Dense Fog in Wisconsin, March 25, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
316 PM CDT SAT MAR 24 2007

.DISCUSSION...FORECAST FOCUS ON COMPLEX WEATHER PATTERN FOR NEXT
48 HOURS.

.SHORT TERM...HAVE PULLED BACK ON TIMING OF NIGHTTIME
PRECIPITATION AS NORTHWARD MOVEMENT OF FRONTAL BOUNDARY FROM
EASTERN NEBRASKA TO WEST CENTRAL ILLINOIS SLOWED BY CONVECTION
OVER IOWA. ALSO MIDDLE AND UPPER LEVEL RIDGING AS PER RUC PROGS
CONTINUE TO HOLD BACK PRECIPITATION APPROACHING CWA FROM
NORTHEAST IOWA. HOWEVER PROGS EVENTUALLY BRING FRONTAL BOUNDARY
CLOSE ENOUGH TO CWA AND MIDDLE/UPPER LEVEL RIDGING BREAKS DOWN
ENOUGH TO ALLOW SHORT WAVE OVER WESTERN IOWA TO GENERATE
PRECIPITATION OVER CWA LATER TONIGHT. GUIDANCE AGAIN GENERATING
AREAS OF DENSE FOG FOR LATE TONIGHT. THIS WILL LIKELY HAPPEN AGAIN
IF APPROACHING PRECIPITATION IS DELAYED FURTHER
OVERNIGHT...ESPECIALLY OVER NORTH AND EASTERN PORTIONS OF CWA.
HOWEVER WILL ONLY MENTION AREAS OF FOG IN BODY OF FORECAST AS
BELIEVE THE COMBINATION OF ARRIVING RAIN AND ENOUGH STIRRING OF
LOW LEVEL WINDS WILL PREVENT DENSE FOG FORMATION.

.LONG TERM...PROGS IN VERY GOOD AGREEMENT IN ALLOWING A FAIRLY
QUIET PERIOD OF WEATHER DURING THE DAYTIME HOURS SUNDAY. RESIDUAL
MORNING CONVECTION WILL RAPIDLY EXIT CWA. EXPECT SOME BREAKS IN
CLOUDS WHICH WILL ALLOW MOIST AIRMASS OVER CWA TO BECOME MORE
UNSTABLE WITH TIME. NOT MUCH ARGUMENT WITH SPC MODERATE/SLIGHT
RISK FOR SEVERE FOR CWA WITH BEST TIMING EXPECTED IN THE MIDDLE TO
LATE AFTERNOON IN THE WEST AND OVER THE ENTIRE CWA THROUGH
MIDNIGHT. CRAS MODEL REFLECTS INITIAL TIMING OF CONVECTION WITH
COOLING CLOUD TOPS AND SQUALL LINE DEVELOPMENT NEAR MISSISSIPPI
RIVER AROUND 21Z SUNDAY. HAVE INCLUDED SEVERE AND HEAVY RAINFALL
WORDING IN ZONES AS SEVERAL SEVERE WEATHER PARAMETERS FOCUS OVER
CWA. AMONG PARAMETERS INCLUDES 0-1KM EHI OF 1-2, 0-6KM BULK SHEAR
50-60 KNOTS, MLCAPE OF 1200-1700 J/KG, 700-500 MB LAPSE RATES
APPROACHING 7C/KM.

.LONG LONG TERM...WEAK HIGH PRESSURE ALLOWS MONDAY TO BE A QUIET
WEATHER DAY...BUT THEN ANOTHER WET AND UNSETTLED PERIOD OF WEATHER
BEGINS LATE MONDAY NIGHT AND LASTS THROUGH FRIDAY.

&&

.AVIATION...BRIEF BUBBLE OF HIGH PRES SCOURING OUT LOWER LEVELS A
BIT THIS AFTN. HOWEVER CONCERN IS HOW EXTENSIVE FOG WILL GET TNGT.
WITH BOUNDARY PROGGD TO MOVE BACK TO THE NORTH TNGT WILL INCREASE AT
LEAST SOME CONFIDENCE IN MOISTURE ADVECTION FAVORABLE OF FOG
FORMATION. WHAT CONCERNS ME THOUGH IS THE WIND FIELDS ARE EXPECTED
TO BE A BIT SREONGER THAN LAST NIGHT AND POSSIBLE CONVECTION ASSOC
WITH APPCH WRM FNT....WHICH LESSENS CONFIDENCE. HOWEVER ANALYSIS OF
BUFKIT SOUNDINGS SHOWS STRONG INVERSION DEVELOPING IN THE LOWEST
LEVELS WHICH LEADS TO NEAR SATURATED CONDITIONS RIGHT AT THE
SURFACE. FOR NOW WILL NOT BUCK THE CONSENSUS OF THE MET/MAV/FWC MOS
AND GO WITH BRINGING BACK THE VLIFR CIGS/VSBYS NEAR AND AFTER 6Z.

&&

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

ZAJDEL/10

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
650 PM CDT SAT MAR 24 2007

WIZ046-047-051-052-056>060-062>072-251000-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
650 PM CDT SAT MAR 24 2007

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

.DAY ONE...TONIGHT

A FLOOD WARNING REMAINS IN EFFECT FOR THE FOX RIVER AT NEW MUNSTER
AND THE ROCK RIVER AT AFTON.

THUNDERSTORMS WILL BE LIKELY TONIGHT. THE THUNDERSTORMS ARE EXPECTED
TO REMAIN BELOW SEVERE LEVELS.

WATCH OUT FOR AREAS OF DENSE FOG NEAR LAKE MICHIGAN TONIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF
SOUTH CENTRAL WISCONSIN INCLUDING THE MONTELLO...GREEN
LAKE...REEDSBURG AND PORTAGE AREAS SUNDAY AFTERNOON AND SUNDAY
NIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE REMAINDER
OF SOUTH CENTRAL AND SOUTHEAST WISCONSIN SUNDAY AFTERNOON AND
SUNDAY NIGHT.

STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN SUNDAY AFTERNOON AND SPREAD
EAST DURING THE EVENING.

THE MAIN SEVERE WEATHER RISKS WILL BE LARGE HAIL IN EXCESS OF ONE
INCH AND DAMAGING WIND GUSTS IN EXCESS OF 60 MPH. ISOLATED TORNADOES
WILL BE POSSIBLE...ESPECIALLY IN THE AREA COVERED BY THE MODERATE
RISK.

BRIEF HEAVY RAINFALL OF ONE HALF INCH TO THREE QUARTERS INCH
SUNDAY NIGHT MAY RESULT IN SEVERAL RIVERS RISING TO ABOVE BANKFUL
OR FLOOD STAGE ON MONDAY...AND MINOR STREET FLOODING.

THE THREAT FOR THUNDERSTORMS CONTINUES MONDAY THROUGH FRIDAY OF
NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED SUNDAY AFTERNOON AND EVENING.

LMZ643>646-665-251000-
SHEBOYGAN TO PORT WASHINGTON-
PORT WASHINGTON TO NORTH POINT LIGHTHOUSE-
NORTH POINT LIGHTHOUSE TO WIND POINT-
WIND POINT TO WINTHROP HARBOR ILLINOIS-
WISCONSIN ADJACENT OPEN WATERS OF LAKE MICHIGAN TO MID LAKE-
650 PM CDT SAT MAR 24 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...TONIGHT

THUNDERSTORMS ARE LIKELY TONIGHT AS WELL AS AREAS OF DENSE FOG.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SMALL CRAFT ADVISORY CONDITIONS MAY BE REACHED SUNDAY AFTERNOON
AND SUNDAY NIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SUNDAY NIGHT. THESE
THUNDERSTORMS MAY PRODUCE DAMAGING WIND GUSTS AND LARGE HAIL.

THUNDERSTORMS WILL BE POSSIBLE MONDAY THROUGH FRIDAY.

WWW.WEATHER.GOV/MKX