Flash Flood Warning 8, NWS Chicago, IL

969 
WGUS73 KLOT 260159
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
859 PM CDT WED MAY 25 2011

ILC091-197-260700-
/O.CON.KLOT.FF.W.0008.000000T0000Z-110526T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANKAKEE IL-WILL IL-
859 PM CDT WED MAY 25 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN AND EASTERN 
WILL AND KANKAKEE COUNTIES UNTIL 200 AM CDT...

AT 859 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH MODERATE TO HEAVY RAIN CONTINUING ACROSS ACROSS 
THE WARNED AREA. DOPPLER RADAR ESTIMATES INDICATE THAT ONE TO TWO 
INCHES OF RAIN FELL THIS EVENING.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR.

LAT...LON 4100 8825 4128 8824 4155 8790 4152 8779
      4147 8779 4147 8759 4101 8759

$$

IZZI

482 
WGUS73 KLOT 260342
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1042 PM CDT WED MAY 25 2011

ILC091-197-260700-
/O.CON.KLOT.FF.W.0008.000000T0000Z-110526T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANKAKEE IL-WILL IL-
1042 PM CDT WED MAY 25 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN WILL AND
KANKAKEE COUNTIES UNTIL 200 AM CDT...

AT 1041 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THAT THE HEAVY RAINFALL WAS BEGINNING TO TAPER OFF. DESPITE 
THIS...RUN OFF FROM THE HEAVY RAIN THAT HAS ALREADY FALLEN WILL 
LIKELY RESULT IN FLASH FLOODING OF LOW LYING AND FLOOD PRONE AREAS. 

LAT...LON 4100 8825 4128 8824 4155 8790 4152 8779
      4147 8779 4147 8759 4101 8759

$$


IZZI

625 
WGUS73 KLOT 260653
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
153 AM CDT THU MAY 26 2011

ILC091-197-260708-
/O.CAN.KLOT.FF.W.0008.000000T0000Z-110526T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANKAKEE IL-WILL IL-
153 AM CDT THU MAY 26 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN WILL AND
KANKAKEE COUNTIES IS CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. 

IF FLOODING WAS OBSERVED PLEASE RELAY YOUR REPORT TO LOCAL LAW
ENFORCEMENT OR TO THE NATIONAL WEATHER SERVICE IN CHICAGO.

&&

LAT...LON 4100 8825 4128 8824 4155 8790 4152 8779
      4147 8779 4147 8759 4101 8759

$$

BEACHLER

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
706 PM CDT WED MAY 25 2011

.MESOSCALE DISCUSSION...
451 PM CDT

QUICK UPDATE...HAVE GONE AHEAD AND EXPANDED THE WATCH EAST TO THE
IL/IN BORDER GENERALLY SOUTH OF THE KANKAKEE RIVER. ISOLATED
STORMS TRYING TO POP UP ALONG THE SYNOPTIC FRONT BUT THE
ENVIRONMENT ISNT OVERLY CONCERNING FOR THESE CELLS. SUFFICIENT
SHEAR/INSTABILITY IS IN PLACE FOR SOME SEVERE THREAT...THOUGH
OVERALL TORNADO THREAT LOOKS FAIRLY LOW.

FARTHER SOUTH...OUTFLOW BOUNDARY THAT WAS ALONG I-70 IS BEGINNING
TO SURGE NORTHWARD. SEVERAL MINI-SUPERCELLS HAVE DEVELOPED ALONG
THE BOUNDARY. AS THE BOUNDARY CONTINUES TO LIFT NORTHWARD
CONCERNED THAT THE MORE FAVORABLE SHEAR/INSTABILITY PARAMETERS CO-
LOCATED WITH THE LEFT-OVER RETREATING OUTFLOW BOUNDARY WILL SPREAD
NORTH INTO OUR SOUTHERN CWA. TORNADO THREAT...WHILE NOT OVER-
WHELMING...DOES LOOK TO INCREASE DURING THE 23-02Z TIME FRAME FOR
OUR SOUTHERN CWA.

FARTHER NORTH...SYNOPTIC BOUNDARY HAS BEGUN TO ACCELERATE
SOUTHWARD AND SHOULD CONTINUE TO MOVE FAIRLY EXPEDIENTLY SOUTH
THIS EVENING. ONCE WINDS SHIFT TO THE NORTHEAST AND AND COOLER AIR
ARRIVES THE TORNADO AND TO A LARGE EXTENT WIND DAMAGE THREAT WILL
BE ABOUT OVER. WILL LIKELY BEGIN TO CHIP AWAY AT THE TORNADO WATCH
OVER OUR WESTERN CWA IN THE NEXT HOUR.

IZZI

353 PM CDT...
CUMULUS FIELD CONTINUES TO PERCOLATE ALONG THE SYNOPTIC FRONT
FROM DEKALB COUNTY SOUTHWEST TO SOUTH OF MOLINE. LARGE SCALE
ASCENT WITH APPROACHING UPPER LOW ALONG WITH CONTINUED HEATING
SEEMS TO BE ELIMINATING REMAINING CONVECTIVE INHIBITION OVER WEST
CENTRAL ILLINOIS WITH CONVECTION STARTING TO DEVELOP ALONG THE
BOUNDARY THERE. WOULD ANTICIPATE ADDITIONAL DEVELOPMENT TO
CONTINUE TO OCCUR TO THE NORTHEAST ALONG THE BOUNDARY THE NEXT
HOUR OR TWO. AREA VWP'S INDICATE THAT THE AXIS OF STRONGER LOW
LEVEL FLOW IS SHIFTING EASTWARD LEAVING OUR WESTERN CWA IN A
REGION OF WEAKER LOW LEVEL SHEAR AND RESULTANT LESSER TORNADO
THREAT. NOT ANTICIPATING ANY APPRECIABLE INCREASE IN THE LOW LEVEL
FLOW WEST OF I-39...SO TORNADO THREAT APPEARS TO BE DIMINISHING
THERE.

LOW LEVEL SHEAR IS EXPECTED TO REMAIN SUFFICIENT FARTHER EAST INTO
THE EARLY EVENING...SO AS DESTABILIZATION OCCURS SLIGHTLY GREATER
TORNADO THREAT MAY SPREAD EASTWARD INTO SOUTHERN PORTIONS OF OUR
CWA. WILL CONTINUE TO MONITOR TRENDS AND SHOULD THINGS DESTABILIZE
MAY END UP EXPANDING THE TORNADO WATCH A BIT FARTHER EAST INTO OUR
CWA.

IZZI

&&

.DISCUSSION...
332 PM CDT

TONIGHT
...SECOND WAVE OF CONVECTION TONIGHT IS THE MAIN FORECAST CONCERN...
...FLASH FLOOD WATCH FOR THE ALL BUT THE NORTHERN TIER OF COUNTIES
IN ILLINOIS FOR TONIGHT...

THERE IS NO SHORTAGE OF CONCERNS WITH TONIGHTS ACTIVITY. A LINE OF
DESTRUCTIVE THUNDERSTORMS AHEAD OF A COLD FRONTAL ZONE...HAVE BEEN
ONGOING ACROSS MISSOURI FOR THE PAST SEVERAL HOURS.
MEANWHILE...ACROSS CENTRAL AND NORTHERN ILLINOIS...SATELLITE IMAGERY
INDICATES A GOOD AMOUNT OF SCATTERED CLOUD COVER. THIS HAS ALLOWED
THE ATMOSPHERE SOUTH OF THE SURFACE FRONTAL BOUNDARY TO RECOVER FROM
THIS MORNINGS THUNDERSTORM COMPLEX. CURRENT RUC MESO ANALYSIS
INDICATES UPWARDS OF 1500 J/KG OF CAPE ACROSS MY SOUTHWESTERN CWA
EARLY THIS AFTERNOON. IN ADDITION...THE 18 UTC SOUNDING OUT OF ILX
INDICATES A WEAKLY CAPPED ENVIRONMENT WITH JUST OVER 1600 J/KG OF
CAPE.

THE EXPECTATION FOR THIS EVENT REMAINS SIMILAR AS TO EARLIER
THINKING. THE MAIN SEVERE THREAT WILL REMAIN SOUTH OF INTERSTATE
80...SOUTH OF THE SURFACE BOUNDARY. SURFACE BASED THUNDERSTORMS WILL
BE THE MOST LIKELY IN THIS AREA. THIS WILL ALLOW FOR A THREAT OF ALL
TYPES OF SEVERE STORMS...INCLUDING TORNADOES. ALTHOUGH MUCH OF THE
CONVECTION MODE APPEARS TO BE IN THE FORM OF QLCS...DEEP LAYER
BULK SHEAR VECTORS APPEAR TO HAVE A LARGE NORMAL COMPONENT TO FORCING
AHEAD OF THE FRONTAL ZONE MOVING ACROSS MISSOURI. BECAUSE OF
THIS...ANY CELLS THAT DEVELOP AHEAD OF THIS COULD LEAD TO MORE
DISCRETE STORM DEVELOPMENT INITIALLY...INCREASING THE TORNADO
THREAT.

NORTH OF INTERSTATE 80...INTO THE CHICAGO AREA...STORMS WILL LIKELY
BE ELEVATED. THEREFORE...LARGE HAIL WILL LIKELY BE THE MAIN THREAT.
HOWEVER...THE THREAT FOR TORNADOES COULD EXTEND JUST TO THE COLD SIDE
OF THE SURFACE FRONTAL ZONE. THIS COULD APPROACH THE INTERSTATE 80
CORRIDOR.

OVERALL...THE SEVERE THREAT SHOULD BEGIN TO DIMINISH ACROSS THE AREA
AFTER MIDNIGHT TONIGHT.

THE OTHER THREAT IS FOR HEAVY RAINFALL.  MODEL BUFFER SOUNDINGS
INDICATE PLENTY OF MOISTURE IN THE COLUMN...WITH UPWARDS OF 1.3
INCH PW'S. WARM CLOUD DEPTHS IN EXCESS OF 10K FEET WILL MAKE THESE
STORMS EFFICIENT RAINFALL PRODUCERS.  COUPLE THIS WITH THE FACT THAT
THE STORMS MAY BE SLOW MOVING AND TRAINING NEAR THE SURFACE
BOUNDARY...WILL NOT MAKE IT TOO DIFFICULT TO LEAD TO HIGH RAINFALL
RATES IN EXCESS OF AN INCH PER HOUR. THEREFORE...I HAVE ISSUED A
FLASH FLOOD WATCH THROUGH TONIGHT. TOTAL RAINFALL AMOUNTS TONIGHT
WILL LIKELY FALL IN THE 1 TO 2 INCH RANGE...WITH LOCALLY HIGHER
AMOUNTS EXPECTED.

KJB

MID RANGE (TOMORROW MORNING THROUGH SATURDAY MORNING)...

MAIN UPPER LEVEL TROUGH WILL BE SWINGING THROUGH THE GREAT
LAKES...AND THE ELONGATED SURFACE LOW SPANNING MUCH OF THE OHIO
VALLEY WILL CONTINUE TO MARCH EAST. HIGH PRESSURE THAT IS PRESENTLY
NOSING INTO THE NORTHERN PLAINS...WILL CONTINUE TO BUILD AND SHIFT
TO THE SOUTHEAST. AS THIS BEGINS TO SHIFT INTO THE AREA...EXPECT
PRECIPITATION TRENDS TO DIMINISH. THE MORNING HOURS WILL LIKELY BE
LEFT WITH SOME SHOWER ACTIVITY LINGERING THROUGH THE MORNING HOURS.
MAIN INSTABILITY AXIS TO BE AHEAD OF THE TROF AND SURFACE LOW...AND
NOT EXPECTING MUCH IF ANY THUNDER IN THE MORNING...AND SHOULD JUST
BE LIGHT SHOWERS BEYOND. AS THE HIGH PRESSURE MOVES
OVERHEAD...PLENTY OF COLD AIR WILL BLAST DOWN FROM THE NORTH AND WE
WILL RETURN TO ANOTHER CHILLY OVERNIGHT PERIOD BY THURSDAY NIGHT.
DRY NORTHWEST FLOW WILL HELP TO ERODE THE CLOUDS BUT A LITTLE LEARY
TO GO COMPLETELY CLEAR AT THIS POINT AS A FEW OF THE MODELS ARE
SHOWING SOME MOISTURE LINGERING. OVERNIGHT LOWS ACROSS THE NORTHEAST
COULD DROP INTO THE UPPER THIRTIES...AND IF WE DO CLEAR OUT ENOUGH -
WE COULD EASILY RADIATE OUT AND THERE IS THEN THE POTENTIAL FOR
FROST. ENSEMBLE PLUME ANALYSIS SHOWS THE BULK OF THE MEMBERS HOVERING
AROUND THE 40 DEGREE MARK...BUT THERE ARE AT LEAST 3 DIFFERENT
MEMBERS THAT DIP CLOSE TO FREEZING ACROSS THE FAR NORTHWESTERN
SUBURBS. AREAS FURTHER EAST...AND INCLUDING THE URBAN HEAT ISLAND OF
CHICAGO...WILL SEE CHILLY CONDITIONS OVERNIGHT...BUT NOWHERE NEAR
FREEZING. FOR NOW...FOR THE NORTHWESTERN BURBS...WILL SIDE ON THE
WARMER AND OPTIMISTIC SIDE OF THE FORECAST...BUT WILL NEED TO
MONITOR AND CHANGE IF NEEDED. MOST OF THE AREA WILL STILL BE UNDER
THE INFLUENCE OF THE COOL NORTHERLY FLOW AND EXPECT DAYTIME HIGHS ON
FRIDAY TO BE ON THE ORDER OF 5 TO 7 DEGREES BELOW THE CLIMATOLOGICAL
NORM ACROSS THE OUTLYING AREAS OF THE CWA...TO CHILLY LOWER AND
MIDDLE 50S /10+ DEGREES BELOW NORM/ FOR AREAS ALONG THE LAKESHORE.
THE SURFACE HIGH WILL CONTINUE TO SHIFT EAST...THOUGH A THERMAL
TROUGH WILL LIKELY LINGER ACROSS THE LAKE INTO SATURDAY KEEPING
LAKESIDE AREAS COOLER. WINDS WILL THEN SHIFT AROUND TO THE EAST AND
GRADUALLY SOUTH...USHERING IN ANOTHER WARM AND HUMID AIRMASS AS THE
NEXT SYSTEM BUILDS ACROSS THE PLAINS AND LIFTS NORTH.

SHEA

LONG TERM (SUNDAY-WEDNESDAY...)

STRONG RIDGING ACROSS THE EASTERN CONUS EVOLVES OVER THE DAYS 4-7
TIME PERIOD AS STRONG 594 UPPER HIGH TAKES HOLD OVER THE SE U.S.
BROAD SOUTHWEST FLOW SURFACE AND ALOFT SETS UP OVER THE LOCAL AREA
FOR MUCH OF THE DURATION OF THE PERIOD BRINGING SUMMER LIKE WARMTH
AND HUMIDITY FOR THE LATTER PART OF THE MEMORIAL DAY WEEKEND.

SURFACE WARM FRONT ASSOCIATED WITH CENTRAL PLAINS SURFACE LOW SURGES
NORTHWARD SATURDAY NIGHT/EARLY SUNDAY ALLOWING GULF MOISTURE TO
SURGE NORTHWARD INTO THE AREA.  EXPECT A ROUND OF SHOWERS/TSTMS TO
BREAK OUT ALONG AND AHEAD OF THE BOUNDARY AS THE WARM FRONT BLASTS
NORTHWARD OVER THE AREA.  ATMOSPHERE LIKELY TO BECOME CAPPED IN THE
WARM SECTOR LATER IN THE DAY SUNDAY WITH MAX TEMPS POSSIBLY FLIRTING
WITH THE 90 DEGREE MARK.  BRISK SW SURFACE/BOUNDARY LAYER FLOW WILL
INHIBIT ANY LAKE BREEZE AND ALLOW HEAT TO PENETRATE THE LAKEFRONT
AND DOWNTOWN CHICAGO.

AFTER A STICKY NIGHT SUNDAY NIGHT (LOWS CLOSE TO 70) EXPECT ANOTHER
VERY WARM AND HUMID DAY FOR THE MEMORIAL DAY HOLIDAY WITH CURRENT
MODEL TRENDS INDICATING CAPPED WARM SECTOR HOLDING OVER THE AREA AND
THUS NO RAIN.  NEXT CHANCE FOR RAIN AND THUNDERSTORMS COMES TUESDAY
AS STRONG UPPER LEVEL LOW RIDES UP BLOCKING UPPER RIDGE MOVING
ACROSS THE UPPER MIDWEST WITH ASSOCIATED SURFACE LOW TRACKING FROM
THE DAKOTAS INTO ONTARIO.  LOW AND UPPER TROUGH DRIVE A COLD FRONT
SOUTH ACROSS THE AREA TUESDAY NIGHT BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS FOLLOWED BY SOMEWHAT DRYER AND COOLER AIR
FILTERING INTO AT LEAST THE NORTHERN SECTIONS OF THE FORECAST AREA
ON WEDNESDAY.

EF

&&

.AVIATION...

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

* THUNDERSTORMS THIS EVENING.

* LIFR CIGS THROUGH THURSDAY MORNING...IMPROVING TO MVFR BY
  THURSDAY AFTERNOON.

* PROLONGED PERIOD OF RAIN OVERNIGHT AND THURSDAY MORNING.

* GUSTY NORTH/NORTHEAST WINDS INCREASING TONIGHT. CMS

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

TWO MAIN CONCERNS THROUGH THE EVENING HOURS ARE THUNDERSTORMS AND
CIGS. COLD FRONT CONTINUES TO MOVE SOUTH...CURRENTLY ALONG/NEAR
I-80. NORTHEAST WINDS BEHIND THIS BOUNDARY WILL CONTINUE TO
INCREASE THROUGH THE EVENING AND TONIGHT. LIFR CIGS WILL PUSH
SOUTH ACROSS NORTHEAST IL AND EXPECT THESE TO REMAIN ACROSS THE
AREA INTO THE OVERNIGHT HRS. LARGE AREA OF THUNDERSTORMS EXTENDS
FROM THE QUAD CITIES ARCHING BACK TO EAST CENTRAL IL. THIS
ACTIVITY WILL LIFT NORTH AND EVENTUALLY WEAKEN AND ELONGATE OVER
NORTHERN IL WITH A PROLONGED PERIOD OF LIGHT/MODERATE RAIN
EXPECTED ACROSS THE TERMINALS INTO THURSDAY MORNING...ENDING FROM
NORTHWEST TO SOUTHEAST DURING THE DAY. CIGS LIKELY TO REMAIN IFR
OR LOWER THROUGH THURSDAY MORNING...WITH IMPROVEMENT EXPECTED BY
LATE THURSDAY MORNING/EARLY THURSDAY AFTERNOON...THOUGH TIMING AND
HEIGHTS WILL LIKELY NEED REFINEMENT WITH LATER FORECASTS. CMS

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

* HIGH CONFIDENCE WINDS WILL REMAIN NORTHEAST THROUGH THE PERIOD.
  MODERATE CONFIDENCE ON SPEEDS/GUSTS.

* HIGH CONFIDENCE LIFR CIGS WILL CONTINUE OVERNIGHT...MODERATE
  CONFIDENCE CIGS WILL LIFT TO MVFR THURSDAY...LOW CONFIDENCE ON
  TIMING.

* MODERATE CONFIDENCE ON THUNDERSTORMS THIS EVENING. MODERATE
  CONFIDENCE ON RAIN OVERNIGHT...ENDING THURSDAY AFTERNOON. CMS

//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...

THURSDAY NIGHT...CHANCE MVFR CIGS/SHRA.

FRIDAY...VFR...POSSIBLE MVFR IN SHRA/TSRA.

SATURDAY...VFR. PSBL MVFR IN SHRA/TSRA.

SUNDAY...VFR. CHC TSRA

MONDAY...VFR.

TUESDAY...VFR.

MDB/CMS

&&

.MARINE...
347 PM CDT

AS LOW PRESSURE TRACKS NORTHEAST FROM THE PLAINS TO JUST SOUTH OF
LAKE MICHIGAN...THE PRIMARY CONCERN THROUGH MUCH OF THURSDAY WILL
BE STRONG NORTHERLY WINDS UP TO 30 KNOTS...CAUSING LARGE WAVES TO
DEVELOP. FURTHERMORE...THROUGH EARLY THURSDAY...THERE WILL BE
PERIODS OF SHOWERS AND THUNDERSTORMS...SOME POSSIBLY CONTAINING
HAIL...FREQUENT LIGHTNING...AND GUSTY WINDS...PRIMARILY OVER THE
SOUTH HALF OF THE LAKE AND NEARSHORE WATERS. AS THE LOW WEAKENS
AND PUSHES FARTHER EAST BY FRIDAY...A WEAK RIDGE OF HIGH PRESSURE
WILL BRIEFLY VISIT THE NORTHERN GREAT LAKES...ALLOWING FOR
DIMINISHING WINDS AND WAVES AND IMPROVED WEATHER CONDITIONS. LOW
PRESSURE WILL SLOWLY APPROACH FROM THE PLAINS OVER THE
WEEKEND...RENEWING SOUTHERLY WINDS AND INTRODUCING A CHANCE FOR
PERIODIC SHOWERS AND THUNDERSTORMS.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
     ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 AM THURSDAY.

IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
     AM THURSDAY.

LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM THURSDAY TO
     10 AM FRIDAY.

     SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...7 AM THURSDAY TO
     10 AM FRIDAY.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
405 PM CDT WED MAY 25 2011

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
262115-
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-
405 PM CDT WED MAY 25 2011 /505 PM EDT WED MAY 25 2011/

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  THUNDERSTORMS...THE STRONGEST MAY PRODUCE:
    DAMAGING WINDS IN EXCESS OF 70 MPH.
    HAIL TO THE SIZE OF GOLF BALLS.
    TORNADOES.
    AND HEAVY RAINFALL WITH THE POTENTIAL FOR FLASH FLOODING.

  AREAS AFFECTED AND TIMING:

  THUNDERSTORMS...SOME POSSIBLY SEVERE...WILL MOVE BACK INTO THE
  OUTLOOK AREA THIS EVENING POTENTIALLY CONTINUING INTO THE
  OVERNIGHT HOURS. WHILE THERE WILL BE SOME THREAT OF SEVERE
  WEATHER ACROSS THE ENTIRE REGION...THE GREATEST THREAT OF
  SEVERE WEATHER APPEARS TO LIE SOUTH OF INTERSTATE 80.

  DISCUSSION:

  A STRONG LOW PRESSURE SYSTEM OVER MISSOURI WILL MOVE EASTWARD.
  CONTINUED SUNSHINE THIS AFTERNOON WILL INCREASE THE INSTABILITY.
  THIS SHOULD RESULT IN RAPID DESTABILIZATION OF THE ATMOSPHERE BY
 EARLY EVENING...PARTICULARLY SOUTH OF INTERSTATE 80.

  AS THE LOW PRESSURE MOVES EASTWARD INTO THIS UNSTABLE AIR MASS
  CONDITIONS WILL BE FAVORABLE FOR SEVERE THUNDERSTORMS TO MOVE
  BACK INTO NORTHERN ILLINOIS THIS EVENING. THE PRIMARY THREAT
  FROM THESE STORMS WILL LIKELY BE LARGE HAIL NORTH OF INTERSTATE
  80...WITH THE THREAT FOR DAMAGING WINDS AND EVEN TORNADOES
  INCREASING SOUTH OF INTERSTATE 80.

  IN ADDITION...SLOW MOVING STORMS AND LOCALLY HEAVY RAINFALL
  COULD RESULT IN FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THUNDERSTORMS WILL CONTINUE INTO THURSDAY AS THE SURFACE LOW
SLOWLY MOVES EAST INTO CENTRAL INDIANA. AREAS OF HEAVY RAINFALL
WILL CONTINUE DURING THIS TIME...WITH SOME POTENTIAL FOR
FLOODING.

THERE IS A CHANCE FOR THUNDERSTORMS OVER THE WEEKEND INTO
MEMORIAL DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS EVENING AND POSSIBLY
INTO THE OVERNIGHT HOURS.

&&

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

LMZ740>745-262115-
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-
405 PM CDT WED MAY 25 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.

STRONG WINDS AND HIGH WAVES WILL LEAD TO HAZARDOUS CONDITIONS FOR
THE ILLINOIS NEAR SHORE WATERS TONIGHT.

THUNDERSTORMS ARE LIKELY ACROSS THE AREA THIS AFTERNOON THROUGH
TONIGHT. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

STRONG WINDS AND HIGH WAVES WILL LEAD TO HAZARDOUS CONDITIONS FOR
THE ILLINOIS NEAR SHORE WATERS EARLY FRIDAY MORNING.

THUNDERSTORMS WILL CONTINUE INTO THURSDAY. THEN THERE IS A CHANCE
FOR THUNDERSTORMS OVER THE WEEKEND INTO MEMORIAL DAY.

&&

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-
870-872-874-876-878-262115-
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-
405 PM CDT WED MAY 25 2011

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

.DAY ONE...TONIGHT.

THUNDERSTORMS ARE LIKELY ACROSS THE SOUTHERN THIRD OF LAKE
MICHIGAN THIS AFTERNOON THROUGH TONIGHT. LARGE HAIL AND DAMAGING
WINDS ARE THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THUNDERSTORMS WILL CONTINUE INTO THURSDAY. THEN THERE IS A CHANCE
FOR THUNDERSTORMS OVER THE WEEKEND INTO MEMORIAL DAY.

&&

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

KJB

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
222 PM CDT WED MAY 25 2011

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

0738 AM     HEAVY RAIN       2 N OTTAWA              41.38N 88.84W
05/25/2011  M0.60 INCH       LA SALLE           IL   COCORAHS

            0.6 INCH IN 20 MINUTES.

0745 AM     HAIL             4 WSW BONFIELD          41.12N 88.13W
05/25/2011  M0.25 INCH       KANKAKEE           IL   COCORAHS

0749 AM     HAIL             5 E LOWELL              41.29N 87.32W
05/25/2011  E0.25 INCH       LAKE               IN   LAW ENFORCEMENT

            NEAR I-65 AND STATE RD 2

0750 AM     LIGHTNING        SANDWICH                41.65N 88.62W
05/25/2011                   DE KALB            IL   FIRE DEPT/RESCUE

            HOUSE STRUCK BY LIGHTNING - 3RD ST. RELAYED BY
            BRISTOL-KENDALL FIRE DEPT.

0830 AM     HEAVY RAIN       1 N CROWN POINT         41.44N 87.36W
05/25/2011  M0.78 INCH       LAKE               IN   COCORAHS

            MEASURED IN THE PAST 30 MINUTES

0851 AM     HAIL             MONEE                   41.42N 87.75W
05/25/2011  M0.75 INCH       WILL               IL   TRAINED SPOTTER

0857 AM     HEAVY RAIN       5 NW POLO               42.04N 89.65W
05/25/2011  M0.95 INCH       OGLE               IL   CO-OP OBSERVER

            LAST 4 HOURS. STANDING WATER IN LOW SPOTS.

0900 AM     HAIL             RICHTON PARK            41.48N 87.73W
05/25/2011  M0.75 INCH       COOK               IL   LAW ENFORCEMENT

0915 AM     HEAVY RAIN       POLO                    41.98N 89.58W
05/25/2011  M1.00 INCH       OGLE               IL   TRAINED SPOTTER

            0.55 INCH IN LAST 45 MINUTES. STANDING WATER IN YARDS.

0915 AM     TORNADO          ST. ANNE                41.02N 87.72W
05/25/2011                   KANKAKEE           IL   FIRE DEPT/RESCUE

            HOUSE DAMAGED.

0919 AM     HEAVY RAIN       PEOTONE                 41.33N 87.80W
05/25/2011  M1.04 INCH       WILL               IL   TRAINED SPOTTER

            IN PAST 2 HOURS.

0920 AM     TSTM WND DMG     5 W BROOK               40.87N 87.46W
05/25/2011                   NEWTON             IN   EMERGENCY MNGR

            POLES DOWN AT 500S AND 600E. TREES DOWN AT SEVERAL
            LOCATIONS IN NEWTON COUNTY INCLUDING 600W AND 300S, 500W
            AND 450E, 550S AND 650W, 1125S AND 600W, 350W AND 800S,
            600N AND MERIDIAN.

0920 AM     TORNADO          2 S MOUNT AYR           40.92N 87.30W
05/25/2011                   NEWTON             IN   EMERGENCY MNGR

            POSSIBLE TORNADO. STATE ROAD 55 AND 600S

0924 AM     TORNADO          2 S MOUNT AYR           40.92N 87.30W
05/25/2011                   NEWTON             IN   EMERGENCY MNGR

            SR 55 AND COUNTY ROAD 600S. POSSIBLE TORNADO. STRUCTURAL
            DAMAGE TO HOUSE...2 FARM SHEDS...AND GRAIN BIN.

0924 AM     TSTM WND DMG     RENSSELAER              40.94N 87.15W
05/25/2011                   JASPER             IN   EMERGENCY MNGR

            TREES DOWN SOUTH SIDE OF TOWN.

0924 AM     TORNADO          RENSSELAER              40.94N 87.15W
05/25/2011                   JASPER             IN   EMERGENCY MNGR

            POSSIBLE TORNADO. POWER LINES DOWN...SHINGLES
            LOST...TRUCK OVERTURNED AT 231 AND DREXEL. ALSO TREE
            LIMBS DOWN ALONG SR114 AND 150E.

0924 AM     TSTM WND DMG     2 E RENSSELAER          40.94N 87.11W
05/25/2011                   JASPER             IN   EMERGENCY MNGR

            TREES DOWN. SR 14 NEAR 200 W.

0925 AM     TSTM WND DMG     BROOK                   40.87N 87.37W
05/25/2011                   NEWTON             IN   EMERGENCY MNGR

            SHED HEAVILY DAMAGED. UTILITY POLES DOWN. NEAR STATE ROAD
            55 AND COUNTY RD 600S.

0950 AM     HEAVY RAIN       2 WSW CROWN POINT       41.41N 87.39W
05/25/2011  M1.15 INCH       LAKE               IN   COCORAHS

            MEASURED 0.69 INCH BETWEEN 730 AND 9 AM. MINOR FLOODING.

1000 AM     HEAVY RAIN       1 W MOKENA              41.53N 87.89W
05/25/2011  M2.54 INCH       WILL               IL   COCORAHS

            IN LAST 3 HOURS. MINOR FLOODING.

1010 AM     HAIL             HEBRON                  41.32N 87.20W
05/25/2011  M0.88 INCH       PORTER             IN   EMERGENCY MNGR

            NICKEL HAIL.

1010 AM     TSTM WND DMG     3 NNE HEBRON            41.36N 87.18W
05/25/2011                   PORTER             IN   EMERGENCY MNGR

            POWER POLE DOWN AT 550 W AND 350 S.

1030 AM     HEAVY RAIN       PEOTONE                 41.33N 87.80W
05/25/2011  M2.26 INCH       WILL               IL   CO-OP OBSERVER

            SINCE 7AM.

1030 AM     HEAVY RAIN       5 ENE MANHATTAN         41.45N 87.90W
05/25/2011  M2.61 INCH       WILL               IL   COCORAHS

            RAIN FELL BETWEEN 730 AND 1030 AM. SOME MINOR FLOODING.

1030 AM     HEAVY RAIN       1 SSE WESTMONT          41.78N 87.97W
05/25/2011  M1.84 INCH       DUPAGE             IL   COCORAHS

            IN 3 HOURS.

1030 AM     HEAVY RAIN       OAK BROOK               41.84N 87.95W
05/25/2011  M1.29 INCH       DUPAGE             IL   CO-OP OBSERVER

            SINCE 7AM.

1033 AM     FLOOD            GLEN ELLYN              41.87N 88.06W
05/25/2011                   DUPAGE             IL   TRAINED SPOTTER

            MINOR STREET FLOODING.

1038 AM     HEAVY RAIN       3 SW MIDWAY AIRPORT     41.75N 87.79W
05/25/2011  M1.50 INCH       COOK               IL   CO-OP OBSERVER

            FELL BETWEEN 730 AM AND 1030 AM.

1040 AM     HEAVY RAIN       1 SE LISLE              41.78N 88.07W
05/25/2011  M1.52 INCH       DUPAGE             IL   COCORAHS

            IN THE PAST 3 HOURS. SOME MINOR FLOODING.

1053 AM     HEAVY RAIN       BERWYN                  41.84N 87.79W
05/25/2011  M1.16 INCH       COOK               IL   TRAINED SPOTTER

            SINCE EARLY THIS MORNING.

1123 AM     HEAVY RAIN       PARK FOREST             41.48N 87.69W
05/25/2011  M1.25 INCH       COOK               IL   TRAINED SPOTTER

            SINCE THIS MORNING.

1237 PM     HEAVY RAIN       CHESTERTON              41.60N 87.06W
05/25/2011  M1.75 INCH       PORTER             IN   TRAINED SPOTTER

            SINCE THIS MORNING.

0100 PM     HEAVY RAIN       AURORA                  41.77N 88.29W
05/25/2011  M0.65 INCH       KANE               IL   ASOS

            RAINFALL FROM 7AM-1PM

0100 PM     HEAVY RAIN       WEST CHICAGO            41.89N 88.22W
05/25/2011  M0.67 INCH       DUPAGE             IL   ASOS

            RAINFALL MEASURED FROM 7AM-1PM

0100 PM     HEAVY RAIN       ROMEOVILLE              41.65N 88.09W
05/25/2011  M1.82 INCH       WILL               IL   OFFICIAL NWS OBS

            RAINFALL FROM 7AM-1PM

0100 PM     HEAVY RAIN       MIDWAY AIRPORT          41.78N 87.75W
05/25/2011  M1.18 INCH       COOK               IL   ASOS

            RAINFALL MEASURED FROM 7AM-1PM

0100 PM     HEAVY RAIN       WAUKEGAN                42.37N 87.87W
05/25/2011  M0.85 INCH       LAKE               IL   ASOS

            RAINFALL FROM 7AM-1PM

0100 PM     HEAVY RAIN       VALPARAISO              41.48N 87.05W
05/25/2011  M0.73 INCH       PORTER             IN   ASOS

            RAINFALL FROM 7AM-1PM

0100 PM     HEAVY RAIN       OHARE AIRPORT           41.98N 87.90W
05/25/2011  M1.79 INCH       COOK               IL   ASOS

            RAINFALL FROM 7AM-1PM

0100 PM     HEAVY RAIN       ROCKFORD AIRPORT        42.20N 89.10W
05/25/2011  M0.57 INCH       WINNEBAGO          IL   ASOS

            RAINFALL UP TO 1 PM

&&

ALLSOPP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
630 PM CDT WED MAY 25 2011

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

1200 PM     HEAVY RAIN       2 SSW BROOKFIELD        41.79N 87.86W
05/25/2011  M1.47 INCH       COOK               IL   TRAINED SPOTTER

            COCORAHS OBSERVER. MORNING RAINFALL TOTAL. DELAYED
            REPORT.

&&

ACS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
702 PM CDT WED MAY 25 2011

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

0701 PM     HAIL             13 W KANKAKEE           41.12N 88.11W
05/25/2011  M0.25 INCH       KANKAKEE           IL   TRAINED SPOTTER

            PEA TO DIME SIZE HAIL

&&

ACS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
744 PM CDT WED MAY 25 2011

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

0740 PM     FLOOD            OGLESBY                 41.29N 89.06W
05/25/2011                   LA SALLE           IL   LAW ENFORCEMENT

            7-8 INCHES OF STANDING WATER ON ROADS NEAR COMMUNITY
            COLLEGE IN OGLESBY.

&&

ACS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
808 PM CDT WED MAY 25 2011

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

0804 PM     HEAVY RAIN       9 WSW MENDOTA           41.50N 89.28W
05/25/2011  M3.84 INCH       BUREAU             IL   TRAINED SPOTTER

            TOTAL RAIN MEASURED

&&

ACS