Severe Thunderstorm Warning 5, NWS Chicago, IL

855 
WWUS53 KLOT 040326
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1026 PM CDT SUN APR 3 2011

ILC063-093-099-040415-
/O.CON.KLOT.SV.W.0005.000000T0000Z-110404T0415Z/
GRUNDY IL-KENDALL IL-LA SALLE IL-
1026 PM CDT SUN APR 3 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR LA SALLE...
KENDALL AND GRUNDY COUNTIES UNTIL 1115 PM CDT...

AT 1023 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PING PONG BALL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM LELAND TO 5 MILES NORTH OF LA
SALLE TO HENNEPIN...MOVING EAST AT 55 MPH.

LOCATIONS IMPACTED INCLUDE...
  OGLESBY...SERENA...OTTAWA...STREATOR...MARSEILLES...SENECA...
  MORRIS...UTICA...SOMONAUK...TONICA...SHERIDAN...NAPLATE...NEWARK...
  GRAND RIDGE...MAZON...COAL CITY...BRACEVILLE...GARDNER...CEDAR
  POINT AND LOSTANT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

&&

LAT...LON 4165 8828 4112 8825 4111 8915 4161 8916
TIME...MOT...LOC 0326Z 270DEG 47KT 4157 8879 4142 8901
          4126 8922
WIND...HAIL 60MPH 1.50IN

$$

MDB/KJB

521 
WWUS53 KLOT 040333
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1033 PM CDT SUN APR 3 2011

ILC063-093-099-040415-
/O.CON.KLOT.SV.W.0005.000000T0000Z-110404T0415Z/
GRUNDY IL-KENDALL IL-LA SALLE IL-
1033 PM CDT SUN APR 3 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR LA SALLE...
KENDALL AND GRUNDY COUNTIES UNTIL 1115 PM CDT...

AT 1027 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PING PONG BALL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM LELAND TO 5 MILES NORTH OF UTICA
TO GRANVILLE...MOVING EAST AT 55 MPH.

IN ADDITION...AT 1028 PM CDT GOLF BALL HAIL WAS REPORTED ON 
INTERSTATE 80 3 MILES NORTHWEST OF PERU WITH THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
  SERENA...OTTAWA...STREATOR...MARSEILLES...SENECA...MORRIS...
  SHERIDAN...TONICA...NAPLATE...NEWARK...GRAND RIDGE...MAZON...COAL
  CITY...BRACEVILLE...GARDNER...LOSTANT...MILLINGTON...LEONORE...
  KANGLEY AND LISBON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

&&

LAT...LON 4165 8828 4112 8825 4111 8915 4161 8916
TIME...MOT...LOC 0332Z 270DEG 47KT 4156 8868 4141 8891
          4126 8912
WIND...HAIL 60MPH 1.50IN

$$

MDB/KJB

685 
WWUS53 KLOT 040351
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1051 PM CDT SUN APR 3 2011

ILC063-093-099-040415-
/O.CON.KLOT.SV.W.0005.000000T0000Z-110404T0415Z/
GRUNDY IL-KENDALL IL-LA SALLE IL-
1051 PM CDT SUN APR 3 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EASTERN LA
SALLE...KENDALL AND GRUNDY COUNTIES UNTIL 1115 PM CDT...

AT 1046 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM NEWARK TO 5 MILES NORTH OF
MARSEILLES TO OTTAWA...MOVING EAST AT 55 MPH. STRONG WINDS FROM THIS 
STORM ARE EXPECTED TO EXTEND ACROSS SOUTHERN LA SALLE AND GRUNDY 
COUNTIES TO THE SOUTH OF THE PARENT THUNDERSTORM. THEREFORE...STRONG 
WINDS MAY OCCUR OUTSIDE OF PRECIPITATION.

LOCATIONS IMPACTED INCLUDE...
  MARSEILLES...SENECA...MORRIS...MAZON...GARDNER...COAL CITY...
  BRACEVILLE...RANSOM...LISBON...KINSMAN...VERONA...CARBON HILL...
  SOUTH WILMINGTON AND EAST BROOKLYN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

&&

LAT...LON 4111 8902 4162 8890 4165 8828 4112 8825
TIME...MOT...LOC 0349Z 270DEG 47KT 4157 8858 4140 8861
          4135 8871
WIND...HAIL 60MPH 1.00IN

$$
MDB/KJB

638 
WWUS53 KLOT 040404
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1104 PM CDT SUN APR 3 2011

ILC063-093-099-040415-
/O.CON.KLOT.SV.W.0005.000000T0000Z-110404T0415Z/
GRUNDY IL-KENDALL IL-LA SALLE IL-
1104 PM CDT SUN APR 3 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHEASTERN
LA SALLE...SOUTHERN KENDALL AND GRUNDY COUNTIES UNTIL 1115 PM CDT...

AT 1100 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
MORRIS...MOVING EAST AT 65 MPH. STRONG WINDS FROM THIS 
STORM ARE EXPECTED TO EXTEND ACROSS SOUTHERN GRUNDY COUNTY TO THE 
SOUTH OF THE PARENT THUNDERSTORM. THEREFORE...STRONG WINDS MAY OCCUR 
OUTSIDE OF PRECIPITATION.

LOCATIONS IMPACTED INCLUDE...
  BRACEVILLE...COAL CITY...SOUTH WILMINGTON...CARBON HILL AND EAST
  BROOKLYN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS EXHIBITED SOME WEAK ROTATION. TORNADOES CAN DEVELOP
QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH ONE IS NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE... SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

&&

LAT...LON 4112 8864 4162 8865 4165 8828 4112 8825
TIME...MOT...LOC 0403Z 262DEG 58KT 4144 8836
WIND...HAIL 60MPH 1.25IN

$$

MDB/KJB

769 
WWUS53 KLOT 040417 RRA
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1117 PM CDT SUN APR 3 2011

ILC063-093-099-040427-
/O.EXP.KLOT.SV.W.0005.000000T0000Z-110404T0415Z/
GRUNDY IL-KENDALL IL-LA SALLE IL-
1117 PM CDT SUN APR 3 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LA SALLE...
SOUTHERN KENDALL AND GRUNDY COUNTIES HAS EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

LAT...LON 4112 8864 4162 8865 4165 8828 4112 8825
TIME...MOT...LOC 0404Z 262DEG 58KT 4143 8834

$$

MDB/KJB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
922 PM CDT SUN APR 3 2011

.DISCUSSION...
921 PM CDT

MESOSCALE UPDATE...

THUNDERSTORMS CONTINUE TO DEVELOP THIS EVENING IN ADVANCE OF DEEP
LOW PRESSURE SYSTEM MOVING EAST ACROSS THE REGION. STORMS
DEVELOPING ACROSS FAR NORTHERN IL AND SOUTHERN WI APPEAR TO BE
ELEVATED ABOVE STABLE BOUNDARY LAYER TO THE NORTH OF THE SURFACE
WARM FRONT WHICH STRETCHES ROUGHLY ALONG I-88 CORRIDOR ACROSS
NORTHERN IL...WHILE STORMS CROSSING THE MISSISSIPPI ARE LIKELY
ROOTED CLOSER TO THE SURFACE. THREAT FROM ELEVATED STORMS TO THE
NORTH IS MAINLY LARGE HAIL THREAT...WHILE FARTHER SOUTH INTO WARM
SECTOR THE RELATIVELY LARGE SFC TEMP-DEW POINT DEPRESSIONS AND
HIGHER LCL HEIGHTS WILL ALSO LIKELY SUPPORT SOME WIND THREAT IN
ADDITION TO HAIL. THE TORNADO THREAT APPEARS TO HAVE DECREASED
SINCE EARLIER IN THE EVENING...THUS IN AGREEMENT WITH SPC HAVE
REPLACED ORIGINAL TOR WATCH WITH A NEW SEVERE THUNDERSTORM WATCH
WHICH EXTENDS EAST ACROSS MUCH OF THE REMAINDER OF THE CWA AND
RUNS THROUGH 3 AM CDT.

RATZER

&&

.PREV DISCUSSION...
315 PM CDT

FORECAST CONCERNS FOCUS ON NEAR TERM...WITH DYNAMIC SYSTEM MOVING
ACROSS THE MIDWEST. CONVECTIVE TRENDS...SEVERE POTENTIAL...
SYNOPTIC WIND FIELD AND TEMPS ALL CLAMORING FOR ATTENTION THIS
AFTERNOON.

20Z SURFACE ANALYSIS DEPICTS DEEP LOW PRESSURE OVER NORTH CENTRAL
IOWA...WITH WARM FRONT EXTENDING EAST/SOUTHEAST ACROSS NORTHERN
ILLINOIS AND WESTERN INDIANA. AS EXPECTED...ELEVATED SHOWERS AND
THUNDERSTORMS WELL NORTH OF SURFACE BOUNDARY HAVE SHIFTED WELL OFF
TO THE NORTHEAST INTO MICHIGAN...WHILE STRONG CAPPING HAS
DEVELOPED ACROSS THE CWA BENEATH IMPRESSIVE ELEVATED MIXED LAYER
(EML). WITH WARM FRONT LIFTING NORTHEAST ACROSS AREA...TEMPS
HAVE SURGED INTO THE 70S/NEAR 80 WITH DEW POINTS IN THE LOW TO MID
50S IN THE WARM SECTOR WHILE READINGS HOVER IN THE MID 40S WITH
AN EASTERLY WIND OFF OF THE LAKE ACROSS THE FAR NORTHERN SUBURBS.
STRONG SOUTHEAST/SOUTH WINDS HAVE BEEN GUSTING TO 45 MPH AT TIMES
ACROSS THE SOUTH/SOUTHEASTERN CWA...AND THOUGH GUSTS SHOULD
GRADUALLY SLACKEN THROUGH THE LATE AFTERNOON HOURS AS BEST
PRESSURE FALLS MOVE OFF ACROSS MICHIGAN AND INDIANA...WILL ALLOW
WIND ADVISORY TO RIDE THROUGH 00Z WITH GUSTS IN 35-40 KT RANGE
STILL NOTED ACROSS EAST CENTRAL IL INTO FAR SOUTHEASTERN CWA.

COLD FRONT TRAILING LOW ACROSS CENTRAL IOWA AND NORTHWEST MISSOURI
IS EXPECTED TO BE FOCUS FOR THUNDERSTORM INITIATION VERY LATE THIS
AFTERNOON OR EARLY THIS EVENING...AS LOW LEVEL FORCING ASSOCIATED
WITH CONVERGENCE ALONG THE FRONT WILL BE NEEDED TO COMBAT STRONG
EML CAPPING ALONG WITH SOME COOLING PROVIDED BY LARGE SCALE ASCENT
WITH HEIGHT FALLS AHEAD OF AMPLIFYING LARGE SCALE TROUGH
APPROACHING FROM THE WEST. VARIOUS CONVECTION-ALLOWING HIGH RES
MODELS SUCH AS THE HRRR/4.5 KM NCEP WRF SUGGEST STORMS WILL
INITIATE ALONG FRONT OVER FAR NORTHERN MO/SOUTHEAST IA TOWARD
00Z...THEN SPREAD EAST WITH THE FRONT INTO IL THIS EVENING. GIVEN
STRENGTH OF CAPPING INVERSION WOULD EXPECT STRONGEST ACTIVITY TO
REMAIN TIED TO THE FRONT...WITH GREATEST SEVERE THREAT LIKELY
ACROSS WEST CENTRAL IL. MORE FAVORABLE DIURNAL TIMING FOR AREAS
WEST/SOUTHWEST OF CWA SUGGEST POTENTIAL FOR MORE DISCRETE STORMS
THERE...BEFORE DEVELOPING INTO A MORE LINEAR NATURE AND PUSHING
ACROSS KLOT CWA TONIGHT. MESOSCALE MODELS INDICATE STORMS MAY
BECOME ORIENTED MORE WEST/SOUTHWEST TO EAST/NORTHEAST ACROSS
SOUTHERN PORTIONS OF FORECAST AREA EARLY MONDAY MORNING WHICH MAY
SUPPORT THREAT OF LOCALLY HEAVY RAINFALL WITH PWATS IN EXCESS OF
AN INCH.

FRONT TO CONTINUE TO SAG TO THE SOUTHEAST MONDAY AS MAIN UPPER
TROUGH AXIS MOVES ACROSS AREA. GUIDANCE CONTINUES TO SQUEEZE OUT
LIGHT QPF BENEATH UPPER TROUGH AXIS SO HAVE HELD ONTO SOME CHANCE
SHOWERS POPS.

NO BIG DEVIATIONS FROM GUIDANCE IN MID/EXTENDED PERIODS WITH SO
MUCH FOCUS IN SHORT TERM TODAY. SURFACE RIDGE MOVES IN LATE
MONDAY/TUESDAY BEFORE NEXT LOW MOVES ACROSS THE MIDWEST TUESDAY
NIGHT WITH NEXT CHANCE OF PRECIP. ANOTHER SYSTEM ARRIVES LATE IN
THE WEEK IN WHAT BECOMES A MORE PROGRESSIVE PATTERN THAN OF LATE.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* POWERFUL THUNDERSTORMS MOVING ACROSS NORTHEAST IL THIS EVENING
  WITH THE POTENTIAL FOR LARGE HAIL...GUSTY WINDS AND HEAVY RAIN.
* THUNDERSTORM TIMING THIS EVENING.
* SOUTHERLY WINDS SHIFTING WEST BEHIND A COLD FRONT BY EARLY
  MONDAY MORNING.
* POTENTIAL FOR LOW MVFR OR IFR CIGS OVERNIGHT INTO MONDAY
  MORNING.
* STRONG/GUSTY NORTHWEST WINDS MONDAY. CMS

//DISCUSSION...UPDATED 00Z...

COLD FRONT MARCHING EAST ACROSS EAST CENTRAL IOWA EARLY THIS
EVENING WITH EXPLOSIVE THUNDERSTORM DEVELOPMENT ALONG THE FRONT.
ACARS SOUNDINGS STILL SHOW AN IMPRESSIVE CAP OR WARM LAYER OVER
THE TERMINALS PREVENTING THUNDERSTORM DEVELOPMENT. THIS CAP WILL
ERODE AS THE FRONT PUSHES EAST...SO EXPECT CURRENT ACTIVITY TO
CONTINUE MOVING EAST. TIMING MAY NEED TO BE TWEAKED WITH LATER
UPDATES BUT MID/LATE EVENING STILL ON TRACK.

MID LEVEL WAVE CATCHES UP WITH THE FRONT OVER THE AREA LATER
THIS EVENING AND THAT MAY SLOW THE FRONTS PROGRESS TO THE EAST/
SOUTHEAST WITH LINGERING SHOWERS NEAR OR OVER NORTHEAST IL INTO
THE EARLY MORNING HRS. AS THIS OCCURS AND THE COOLER ADVECTS INTO
THIS RAIN AND MOISTURE...EXPECT LOW CLOUDS TO DEVELOP AND HAVE
LOWERED CIGS TO 1KFT WITH IFR POSSIBLE. CIGS SHOULD LIFT MONDAY
MORNING.

EXTENSIVE CLOUD COVER ACROSS NORTHERN IL HAS PREVENT/MINIMIZED
MIXING AND NOW GRADIENT IS WEAKENING WITH THE APPROACH OF THE
SURFACE LOW. AS A RESULT...TRIMMED WIND SPEEDS/GUSTS A BIT. WINDS
WILL SHIFT TO THE WEST BEHIND THE FRONT AND THEN TO THE NORTHWEST
BY MORNING. COLD AIR ADVECTION AND MIXING WILL ALLOW NORTHWEST
WINDS TO INCREASE STEADILY MONDAY MORNING INTO THE AFTERNOON WITH
GUSTS INTO THE 25-30KT RANGE POSSIBLE. CMS

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* MEDIUM CONFIDENCE REGARDING STRENGTH/TIMING OF THUNDERSTORMS.
* LOW CONFIDENCE REGARDING WIND SPEEDS/GUSTS THIS EVENING.
* MEDIUM CONFIDENCE FOR LOW MVFR/IFR CIGS OVERNIGHT/MONDAY MORNING.
* MEDIUM CONFIDENCE REGARDING STRONG NORTHWEST WINDS MONDAY. CMS

//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...

TUESDAY...VFR.
WEDNESDAY...VFR. SLIGHT CHANCE OF SHOWERS.
THURSDAY...MVFR POSSIBLE. CHANCE OF SHOWERS. ISOLATED THUNDER.
FRIDAY...MVFR POSSIBLE. CHANCE OF SHOWERS.
SATURDAY...MVFR POSSIBLE. CHANCE OF SHOWERS AND THUNDER. CMS

&&

.MARINE...
221 PM CDT

A POTENT AREA OF LOW PRESSURE...CURRENTLY ACROSS IOWA...HAS
PRODUCED SIGNIFICANT SOUTHEASTERLY WINDS AHEAD OF IT. IN SPITE OF THE
FACT THAT WARM TEMPERATURES HAVE BEEN ADVECTING OVER THE COOL LAKE
WATERS...WINDS HAVE BEEN AROUND LOW END GALES ACROSS THE OPEN WATERS
AND ILLINOIS AND INDIANA NEAR SHORES. THEREFORE I UPDATED THE
FORECAST EARLIER TO ISSUE A GALE WARNING FOR THIS AFTERNOON. THE
WINDS SHOULD ABATE ACROSS THE LAKE BY EARLY EVENING AS THE SURFACE
LOW APPROACHES WESTERN LAKE MICHIGAN.

IT APPEARS THE WINDS WILL PICK UP AGAIN TOMORROW AFTERNOON AS THE
WINDS TURN NORTHWEST AND TRANSPORT COLDER AIR ACROSS THE LAKE.
BUFFER SOUNDINGS INDICATE AROUND 40 KT WITHIN THE MIXING LAYER
TOMORROW AFTERNOON AND EVENING. IT APPEARS THE BEST CHANCE FOR GALE
FORCE WINDS WILL OCCUR LATE TOMORROW AFTERNOON THROUGH EARLY TUESDAY
MORNING. GIVEN THAT THIS IS STILL A GOOD 24 HOURS OUT...I DECIDED TO
HOLD OFF ON A WARNING AND WILL LET THE OVERNIGHT SHIFT GET ANOTHER
LOOK AT IT BEFORE UPGRADING TO A WARNING.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
     LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...11 AM MONDAY TO 2 PM
     TUESDAY.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
428 PM CDT SUN APR 3 2011

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
042130-
WINNEBAGO-BOONE-MCHENRY-LAKE ILLINOIS-OGLE-LEE-DE KALB-KANE-
DUPAGE-COOK-LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-
IROQUOIS-FORD-LAKE INDIANA-PORTER-NEWTON-JASPER-BENTON-
428 PM CDT SUN APR 3 2011 /528 PM EDT SUN APR 3 2011/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  THUNDERSTORMS...SOME MAY BE SEVERE WITH THE POTENTIAL TO
  PRODUCE: CLOUD TO GROUND LIGHTNING. LARGE HAIL OF 1 TO 2 INCHES.
  STRONG DAMAGING WIND GUSTS IN EXCESS OF 60 MPH. LOCALLY HEAVY
  RAINFALL. ISOLATED TORNADOES.

  AREAS AFFECTED AND TIMING:

  THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A COLD FRONT ACROSS
  SOUTHEAST IOWA VERY LATE THIS AFTERNOON OR EARLY THIS EVENING...
  AND THEN SPREAD EAST INTO ILLINOIS DURING THE EVENING HOURS AND
  INTO NORTHWEST INDIANA DURING THE LATE EVENING AND EARLY
  OVERNIGHT HOURS. THUNDERSTORMS WOULD LIKELY AFFECT NORTH CENTRAL
  ILLINOIS AFTER 7 OR 8 PM...REACHING NORTHEAST ILLINOIS AFTER 9
  OR 10 PM AND NORTHWEST INDIANA TOWARD MIDNIGHT.

  DISCUSSION:

  DEEP LOW PRESSURE OVER NORTHERN IOWA WILL TRACK NEAR THE
  ILLINOIS WISCONSIN BORDER TO SOUTHERN LAKE MICHIGAN THIS
  EVENING...AND TO CENTRAL LOWER MICHIGAN BY MONDAY MORNING. VERY
  WARM AND MOIST AIR WILL CONTINUE TO SPREAD NORTH ACROSS THE
  OUTLOOK AREA AHEAD OF THE LOW THIS EVENING. THUNDERSTORMS ARE
  EXPECTED TO DEVELOP ACROSS SOUTHEAST IOWA AND NORTHERN MISSOURI
  ALONG A COLD FRONT TRAILING FROM THE LOW TOWARD EVENING...AND
  WILL MOVE INTO NORTHERN ILLINOIS DURING THE EVENING HOURS AND
  INTO INDIANA OVERNIGHT. THE COMBINATION OF WARM AND MOIST LOW
  LEVEL AIR...AND STRONG WINDS BOTH AT THE SURFACE AND ALOFT WILL
  SUPPORT THE DEVELOPMENT OF SEVERE STORMS...THOUGH WARM AIR ALOFT
  WILL LIKELY LIMIT THE DEVELOPMENT OF THUNDERSTORMS EXCEPT NEAR
  THE COLD FRONT. THEREFORE THE GREATEST POTENTIAL FOR SEVERE
  WEATHER IS EXPECTED TO BE OVER WESTERN PORTIONS OF ILLINOIS AND
  THE WESTERN PORTIONS OF THE OUTLOOK AREA. STORMS MAY INITIALLY
  BE MORE DISCRETE AND MAY POSE A THREAT OF VERY LARGE
  HAIL...DAMAGING WINDS AND EVEN ISOLATED TORNADOES DURING THE
  EARLY TO MID EVENING HOURS. STORMS SHOULD EVENTUALLY MERGE INTO
  A SQUALL LINE...WITH THE MAIN THREAT SHIFTING TO DAMAGING WIND
  AS THE LINE PUSHES ACROSS THE EASTERN PORTIONS OF THE OUTLOOK
  AREA OVERNIGHT. SOME DECREASE IN INSTABILITY OVERNIGHT WILL
  LIKELY RESULT IN SOME WEAKENING OF STORMS AS THEY MOVE TO THE
  EAST. THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WILL ALSO
  INCREASE OVERNIGHT...PARTICULARLY ACROSS SOUTHERN PARTS OF THE
  OUTLOOK AREA.

  GUSTY SOUTH WINDS AHEAD OF THE LOW WILL ALSO PRODUCE GUSTS UP TO
  45 MPH PRIOR TO SUNSET THIS EVENING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THERE IS A CHANCE OF THUNDERSTORMS MONDAY MORNING ACROSS
SOUTHEASTERN PORTIONS OF THE OUTLOOK AREA...MAINLY SOUTHEAST OF A
LINE FROM PONTIAC TO VALPARAISO.

THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS THURSDAY AND
THURSDAY NIGHT...AND AGAIN SATURDAY NIGHT AND SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS MAY BE NEEDED THIS EVENING THROUGH THE NIGHT TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

LMZ740>745-042130-
WINTHROP HARBOR TO WILMETTE HARBOR-
WILMETTE HARBOR TO NORTHERLY ISLAND-
NORTHERLY ISLAND TO CALUMET HARBOR-CALUMET HARBOR TO GARY-
GARY TO BURNS HARBOR-BURNS HARBOR TO MICHIGAN CITY-
428 PM CDT SUN APR 3 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE
MICHIGAN.

.DAY ONE...TONIGHT.

SOUTH GALES WILL DIMINISH THIS EVENING. HOWEVER...WINDS WILL
REMAIN GUSTY AND MAY CONTINUE TO POSE A HAZARD TO SMALL CRAFT
OVERNIGHT.

THUNDERSTORMS ARE LIKELY OVERNIGHT AND MAY PRODUCE LOCALLY STRONG
AND GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

STRONG WINDS AND HIGH WAVES WILL LEAD TO HAZARDOUS CONDITIONS FOR
SMALL CRAFT MONDAY THROUGH EARLY TUESDAY.

THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS THURSDAY AND
THURSDAY NIGHT...AND AGAIN SATURDAY NIGHT AND SUNDAY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-042130-
LAKE MICHIGAN FROM MICHIGAN CITY IN TO ST. JOSEPH MI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN SOUTH OF A LINE FROM SEUL CHOIX POINT TO THE
MACKINAC BRIDGE AND NORTH OF A LINE FROM CHARLEVOIX MI TO SOUTH
FOX ISLAND 5 NM OFFSHORE-
LAKE MICHIGAN FROM CHARLEVOIX TO POINT BETSIE MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM POINT BETSIE TO MANISTEE MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI-
LAKE MICHIGAN FROM STURGEON BAY TO TWO RIVERS WI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM TWO RIVERS TO SHEBOYGAN WI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM SHEBOYGAN TO PORT WASHINGTON WI 5 NM OFFSHORE
TO MID LAKE-
LAKE MICHIGAN FROM PORT WASHINGTON TO NORTH POINT LIGHT WI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM NORTH POINT LIGHT TO WIND POINT WI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WIND POINT WI TO WINTHROP HARBOR IL 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WINTHROP HARBOR TO WILMETTE HARBOR IL 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WILMETTE HARBOR IL TO MICHIGAN CITY IN 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM WHITEHALL TO PENTWATER MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM GRAND HAVEN TO WHITEHALL MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM HOLLAND TO GRAND HAVEN MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM SOUTH HAVEN TO HOLLAND MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM ST. JOSEPH TO SOUTH HAVEN MI 5 NM OFFSHORE TO
MID LAKE-
428 PM CDT SUN APR 3 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE
MICHIGAN.

.DAY ONE...TONIGHT.

SOUTHEAST GALE FORCE WINDS WILL AFFECT THE LAKE THIS EVENING.

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE TONIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NORTHWEST WINDS WILL INCREASE TO GALE FORCE MONDAY AND WILL
CONTINUE INTO MONDAY NIGHT BEFORE DIMINISHING.

THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS ACROSS FAR SOUTHERN
LAKE MICHIGAN THURSDAY AND THURSDAY NIGHT...AND AGAIN SATURDAY
NIGHT AND SUNDAY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

RATZER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
944 PM CDT SUN APR 3 2011

ILZ010-040315-
LEE IL- 942 PM CDT SUN APR 3 2011

...SIGNIFICANT WEATHER ALERT...

AT 937 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 12 MILES WEST OF WALTON...MOVING EAST AT 55 MPH.

ONE HALF INCH DIAMETER HAIL...WINDS UP TO 50 MPH...OCCASIONAL CLOUD
TO GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
  WALTON...             AMBOY...              SUBLETTE...
  WEST BROOKLYN...      COMPTON...            PAW PAW...

ADDITIONAL STRONG THUNDERSTORMS ARE ALSO MOVING ACROSS NORTHERN LEE
COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS
TREES. HEAVY RAINFALL CAN LEAD TO FLOODING OF LOW LYING AREAS SUCH AS
DITCHES...VIADUCTS...UNDERPASSES...CREEKS AND DRAINAGE AREAS. SEEK
SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.

LAT...LON 4179 8896 4166 8897 4162 8924 4160 8963
      4181 8963

MDB/KJB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
949 PM CDT SUN APR 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0946 PM     HAIL             ROCHELLE                41.92N 89.06W
04/03/2011  M1.00 INCH       OGLE               IL   PUBLIC

            RELAYED BY MEDIA

&&

CM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
959 PM CDT SUN APR 3 2011

ILZ019-040400-
LA SALLE IL- 959 PM CDT SUN APR 3 2011

...SIGNIFICANT WEATHER ALERT...

AT 955 PM CDT...ALONG A LINE EXTENDING FROM MENDOTA TO 13 MILES WEST
OF PERU TO 25 MILES WEST OF PERU...MOVING EAST AT 60 MPH.

NICKEL SIZE HAIL...WINDS UP TO 50 MPH...FREQUENT CLOUD TO GROUND
LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
  MENDOTA...            TROY GROVE...         PERU...
  UTICA...              LA SALLE...           EARLVILLE...
  CEDAR POINT...        OGLESBY...            LELAND...
  SERENA...             TONICA...             OTTAWA...
  NAPLATE...            LOSTANT...            LEONORE...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS
TREES. HEAVY RAINFALL CAN LEAD TO FLOODING OF LOW LYING AREAS SUCH AS
DITCHES...VIADUCTS...UNDERPASSES...CREEKS AND DRAINAGE AREAS. SEEK
SHELTER IN A STURDY STRUCTURE UNTIL THESE STORMS HAVE PASSED.

LAT...LON 4162 8861 4112 8860 4111 8915 4161 8915

MDB/KJB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1004 PM CDT SUN APR 3 2011

ILZ011-012-020-040400-
DEKALB IL-KANE IL-KENDALL IL- 1004 PM CDT SUN APR 3 2011

...SIGNIFICANT WEATHER ALERT...

AT 1000 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM HAMPSHIRE TO LITTLE
ROCK...MOVING EAST AT 60 MPH.

NICKEL SIZE HAIL...WINDS GREATER THAN 40 MPH...FREQUENT CLOUD TO
GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THESE
STORMS.

LOCATIONS IMPACTED INCLUDE...
  YORKVILLE...          SUGAR GROVE...        HAMPSHIRE...
  ELBURN...             PINGREE GROVE...      OSWEGO...
  NORTH AURORA...       MONTGOMERY...         GILBERTS...
  BOULDER HILL...       WEST DUNDEE...        ST. CHARLES...
  SOUTH ELGIN...        SLEEPY HOLLOW...      GENEVA...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. HEAVY
RAINFALL CAN LEAD TO FLOODING OF LOW LYING AREAS SUCH AS DITCHES...
VIADUCTS...UNDERPASSES...CREEKS AND DRAINAGE AREAS. SEEK SHELTER IN A
STURDY STRUCTURE UNTIL THESE STORMS HAVE PASSED.

LAT...LON 4214 8827 4147 8827 4147 8859 4215 8861

MDB/KJB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1005 PM CDT SUN APR 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1004 PM     HAIL             DE KALB                 41.93N 88.75W
04/03/2011  M0.25 INCH       DEKALB             IL   TRAINED SPOTTER

&&

ALLSOPP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1011 PM CDT SUN APR 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1006 PM     HAIL             SYCAMORE                41.98N 88.70W
04/03/2011  M0.75 INCH       DEKALB             IL   TRAINED SPOTTER

            DIME SIZE HAIL.

&&

ALLSOPP