Flash Flood Warning 7, NWS Chicago, IL

277 
WGUS73 KLOT 070536
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1236 AM CDT MON MAY 7 2012

ILC063-093-099-105-071200-
/O.CON.KLOT.FF.W.0007.000000T0000Z-120507T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENDALL IL-LA SALLE IL-LIVINGSTON IL-GRUNDY IL-
1236 AM CDT MON MAY 7 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR GRUNDY...NORTHERN
LIVINGSTON...SOUTHERN LA SALLE AND SOUTH CENTRAL KENDALL COUNTIES
UNTIL 700 AM CDT...

AT 1228 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR 
INDICATES THAT ONE AND A HALF TO TWO INCHES OF RAIN HAS FALLEN OVER 
THE LAST HOUR ACROSS SOUTHERN LA SALLE AND MUCH OF GRUNDY COUNTY. 
ISOLATED AMOUNTS OF AROUND 3 INCHES MAY HAVE ALSO OCCURRED. UP TO 
AROUND AN INCH OF RAIN IS ESTIMATED TO HAVE FALLEN ACROSS CENTRAL 
AND NORTHERN LIVINGSTON COUNTY OVER THE LAST HOUR. LAW ENFORCEMENT 
REPORTS THAT WEST SOUTHMOR ROAD NEAR MORRIS IS IMPASSABLE DUE TO 
FLOODING.

ADDITIONAL RAINFALL WILL CONTINUE OVER THE NEXT FEW HOURS WITH 
ANOTHER ONE HALF TO ONE INCH POSSIBLE. EVEN MORE RAINFALL MAY OCCUR 
LATER ON TONIGHT.  

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
DWIGHT...MARSEILLES...MORRIS...OGLESBY...OTTAWA...PONTIAC...SENECA...
STREATOR...BRACEVILLE...COAL CITY...CULLOM...FLANAGAN...GARDNER...
GRAND RIDGE...MAZON...NAPLATE...ODELL...TONICA AND UTICA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE ELEVATED LEVELS ON SMALL
CREEKS AND STREAMS...PONDING OF WATER ON ROADS...URBAN AREAS...
HIGHWAYS... UNDERPASSES AND LOW LYING AREAS.

&&

LAT...LON 4151 8828 4083 8824 4088 8894 4092 8894
      4092 8905 4093 8905 4110 8905 4110 8906
      4110 8912 4111 8917 4131 8917

$$

MDB

352 
WGUS73 KLOT 070711
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
211 AM CDT MON MAY 7 2012

ILC063-093-099-105-071200-
/O.CON.KLOT.FF.W.0007.000000T0000Z-120507T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENDALL IL-LA SALLE IL-LIVINGSTON IL-GRUNDY IL-
211 AM CDT MON MAY 7 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR GRUNDY...NORTHERN
LIVINGSTON...SOUTHERN LA SALLE AND SOUTH CENTRAL KENDALL COUNTIES
UNTIL 700 AM CDT...

AT 205 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS ACROSS SOUTHEAST LA SALLE...GRUNDY...AND NORTHERN 
LIVINGSTON COUNTIES. HEAVY DOWNPOURS WILL CONTINUE FROM THESE STORMS 
WITH AN ADDITIONAL ONE HALF TO ONE INCH OF RAIN POSSIBLE IN SOME 
SPOTS. THE HEAVIEST STORMS WILL BE EXITING THE AREA OVER THE NEXT 
HOUR BUT ADDITIONAL SHOWERS AND THUNDERSTORMS MAY DEVELOP AND MOVE 
IN FROM THE SOUTHWEST LATER TONIGHT.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
DWIGHT...MARSEILLES...MORRIS...OGLESBY...OTTAWA...PONTIAC...SENECA...
STREATOR...BRACEVILLE...COAL CITY...CULLOM...FLANAGAN...GARDNER...
GRAND RIDGE...MAZON...NAPLATE...ODELL...TONICA AND UTICA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES... AS WELL AS
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4151 8828 4083 8824 4088 8894 4092 8894
      4092 8905 4093 8905 4110 8905 4110 8906
      4110 8912 4111 8917 4131 8917

$$

MDB

663 
WGUS73 KLOT 070932
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
432 AM CDT MON MAY 7 2012

ILC063-093-099-105-071200-
/O.CON.KLOT.FF.W.0007.000000T0000Z-120507T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENDALL IL-LA SALLE IL-LIVINGSTON IL-GRUNDY IL-
432 AM CDT MON MAY 7 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR GRUNDY...NORTHERN
LIVINGSTON...SOUTHERN LA SALLE AND SOUTH CENTRAL KENDALL COUNTIES
UNTIL 700 AM CDT...

AT 427 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
ANOTHER BAND OF SHOWERS AND THUNDERSTORMS APPROACHING THE WARNED 
AREA FROM THE WEST. AN ADDITIONAL ONE QUARTER TO THREE QUARTERS OF 
AN INCH MAY FALL...WITH ISOLATED AMOUNTS OF AROUND ONE INCH POSSIBLE 
THROUGH MID MORNING. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
DWIGHT...MARSEILLES...MORRIS...OGLESBY...OTTAWA...PONTIAC...SENECA...
STREATOR...BRACEVILLE...COAL CITY...CULLOM...FLANAGAN...GARDNER...
GRAND RIDGE...MAZON...NAPLATE...ODELL...TONICA AND UTICA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES... AS WELL AS
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4151 8828 4083 8824 4088 8894 4092 8894
      4092 8905 4093 8905 4110 8905 4110 8906
      4110 8912 4111 8917 4131 8917

$$

MDB

572 
WGUS73 KLOT 071203
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
703 AM CDT MON MAY 7 2012

ILC063-093-099-105-071217-
/O.EXP.KLOT.FF.W.0007.000000T0000Z-120507T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENDALL IL-LA SALLE IL-LIVINGSTON IL-GRUNDY IL-
703 AM CDT MON MAY 7 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR GRUNDY...NORTHERN
LIVINGSTON...SOUTHERN LA SALLE AND SOUTH CENTRAL KENDALL COUNTIES HAS
BEEN REPLACED BY AN AREAL FLOOD WARNING IS NOW IN EFFECT DUE TO 
ONGOING FLOODING AND MINIMAL ADDITIONAL RAINFALL.

LAT...LON 4151 8828 4083 8824 4088 8894 4092 8894
      4092 8905 4093 8905 4110 8905 4110 8906
      4110 8912 4111 8917 4131 8917

$$

MDB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1105 PM CDT SUN MAY 6 2012

.MESOSCALE DISCUSSION...
358 PM CDT

ONGOING CONVECTION ACROSS THE SOUTHERN FORECAST AREA IS ROOTED
ALONG THE SURFACE SYNOPTIC BOUNDARY AS WELL AS NEAR AN OLD OUTFLOW
BOUNDARY FROM MORNING CONVECTION. A TIGHT SURFACE BASED
INSTABILITY GRADIENT EXISTS IN THIS AREA...WITH NEARLY 4000 J/KG
OF UNINHIBITED CAPE TO THE IMMEDIATE SOUTH. REPORTS OF WALL
CLOUDS/LOWERING ROTATION HAVE VERIFIED THESE STORMS ARE ROOTED
LOW...ESPECIALLY IN THE DISCRETE SUPERCELLULAR STORMS WITHIN THIS
DEVELOPING COMPLEX. THE TORNADO THREAT IS ENHANCED IN THIS
ISOLATED AREA FROM THE PANHANDLE OF LASALLE COUNTY THROUGH
SOUTHERN NEWTON COUNTY AND SOUTHWARD...BY A POOL OF OVER 100 J/KG
OF 0-3 KM MLCAPE...AS WELL AS BACKED LOW-LEVEL MOIST INFLOW.
THERE WILL CONTINUE TO BE A TORNADO AND LARGE HAIL THREAT WITH ANY
OF THESE MORE DISCRETE STORMS...BUT A PRIMARY HEAVY RAIN THREAT IN
THIS AREA AND POTENTIALLY A DEVELOPING WIND THREAT AS A COLD POOL
ORGANIZES AND CELL MERGERS OCCUR. THE RAINFALL RATES WITH THESE
STORMS ARE VERY HEAVY AND PROPORGATION IS SLOW...WITH ANALYZED
PROPAGATION VECTORS INDICATING A GRADUAL EAST DRIFT.

MTF

&&

.DISCUSSION...
743 PM CDT

MESOSCALE UPDATE...

CLUSTER OF SEVERE THUNDERSTORMS WHICH HAD FORMED ALONG WARM FRONTAL
BOUNDARY DURING THE AFTERNOON HAVE MOVED SOUTHEAST OF THE CWA AS OF
645 PM CDT. OUTFLOW BOUNDARY FROM THIS CLUSTER OF STORMS HAS PUSHED
THE EFFECTIVE SURFACE FRONT SOUTH OF THE CWA...TO AN APPROXIMATELY
GALESBURG...PEORIA...SOUTH OF CHAMPAIGN LINE PER RADAR FINE LINE
ECHO AND METAR OBSERVATIONS. FARTHER WEST...THE FRONT THEN EXTENDS
WEST INTO FAR SOUTHEAST IOWA TO A 1008 MB AREA OF SURFACE LOW
PRESSURE. ALOFT...SIGNIFICANT ELEVATED CAPE APPEARS TO BE PRESENT
STILL ACROSS EASTERN IA/NORTHERN IL PER SPC RAP OBJECTIVE ANALYSIS
FIELDS...AND INDEED THE 00Z RAOB FROM DVN AND RECENT AMDAR ASCENT
SOUNDINGS FROM ORD INDICATE LITTLE INHIBITION AND IN EXCESS OF 2000
J/KG FOR PARCELS FORCED FROM AROUND 900 MB. SURFACE/NEAR SURFACE
INSTABILITY REMAINS ALONG/SOUTH OF SURFACE FRONT PARTICULARLY FROM
SOUTHEAST IA/NORTHEAST MO INTO WEST CENTRAL IL WITH 3000 J/KG MLCAPE
ANALYZED IN SPC/RAP.

IN THE NEAR TERM...NEXT 1-2 HOURS...THE FORECAST AREA APPEARS TO BE
SOMEWHAT BETWEEN AREAS OF LARGER SCALE FORCING FOR ASCENT. ANALYSIS
OF LATE AFTERNOON PROFILER/VWP DATA SUGGESTS ONE MID-LEVEL SHORT
WAVE TROUGH AND ASSOCIATED 35 KT MID-LEVEL SPEED MAXIMA TRANSLATING
EAST ACROSS NORTHERN INDIANA AND LOWER MICHIGAN...WHILE ANOTHER WAS
LOCATED UPSTREAM ACROSS THE LOWER MISSOURI RIVER VALLEY REGION OF
WESTERN MO/SOUTHWEST IA WHERE ADDITIONAL CLUSTERS OF CONVECTION WERE
NOTED PER SATELLITE/RADAR/LIGHTNING DATA. ISOLATED THUNDERSTORMS
WERE DEVELOPING HOWEVER ACROSS FAR SOUTHEAST IOWA...IN
AFOREMENTIONED LOW LEVEL CAPE MAXIMA WHICH ALSO COINCIDES WITH
LOWEST ANALYZED LFC HEIGHTS. WEAK BUT PERSISTENT WARM/MOIST ASCENT
ATOP THE LOW LEVEL BOUNDARY/FRONT AND FALLING SURFACE PRESSURES
ACROSS WESTERN IL SUGGEST THIS CONVECTIVE ACTIVITY MAY EXPAND IN
COVERAGE OVER THE NEXT FEW HOURS...AND WILL LIKELY SPREAD BACK INTO
THE WEST/SOUTH PORTIONS OF THE CWA DURING THE MID-LATE EVENING HOURS
AS LOWER MISSOURI VALLEY SHORT WAVE APPROACHES FROM THE SOUTHWEST.
OTHER ELEVATED STORMS ACROSS SOUTHERN WI/LAKE MICHIGAN APPEAR TO BE
ASSOCIATED WITH CONVERGENT AXIS NOTED IN 925-850 MB VWP/PROFILER
ANALYSIS WHERE STRONGER SOUTH/SOUTHEAST FLOW IS NOTED... BUT WE MAY
SEE SOME OF THIS FILL BACK TO THE SOUTHWEST AS OVERALL FORCING FOR
DEEP ASCENT BECOMES MORE FAVORABLE BACK ACROSS WESTERN ILLINOIS.

DECREASING MID-LEVEL FLOW AND RESULTING DEEP LAYER SHEAR WILL LIKELY
REDUCE THE OVERALL SEVERE THREAT ACROSS THE AREA...WITH AREAS
CLOSER TO THE SURFACE WARM FRONT AND OUTFLOW BOUNDARIES IN THE FAR
SOUTH/SOUTHWEST CWA PERHAPS ABLE TO MAINTAIN SOME MINIMAL THREAT FOR
HAIL/DAMAGING WINDS FOR STORMS ROOTED CLOSER TO THE SURFACE/BOUNDARY
LAYER. OTHERWISE THE MAIN THREATS INTO THE OVERNIGHT HOURS FOCUS ON
THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL...PARTICULARLY WHERE
PREVIOUS STORMS HAVE PRODUCED VERY HEAVY RAINFALL SOUTH OF I-80 THIS
AFTERNOON. AXIS OF VERY MOIST 925-850 MB LAYER WITH DEW POINTS 16-20
DEG C...PWATS OF 1.5-1.8...DIFFLUENT DEEP LAYER THICKNESS FIELD
ACROSS THE SOUTHEAST CWA...AND APPROACHING SHORT WAVE ALL POINT TO
CONTINUED HEAVY RAIN THREAT.

BASED ON ABOVE...AND IN COORDINATION WITH SPC AND WFO ILX...WILL GO
AHEAD AND CANCEL SEVERE THUNDERSTORM WATCH 258 AT THIS TIME BUT
WILL MAINTAIN FLASH FLOOD WATCH.

RATZER

//PREV DISCUSSION...
358 PM CDT

FORECAST CONCERNS HAVE BEEN CENTERED ON THE SHORT TERM...FROM NOW
THROUGH MONDAY WITH ONGOING CONVECTIVE AND HEAVY RAIN THREAT.

TONIGHT...A VERY CHALLENGING FORECAST AS ONGOING CONVECTION MAY
ALTER THE ATMOSPHERE ENOUGH TO HAVE A MAJOR IMPACT ON HOW
WIDESPREAD THE ACTIVITY TONIGHT MAY BE. IN GENERAL...THE TREND
WITH THE FORECAST WAS TO FOCUS THE HIGHER RAINFALL AMOUNTS FOR
TONIGHT FURTHER SOUTH IN THE FORECAST AREA...MAINLY SOUTH OF
INTERSTATE 88...WITH AN EMPHASIS SOUTH OF INTERSTATE 80.

CONVECTIVE COMPLEX EVOLVING FROM THE LACON AREA EASTWARD TOWARD
JUST SOUTH OF KANKAKEE HAS BEEN VERY SLOW MOVING...AND IS ROOTED
ALONG THE LOW-LEVEL THERMAL BOUNDARY WHERE CONVERGENCE IS
MAXIMIZED. A GRADUAL MCV OR COLD POOL EVOLUTION IS FAVORED...WHICH
SHOULD HELP TO PROGRESS THIS SOUTHEAST. CONTINUED MOISTURE
TRANSPORT INTO THE REGION THROUGH THIS EVENING WILL LIKELY OFFSET
THIS OVERALL MOTION SOME...LEADING TO POTENTIALLY VERY HEAVY
RAINFALL AMOUNTS TOWARD 4-5 INCHES IN PLACES. BULK SHEAR IS
MARGINAL...HOWEVER THE STORMS HAVE ALREADY THIS AFTERNOON SHOWN
THEMSELVES AS BEING ORGANIZED AND ROOTED IN THE SURFACE. SO A
SUSTAINED COLD POOL WILL LIKELY HELP IN POTENTIALLY PRODUCING
WIND...AS WELL AS AN ONGOING HAIL THREAT...ESPECIALLY THIS
EVENING.

TO THE NORTH OF THIS AREA...THE MOISTURE TRANSPORT IS
LESS...HOWEVER SHORT CONTINUED BROAD QG FORCING AND SHORT WAVE
RIPPLES ARE LIKELY TO TRIGGER AT LEAST SOME ELEVATED ACTIVITY.
MUCAPE VALUES ARE DIAGNOSED AT OVER 2000 J/KG PER THE RAP MODEL
BACK INTO NW AND NORTH CENTRAL IL. WHILE THE LOW-LEVEL AIR IS
SOMEWHAT WORKED OVER...THIS UPPER INSTABILITY AND CONTINUE HIGH
PWAT AIR IS ENOUGH TO HAVE HEAVY RAIN WITH A SCATTERED SEVERE
THREAT. HIGH RES MODELS VARY SIGNIFICANTLY ON HOW THIS WILL PAN
OUT. SO HOW WIDESPREAD THE CONVECTION FURTHER NORTH WILL BECOME IS
HIGHLY UNCERTAIN...ESPECIALLY DUE TO THE ONGOING CONVECTION TO THE
SOUTH. A CONTINUED HEAVY RAIN THREAT WILL EXIST WITH ANY
CONVECTION TO THE NORTH AS WELL...SO WILL CONTINUE THE FLASH FLOOD
WATCH ALL THE WAY TO THE WI BORDER.

MONDAY...SOME CONVECTION WILL LIKELY LINGER MONDAY MORNING AND
POSSIBLY EARLY AFTERNOON AS THE SYNOPTIC COLD FRONT EVOLVES EAST.
THE LOW-LEVEL JET FOCUS WILL BE MORE TO THE SOUTHEAST
HOWEVER...SO THE EMPHASIS FOR HEAVY RAIN AND THE SEVERE THREAT
SHOULD BE DIMINISHING. LINGERING CLOUD COVER WILL LIKELY IMPEDE
TEMPERATURES FROM CLIMBING MUCH THROUGH THE MORNING. A STRONGER
NORTHWEST PUSH IS LIKELY IN THE AFTERNOON...AIDING IN SCOURING OF
THE CLOUD COVER.

TUESDAY AND BEYOND...LITTLE CHANGES MADE TO THE GOING FORECAST FOR
THIS PERIOD DUE TO ONGOING SEVERE AND HEAVY RAIN THREATS. THE
POSTIIVELY TITLED UPPER TROUGH CENTERED OVER SOUTHERN MANITOBA
WILL GRADUALLY WORK EAST ACROSS THE WESTERN GREAT LAKES TUESDAY
NIGHT INTO WEDNESDAY...POSSIBLY BRINGING SOME SHOWERS.

MTF

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 04Z...

* DURATION AND LOCATION OF ONGOING THUNDERSTORMS

* POSSIBLE LOWERING CEILINGS

* TRENDS TOWARD MORNING RUSH

LENNING

//DISCUSSION...UPDATED 04Z...

A WEST TO EAST ORIENTED LINE OF SHOWERS AND THUNDERSTORMS RUNS
FROM THE SOUTH SHORE OF LAKE MICHIGAN BACK INTO THE QUAD CITIES
AREA. FARTHER WEST THERE IS WIDESPREAD ACTIVITY OVER SOUTHERN IOWA
AND MOST OF NORTHERN MISSOURI. THE ATMOSPHERE CONTINUES TO APPEAR
FAVORABLE FOR THIS CONVECTION TO PERSIST FOR QUITE A FEW HOURS.
GIVEN PRESENT RADAR TRENDS...THE MOST LIKELY CORRIDOR IS THROUGH
MDW AND JUST SOUTH OF ORD. UNSURE OF HOW THIS ACTIVITY WILL AFFECT
CEILINGS. THERE ARE SOME MUCH LOWER...LIFR...CIGS ALONG THE WI
LINE...BUT THESE ARE SEPARATE FROM THE LINES OF CONVECTION.

LENNING

//ORD AND MDW CONFIDENCE...UPDATED 04Z...

* HIGH CONFIDENCE IN TSRA CONTINUING FOR THE NEXT COUPLE OF HOURS.
  LOWER CONFIDENCE AFTER THAT.

* MEDIUM CONFIDENCE IN CIGS AND VSBYS STAYING UP EXCEPT FOR DURING
  STRONGEST TSRA CELLS.

* MEDIUM CONFIDENCE IN WIND SPEEDS AND DIRECTIONS...GENERALLY
  LIGHT AND NORTHERLY.

* LOW CONFIDENCE IN CIG/VSBY TRENDS TOWARD MORNING.

LENNING

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

TUESDAY...VFR...SLIGHT CHANCE OF SHOWERS.

WEDNESDAY...VFR...CHANCE OF SHOWERS.

THURSDAY...VFR.

FRIDAY...VFR.

SATURDAY...VFR...CHANCE OF SHOWERS.

LENNING

&&

.MARINE...
256 AM CDT

HIGH PRESSURE CONTINUES TO STRETCH FROM WESTERN HUDSON BAY SOUTHEAST
INTO NORTHERN NEW ENGLAND. LOW PRESSURE CENTERED OVER THE OK/TX
PANHANDLE REGION WILL DRIFT EASTWARD TODAY WITH AN INVERTED TROUGH
STRETCHING TO ITS NORTH. THIS TROUGH AXIS THEN ARCS NORTHWESTWARD TO
A DEVELOPING LOW OVER SOUTHERN SASKATCHEWAN. EASTERLY WINDS WILL
CONTINUE THIS MORNING BEFORE A WARM FRONTAL BOUNDARY SETS UP ACROSS
THE CENTRAL PART OF THE LAKE. THIS WILL ALLOW WINDS ACROSS THE NORTH
TO TURN NORTHEASTERLY AND TO A MORE SOUTHEASTERLY DIRECTION ACROSS
THE SOUTHERN PART OF THE LAKE. THE SURFACE LOW WILL WEAKEN AS IT
CROSSES THE SOUTHERN PART OF THE LAKE MONDAY MORNING. WINDS WILL
TURN NORTHERLY ACROSS THE ENTIRE LAKE AS THE LOW MOVES TO THE EAST
MONDAY AFTERNOON. THE SASKATCHEWAN LOW WILL THEN CROSS THE LAKE AS
MORE OF AN OPEN TROUGH THAN A CLOSED LOW. FAIRLY STRONG HIGH
PRESSURE WILL FOLLOW IN ITS WAKE LEADING TO A PERIOD OF ELEVATED
WINDS WEDNESDAY THANKS TO AN INCREASED PRESSURE GRADIENT. THE HIGH
WILL THEN SLOWLY MOVE EAST ACROSS THE REGION THROUGH THE END OF THE
WEEK KEEPING A NORTHERLY WIND THROUGH THURSDAY WITH A FLIP TO A
SOUTHERLY DIRECTION FRIDAY. THERE IS THEN GOOD AGREEMENT ON A FRONT
CROSSING THE REGION AGAIN SATURDAY WITH ANOTHER AREA OF HIGH
PRESSURE BUILDING IN BEHIND IT.

MDB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
     ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
     ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 AM MONDAY.

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

LM...NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
901 PM CDT SUN MAY 6 2012

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
080215-
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-
901 PM CDT SUN MAY 6 2012 /1001 PM EDT SUN MAY 6 2012/

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  THUNDERSTORMS...SOME MAY PRODUCE...
   HEAVY RAINFALL...PRODUCING LOCALIZED FLASH FLOODING
   HAIL TO THE SIZE OF GOLF BALLS
   WIND GUSTS IN EXCESS OF 60 MPH
   CLOUD TO GROUND LIGHTNING

  AREAS AFFECTED AND TIMING:

   ISOLATED THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS EVENING
   ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA AND CONTINUE
   THROUGH THE OVERNIGHT PERIOD.

  DISCUSSION:

  VERY MOIST ATMOSPHERE REMAINS OVER NORTHERN ILLINOIS AND
  NORTHWEST INDIANA THIS EVENING...AND WILL CONTINUE THROUGH
  THE OVERNIGHT PERIOD. THE MAIN FOCAL POINT FOR ADDITIONAL
  THUNDERSTORMS TO DEVELOP WILL BE ALONG A FRONTAL BOUNDARY
  THAT HAS PUSHED SOUTH OF U.S. HIGHWAY 24 OR ALONG AND SOUTH
  OF A FAIRBURY ILLINOIS TO KENTLAND INDIANA LINE. ISOLATED
  THUNDERSTORMS ARE EXPECTED TO DEVELOP NORTH OF THIS BOUNDARY
  THIS EVENING AND MAY STRENGTHEN TO ISOLATED SUPERCELLS.
  THE THREAT FOR HEAVY RAINFALL IS HIGH WITH THIS ACTIVITY.

  HIGHER AMOUNTS ARE LIKELY...ESPECIALLY IN SOUTHERN AREAS.
  LOCALIZED FLASH FLOODING MAY RESULT IN THOSE COMMUNITIES THAT
  SEE THESE MAXIMUM RAINFALL AMOUNTS.

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

THUNDERSTORMS ARE LIKELY DURING THE DAY ON MONDAY ACROSS A LARGE
PORTION OF THE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

&&

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

LMZ740>745-080215-
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-
901 PM CDT SUN MAY 6 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 THESE STORMS
MAY PRODUCE WIND GUSTS ABOVE 34 KNOTS.

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

THERE IS A CHANCE OF THUNDERSTORMS MONDAY.

&&

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-
870-872-874-876-878-080215-
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-
901 PM CDT SUN MAY 6 2012

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS TONIGHT...MAINLY ACROSS THE
SOUTHERN HALF OF THE LAKE. SOME OF THESE STORMS MAY PRODUCE WIND
GUSTS ABOVE 34 KNOTS...MAINLY ACROSS FAR SOUTHERN LAKE MICHIGAN.

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

THERE IS A CHANCE OF THUNDERSTORMS MONDAY.

&&

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

BEACHLER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1046 PM CDT SUN MAY 06 2012

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

0500 PM     TORNADO          3 E WATSEKA             40.77N 87.67W
05/06/2012                   IROQUOIS           IL   EMERGENCY MNGR

            DELAYED REPORT. TIME BASED OFF RADAR. POSSIBLE TORNADO.
            DAMAGE STARTED ON SE SIDE OF WATSEKA E OF RT 1 AND S OF
            RT 24. MULTIPLE TREES DOWN. SIDING RIPPED OFF BLDGS.
            SIGNS MANGLED. ON A PROPERTY ON CR 1730N...A 40X40 CINDER
            BLOCK BLDG WAS TORN APART...WITH CINDER BLOCKS TOSSED AND
            LIGHTER DEBRIS FROM BLDG TOSSED 1-1.5 MILES DOWNSTREAM TO
            THE NEXT PROPERTY. HERE...A HOUSE HAD WINDOWS BLOWN OUT
            AND A CAMPER INSIDE A GARAGE WAS IMPALED BY A BOARD.
            DAMAGE CONTINUED TO NEAR STATE LINE.

&&

RC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1108 PM CDT SUN MAY 06 2012

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

1104 PM     HAIL             STREATOR                41.13N 88.83W
05/06/2012  M1.00 INCH       LA SALLE           IL   TRAINED SPOTTER

&&

LENNING

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1109 PM CDT SUN MAY 06 2012

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

1101 PM     HAIL             STREATOR                41.13N 88.83W
05/06/2012  E0.50 INCH       LA SALLE           IL   TRAINED SPOTTER

            DIME SIZE HAIL LASTED 3 MINUTES.

&&

BN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1109 PM CDT SUN MAY 6 2012

ILZ019-021-032-070445-
GRUNDY IL-LA SALLE IL-LIVINGSTON IL-
1109 PM CDT SUN MAY 6 2012

...SPECIAL WEATHER STATEMENT...

AT 1105 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR STREATOR...MOVING EAST AT 20 MPH.

UP TO PENNY SIZE HAIL...FREQUENT CLOUD TO GROUND LIGHTNING...AND
HEAVY RAINFALL ARE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  STREATOR...DWIGHT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES.  SEEK SHELTER IN
A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.

LAT...LON 4129 8849 4108 8841 4104 8882 4118 8890
TIME...MOT...LOC 0409Z 253DEG 18KT 4113 8871

BIRK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1114 PM CDT SUN MAY 06 2012

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

1057 PM     FLASH FLOOD      MARSEILLES              41.33N 88.69W
05/06/2012                   LA SALLE           IL   TRAINED SPOTTER

            RYALL STREET IMPASSABLE AND CLOSED DUE TO FLOODING. ABOUT
            2 FEET OF WATER COVERING ROAD...WITH RUNOFF CONTINUING
            DOWNHILL INTO AREA.

&&

RC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1120 PM CDT SUN MAY 06 2012

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

0558 PM     TSTM WND DMG     OTTERBEIN               40.49N 87.11W
05/06/2012                   BENTON             IN   LAW ENFORCEMENT

            DELAYED REPORT. TIME ESTIMATED FROM RADAR. 2 POWERPOLES
            DOWN AND A LARGE TREE LIMB ACROSS A ROAD.

&&

RC