Flash Flood Warning 18, NWS Chicago, IL

234 
WGUS73 KLOT 270219
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
919 PM CDT SUN AUG 26 2012

ILC031-043-089-093-197-270700-
/O.CON.KLOT.FF.W.0018.000000T0000Z-120827T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE IL-KENDALL IL-WILL IL-DUPAGE IL-COOK IL-
919 PM CDT SUN AUG 26 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL COOK...DUPAGE...
NORTHWESTERN WILL...NORTHEASTERN KENDALL AND SOUTHEASTERN KANE
COUNTIES UNTIL 200 AM CDT...

AT 914 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE THUNDERSTORMS WITH VERY HEAVY RAINFALL WERE BEGINNING TO EXIT 
THE AREA. RAINFALL REPORTS OF 1 TO 3 INCHES HAVE BEEN COMMON ACROSS 
MUCH OF THE WARNED AREA THIS EVENING. RUNOFF FROM THIS ACTIVITY HAS 
LED TO STANDING WATER SEVERAL INCHES DEEP ON ROUTE 34 IN 
NAPERVILLE. CONDITIONS SHOULD SLOWLY IMPROVE OVER THE NEXT SEVERAL 
HOURS AS THE RAINFALL COMES TO AN END. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
ADDISON...AURORA...NAPERVILLE...BATAVIA...BOLINGBROOK...BURR 
RIDGE...CAROL STREAM...DOWNERS GROVE...DUPAGE 
AIRPORT...ELMHURST...GENEVA...GLEN
ELLYN...HINSDALE...LEMONT...LISLE AND LOMBARD.



PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4194 8790 4163 8788 4163 8845 4192 8833

$$

180 
WGUS73 KLOT 270341
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1041 PM CDT SUN AUG 26 2012

ILC031-043-089-093-197-270700-
/O.CON.KLOT.FF.W.0018.000000T0000Z-120827T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE IL-KENDALL IL-WILL IL-DUPAGE IL-COOK IL-
1041 PM CDT SUN AUG 26 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL COOK...DUPAGE...
NORTHWESTERN WILL...NORTHEASTERN KENDALL AND SOUTHEASTERN KANE
COUNTIES UNTIL 200 AM CDT...

AT 1035 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE HEAVY RAINFALL THREAT WAS ENDING ACROSS MUCH OF THE WARNED 
AREA. HOWEVER...SOME LIGHT TO MODERATE RAINFALL STILL CONTINUES 
ACROSS SOUTHERN SECTIONS OF THE WARNED AREA. THIS AREA OF RAINFALL 
SHOULD EXIT THE REGION IN THE NEXT FEW OF HOURS. RAINFALL AMOUNTS OF 
BETWEEN 1 AND 3 INCHES HAVE BEEN COMMON ACROSS THE AREA THIS 
EVENING. RUNOFF FROM THIS ACTIVITY HAS LED TO STANDING WATER ON AREA 
ROADS. CONDITIONS SHOULD SLOWLY IMPROVE OVER THE NEXT FEW HOURS. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
ADDISON...AURORA...NAPERVILLE...BATAVIA...BOLINGBROOK...BURR 
RIDGE...CAROL STREAM...DOWNERS GROVE...DUPAGE 
AIRPORT...ELMHURST...GENEVA...GLEN
ELLYN...HINSDALE...LEMONT...LISLE AND LOMBARD.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4194 8790 4163 8788 4163 8845 4192 8833

$$

BIRK

734 
WGUS73 KLOT 270509
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1209 AM CDT MON AUG 27 2012

ILC031-043-089-093-197-270700-
/O.CON.KLOT.FF.W.0018.000000T0000Z-120827T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE IL-KENDALL IL-WILL IL-DUPAGE IL-COOK IL-
1209 AM CDT MON AUG 27 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL COOK...DUPAGE...
NORTHWESTERN WILL...NORTHEASTERN KENDALL AND SOUTHEASTERN KANE
COUNTIES UNTIL 200 AM CDT...

AT 1205 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE AREA OF RAINFALL HAD ENDED ACROSS THE WARNED AREA. 
RAINFALL AMOUNTS OF 1 TO 3 INCHES WERE COMMON ACROSS MUCH OF THE 
WARNED AREA ON SUNDAY EVENING. RUNOFF FROM THIS ACTIVITY HAS CAUSED 
SOME FLOODING OF LOW LYING AREAS. HOWEVER...CONDITIONS SHOULD 
CONTINUE TO IMPROVE OVER THE NEXT COUPLE OF HOURS AS THE RUNOFF FROM 
SUNDAY EVENINGS ACTIVITY CONTINUES TO ABATE.  

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...ADDISON...AURORA...BATAVIA...
BOLINGBROOK...BURR RIDGE...CAROL STREAM...DOWNERS GROVE...DUPAGE
AIRPORT...ELMHURST...GENEVA...GLEN ELLYN...HINSDALE...LEMONT...LISLE
AND LOMBARD.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4194 8790 4163 8788 4163 8845 4192 8833

$$
BIRK

597 
WGUS73 KLOT 270652
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
152 AM CDT MON AUG 27 2012

ILC031-043-089-093-197-270706-
/O.EXP.KLOT.FF.W.0018.000000T0000Z-120827T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE IL-KENDALL IL-WILL IL-DUPAGE IL-COOK IL-
152 AM CDT MON AUG 27 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL COOK...
DUPAGE...NORTHWESTERN WILL...NORTHEASTERN KENDALL AND SOUTHEASTERN
KANE COUNTIES WILL BE ALLOWED TO EXPIRE AT 200 AM CDT...

THROUGH REPORTS FROM LAW ENFORCEMENT...THE NATIONAL WEATHER SERVICE 
HAS DETERMINED THAT EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER 
THE WARNED AREA. MOST OF THE STREAMS AND CREEKS IN THE WARNED 
AREA HAVE RECEDED OR WERE BEGINNING TO RECEDE...ENDING THE FLOOD 
THREAT. THERE MAY REMAIN WATER COVERING ROADWAYS IN A FEW LOCATIONS. 
WATER COVERED ROADWAYS AT NIGHT CAN BE EXTREMELY DANGEROUS. NEVER 
CROSS A FLOODED ROADWAY. IF FLOODING HAS BEEN OBSERVED...PLEASE 
REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 4194 8790 4163 8788 4163 8845 4192 8833

$$

MTF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
549 PM CDT SUN AUG 26 2012

.DISCUSSION...
228 PM CDT

MAIN FORECAST CONCERNS ARE WITH RAINFALL TRENDS TONIGHT INTO
MONDAY...AND THEN A PERIOD OF DRY WEATHER THROUGH MID-WEEK BEFORE
REMNANTS OF TROPICAL SYSTEM ISAAC FLIRT WITH THE MIDWEST AND OHIO
VALLEY LATER IN THE WEEK.

EARLY AFTERNOON REGIONAL RADAR MOSAIC DEPICTS AN AREA OF FAIRLY
HEALTHY RAINFALL OCCURRING FROM SOUTHEAST IOWA INTO NORTHWEST AND
NORTH CENTRAL IL...AND ACROSS PARTS OF SOUTHEAST WI. THIS AREA OF
PRECIPITATION IS IN ASSOCIATION WITH AN ELONGATED POSITIVE-TILT
UPPER TROUGH OVER THE MIDWEST...WITH A FAIRLY WELL-PRONOUNCED
MID-LEVEL CIRCULATION NOTED OVER SOUTHEAST IA AND A SURFACE LOW
PRESSURE WAVE ALONG THE IA/MO BORDER. 12Z SOUNDINGS FROM NEARBY AND
UPSTREAM LOCATIONS INCLUDING DVN/ILX...TOP AND SGF INDICATE PRESENCE
OF A FAIRLY DEEP MOISTURE PLUME WITH PRECIPITABLE WATER VALUES NEAR
2.0 INCHES. WHILE RAINFALL HAS BEEN SOMEWHAT PATCHY ACROSS THE CWA
THROUGH THE MORNING...STEADIER AND LOCALLY HEAVY RAINFALL ACROSS
EASTERN IA AND NORTHWEST IL SHOULD SPREAD ACROSS ESPECIALLY THE
ILLINOIS PORTIONS OF THE FORECAST AREA THROUGH THIS EVENING AS THE
MID-LEVEL CIRCULATION PROPAGATES TO THE EAST-NORTHEAST. GUIDANCE
CONTINUES TO PRODUCE BETWEEN ROUGHLY 0.80 AND GREATER THAN 2.00
INCHES OF QPF WITH THE HEAVIER RAINFALL LATE THIS AFTERNOON THROUGH
THIS EVENING ACROSS PARTS OF NORTHERN IL...AND GIVEN IMPRESSIVE
RAINFALL RATES IN SOME OF THE HEAVIER SHOWERS SO FAR THIS MORNING
AND SOME REPORTS OF 2+ INCHES OF RAINFALL FROM SOUTHERN/SOUTHEASTERN
IA...EXPECT THAT SOME LOCAL AREAS WITHIN CWA WILL SEE SOME
IMPRESSIVE RAIN AMOUNTS. WHILE VERY LITTLE CLOUD-GROUND LIGHTNING
HAS BEEN DETECTED WITH THIS ACTIVITY...SOLID FORCING...LOCATION OF
CWA WITHIN RIGHT ENTRANCE REGION OF UPPER JET STREAK TRANSLATING
ACROSS ONTARIO/NORTHERN GREAT LAKES...AND  FORECAST SOUNDINGS WHICH
INDICATE DEEP MOIST-ADIABATIC LAPSE RATES SHOULD SUPPORT AT LEAST
OCCASIONAL EMBEDDED THUNDERSTORMS ACROSS THE AREA...FURTHER
ENHANCING POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL.

MID-LEVEL TROUGH AXIS AND SURFACE LOW PRESSURE WAVE ARE PROGGED TO
BE MOVING OUT OF NORTHEAST IL/FAR NORTHWEST INDIANA EARLY MONDAY
MORNING...WITH SURFACE COLD FRONT PUSHING ACROSS THE SOUTHEASTERN
COUNTIES OF THE CWA THROUGH MID-MORNING OR SO. SHARP DRYING IN
MID/UPPER LEVELS NOTED IN FORECAST SOUNDINGS ACROSS THE NORTHWEST
PARTS OF THE CWA BY SUNRISE...THOUGH WOULD SUSPECT SOME LINGERING
LOW CLOUD COVER. RELATIVELY LIGHT SFC WINDS AND VERY MOIST GROUND
CONDITIONS WILL LIKELY SUPPORT SOME FOG DEVELOPMENT EARLY MONDAY
MORNING...POSSIBLY BECOMING LOCALLY DENSE IF LOW CLOUDS CLEAR.
OTHERWISE...SHOULD SEE CLEARING FROM THE NORTHWEST THROUGH THE
MORNING HOURS AS THE SYSTEM PULLS AWAY TO THE EAST AND SURFACE HIGH
PRESSURE DEVELOPS ACROSS THE UPPER MIDWEST. NO REAL PUSH OF COOLER
AIR BEHIND THE FRONT...WITH TEMPS IN THE MID-UPPER 80S ANTICIPATED.
DRIER LOW LEVEL AIR AND LIGHT WINDS ASSOCIATED WITH APPROACHING SFC
HIGH PRESSURE RIDGE SHOULD SET UP COOLER CONDITIONS MONDAY NIGHT
HOWEVER...WITH LOWS IN THE 50S LIKELY AWAY FROM CHICAGO/LAKE
MICHIGAN.

DRY/MILD CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE MID-WEEK
PERIOD AS UPPER RIDGE BUILDS ACROSS THE ROCKIES/HIGH PLAINS AND
TROUGH LINGERS OVER THE EAST COAST. THIS MAINTAINS SURFACE HIGH
PRESSURE OVER THE GREAT LAKES REGION THROUGH WEDNESDAY. ATTENTION
TURNS SOUTH TOWARD ISAAC...WHICH GUIDANCE AND NHC FORECASTS BRING TO
THE GULF COAST WEDNESDAY MORNING. AFTER LANDFALL...VARIOUS MODELS
AND ENSEMBLES CONTINUE TO SHOW CONSIDERABLE SPREAD AND LESS THAN
AVERAGE CONFIDENCE IN WHERE ISAAC WILL TRACK. WHILE GFS AND SOME
GEFS MEMBERS TAKE REMNANTS FARTHER WEST/NORTH...AT THIS POINT HAVE
PUT MORE WEIGHT BEHIND ENSEMBLE MEANS AND 00/12Z ECMWF SOLUTIONS
WHICH BRING ISAAC NORTH INTO THE LOWER OH VALLEY FRIDAY...THEN
NORTHEAST THROUGH THE OH VALLEY THROUGH SATURDAY. THIS MAINTAINS
DRY/WARM CONDITIONS ACROSS THE CWA THURSDAY/FRIDAY IN REGION OF
UPPER RIDGE/ENHANCED SUBSIDENCE NORTH OF REMNANTS OF ISAAC...THEN
BRINGS A CHANCE OF PRECIP MAINLY ACROSS SOUTHERN HALF OF CWA FRIDAY
NIGHT/SATURDAY AS THE SYSTEM MOVES UP THE OHIO VALLEY. BASED ON THIS
SCENARIO HAVE MAINTAINED WARMER TEMPS FROM PREVIOUS FORECAST
THURSDAY AND FRIDAY...WHICH ARE A LITTLE WARMER THAN THE WARMEST
GEFS ENSEMBLE MOS NUMBERS.

RATZER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* BRIEF BREAK IN -SHRA AND RA BEFORE LARGE AREA OF -RA WITH
  EMBEDDED HEAVIER CELLS MOVING IN FROM THE SW WITH HEAVIER RA
  ARRIVING AROUND 00Z.

* VARYING VISIBILITY AND CEILING..WITH MVFR PREVAILING DURING
  HEAVIER RA/SHRA.
* ISOLATED TS THROUGH MID EVENING.

* CEILINGS TRENDING DOWN TO PREVAILING IFR BY MID EVE AND
  REMAINING THROUGH OVERNIGHT...AND VISIBILITIES DURING OVERNIGHT.

TRS

//DISCUSSION...UPDATED 18Z...

WEAK LOW PRESSURE OVER SOUTH-CENTRAL IOWA WILL DRIFT SLOWLY EAST
NORTHEAST TO NORTHERN IL THIS EVENING. A SURGE OF VERY TROPICAL
AIR AHEAD OF THE LOW HAS GENERATED WIDESPREAD RAIN WITH SCATTERED
HEAVIER SHOWERS ACROSS THE AREA...WITH THE HEAVIER SHOWERS
OCCASIONALLY DROPPING VISIBILITY TO IFR LEVELS FOR BRIEF PERIODS.
AS THE MOISTURE CONTINUES TO STREAM INTO THE REGION...CEILINGS
WILL LOWER TO PREVAILING LOWER END MVFR THIS AFTERNOON. WHILE
THERE WILL STILL BE A CHANCE FOR ISOLATED/EMBEDDED THUNDERSTORMS
THIS AFTERNOON...THE LIKELIHOOD OF ANY THUNDERSTORMS TO DIRECTLY
IMPACT THE TERMINALS IS SMALL.

AS THE SFC LOW MOVES OVER NRN IL BY EARLY THIS EVENING...EXPECT
CEILINGS TO CONTINUE TO LOWER...BECOMING PREVAILING IFR.
ALSO...WITH NO SIGNIFICANT PUSH OF COOLER AIR BEHIND THE COLD
FRONT CROSSING THE REGION...DO NOT ANTICIPATE ANY IMPROVEMENT
OVERNIGHT...AND IT IS MORE LIKELY THAT CIGS MAY EVEN DROP EVEN
LOWER...SO HAVE ADDED A TEMPO GROUP FOR 400FT CIGS FOR THE EARLY
MORNING HOURS. SIGNIFICANT IMPROVEMENT IS NOT EXPECTED UNTIL LATER
TOMORROW MORNING WHEN DRIER AIR FINALLY WORKS INTO THE
AREA...BRINGING CLEARING SKIES WITH LIGHT NWLY WINDS FOR TOMORROW.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* MODERATE CONFIDENCE IN TIMING OF HEAVIER SHRA/RA THROUGH LATE
  EVENING.

* HIGH CONFIDENCE OF ISOLATED EMBEDDED TS TIL MID EVENING...WITH
  LOW THREAT OF DIRECTLY IMPACTING TERMINAL.

* LOW TO MODERATE CONFIDENCE ON SPECIFIC CIGS/VSBYS TRENDS FOR
  EVENING.

* MODERATE TO HIGH CONFIDENCE IN TREND OF DETERIORATION DOWN TO
  PREVAILING IFR DURING THE EVENING AND OVERNIGHT.

* LOW TO MODERATE CONFIDENCE ON SPECIFIC TIMING OF IFR TONIGHT.

* HIGH CONFIDENCE IN WINDS.

TRS

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

MONDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.

SATURDAY...VFR. SLIGHT CHANCE TSRA.

ALLSOPP

&&

.MARINE...
236 PM CDT

LOW PRESSURE IS APPROACHING HUDSON BAY THIS AFTERNOON WITH A
SECONDARY AREA OF LOW PRESSURE OVER NORTHERN MISSOURI AND SOUTHERN
IOWA. THIS SECOND LOW WILL MOVE EAST PASSING SOUTH OF LAKE MICHIGAN
TONIGHT...WHILE A FRONTAL BOUNDARY BETWEEN THE TWO LOWS WILL SWEEP
ACROSS LAKE MICHIGAN TURNING WINDS TO THE WEST...THEN NORTHWEST.
MONDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL BEGIN TO BUILD ACROSS
THE UPPER MIDWEST INTO THE WESTERN GREAT LAKES REGION ALLOWING
NORTHERLY WINDS TO DIMINISH. THE HIGH WILL SETTLE TO THE EAST
OVER THE UPPER OHIO VALLEY THURSDAY INTO FRIDAY WHILE ANOTHER AREA
OF LOW PRESSURE MOVES ACROSS THE CANADIAN PRAIRIES. SOUTH TO
SOUTHWESTERLY WINDS WILL FRESHEN UP... PARTICULARLY OVER THE
NORTHERN HALF OF THE LAKE WHERE WINDS OF 20 TO 25 KT ARE
POSSIBLE.

BMD

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
350 PM CDT SUN AUG 26 2012

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
272100-
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-
350 PM CDT SUN AUG 26 2012 /450 PM EDT SUN AUG 26 2012/

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  SCATTERED THUNDERSTORMS...WHICH WILL PRODUCE:
   LOCALLY HEAVY RAINFALL.
   OCCASIONAL CLOUD TO GROUND LIGHTNING.

  AREAS AFFECTED AND TIMING:

  A LARGE AREA OF RAIN AND SCATTERED EMBEDDED THUNDERSTORMS OVER
  PORTIONS OF WESTERN AND NORTHERN ILLINOIS THIS AFTERNOON WILL
  CONTINUE TO SPREAD TO THE EAST NORTHEAST THIS EVENING ACROSS THE
  REMAINDER OF NORTHERN ILLINOIS AND NORTHWEST INDIANA.

  DISCUSSION:

  RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH AN AREA OF LOW
  PRESSURE AND A COLD FRONT WILL PUSH ACROSS THE REGION THIS EVENING.
  ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR...THOUGH OCCASIONAL
  HEAVY SHOWERS EVEN WITHOUT THUNDER WILL BRING LOCALLY HEAVY RAIN OF
  AN INCH OR MORE TO SOME PORTIONS OF NORTHERN ILLINOIS AND NORTHWEST
  INDIANA. THE HEAVIEST RAIN WILL BE ACROSS NORTHERN ILLINOIS DURING
  THE LATE AFTERNOON HOURS...SHIFTING EAST ACROSS NORTHWEST INDIANA
  LATER THIS EVENING AND TONIGHT. THE LOW PRESSURE CENTER AND COLD
  FRONT WILL MOVE OUT OF THE AREA MONDAY MORNING...WITH RAIN ENDING
  FROM NORTHWEST TO SOUTHEAST EARLY IN THE DAY.

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

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS MAINLY ALONG AND SOUTH OF
THE INTERSTATE 80 CORRIDOR FRIDAY NIGHT THROUGH SATURDAY.

.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>745-272100-
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-
350 PM CDT SUN AUG 26 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 THIS EVENING..

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

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS SATURDAY.

&&

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-
870-872-874-876-878-272100-
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-
350 PM CDT SUN AUG 26 2012

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS OVER MAINLY SOUTHERN LAKE
MICHIGAN TONIGHT.

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

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS OVER FAR SOUTHERN LAKE
MICHIGAN SATURDAY.

&&

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

RATZER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
640 PM CDT SUN AUG 26 2012

ILZ012>014-020>022-270145-
KANE-DUPAGE-COOK-KENDALL-GRUNDY-WILL-
INCLUDING THE CITIES OF...AURORA...WHEATON...CHICAGO...OSWEGO...
MORRIS...JOLIET
640 PM CDT SUN AUG 26 2012

...PERIODS OF HEAVY RAIN THIS EVENING...

A LARGE AREA OF SHOWERS...WITH A FEW EMBEDDED THUNDERSTORMS...HAVE
MOVED BACK ACROSS THE CHICAGO METRO AREA EARLY THIS EVENING. THESE
SHOWERS WILL CONTINUE THROUGH MUCH OF THE EVENING BEFORE THEY
BEGIN TO SHIFT SOUTHEAST OF THE AREA LATER TONIGHT. DUE TO THE
LARGE MOISTURE CONTENT IN THE ATMOSPHERE...THESE SHOWERS WILL BE
CAPABLE OF PRODUCING PERIODS OF VERY HEAVY RAINFALL ACROSS THE
AREA. THE HEAVIEST SHOWERS COULD DROP THE VISIBILITIES DOWN AROUND
A MILE AND RESULT IN RAINFALL AMOUNTS UP TO AROUND AN INCH PER
HOUR. THESE HEAVY RAINFALL AMOUNTS WILL LEAD TO PONDING ON AREA
ROADWAYS AND COULD ALSO RESULT IN SOME MINOR FLOODING IN LOW LYING
AREAS. IF TRAVEL IS PLANNED ACROSS THE AREA THIS EVENING...BE
PREPARED FOR RAPID CHANCES IN THE VISIBILITIES WITHIN THE HEAVIER
SHOWERS AND SLOW DOWN TO PREVENT HYDROPLANING.

KJB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
643 PM CDT SUN AUG 26 2012

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

0615 PM     HEAVY RAIN       ESE PONTIAC             40.88N 88.64W
08/26/2012  M1.05 INCH       LIVINGSTON         IL   COCORAHS

            1.05 INCHES SINCE 7 AM WITH 0.42 OF THAT IN THE LAST 60
            MINUTES.

&&

BN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
715 PM CDT SUN AUG 26 2012

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

0705 PM     HEAVY RAIN       3 SW NORTH AURORA       41.77N 88.37W
08/26/2012  M2.63 INCH       KANE               IL   TRAINED SPOTTER

            TOTAL SO FAR WITH 2.00 IN THE LAST 90 MINUTES.

&&

BN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
737 PM CDT SUN AUG 26 2012

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

0645 PM     HEAVY RAIN       1 NW OTTAWA             41.36N 88.85W
08/26/2012  M1.18 INCH       LA SALLE           IL   COCORAHS

            TOTAL SO FAR.

&&

BN