Severe Thunderstorm Warning 34, NWS Chicago, IL

756 
WWUS53 KLOT 210100
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
800 PM CDT SUN MAY 20 2012

ILC063-091-105-197-210145-
/O.CON.KLOT.SV.W.0034.000000T0000Z-120521T0145Z/
KANKAKEE IL-LIVINGSTON IL-WILL IL-GRUNDY IL-
800 PM CDT SUN MAY 20 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EASTERN
GRUNDY...SOUTHWESTERN WILL...NORTHEASTERN LIVINGSTON AND WESTERN
KANKAKEE COUNTIES UNTIL 845 PM CDT...

AT 756 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED TWO 
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL AND 
DAMAGING WINDS IN EXCESS OF 60 MPH.  THE FIRST STORM WAS LOCATED 6 
MILES SOUTHEAST OF ODELL...THE OTHER WAS NEAR DIAMOND. BOTH WERE 
MOVING NORTHEAST AT 20 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  DIAMOND AROUND 805 PM CDT.
  BRACEVILLE AROUND 810 PM CDT.
  BRAIDWOOD AROUND 820 PM CDT.
  WILMINGTON AND ELWOOD AROUND 835 PM CDT.
  LAKEWOOD SHORES AND MANHATTAN AROUND 845 PM CDT.

SEEK SHELTER INDOORS AND STAY AWAY FROM WINDOWS!

LAT...LON 4090 8866 4137 8835 4142 8813 4144 8790
      4119 8803 4099 8822 4099 8825 4095 8826
      4081 8842
TIME...MOT...LOC 0100Z 226DEG 16KT 4095 8843 4133 8824
WIND...HAIL 60MPH 1.00IN

$$

IZZI

374 
WWUS53 KLOT 210120
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
820 PM CDT SUN MAY 20 2012

ILC063-091-105-197-210145-
/O.CON.KLOT.SV.W.0034.000000T0000Z-120521T0145Z/
KANKAKEE IL-LIVINGSTON IL-WILL IL-GRUNDY IL-
820 PM CDT SUN MAY 20 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
GRUNDY...SOUTHWESTERN WILL...NORTHEASTERN LIVINGSTON AND WESTERN
KANKAKEE COUNTIES UNTIL 845 PM CDT...

AT 815 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED TWO 
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THE FIRST STORM WAS 
LOCATED 6 MILES EAST OF ODELL AND THE OTHER WAS NEAR CHANNAHON. BOTH 
WERE MOVING NORTHEAST AT 20 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  BRACEVILLE AROUND 825 PM CDT.
  BRAIDWOOD AROUND 835 PM CDT.
  ELWOOD...WILMINGTON...LAKEWOOD SHORES AND MANHATTAN AROUND 845 PM
  CDT.


LAT...LON 4094 8857 4138 8832 4142 8813 4144 8790
      4119 8803 4099 8822 4099 8825 4095 8826
      4081 8842
TIME...MOT...LOC 0120Z 226DEG 16KT 4102 8839 4138 8820
WIND...HAIL 60MPH 1.00IN

$$

IZZI

568 
WWUS53 KLOT 210134
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
834 PM CDT SUN MAY 20 2012

ILC063-091-105-197-210145-
/O.CON.KLOT.SV.W.0034.000000T0000Z-120521T0145Z/
KANKAKEE IL-LIVINGSTON IL-WILL IL-GRUNDY IL-
834 PM CDT SUN MAY 20 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
GRUNDY...SOUTHWESTERN WILL...NORTHEASTERN LIVINGSTON AND WESTERN
KANKAKEE COUNTIES UNTIL 845 PM CDT...

AT 834 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM ODELL TO GARDNER TO ELWOOD...MOVING NORTHEAST AT 20 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  GARDNER...ELWOOD...WILMINGTON AND LAKEWOOD SHORES AROUND 845 PM
  CDT.


LAT...LON 4094 8857 4137 8832 4142 8813 4144 8790
      4119 8803 4099 8822 4099 8825 4095 8826
      4091 8850
TIME...MOT...LOC 0135Z 226DEG 16KT 4103 8855 4116 8834
          4143 8814
WIND...HAIL 60MPH <.50IN

$$

IZZI

920 
WWUS53 KLOT 210144
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
844 PM CDT SUN MAY 20 2012

ILC063-091-105-197-210154-
/O.EXP.KLOT.SV.W.0034.000000T0000Z-120521T0145Z/
KANKAKEE IL-LIVINGSTON IL-WILL IL-GRUNDY IL-
844 PM CDT SUN MAY 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN GRUNDY...
SOUTHWESTERN WILL...NORTHEASTERN LIVINGSTON AND WESTERN KANKAKEE
COUNTIES WILL EXPIRE AT 845 PM CDT...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED BELOW
SEVERE LIMITS.

LAT...LON 4094 8857 4137 8832 4142 8813 4144 8790
      4119 8803 4099 8822 4099 8825 4095 8826
      4091 8850
TIME...MOT...LOC 0144Z 226DEG 16KT 4106 8851 4119 8830
          4146 8810

$$

IZZI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
706 PM CDT SUN MAY 20 2012

.MESOSCALE DISCUSSION...
UPDATED 455 PM CDT...

MORE ROBUST CONVECTION DEVELOPED OVER NORTHERN ILLINOIS THOUGH RADAR
IMAGERY SHOWS GUST FRONT OUTRUNNING AREA OF THUNDERSTORMS WITH A
WEAKENING TREND FOR ONGOING THUNDERSTORMS. A FEW SHOWERS HAVE TRIED
TO DEVELOP AS THIS NEW BOUNDARY PUSHES EAST...BUT OVERALL NEW
DEVELOPMENT HAS NOT BEEN ABLE TO TAKE OFF DESPITE NEARLY 1500 J/KG
MLCAPE. THE EXCEPTION IS ALONG THE SOUTHERN PORTIONS OF THE GUST
FRONT //NORTHERN LASALLE COUNTY// WHERE BETTER CONVERGENCE IS
HELPING SUSTAIN DEVELOPMENT. GIVEN THE MODERATELY UNSTABLE WEAKLY
SHEARED ENVIRONMENT OUT AHEAD OF THE LINE...CONTINUE TO CALL FOR A
LOW BUT NON ZERO SEVERE THREAT AS WE HEAD INTO THE EVENING...AND ANY
SEVERE WEATHER THAT DOES OCCUR WILL LIKELY BE PULSY AND SHORT
LIVED. BMD

&&

.DISCUSSION...
328 AM CDT

ANOTHER HOT DAY WILL BE ON TAP BEFORE THE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THIS AFTERNOON AND EVENING AS A COLD FRONT
MOVES THROUGH. COOLER TEMPERATURES WILL THEN GREET THE START OF
THE WEEK BEFORE A STRONG HEATING MAKES THE END OF THE WEEK HOT!

AT THE SURFACE...LOW PRESSURE IS LIFTING UP THROUGH SOUTHEASTERN
MINNESOTA THIS MORNING AND WILL CONTINUE TO PULL INTO WISCONSIN.
DRAPED SOUTHWEST FROM THIS LOW IS A COLD FRONT THAT WILL BRING THE
MAIN FOCUS FOR SHOWERS AND THUNDERSTORMS TO THE AREA. PRIOR TO
THE ARRIVAL OF THE FRONT...STRONG SOUTHERLY FLOW AND A SKY WITH A
FEW CLOUDS WILL ALLOW MOST LOCATIONS TO HEAT TO THE SAME LEVELS AS
THEY DID YESTERDAY...LIKELY EVEN A DEGREE OR TWO WARMER. THE GFS
AND LOCAL WRF RUNS HAVE BEEN PRETTY CONSISTENT AT DEVELOPING SOME
PREFRONTAL THUNDERSTORMS EARLY IN THE AFTERNOON. THESE MODELS ARE
PICKING UP ON A WEAK WAVE THAT IS LIFTING NORTHEAST THROUGH
NORTHEASTERN OKLAHOMA THIS MORNING. ALL INDICATIONS THROUGH SPC/S
RAP OBJECTIVE ANALYSIS...AS WELL AS FORECAST/RAW SOUNDINGS
INDICATE THAT THE AREA WILL BECOME UNSTABLE EARLY THIS MORNING.
SURFACE BASED CAPE IS PROGGED TO BE 1500-2000+ J/KG...AND THIS WAVE
MOVING ACROSS COULD PROVIDE JUST ENOUGH SHEAR AID IN THUNDERSTORM
DEVELOPMENT. COUPLE THAT WITH SOME COOLING ALOFT AND STRONG
SURFACE HEATING TO KEEP LAPSE RATES HIGH...AND THAT WOULD SUGGEST
THAT THERE IS THE POTENTIAL FOR SOME STORMS TO SUPPORT MARGINAL
HAIL...BUT MORE CONCERNED WITH THE INVERTED V SIGNATURE ON THE
SOUNDINGS AND 1200+ J/KG OF DCAPE AVAILABLE...THINKING IS THAT THE
POTENTIAL FOR WET MICROBURSTS AND STRONG WINDS WILL BE THE BIGGEST
THREAT. PWATS HAVE DOUBLED OVER THE LAST 24 HOURS AT BOTH LINCOLN
AND DAVENPORT...AND GUIDANCE IS SUGGESTING THAT ANYWHERE FROM 1.3
TO 1.5 INCHES OF PRECIPITABLE WATER WILL BE AVAILABLE IN THE LOWER
400 MB OF THE ATMOSPHERE THIS AFTERNOON. WHILE THIS WILL NOT LEAD
TO TORRENTIAL AND EXTREMELY EFFICIENT RAIN PRODUCING STORMS...IT
WILL STILL LEAVE THE POTENTIAL FOR FLASH FLOODING ACROSS HIGHLY
URBANIZED AREAS. THE GOING FORECAST STILL SEEMS PRETTY WELL ON
TRACK WITH OVERALL TIMING...BUT SUGGESTIONS ARE THAT THE FRONT IS
A SMIDGEN QUICKER THAN EARLIER THINKING. PRESENT TIMING FOR THE
MAIN THUNDERSTORMS TRIGGERED BY THE FRONT WILL PUSH THROUGH
ROCKFORD IN THE LATE AFTERNOON TO EARLY EVENING...AND THEN EAST
AND INTO CHICAGO A FEW HOURS BEYOND. THIS IS JUST A SLIGHT NUDGE
QUICKER THAN THE INHERITED FORECAST. IF THE AREA DOES MANAGE TO
SQUEEZE OUT THUNDERSTORMS THIS AFTERNOON WELL AHEAD OF THE
FRONT...THAT WILL INJECT MORE CLOUDS INTO THE SKIES AND THAT WOULD
LEAD TO HIGH BUST POTENTIAL WITH REGARDS TO THE LOWER 90S
ANTICIPATED TODAY. FOR NOW WILL LEAN THE FORECAST TOWARDS SHOWERS
AND THUNDERSTORMS WITH THE INITIAL FRONT.

WINDS WILL THEN TURN WEST AND NORTHWESTERLY BEHIND THE FRONT AND THE
ATMOSPHERE WILL THEN BEGIN TO DRY FROM THE MID LEVELS DOWN. BELIEVE
WE WILL HAVE SOME CLOUDS LOCKED IN PLACE WITH A SUBSIDENCE
INVERSION...AND THAT COULD HELP TO KEEP HIGHS ON MONDAY RIGHT AROUND
70 FOR MOST OF THE AREA...WITH RIGHT AROUND 60 FOR AREAS ALONG THE
LAKE FRONT. UPPER LEVEL TROUGH WILL THEN PUSH BEYOND THE CWA LATE
MONDAY AFTERNOON AND INTO THE EVENING HOURS...AND SURFACE HIGH
PRESSURE WILL BUILD IN. THROUGH AT LEAST WEDNESDAY...WINDS WILL REMAIN
NORTHERLY AS COOL NORTHWESTERLY FLOW ALOFT WILL KEEP HIGHS NEAR
NORMAL FOR MID MAY /LOWER 70S/. FLOW WILL SLOWLY BECOME SOUTHERLY BY
MIDWEEK AND LONG RANGE GUIDANCE CONTINUES TO SUGGEST THE BIG THREAT
FOR HEAT TO BE LURKING BY NEXT WEEKEND. BOTH THE GEM AND EC INDICATE
+20 TO +24 DEGREE AIR AT H8 OVERHEAD BY THE WEEKEND. TRANSLATED DOWN
TO THE SURFACE...AND MUCH OF THE AREA COULD SEE HIGHS IN THE LOWER
TO MID 90 RANGE...WITH HIGHER VALUES POSSIBLE. THE GFS IS NOT
SHOWING AS STRONG OF A WARMING SIGNAL AT THIS POINT...AND WILL ONLY
CARRY LOWER 90S IN THAT TIME. PRECIP CHANCES LOOK TO BE MINIMAL
THROUGH MUCH OF THE WEEK. BY THURSDAY...AN UPPER LEVEL TROUGH WILL
LIFT THROUGH THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...WITH
A SURFACE LOW LIFTING NORTH INTO WISCONSIN AND ONTARIO. AN ATTENDANT
COLD FRONT HAD BEEN PROGGED TO STALL OUT OVER CENTRAL WISCONSIN AND
NOT IMPACT THE CWA...BUT THE 00Z ECMWF IS INDICATING THAT THE FRONT
COULD SAG SOUTH AND STALL ACROSS THE WEATHER DIVIDING INTERSTATE 80.
THIS IS A BIT OF A SHIFT OVER MULTIPLE PREVIOUS RUNS...KEEPING THE
HEART OF THE STRONG UPPER LEVEL RIDGE ACROSS THE ARKLATEX REGION VS
MIDDLE MISSISSIPPI VALLEY. NOT SURE IF THIS IS JUST AN ODD ONE RUN
BLIP FROM THE EC OR IF IT IS CATCHING ONTO A TREND.
REGARDLESS...WILL KEEP A MINIMAL MENTION LATE IN THE WEEK AND THEN
DRY OUT AS THE FURNACE BEGINS TO CRANK OUT STRONG SUMMERLIKE
TEMPERATURES.

SHEA

&&

.AVIATION...

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

* PSBL TS THRU 02Z AT MDW.

* WIND VEERING FROM SOUTHWEST TO WEST...THEN NORTHWEST AS FRONT
  APPROACHES.

* PSBL PATCHY MVFR CIGS LATE TONIGHT/EARLY MONDAY.

BEACHLER

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

UPPER LEVEL DISTURBANCE CONTINUES TO PUSH EAST ACROSS NORTHERN
IL/NORTHWEST IN EARLY THIS EVENING. ISOLATED SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED AHEAD OF A COLD FRONT THIS AFTERNOON
AND WILL CONTINUE TO PUSH EAST THROUGH THIS EVENING. AT THIS TIME
IT APPEARS THE THUNDER THREAT WILL REMAIN SOUTHEAST OF ORD...WHILE
MDW/GYY CONTINUE TO SEE A HIGHER PROBABILITY OF SEEING THUNDER.
THUS HAVE MAINTAINED MENTION OF THUNDER AS A TEMPO GROUP FOR THOSE
SITES. IN ADDITION GUSTY WINDS MAY CONTINUE THROUGH 02Z FROM THE
SOUTHWEST...THEN ARND SUNSET THE WINDS WILL BEGIN TO DIMINISH AND
WIND DIR VEERS TO THE NORTHWEST AND EVENTUALLY NORTH OVERNIGHT.
THE NEXT CONCERN OVERNIGHT WILL BE THE POSSIBILITY FOR MVFR CIGS.
AT THIS TIME IT APPEARS THE BEST CHANCE FOR MVFR CIGS TO DEVELOP
WILL BE ACROSS SOUTHERN WISC AIRFIELDS...HOWEVER HAVE HELD ONTO
SCT CIGS AT 2-3KFT AGL. FEEL MORE CONFIDENT THAT ENOUGH DRY AIR
WILL PUSH INTO THE NORTHERN IL AIRFIELDS AND LIMIT SKY COVER.

HIGH PRESSURE BUILDS IN FROM THE WEST OVERNIGHT...AS WINDS VEER
FURTHER NORTHEAST BY DAYBREAK. THIS WILL ALLOW A STEADY FEED OF
NORTHEAST WINDS TO ORD/MDW AIRFIELDS...WITH OCCASIONAL GUSTS TO
20KT BY MIDDAY MON. AT THIS TIME SCT TO PSBLY BKN CIGS WILL OCCUR
MIDDAY...WITH BASES ARND 5KFT AGL.

BEACHLER

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

* HIGH CONFIDENCE IN ORD REMAINING DRY THIS EVENING AND NO
  THUNDER.

* MEDIUM CONFIDENCE IN MDW TEMPO GROUP OF TSRA.

* HIGH CONFIDENCE IN WIND DIR/SPEED...ALONG WITH WINDS VEERING
  NORTHWEST THEN NORTHEAST EARLY MONDAY.

* MEDIUM CONFIDENCE IN CIGS FORECAST OVERNIGHT EARLY MONDAY.

BEACHLER

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

TUESDAY THROUGH WEDNESDAY...VFR.
THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE.
FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA.
SATURDAY...VFR.

BEACHLER

&&

.MARINE...
241 PM CDT

AT MID AFTERNOON...LOW PRES WAS OVER THE WESTERN U.P. OF MI WITH
A COLD FRONT EXTENDING SSW ACROSS WI...NW AND W CENTRAL IL...THEN
CURVING SW ACROSS MO. AS THE LOW CONTINUES MOVING NE ACROSS LAKE
SUPERIOR AND INTO ONTARIO THIS EVENING...THE ASSOCIATED COLD FRONT
WILL PUSH E ACROSS LAKE MI SHIFTING WINDS FROM S AND SW TO W AND
NW AT MODERATE STRENGTH.

BEHIND THE COLD FRONT...HIGH PRES WILL MOVE SE FROM THE NORTHERN
AND CENTRAL PLAINS TO THE UPPER MIDWEST...MID MO VALLEY AND THE
SOUTHERN PLAINS OVERNIGHT. STRONG COLD AIR ADVECTION AND PRES
RISES DO NOT ARRIVE UNTIL OVERNIGHT/EARLY MON MORNING...AFTER THE
MID AND UPPER LEVEL TROF AXISES MOVE E OVER THE LAKE.

WITH THE RIDGE OF HI PRES SHIFTING E OVER THE UPPER GREAT
LAKES...MID MS VALLEY AND THE OZARKS DURING MON AND MON NIGHT THE
N WINDS WILL SLACKEN...AND EVENTUALLY BECOME LIGHT WHILE THE RIDGE
CROSSES LAKE MI BEFORE A RETURN FLOW OF SE AND S WINDS KICK IN ON
THE BACK SIDE HIGH DURING TUE NIGHT. THE S WINDS INCREASE TO
MODERATE STRENGTH WED NIGHT AND THU AS ANOTHER LOW PRES AND COLD
FRONT COMBO APPROACH LAKE MI FROM THE W.

WITH THE DELAYED ONSET OF STRONGER N WINDS REACHING THE S END OF
LAKE MI OVERNIGHT AND THE PRES GRADIENT STARTING TO LESSEN MON
MORNING LO LONGER APPEARS THAT WINDS NOR WAVES WILL REACH SMALL
CRAFT ADVISORY CRITERIA SO WILL BE CANCELED.

TRS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
423 PM CDT SUN MAY 20 2012

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
212130-
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-
423 PM CDT SUN MAY 20 2012 /523 PM EDT SUN MAY 20 2012/

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  THUNDERSTORMS...A FEW MAY MAY PRODUCE:
  STRONG DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
  HAIL TO ONE INCH.
  LOCALLY HEAVY RAINFALL.

  AREAS AFFECTED AND TIMING:

  THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON
  ACROSS NORTHCENTRAL ILLINOIS STRETCHING SOUTH THROUGH CENTRAL
  ILLINOIS AHEAD OF A COLD FRONT. ADDITIONAL ISOLATED
  TO SCATTERED THUNDERSTORMS MAY DEVELOP ACROSS PORTIONS OF
  NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA AHEAD OF THE
  MAIN AREA OF THUNDERSTORMS ASSOCIATED WITH THE COLD FRONT.
  ONCE THE COLD FRONT MOVES ACROSS THE AREA THIS EVENING...
  THUNDERSTORMS WILL COME TO AN END FROM WEST TO EAST.

  DISCUSSION:

  A LOW PRESSURE SYSTEM CENTERED OVER NORTHCENTRAL WISCONSIN
  CONTINUES TO LIFT NORTHEAST THIS AFTERNOON...AS A TRAILING
  COLD FRONT STRETCHES SOUTHWEST THROUGH FAR NORTHWEST ILLINOIS
  AND SOUTHEAST IOWA WILL PUSH EAST ACROSS NORTHERN ILLINOIS
  LATER THIS EVENING...AND PUSH THROUGH NORTHWEST INDIANA
  SHORTLY AFTER MIDNIGHT.

  THE ATMOSPHERE HAS BECOME MOIST AND UNSTABLE AHEAD OF THIS COLD
  FRONT OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. SCATTERED
  THUNDERSTORMS HAVE DEVELOPED THIS AFTERNOON ALONG AND AHEAD OF
  THE COLD FRONT. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE
  WITH THE MAIN THREAT BEING THE POTENTIAL FOR MICRO BURSTS
  WHICH COULD PRODUCE STRONG DAMAGING WIND GUSTS.

  THERE IS ALSO A SMALL THREAT OF LARGE HAIL DUE TO THE COLD
  AIR ALOFT. HOWEVER...THIS THREAT WILL BE LIMITED
  DUE TO THE OVERALL WEAK DEEP LAYER WIND SHEAR. A FEW PRE
  FRONTAL THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON...BUT
  THE MAJORITY OF THUNDERSTORMS ARE EXPECTED LATER THIS AFTERNOON
  AND EVENING WITH THE ARRIVAL OF THE COLD FRONT.

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

  THERE IS A CHANCE OF UNSEASONABLY HOT AND HUMID CONDITIONS
  DEVELOPING BY NEXT WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.

&&

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

LMZ740>745-212130-
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-
423 PM CDT SUN MAY 20 2012

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS TONIGHT...SOME OF THE
THUNDERSTORMS COULD PRODUCE WIND GUSTS IN EXCESS OF 35 KNOTS.

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

STRONG WINDS AND HIGH WAVES WILL LEAD TO HAZARDOUS CONDITIONS FOR
SMALL CRAFT FOR THE ILLINOIS AND INDIANA NEARSHORE WATERS FROM
NORTHERLY ISLAND THROUGH MICHIGAN CITY INDIANA MONDAY AFTERNOON
THROUGH TUESDAY MORNING.

&&

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-
870-872-874-876-878-212130-
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-
423 PM CDT SUN MAY 20 2012

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS OVER ALL OF LAKE MICHIGAN
TONIGHT...WITH SOME THUNDERSTORMS POSSIBLY LINGERING OVER THE
FAR SOUTHEASTERN PORTION OF THE LAKE INTO EARLY MONDAY MORNING.

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

THERE IS ANOTHER CHANCE FOR THUNDERSTORMS OVER THE NORTHERN
PORTIONS OF THE LAKE THURSDAY NIGHT.

&&

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

BEACHLER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
713 PM CDT SUN MAY 20 2012

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

0706 PM     TSTM WND GST     GRANT PARK              41.24N 87.64W
05/20/2012  M59 MPH          KANKAKEE           IL   TRAINED SPOTTER

            STATE LINE RD AND 10500N. ALSO HALF INCH HAIL.

&&

ACS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
721 PM CDT SUN MAY 20 2012

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

0410 PM     TSTM WND GST     MARENGO                 42.25N 88.60W
05/20/2012  M58.00 MPH       MCHENRY            IL   TRAINED SPOTTER

0410 PM     HAIL             MARENGO                 42.25N 88.60W
05/20/2012  M1.00 INCH       MCHENRY            IL   TRAINED SPOTTER

&&

ACS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
729 PM CDT SUN MAY 20 2012

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

0727 PM     HAIL             MOMENCE                 41.16N 87.66W
05/20/2012  M0.75 INCH       KANKAKEE           IL   TRAINED SPOTTER

&&

ACS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
738 PM CDT SUN MAY 20 2012

ILZ021>023-210115-
GRUNDY IL-KANKAKEE IL-WILL IL-
738 PM CDT SUN MAY 20 2012

...SPECIAL WEATHER STATEMENT...

AT 733 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG
THUNDERSTORM NEAR GARDNER...MOVING NORTHEAST AT 25 MPH.

UP TO PENNY SIZE HAIL...WINDS UP TO 50 MPH...ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
  BRACEVILLE...         GARDNER...            MAZON...
  BRAIDWOOD...          DIAMOND...            COAL CITY...
  LAKEWOOD SHORES...    WILMINGTON...         ELWOOD...

THE FOLLOWING LOCATIONS MAY ALSO BE IMPACTED...
KANKAKEE RIVER STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND.  SEEK SHELTER IN A STURDY STRUCTURE UNTIL
THIS STORM HAS PASSED.

LAT...LON 4143 8809 4116 8791 4112 8845 4121 8849
TIME...MOT...LOC 0038Z 230DEG 23KT 4120 8825

BIRK/RC

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
741 PM CDT SUN MAY 20 2012

ILZ021-023-032-033-039-210115-
FORD IL-GRUNDY IL-IROQUOIS IL-KANKAKEE IL-LIVINGSTON IL-
741 PM CDT SUN MAY 20 2012

...SPECIAL WEATHER STATEMENT...

AT 738 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM DWIGHT TO CULLOM...MOVING
EAST AT 20 MPH.

UP TO PENNY SIZE HAIL...WINDS TO 50 MPH...BRIEF HEAVY DOWNPOURS...
ARE POSSIBLE WITH THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
  ODELL...              DWIGHT...             CULLOM...
  HERSCHER...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND. HEAVY RAINFALL COULD LEAD TO STANDING WATER
ON ROADWAYS AND POOR VISIBILITY. SEEK SHELTER IN A STURDY STRUCTURE
UNTIL THESE STORMS HAVE PASSED.

LAT...LON 4115 8815 4091 8801 4078 8856 4108 8874
TIME...MOT...LOC 0041Z 249DEG 15KT 4106 8846 4085 8840

BIRK/RC

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
742 PM CDT SUN MAY 20 2012

ILZ021>023-210115-
GRUNDY IL-KANKAKEE IL-WILL IL-
742 PM CDT SUN MAY 20 2012

...SPECIAL WEATHER STATEMENT...

AT 733 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG
THUNDERSTORM NEAR GARDNER...MOVING NORTHEAST AT 25 MPH.

UP TO PENNY SIZE HAIL...WINDS TO 50 MPH...ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
  BRACEVILLE...         GARDNER...            MAZON...
  BRAIDWOOD...          DIAMOND...            COAL CITY...
  LAKEWOOD SHORES...    WILMINGTON...         ELWOOD...

THE FOLLOWING LOCATIONS MAY ALSO BE IMPACTED...
KANKAKEE RIVER STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND.  SEEK SHELTER IN A STURDY STRUCTURE UNTIL
THIS STORM HAS PASSED.

LAT...LON 4143 8809 4116 8791 4112 8845 4121 8849
TIME...MOT...LOC 0038Z 230DEG 23KT 4120 8825

BIRK/RC