE FAR NORTHERN
COUNTIES...TO AROUND 2.50 INCHES IN THE SOUTHERN COUNTIES...ARE
FORECAST TUESDAY THROUGH WEDNESDAY NIGHT. THIS WILL LEAD TO RISING
RIVER STAGES AND SOME MINOR FLOODING ON THE USUAL QUICK RESPONDING
RIVERS. NORTH/NORTHEAST LOW LEVEL FLOW WILL KEEP THE AREA COOL
DURING THIS TIME...ESPECIALLY NEAR THE LAKE.

MAIN ISSUE WILL BE PRECIPITATION TYPES WEDNESDAY NIGHT AND
THURSDAY ACROSS THE AREA. AREA FORECAST SOUNDINGS FROM THE GFS
ACROSS ALL BUT THE FAR SOUTHEASTERN COUNTIES WEDNESDAY NIGHT
INDICATE COLDER AIR SHIFTING INTO THE AREA. THIS LEAVES A WARM
LAYER IN THE 4000 TO 9000 FOOT ABOVE GROUND LEVEL RANGE. ICE
CRYSTALS ARE LOST ABOVE THIS LAYER. TOP DOWN METHOD FOR
PRECIPITATION TYPES LEAD TO RAIN WITH TEMPERATURES ABOVE FREEZING
AT THE SURFACE...AND FREEZING RAIN WITH TEMPERATURES AT OR BELOW
FREEZING.

TEMPERATURES ARE EXPECTED TO FALL TO OR BELOW FREEZING ACROSS ALL
BUT THE FAR SOUTHEAST COUNTIES LATER WEDNESDAY NIGHT. FAIRLY
STRONG 850MB TO 700MB AND 700MB TO 500MB FRONTOGENESIS RESPONSE
SHIFT THROUGH THE WESTERN AND NORTHWESTERN COUNTIES BETWEEN 06Z
AND 12Z THURSDAY. THUS...POTENTIAL FOR A FREEZING RAIN EVENT TO
OCCUR. FOR NOW...WILL GO WITH RAIN AND FREEZING RAIN WEDNESDAY
NIGHT IN THE NORTH AND WEST...AND KEEP CHANCE OF SNOW LATER
WEDNESDAY NIGHT. EXPANDED THIS AREA SOUTHEAST LATER IN THE
NIGHT...WITH A CHANCE OF LIGHT FREEZING RAIN IN THE FAR
SOUTHEAST COUNTIES. THIS PERIOD WILL HAVE TO BE WATCHED AS WE GET
CLOSER TO THE EVENT.

FRONTOGENESIS RESPONSE MENTIONED ABOVE MOVES NORTHEAST OUT OF THE
AREA THURSDAY MORNING...THOUGH 500MB LOW SHIFTS NORTHEAST INTO THE
REGION. COLDER AIR ALOFT SHOULD ALLOW PRECIPITATION TO BECOME ALL
LIGHT TO MODERATE SNOW ACROSS ALL BUT THE FAR SOUTHEAST COUNTIES
THURSDAY MORNING...WITH MILDER TEMPERATURES ALLOWING FOR A MIX IN
THE NORTHERN COUNTIES AND RAIN IN THE SOUTHERN COUNTIES THURSDAY
AFTERNOON.

THE FAR SOUTHEAST WILL BE SOMEWHAT WARMER ALOFT AND AT THE SURFACE
THURSDAY MORNING...WHICH MAY LEAD TO MORE OF A MIX OF RAIN AND
SNOW...WITH SOME LIGHT FREEZING RAIN POSSIBLE. WILL TREND FORECAST
FOR THURSDAY THIS WAY. COULD SEE A FEW INCHES OF WET AND HEAVY
SNOW ACCUMULATION...ESPECIALLY IN THE NORTHERN AND WESTERN
COUNTIES. PRECIPITATION SHOULD BECOME LIGHT AND END BY LATER
THURSDAY NIGHT.

FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS MEDIUM.

ECMWF AND GFS ARE IN FAIR AGREEMENT WITH TRENDS DURING THIS
PERIOD. THEY SHOW 500MB LOW SHIFTING EAST OF THE REGION
FRIDAY...WITH WEAK 500MB RIDGING SHIFTING EAST THROUGH THE REGION
FRIDAY NIGHT THROUGH SATURDAY NIGHT. SURFACE HIGH PRESSURE SLIDES
EAST THROUGH THE REGION DURING THIS TIME...WHICH SHOULD BRING
QUIET WEATHER. TEMPERATURES WILL REMAIN ON THE COOL SIDE THROUGH
THIS PERIOD.

THEY THEN BRING LOW PRESSURE FROM THE NORTHERN PLAINS INTO
NORTHERN MINNESOTA SUNDAY. WARM AIR ADVECTION TAKES HOLD OF THE
AREA...WITH MOISTURE MOVING INTO THE REGION AS WELL. THIS LEADS TO
QPF WITH RAIN OCCURRING ACROSS THE REGION. THIS SHOULD ALSO LEAD
TO MILDER TEMPERATURES. USED CONSENSUS POPS AND TEMPERATURES FOR
SUNDAY.

AVIATION/12Z TAFS/...

ADDED WIND SHEAR FOR A FEW HOURS TO THE TAFS AS 2K FT WINDS HAVE
INCREASED TO 35 TO 40 KTS OVER WRN CWA...AND WILL PUSH EAST AHEAD
OF SHORT WAVE THROUGH THE EARLY MORNING. THE RAIN WITH THIS WAVE
WILL DROP CIGS/VSBYS TO MVFR LEVELS...WITH IFR POSSIBLE WITH THE
HEAVIER RAIN. LOOKS AS IF STEADY PCPN WILL END AT KMSN AROUND
16Z...BETWEEN 17Z AND 18Z AT KUES AND 18Z AT KMKE AND KENW.

WILL SEE A RETURN TO VFR BEHIND THE WAVE. SOUNDINGS SHOW SOME
INSTABILITY THIS AFTERNOON...WITH GFS PRODUCING SOME QPF WITH
STATIONARY FRONT LINGERING IN THE REGION. MORE OF A VICINITY
SHOWER SITUATION AND WILL LEAVE OUT FOR NOW.

PCPN RETURNS LATE TONIGHT WITH MID-LEVEL WARM AIR ADVECTION AS
FLOW BACKS AHEAD OF DEEP WESTERN WAVE. MOST LIKELY TO REACH KMSN
BY 12Z TUE...BUT CANT RULE OUT EASTERN SITES SEEING LIGHT PCPN.
MOS GUIDANCE HAS IFR CIGS/VSBYS WITH DEVELOPING EAST WINDS AT
EASTERN SITES...WITH IFR CIGS WITH THE PCPN AT KMSN.

MARINE...

STRENGTHENING EASTERLY WINDS AHEAD OF SURFACE LOW REFLECTION OF
500 MB WAVE CROSSING THE REGION WILL REMAIN LOW ENOUGH TO KEEP
WAVES BELOW SMALL CRAFT CRITERIA. BETTER CHANCE OF SMALL CRAFT
CONDITIONS WILL COME BRIEFLY TUESDAY AFTERNOON/EVENING...AND AGAIN
LATE WEDNESDAY AFTERNOON THROUGH THURSDAY NIGHT. NO HEADLINE YET
AS BETTER CHANCE COMES BEYOND CURRENT FORECAST.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

UPDATE...DDV
TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...WOOD

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1044 AM CDT MON APR 8 2013

WIZ046-047-051-052-056>060-062>072-091100-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
1044 AM CDT MON APR 8 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS TODAY AS LOW PRESSURE
CROSSES THE AREA.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SEVERAL ROUNDS OF MODERATE RAINFALL...INCLUDING ISOLATED
THUNDERSTORMS...ARE EXPECTED THROUGH WEDNESDAY. RIVER LEVELS WILL
RISE ONCE AGAIN WITH MANY REACHING BANKFULL STAGE WITH SOME
REACHING MINOR FLOOD STAGE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED IN THE NEXT SEVEN DAYS.

LMZ643>646-091100-
SHEBOYGAN TO PORT WASHINGTON WI-
PORT WASHINGTON TO NORTH POINT LIGHT WI-
NORTH POINT LIGHT TO WIND POINT WI-
WIND POINT WI TO WINTHROP HARBOR IL-
1044 AM CDT MON APR 8 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

WINDS MAY GUST TO 30 KNOTS AT TIMES FROM WINTHROP HARBOR TO NORTH
POINT LIGHT INTO EARLY AFTERNOON.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

STRONG LOW PRESSURE WILL SLOWLY MOVE FROM THE SOUTHERN GREAT PLAINS
TO THE LOWER GREAT LAKES THIS WEEK. BRISK NORTHEAST WINDS AND HIGH
WAVES ARE EXPECTED FROM TUESDAY AFTERNOON THROUGH THURSDAY NIGHT.
ISOLATED THUNDERSTORMS WILL ALSO OCCUR AT TIMES FROM TODAY THROUGH
WEDNESDAY.

REM/DDV
WWW.WEATHER.GOV/MKX