Alert archive / Illinois / Flash Flood Warnings in 2011

Flash Flood Warning 6, NWS Chicago, IL

May 22, 20115 counties in Illinois

NWS Chicago, IL issued this flash flood warning at May 22, 2011, 9:06 PM CDT for 5 counties in Illinois. It was in force for 5 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 22, 2011, 9:06 PM CDT (02:06 UTC)
Expired
May 23, 2011, 1:47 AM CDT
In force
5 hr
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Flood severity
None

Counties Boone County, IL, DeKalb County, IL, Lee County, IL, Ogle County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 115 km from the middle of the area, began a volume at 02:10 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 22, 9:35 PM CDTHEAVY RAIN 25 Nw Polo, ILSINCE 715 PM.
May 22, 11:37 PM CDTHEAVY RAIN 2.423 Nnw Dixon, ILTOTAL RAINFALL IN 6 HOURS. OF THAT TOTAL, 1.5 INCHES FELL FROM 9 TO 10 PM. COCORAHS OBSERVER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.1 hours before the alert went out and 112 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2011-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1935 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2011-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 271 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1935 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
935 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
271 m²/s²
0-3 km storm-relative helicity
364 m²/s²
Significant tornado parameter
3.4
Supercell composite
19.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

578 
WGUS53 KLOT 230206
FFWLOT
ILC007-037-103-141-201-230800-
/O.NEW.KLOT.FF.W.0006.110523T0206Z-110523T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
906 PM CDT SUN MAY 22 2011

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  LEE COUNTY IN NORTH CENTRAL ILLINOIS...
  NORTHWESTERN DE KALB COUNTY IN NORTH CENTRAL ILLINOIS...
  OGLE COUNTY IN NORTH CENTRAL ILLINOIS...
  WESTERN BOONE COUNTY IN NORTH CENTRAL ILLINOIS...
  WINNEBAGO COUNTY IN NORTH CENTRAL ILLINOIS...

* UNTIL 300 AM CDT

* AT 902 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL CONTINUING TO   
  MOVE ACROSS THE WARNED AREA. RADAR RAINFALL ESTIMATES OF UP TO     
  THREE INCHES EXTEND FROM AREAS NEAR POLO NORTHEAST TO FORRESTON    
  AND PECATONICA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BELVIDERE...DIXON...LOVES PARK...MACHESNEY PARK...MOUNT MORRIS...
  OREGON...ROCHELLE...ROCKFORD...ROCKFORD AIRPORT...ROCKTON...SOUTH
  BELOIT...WALTON...AMBOY...ASHTON...BYRON...CHERRY VALLEY...
  DURAND...FORRESTON...FRANKLIN GROVE...HILLCREST...LAKE SUMMERSET...
  PECATONICA...POLO...ROSCOE...STILLMAN VALLEY AND WINNEBAGO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4249 8880 4213 8886 4158 8923 4158 8963
      4192 8963 4193 8969 4220 8970 4221 8940
      4250 8940

$$

RODRIGUEZ
3 follow-up statements
667 
WGUS73 KLOT 230316
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1016 PM CDT SUN MAY 22 2011

ILC007-037-103-141-201-230800-
/O.CON.KLOT.FF.W.0006.000000T0000Z-110523T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
OGLE IL-WINNEBAGO IL-BOONE IL-DE KALB IL-LEE IL-
1016 PM CDT SUN MAY 22 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR LEE...NORTHWESTERN DE
KALB...WESTERN BOONE...WINNEBAGO AND OGLE COUNTIES UNTIL 300 AM
CDT...

AT 1009 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR 
RAINFALL ESTIMATES PRECIPITATION IN EXCESS OF 4 INCHES FELL ACROSS 
PORTIONS OF WESTERN AND SOUTHWESTERN OGLE COUNTY AND FAR 
NORTHWESTERN LEE COUNTY. SHOWERS AND THUNDERSTORMS CONTINUE TO 
DEVELOP WEST AND SOUTHWEST OF THE WARNED AREA AND COULD DROP AN 
ADDITIONAL HALF INCH TO AN INCH OF PRECIPITATION.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
BELVIDERE...DIXON...LOVES PARK...MACHESNEY PARK...MOUNT MORRIS...
OREGON...ROCHELLE...ROCKFORD...ROCKFORD AIRPORT...ROCKTON...SOUTH
BELOIT...WALTON...AMBOY...ASHTON...BYRON...CHERRY VALLEY...DURAND...
FORRESTON...FRANKLIN GROVE...HILLCREST...LAKE SUMMERSET...
PECATONICA...POLO...ROSCOE...STILLMAN VALLEY AND WINNEBAGO.

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 4249 8880 4213 8886 4158 8923 4158 8963
      4192 8963 4193 8969 4220 8970 4221 8940
      4250 8940

$$

BMD
262 
WGUS73 KLOT 230434
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1134 PM CDT SUN MAY 22 2011

ILC007-037-103-141-201-230800-
/O.CON.KLOT.FF.W.0006.000000T0000Z-110523T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
OGLE IL-WINNEBAGO IL-BOONE IL-DE KALB IL-LEE IL-
1134 PM CDT SUN MAY 22 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR LEE...NORTHWESTERN DE
KALB...WESTERN BOONE...WINNEBAGO AND OGLE COUNTIES UNTIL 300 AM
CDT...

AT 1131 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
SHOWERS AND THUNDERSTORMS ACROSS THE WARNED AREA. RADAR RAINFALL 
ESTIMATES THAT PRECIPITATION IN EXCESS OF 4 INCHES FELL ACROSS 
PORTIONS OF WESTERN AND SOUTHWESTERN OGLE COUNTY AND FAR 
NORTHWESTERN LEE COUNTY. SHOWERS AND THUNDERSTORMS ARE 
WEAKENING...BUT LOCALIZED AMOUNTS OF UP TO AN ADDITIONAL QUARTER 
INCH IS POSSIBLE.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
BELVIDERE...DIXON...LOVES PARK...MACHESNEY PARK...MOUNT MORRIS...
OREGON...ROCHELLE...ROCKFORD...ROCKFORD AIRPORT...ROCKTON...SOUTH
BELOIT...WALTON...AMBOY...ASHTON...BYRON...CHERRY VALLEY...DURAND...
FORRESTON...FRANKLIN GROVE...HILLCREST...LAKE SUMMERSET...
PECATONICA...POLO...ROSCOE...STILLMAN VALLEY AND WINNEBAGO.

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 4249 8880 4213 8886 4158 8923 4158 8963
      4192 8963 4193 8969 4220 8970 4221 8940
      4250 8940

$$

BMD
112 
WGUS73 KLOT 230647
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
147 AM CDT MON MAY 23 2011

ILC007-037-103-141-201-230701-
/O.CAN.KLOT.FF.W.0006.000000T0000Z-110523T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
OGLE IL-WINNEBAGO IL-BOONE IL-DE KALB IL-LEE IL-
147 AM CDT MON MAY 23 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR LEE...NORTHWESTERN
DE KALB...WESTERN BOONE...WINNEBAGO AND OGLE 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. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4249 8880 4213 8886 4158 8923 4158 8963
      4192 8963 4193 8969 4220 8970 4221 8940
      4250 8940

$$

BEACHLER

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before this flash flood warning went out at May 22, 7:30 PM CDT, 1 hour 36 minutes earlier.

Area forecast discussion, May 22, 7:30 PM CDT, 1 hour 36 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
730 PM CDT SUN MAY 22 2011

.MESOSCALE DISCUSSION...
205 PM CDT

AS THE ATMOSPHERE CONTINUES TO QUICKLY DESTABILIZE EARLY THIS
AFTERNOON...THUNDERSTORMS CAN BE SEEN DEVELOPING ALONG A REMNANT
BOUNDARY/GRAVITY WAVE PROPAGATING EAST ACROSS PORTIONS OF CENTRAL
ILLINOIS. WITH CU RAPIDLY DEVELOPING AND LATEST GUIDANCE INDICATING
THAT THE ATMOSPHERE HAS BECOME MODERATELY TO STRONGLY UNSTABLE
ACROSS CENTRAL ILLINOIS...ITS QUITE POSSIBLE THAT THERE COULD BE
UPSCALE THUNDERSTORM GROWTH INTO THE SOUTHERN PORTIONS OF THE
CWA...WHICH WOULD INCLUDE AREAS SOUTH OF INTERSTATE 80. THIS IS
OUT AHEAD OF MAIN THUNDERSTORM DEVELOPMENT STILL ONGOING ACROSS
FAR WESTERN ILLINOIS AND EASTERN IOWA. STILL MONITORING THE
OVERALL SEVERE THREAT EARLY THIS AFTERNOON ACROSS THIS AREA...AS
THEIR IS ALMOST A RACE BETWEEN THIS GRAVITY WAVE PUSHING EAST AND
DESTABILIZATION OF THE ATMOSPHERE. EITHER WAY...THUNDERSTORMS TO
PUSH EAST EARLY THIS AFTERNOON ALONG AND SOUTH OF INTERSTATE 80
WITH DAMAGING WINDS AND HAIL THE MAIN THREATS...WITH THE TORNADO
THREAT ISOLATED AT THIS TIME AS FLOW REMAINS WEAKER AND MORE
UNIDIRECTIONAL...WITH HIGH DEWPOINT DEPRESSIONS IN PLACE.

STILL ANTICIPATE THUNDERSTORM DEVELOPMENT OFF TO THE WEST TO
CONTINUE TODAY WITH BETTER CHANCES FOR WIDESPREAD COVERAGE INTO
LATE AFTERNOON AND EVENING. TORNADO THREAT COULD STILL POSSIBLY
INCREASE THIS AFTERNOON INTO THE EVENING AS LOW LEVEL MOISTURE
INCREASES AND LLJ RAMPS UP.

RODRIGUEZ

&&

.DISCUSSION...
326 PM CDT

CURRENT SATELLITE TRENDS/SFC OBSERVATIONS SHOW HIGHER DEW POINT AIR
CONTINUING TO ADVECT RAPIDLY NWD ACROSS AREA.  SURFACE DEW POINTS IN
MID-UPPER 60S WILL OVERSPREAD THE REMAINDER OF NRN IL...AS REGION OF
STEEPER MID LEVEL LAPSE RATES SHIFT EWD ACROSS REGION WITH THE
PROGRESSION OF THE UPPER LOW CENTER OVER SRN MN.  THIS WILL ALLOW
THE AIR MASS OVER THE ENTIRE FORECAST AREA TO BECOME VERY UNSTABLE
HEADING INTO THIS EVENING.  THEREFORE...WILL MAKE LITTLE CHANGE TO
FORECAST POPS...KEEPING LIKELY PROBABILITIES OF THUNDER THROUGH AT
LEAST 06Z OVER WRN CWA...AND OVERNIGHT ACROSS NWRN INDIANA.
SATELLITE IMAGERY ALSO SHOWS TWO AREAS OF VIGOROUS THUNDERSTORM
DEVELOPMENT.  THE LEADING AREA HAS BLOSSOMED ALONG A GRAVITY WAVE
FROM JUST WEST OF STL TO NEAR PONTIAC.  ANVIL GROWTH AND CLOUD TOP
TEXTURE SUGGEST THE STORM OVER LIVINGSTON COUNTY IS VERY INTENSE.
THE NORTHEAST TERMINUS OF THIS LINE HAS SHOWN SOME INCREASED CUMULUS
GROWTH...BUT AT THE MOMENT RELATIVELY LOW DEW POINTS ARE LIMITING
DEVELOPMENT OVER CHICAGO. THIS AREA OF STORMS IS EXPECTED TO
CONTINUE TO INCREASE IN COVERAGE ACROSS NERN/EAST CENTRAL IL INTO
NWRN INDIANA.

ANOTHER AREA OF STORMS IS FORMING A LINE FROM SERN KS...THROUGH ERN
IA AND INTO WRN WI/EAST CENTRAL MN.  THIS LINE IS EXPECTED TO FORM
INTO A SQUALL LINE THIS EVENING...THEN ADVANCE ACROSS THE AREA
DURING THE COURSE OF THE EVENING.   WILL BEGIN TO LOWER POPS BACK
INTO CHC CATEGORY FROM WEST TO EAST AFTER 06Z.

ON MONDAY...CHANCES OF ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT
ARE LOOKING MORE PROBABLE.  DIURNAL HEATING IS FORECAST TO ALLOW SFC
TEMPS TO INCREASE TO AROUND 80...AS REMNANT UPPER LEVEL COLD POOL
ASSD WITH WEAKENING UPPER CIRCULATION OVER THE NRN GREAT LAKES
ALLOWS FOR RATHER STEEP LAPSE RATES TO DEVELOP BY AFTERNOON. FOR NOW
WILL GO WITH INHERITED CHC POPS...BUT SUSPECT THAT
COVERAGE...ESPECIALLY OVER FAR NRN IL...WILL BECOME GREAT ENOUGH TO
BUMP UP TO AT LEAST LIKELY CAT BY 18Z.   THIS ACTIVITY WILL DIMINISH
WITH APPROACH OF SUNSET...AND AS AREA COMES UNDER SUBSIDENT REGION
IN THE WAKE OF DEPARTING SHORT WAVE.

MONDAY NIGHT...A COLD FRONT WILL BE DROPPING SWD ACROSS THE WESTERN
GREAT LAKES REGION.  AS WINDS TURN NE LATE MONDAY NIGHT...AND
INCREASE IN SPEED ON TUESDAY...CHILLY AIR OFF THE LAKES WILL ACCOUNT
FOR ABOUT A 25 DEGREE 24-HOUR DROP IN TEMPS IN SOME AREAS...THUS
WILL MAINTAIN "MUCH COOLER" TERMINOLOGY IN FORECAST.

TUESDAY IS EXPECTED TO BE CLOUDY AND COOL...BUT DRY AS AREA COMES
UNDER RIDGING BOTH SFC AND ALOFT.

BY LATE TUESDAY NIGHT...POPS TO BEGIN TO INCREASE AGAIN FROM S-N AS
ZONE OF INCREASING THETA-E CONVERGENCE DEVELOPS IN RESPONSE TO
STRENGTHENING LOW LEVEL JET AHEAD OF THE NEXT SOUTHERN PLAINS LOW.
THIS NEXT SYSTEM IS THEN TO PASS JUST SOUTH OF THE FORECAST AREA
WED-WED NIGHT. GUIDANCE FAIRLY CONSISTENT IN DEVELOPING A STRONG
FRONTOGENETIC ZONE FROM ERN KS...NEWD TO SRN LOWER MI. IN ADDITION
TO A HIGH PRECIPITATION THREAT...TEMPERATURES WILL LIKELY VARY BY AT
LEAST 20 DEG ACROSS THE REGION ON WEDNESDAY.  PRECIPITATION THREAT
WILL SLOWLY DIMINISH THURSDAY INTO THURSDAY EVENING AS THIS SYSTEM
HEADS EAST.

EXTENDED PERIOD...AFTER A COOL PERIOD FRIDAY...INCREASING SLY-SWLY
FLOW NEXT WEEKEND...AS SFC HIGH HEADS TO EAST OF REGION...AND WITH
UPPER LEVEL HEIGHTS FORECAST TO UNDERGO SIGNIFICANT RISES...MEMORIAL
DAY WEEKEND MAY ACTUALLY TURN RATHER SUMMERLIKE.

MERZLOCK

&&

.AVIATION...

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

* TIMING AND INTENSITY OF THUNDERSTORMS AND THEIR IMPACT ON THE
  TERMINALS THIS EVENING
* POTENTIAL FOR DAMAGING WIND GUSTS AND HAIL
* TORNADO WATCH REMAINS IN EFFECT UNTIL 10 PM CDT

ED F

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

AIR MASS REMAINS UNSTABLE BETWEEN LINES OF THUNDERSTORMS OVER THE
LOCAL AREA THIS EVENING ESPECIALLY NORTH AND WEST OF THE
TERMINALS. LOW LEVEL JET STREAK CONTINUES TO PUMP WARM MOIST AIR
IN THE LOW LEVELS OF THE ATMOSPHERE NORTHWARD. INSTABILITY
COMBINED WITH SHEAR DUE TO VEERING AND INCREASING WINDS WITH
HEIGHT FUELING EXPLOSIVE THUNDERSTORMS WITH DAMAGING WIND GUSTS IN
EXCESS OF 60 KTS AND HAIL UP TO GOLF BALL SIZED.

AIR MASS OVER TERMINALS AND POINTS EAST AND SOUTH LESS UNSTABLE DUE
TO EARLIER CONVECTION. CELLS TO THE WEST STILL ON TRACK TO
COALESCE INTO SOMEWHAT OF A SQUALL LINE BEFORE MOVING EAST ACROSS
ORD/MDW TERMINALS THIS EVENING. TIMING OF SUCH LOOKING TO BE
BETWEEN 0130Z AND 03Z WITH LINGERING SHOWERS HANGING AROUND A
COUPLE OF HOURS AFTER THAT.

ED F

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

* MEDIUM CONFIDENCE IN THE TIMING OF A SQUALL LINE TO PLOW ACROSS
  THE AREA THIS EVENING... IMPACTING ORD AND MDW BETWEEN 02Z TO
  0330Z.
* LOW CONFIDENCE THAT DAMAGING WINDS OR LARGE HAIL MAY IMPACT
  TERMINALS - PLEASE MONITOR FOR LATER WARNINGS

ED F

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

TUESDAY...VFR.

WEDNESDAY...VFR OCNL MVFR SHOWERS.

THURSDAY...VFR.

FRIDAY...VFR.

SATURDAY...VFR SCT SHOWERS.

ED F

&&

.MARINE...
437 PM CDT

INTENSE LOW PRESSURE OVER MINNESOTA WILL MOVE NORTHEAST TO LAKE
SUPERIOR TONIGHT MAINTAINING A BRISK SOUTHERLY FLOW ACROSS LAKE
MICHIGAN. WARM MOIST AIR MASS MOVING OVER CHILLY WATERS RESULTING
IN VERY STABLE PROFILE NEAR THE LAKE SURFACE INHIBITING HIGHER
WINDS FROM MIXING DOWN. THIS SCENARIO ALSO RESULTING IN AREAS OF
DENSE FOG ACROSS THE LAKE. LEADING COLD FRONT WILL SWEEP SOUTHEAST
ACROSS THE LAKE LATE TONIGHT AND EARLY MONDAY WITH A SECONDARY
COLD FRONT DROPPING SOUTH ACROSS THE LAKE MONDAY NIGHT.

A STRONG AREA OF HIGH PRESSURE WILL BUILD SOUTHWARD INTO ONTARIO
BY MID WEEK AS AN AREA OF LOW PRESSURE ORGANIZES OVER THE CENTRAL
PLAINS. THE LOW WILL MOVE EAST INTO THE LOWER OHIO VALLEY BY
THURSDAY RESULTING IN A BRISK NE FLOW ACROSS LAKE MICHIGAN.

ED F

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
Hazardous weather outlook, May 22, 4:26 PM CDT, 4 hours 40 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
426 PM CDT SUN MAY 22 2011

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
232130-
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-
426 PM CDT SUN MAY 22 2011 /526 PM EDT SUN MAY 22 2011/

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

.DAY ONE...TONIGHT.

* WEATHER HAZARDS EXPECTED:

  THUNDERSTORMS...SOME OF WHICH MAY PRODUCE:

  VERY LARGE HAIL.
  DAMAGING WINDS.
  A FEW TORNADOES.

* AREAS AFFECTED AND TIMING:

  A LINE OF SEVERE THUNDERSTORMS FROM SOUTHERN LAKE
  MICHIGAN...SOUTHWEST ALONG INTERSTATE 57 THROUGH FORD
  COUNTY...WILL CONTINUE NORTHEAST ACROSS EAST CENTRAL ILLINOIS
  AND NORTHWEST INDIANA THROUGH 6 PM CDT THIS EVENING.

  A SECOND LINE OF STORMS...NOW APPROACHING THE MISSISSIPPI
  RIVER...WILL BE REACHING AREAS WEST OF INTERSTATE 39 AFTER 7 PM
  CDT...AND WILL REACH THE CHICAGO AREA AFTER 9 PM CDT.

* DISCUSSION: LOW PRESSURE CENTERED OVER CENTRAL MINNESOTA WILL
  CONTINUE TO LIFT NORTHEAST ACROSS NORTHWEST WISCONSIN TONIGHT.
  AS IT DOES SO...A POOL OF VERY UNSTABLE AIR AHEAD OF THIS SYSTEM
  WILL CONTINUE TO STREAM NORTHWARD ACROSS THE OUTLOOK AREA.
  MEANWHILE...A 70 KT MID LEVEL JET MAX WILL PUNCH ACROSS THE
  UPPER MISSISSIPPI VALLEY. WIND PROFILES SUGGEST THAT SOME
  DISCRETE STORMS THAT FORM THROUGH EARLY THIS EVENING WILL LIKELY
  BECOME SUPERCELLULAR...WITH A POTENTIAL FOR A FEW TORNADOES
  AND VERY LARGE HAIL. THIS IS MOST LIKELY FROM EASTERN IOWA AND
  FAR NORTHEAST MISSOURI...NORTHEASTWARD ACROSS ADJACENT AREAS OF
  WISCONSIN...AND WESTERN THROUGH NORTH CENTRAL ILLINOIS.

  DURING THE EVENING HOURS...THESE STORMS ARE EXPECTED TO EVOLVE
  INTO A SQUALL LINE AT THE NOSE OF THE MID LEVEL JET MAX. THIS
  WILL SUPPORT BOWING STRUCTURES WITHIN THIS LINE...WITH THE
  PRIMARY SEVERE THREAT SHIFTING MORE TO A DAMAGING STRAIGHT LINE
  WIND EVENT ACROSS NORTHEAST ILLINOIS AND NORTHWEST INDIANA
  THROUGH THE EVENING HOURS.

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

THERE WILL BE PERIODIC CHANCES OF THUNDERSTORMS MONDAY INTO
MONDAY NIGHT.

THUNDERSTORMS ARE LIKELY ACROSS THE AREA WEDNESDAY INTO WEDNESDAY
NIGHT. A CHANCE OF THUNDERSTORMS WILL REMAIN FROM EAST CENTRAL
ILLINOIS ACROSS NORTHWEST INDIANA ON THURSDAY.

PORTIONS OF THE KANKAKEE RIVER IN NORTHWEST INDIANA WILL REMAIN
IN FLOOD MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS WILL BE NEEDED THROUGH THIS EVENING.

&&

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

LMZ740>745-232130-
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-
426 PM CDT SUN MAY 22 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.

THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS NORTHERN ILLINOIS
AND NORTHWEST INDIANA THIS EVENING. SOME STORMS MAY BECOME SEVERE
AND PRODUCE LARGE HAIL...INTENSE LIGHTNING...AND WIND GUSTS IN
EXCESS OF 50 KT.

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

THERE IS A CHANCE OF THUNDERSTORMS MONDAY INTO MONDAY NIGHT.

THUNDERSTORMS ARE LIKELY WEDNESDAY AND WEDNESDAY NIGHT...WITH A
SLIGHT CHANCE OF THUNDERSTORMS LINGERING INTO THURSDAY.

&&

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-
870-872-874-876-878-232130-
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-
426 PM CDT SUN MAY 22 2011

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

.DAY ONE...TONIGHT.

THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS EVENING. SOME STORMS
MAY BECOME SEVERE AND PRODUCE LARGE HAIL...INTENSE LIGHTNING...AND
WIND GUSTS IN EXCESS OF 50 KT.

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

THUNDERSTORMS ARE LIKELY WEDNESDAY AND WEDNESDAY NIGHT ON
SOUTHERN LAKE MICHIGAN WITH A CHANCE OF THUNDERSTORMS CENTRAL
SECTIONS.

&&

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

MERZLOCK

In the hours before

Local storm report, May 22, 8:26 PM CDT, 40 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
826 PM CDT SUN MAY 22 2011

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

0725 PM     TSTM WND DMG     HEBRON                  42.47N 88.43W
05/22/2011                   MCHENRY            IL   TRAINED SPOTTER

            AT LEAST 8 LARGE TREES UPROOTED BLOWN DOWN IN HEBRON AREA
            IN A NORTHWEST TO SOUTHEAST DIRECTION...INDICATIVE OF
            STRAIGHT LINE WIND DAMAGE. ESTIMATED 10 INCH DIAMETER
            TREES.7 POWERPOLES BLOWN DOWN ALONG ROUTE 47 3 MILES
            SOUTH OF HEBRON.

&&

RC
Local storm report, May 22, 8:34 PM CDT, 32 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
834 PM CDT SUN MAY 22 2011

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

0725 PM     TSTM WND DMG     HEBRON                  42.47N 88.43W
05/22/2011                   MCHENRY            IL   TRAINED SPOTTER

            POWER OUT EAST OF ROUTE 47. LARGE TREES DOWN. FENCE DOWN
            AT SCHOOL.

&&

RC
Local storm report, May 22, 8:41 PM CDT, 25 minutes before
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
841 PM CDT SUN MAY 22 2011

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

0251 PM     TSTM WND GST     PONTIAC                 40.88N 88.64W
05/22/2011  M60.00 MPH       LIVINGSTON         IL   TRAINED SPOTTER

            ALSO REPORTED NICKEL SIZE HAIL.

0303 PM     HAIL             ARLINGTON HEIGHTS       42.09N 87.98W
05/22/2011  E0.50 INCH       COOK               IL   EMERGENCY MNGR

            DIME SIZED HAIL AT ARLINGTON HEIGHTS RD AND GOLF RD

0305 PM     HAIL             1 NW VILLA PARK         41.90N 87.99W
05/22/2011  E0.25 INCH       DUPAGE             IL   TRAINED SPOTTER

            PEA SIZE HAIL. COCORAHS OBSERVER.

0306 PM     HAIL             LOMBARD                 41.87N 88.01W
05/22/2011  E0.75 INCH       DUPAGE             IL   TRAINED SPOTTER

            PENNY SIZED HAIL

0307 PM     HAIL             ARLINGTON HEIGHTS       42.09N 87.98W
05/22/2011  E1.00 INCH       COOK               IL   TRAINED SPOTTER

            E SEEGARS RD

0310 PM     HAIL             LOMBARD                 41.87N 88.01W
05/22/2011  E1.00 INCH       DUPAGE             IL   TRAINED SPOTTER

            W MADISON ST

0318 PM     TSTM WND GST     FORREST                 40.75N 88.41W
05/22/2011  M60.00 MPH       LIVINGSTON         IL   TRAINED SPOTTER

            POWER WENT OUT

0320 PM     HAIL             RIVERWOODS              42.17N 87.90W
05/22/2011  E0.25 INCH       LAKE               IL   TRAINED SPOTTER

            1/4 IN TO 3/8 IN HAIL. COCORAHS OBSERVER.

0326 PM     HAIL             2 NW MELROSE PARK       41.92N 87.89W
05/22/2011  E0.25 INCH       COOK               IL   TRAINED SPOTTER

            1/4 INCH TO 3/8 INCH

0326 PM     HAIL             5 W BOURBONNAIS         41.16N 87.98W
05/22/2011  E0.25 INCH       KANKAKEE           IL   AMATEUR RADIO

            3000 N AND 5000 W

0335 PM     HAIL             OLYMPIA FIELDS          41.52N 87.69W
05/22/2011  E0.50 INCH       COOK               IL   AMATEUR RADIO

            DIME SIZED HAIL AT VOLLMER AND GOVERNORS HWY.

0336 PM     HAIL             1 S WAUKEGAN            42.36N 87.87W
05/22/2011  E0.88 INCH       LAKE               IL   TRAINED SPOTTER

            NEAR JACKSON AND BELVIDERE RD.

0339 PM     HAIL             BRADLEY                 41.15N 87.86W
05/22/2011  M0.50 INCH       KANKAKEE           IL   TRAINED SPOTTER

            PEA TO MARBLE SIZE HAIL REPORTED AT RT. 50 AND NORTH
            STREET.

0339 PM     HAIL             NORTH CHICAGO           42.32N 87.86W
05/22/2011  E0.75 INCH       LAKE               IL   TRAINED SPOTTER

            1/2 IN TO 3/4 IN HAIL AT 5TH AND SHERIDAN.

0340 PM     HAIL             CHICAGO                 41.88N 87.63W
05/22/2011  E1.00 INCH       COOK               IL   TRAINED SPOTTER

            3/4 IN TO 1 INCH HAIL. 59TH AND HALSTEAD. LASTED AROUND 8
            MINUTES.

0340 PM     HAIL             KANKAKEE                41.12N 87.86W
05/22/2011  E0.50 INCH       KANKAKEE           IL   TRAINED SPOTTER

            CURTIS AND GRACE

0340 PM     TSTM WND DMG     KANKAKEE                41.12N 87.86W
05/22/2011                   KANKAKEE           IL   TRAINED SPOTTER

            WEST SIDE OF CITY - 4-6 INCH DIA TREE BRANCHES DOWN. ONE
            10 INCH DIA TREE DOWN AT SMALL PARK AND A LARGE BRANCH
            FELL ON A VAN ON WEST HAWKINS ST.

0341 PM     HAIL             KANKAKEE                41.12N 87.86W
05/22/2011  E0.50 INCH       KANKAKEE           IL   TRAINED SPOTTER

0342 PM     HAIL             KANKAKEE                41.12N 87.86W
05/22/2011  E0.75 INCH       KANKAKEE           IL   AMATEUR RADIO

            GRINNEL RD AND I-57.

0343 PM     HAIL             KANKAKEE                41.12N 87.86W
05/22/2011  E0.88 INCH       KANKAKEE           IL   TRAINED SPOTTER

            NEAR CURTIS AND STATION ST.

0343 PM     TSTM WND DMG     ASHKUM                  40.88N 87.95W
05/22/2011                   IROQUOIS           IL   EMERGENCY MNGR

            TREE DOWN AND GRAIN BIN BLOWN OVER.

0345 PM     HAIL             CHICAGO                 41.88N 87.63W
05/22/2011  E0.50 INCH       COOK               IL   PUBLIC

            DIME TO PEA SIXED HAIL. FAR WEST SIDE. CUMBERLAND AND
            IRVING PARK RD.

0346 PM     HAIL             BRADLEY                 41.15N 87.86W
05/22/2011  E1.50 INCH       KANKAKEE           IL   TRAINED SPOTTER

            NORTH ST AND IL-50.

0348 PM     HAIL             3 N BEECHER             41.39N 87.61W
05/22/2011  E0.50 INCH       WILL               IL   TRAINED SPOTTER

            PEA TO DIME SIZED HAIL AT I394 AND GOODNOW RD.

0353 PM     HAIL             2 S BEECHER             41.32N 87.61W
05/22/2011  E1.25 INCH       WILL               IL   TRAINED SPOTTER

            2 MILES S OF BEECHER ON IL-1.

0355 PM     HAIL             CHICAGO                 41.88N 87.63W
05/22/2011  E0.25 INCH       COOK               IL   AMATEUR RADIO

            HAIL, 2 TO 2 1/2 INCHES IN DEPTH, COVERING THE GROUND.

0356 PM     HAIL             1 S BEECHER             41.33N 87.61W
05/22/2011  E1.75 INCH       WILL               IL   STORM CHASER

            TRAVELING SOUTHWARD ON IL-1

0400 PM     HEAVY RAIN       PONTIAC                 40.88N 88.64W
05/22/2011  E1.12 INCH       LIVINGSTON         IL   TRAINED SPOTTER

            RAINFALL IN 30 MINUTES. WATER OVERFLOWING MANY STREETS.
            NICKEL TO QUARTER SIZE HAIL OCCURRED EARLIER. COCORAHS
            OBSERVER.

0402 PM     HAIL             BEECHER                 41.35N 87.61W
05/22/2011  E1.25 INCH       WILL               IL   EMERGENCY MNGR

            QUARTER TO HALF DOLLER SIZED HAIL AT ASHLAND RD AND
            PEOTONE-BEECHER RD. HOUSE FIRE STARTED BY LIGHTNING.

0411 PM     HAIL             HAMMOND                 41.62N 87.49W
05/22/2011  E0.50 INCH       LAKE               IN   PUBLIC

            NORTH HAMMOND. HAIL SLIGHTLY LARGER THAN 1/2 INCH IN
            SIZE. RELAYED BY CHICAGO FOX NEWS.

0412 PM     HAIL             WHITING                 41.68N 87.49W
05/22/2011  E1.00 INCH       LAKE               IN   PUBLIC

            RELAYED BY CHICAGO FOX NEWS.

0418 PM     HAIL             CEDAR LAKE              41.37N 87.44W
05/22/2011  E0.25 INCH       LAKE               IN   EMERGENCY MNGR

0419 PM     FLOOD            GRANT PARK              41.24N 87.64W
05/22/2011                   KANKAKEE           IL   AMATEUR RADIO

            4000 E AND 9000 N - WATER COER ROADS.

0425 PM     HEAVY RAIN       3 SSE BEECHER           41.31N 87.59W
05/22/2011  E1.09 INCH       WILL               IL   TRAINED SPOTTER

            RAINFALL IN 40 MINUTES. 1/2 IN TO 3/4 IN HAIL FROM 350 PM
            TO 410 PM. COCORAHS OBSERVER.

0430 PM     HAIL             5 NNW POLO              42.05N 89.62W
05/22/2011  E0.75 INCH       OGLE               IL   CO-OP OBSERVER

0434 PM     TSTM WND GST     CRESCENT CITY           40.77N 87.86W
05/22/2011  E60.00 MPH       IROQUOIS           IL   EMERGENCY MNGR

            ESTIMATED WIND GUSTS OF 50 TO 60 MPH.

0437 PM     TSTM WND DMG     RENSSELAER              40.94N 87.15W
05/22/2011                   JASPER             IN   TRAINED SPOTTER

            POSSIBLE TORNADO. 1/4 MILE NORTH OF TOWN ALONG ROUTE 231.
            DAMAGE TO 2 BUILDINGS AND ONE BUILDING, FARM BUREAU
            OFFICE, DESTROYED. ONE BUILDING ON FIRE. LOTS OF POWER
            LINES DOWN.

0445 PM     HAIL             DIXON                   41.85N 89.48W
05/22/2011  E0.50 INCH       LEE                IL   TRAINED SPOTTER

0447 PM     TSTM WND DMG     4 W BUCKLEY             40.60N 88.11W
05/22/2011                   IROQUOIS           IL   EMERGENCY MNGR

            POWER POLES DOWN BETWEEN GILMAN AND GIBSON CITY.

0452 PM     FLOOD            WATSEKA                 40.78N 87.73W
05/22/2011                   IROQUOIS           IL   EMERGENCY MNGR

            RAINFALL CAUSING STREET FLOODING.

0455 PM     TSTM WND GST     CISSNA PARK             40.57N 87.89W
05/22/2011  E63.00 MPH       IROQUOIS           IL   EMERGENCY MNGR

            AT 1359 E RD AND 1129 N RD.

0506 PM     HAIL             MOUNT MORRIS            42.05N 89.43W
05/22/2011  E0.75 INCH       OGLE               IL   AMATEUR RADIO

0509 PM     HAIL             MOUNT MORRIS            42.05N 89.43W
05/22/2011  E1.00 INCH       OGLE               IL   TRAINED SPOTTER

0519 PM     HAIL             OREGON                  42.01N 89.34W
05/22/2011  E0.25 INCH       OGLE               IL   PUBLIC

            RELAYED BY WREX-TV ROCKFORD

0520 PM     HAIL             BYRON                   42.13N 89.26W
05/22/2011  E0.25 INCH       OGLE               IL   PUBLIC

0525 PM     HEAVY RAIN       5 W WATSEKA             40.78N 87.83W
05/22/2011  E1.61 INCH       IROQUOIS           IL   TRAINED SPOTTER

            RAINFALL IN 75 MINUTES. PEA SIZED HAIL FELL DURING STORM.

0535 PM     HAIL             LOVES PARK              42.34N 89.01W
05/22/2011  E0.50 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            CLINTON RD AND WINDSOR.

0536 PM     HAIL             LOVES PARK              42.34N 89.01W
05/22/2011  E1.00 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            US 251 AND LOVES PARK DR.

0540 PM     TSTM WND DMG     8 NE FOWLER             40.70N 87.21W
05/22/2011                   BENTON             IN   PUBLIC

            COUNTY RD 800E AND 400N. TREE DOWN FELL ON OTHER TREES
            AND CAUSED DAMAGE TO LAWN DECORATIONS

0547 PM     HAIL             MACHESNEY PARK          42.36N 89.04W
05/22/2011  E0.25 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            US 251 AND FOREST HILLS RD.

0605 PM     HAIL             PECATONICA              42.31N 89.36W
05/22/2011  E1.25 INCH       WINNEBAGO          IL   PUBLIC

            RELAYED BY WREX-TV

0606 PM     HAIL             PECATONICA              42.31N 89.36W
05/22/2011  E0.25 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            N OF US-20

0634 PM     TSTM WND GST     MOUNT MORRIS            42.05N 89.43W
05/22/2011  E80.00 MPH       OGLE               IL   TRAINED SPOTTER

            70 TO 80 MPH NEARLY SUSTAINED FOR 5 TO 6 MINUTES. POWER
            POLES SNAPPED. JUST S OF TOWN. ALSO PEA SIZED HAIL.

0635 PM     TSTM WND DMG     5 SSE MOUNT MORRIS      41.98N 89.39W
05/22/2011                   OGLE               IL   TRAINED SPOTTER

            BARNS AND BUILDINGS BLOWN APART

0635 PM     TSTM WND DMG     ROSCOE                  42.42N 89.01W
05/22/2011                   WINNEBAGO          IL   PUBLIC

            TREE KNOCKED DOWN ACROSS ROAD.

0643 PM     TSTM WND DMG     WINNEBAGO               42.27N 89.24W
05/22/2011                   WINNEBAGO          IL   TRAINED SPOTTER

            NUMEROUS 1 FOOT DIAMETER TREES DOWN

0649 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  M0.75 INCH       WINNEBAGO          IL   AMATEUR RADIO

            IN SOUTHWEST ROCKFORD.

0649 PM     TSTM WND GST     ROCKFORD                42.27N 89.06W
05/22/2011  E70.00 MPH       WINNEBAGO          IL   TRAINED SPOTTER

            ALPINE ROAD AND HARRISON AVENUE IN SOUTHEAST ROCKFORD.

0649 PM     TSTM WND DMG     ROCKFORD                42.27N 89.06W
05/22/2011                   WINNEBAGO          IL   AMATEUR RADIO

            SEVERAL 4-5 INCH DIAMETER TREE BRANCHES DOWN.

0650 PM     TSTM WND DMG     WINNEBAGO               42.27N 89.24W
05/22/2011                   WINNEBAGO          IL   BROADCAST MEDIA

            LARGE TREE BRANCHES DOWN AND DEBRIS FLYING THROUGH THE
            AIR OUTSIDE WREX STUDIOS.

0650 PM     TSTM WND GST     ROCKFORD                42.27N 89.06W
05/22/2011  E75.00 MPH       WINNEBAGO          IL   TRAINED SPOTTER

            NEAR I-90 AND BUS US-20.

0650 PM     TSTM WND DMG     ROCKFORD                42.27N 89.06W
05/22/2011                   WINNEBAGO          IL   PUBLIC

            ROOF DAMAGE AT KENNEDY MIDDLE SCHOOL. RELAYED BY WREX.

0650 PM     TSTM WND DMG     ROCKFORD                42.27N 89.06W
05/22/2011                   WINNEBAGO          IL   PUBLIC

            *** 1 INJ *** TREE FELL ONTO HOUSE ON CROSBY STREET.
            RELAYED BY WREX.

0650 PM     TSTM WND GST     ROCKFORD                42.27N 89.06W
05/22/2011  E50.00 MPH       WINNEBAGO          IL   TRAINED SPOTTER

            SEVERAL SMALL TREE BRANCHES/LIMBS DOWN IN EAST CENTRAL
            ROCKFORD

0650 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  E1.00 INCH       WINNEBAGO          IL   PUBLIC

            HUFFMAN BLVD AND AUBURN ST.

0650 PM     HAIL             STILLMAN VALLEY         42.10N 89.18W
05/22/2011  M0.88 INCH       OGLE               IL   TRAINED SPOTTER

            JUST NORTH OF TOWN ALONG STILLMAN VALLEY ROAD. ALSO
            ESTIMATED 45-50 MPH WIND GUSTS.

0653 PM     HAIL             4 NW ROCKFORD           42.31N 89.12W
05/22/2011  E1.00 INCH       WINNEBAGO          IL   CO-OP OBSERVER

            NICKEL TO QUARTER SIZE

0654 PM     TSTM WND DMG     MACHESNEY PARK          42.36N 89.04W
05/22/2011                   WINNEBAGO          IL   TRAINED SPOTTER

            TREE LIMBS DOWN. SMALL HAM RADIO TOWERS DOWN.

0654 PM     TSTM WND GST     ROCKFORD AIRPORT        42.20N 89.10W
05/22/2011  M61.00 MPH       WINNEBAGO          IL   ASOS

0655 PM     TSTM WND GST     ROCKFORD                42.27N 89.06W
05/22/2011  E70.00 MPH       WINNEBAGO          IL   TRAINED SPOTTER

            EAST SIDE OF ROCKFORD

0656 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  E1.00 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            ALPINE ROAD AND HARRISON ROAD IN SOUTHEAST ROCKFORD.

0656 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  E0.75 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            IN EAST CENTRAL ROCKFORD.

0658 PM     TSTM WND DMG     ROSCOE                  42.42N 89.01W
05/22/2011                   WINNEBAGO          IL   PUBLIC

            FLAGPOLE AT DAIRY QUEEN BENT IN HALF. RELAYED BY WREX.

0700 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  E1.50 INCH       WINNEBAGO          IL   TRAINED SPOTTER

0700 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  E1.25 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            COVERING GROUND...NORTHEAST PORTION OF THE CITY.

0700 PM     HAIL             ROCKFORD                42.27N 89.06W
05/22/2011  E1.25 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            COURT AND JOHN ST. NORTH OF DOWNTOWN.

0704 PM     TSTM WND DMG     BELVIDERE               42.25N 88.85W
05/22/2011                   BOONE              IL   TRAINED SPOTTER

            SMALL TREE BRANCHES BLOWN DOWN. ESTIMATED WIND GUSTS
            ABOUT 50 MPH.

0709 PM     TSTM WND GST     ROSCOE                  42.42N 89.01W
05/22/2011  E60.00 MPH       WINNEBAGO          IL   TRAINED SPOTTER

            PEA SIZED HAIL AND TREE LIMBS DOWN.

0710 PM     HAIL             BELVIDERE               42.25N 88.85W
05/22/2011  E1.00 INCH       BOONE              IL   PUBLIC

            NEAR I90 AND US 20. 1/4 MI E OF CHRYSLER PLANT.

0714 PM     HAIL             BELVIDERE               42.25N 88.85W
05/22/2011  E0.25 INCH       BOONE              IL   TRAINED SPOTTER

0725 PM     TSTM WND DMG     HEBRON                  42.47N 88.43W
05/22/2011                   MCHENRY            IL   TRAINED SPOTTER

            AT LEAST 8 LARGE TREES UPROOTED BLOWN DOWN IN HEBRON AREA
            IN A NORTHWEST TO SOUTHEAST DIRECTION...INDICATIVE OF
            STRAIGHT LINE WIND DAMAGE. ESTIMATED 10 INCH DIAMETER
            TREES.7 POWERPOLES BLOWN DOWN ALONG ROUTE 47 3 MILES
            SOUTH OF HEBRON.

0725 PM     TSTM WND DMG     HEBRON                  42.47N 88.43W
05/22/2011                   MCHENRY            IL   TRAINED SPOTTER

            POWER OUT EAST OF ROUTE 47. LARGE TREES DOWN. FENCE DOWN
            AT SCHOOL.

0819 PM     TSTM WND GST     MENDOTA                 41.55N 89.12W
05/22/2011  E60.00 MPH       LA SALLE           IL   NWS EMPLOYEE

            WIND GUSTS ESTIMATED TO 60 MPH. NOTED BRANCHES DOWN AND
            SHELF CLOUD OVERHEAD...MOVING NORTHEAST.

&&

SHEA
Local storm report, May 22, 8:54 PM CDT, 12 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
854 PM CDT SUN MAY 22 2011

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

0545 PM     FLASH FLOOD      WATSEKA                 40.78N 87.73W
05/22/2011                   IROQUOIS           IL   EMERGENCY MNGR

            STREETS CLOSED AND BARRICADED DUE TO FLOODING.

&&

RC
Local storm report, May 22, 8:58 PM CDT, 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
858 PM CDT SUN MAY 22 2011

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

0704 PM     TSTM WND DMG     POPLAR GROVE            42.37N 88.82W
05/22/2011                   BOONE              IL   EMERGENCY MNGR

            TREES AND WIRES DOWN ALL ACROSS NORTHERN PORTION OF
            COUNTY.

&&

RC
Local storm report, May 22, 9:06 PM CDT, 0 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
906 PM CDT SUN MAY 22 2011

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

0828 PM     HAIL             WAUCONDA                42.27N 88.14W
05/22/2011  E0.88 INCH       LAKE               IL   TRAINED SPOTTER

            AT INTERSECTION OF ROUTE 12 AND OLD MCHENRY ROAD.

&&

RC

The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 7:10 PM CDTAreal Flood AdvisoryLOTBoone, Lee, Ogle, Winnebago119 min
May 22, 7:22 PM CDTSevere Thunderstorm WarningLOTLake, McHenry53 min
May 22, 7:29 PM CDTSevere Thunderstorm WarningLOTLee, Ogle, Winnebago61 min
May 22, 8:10 PM CDTSevere Thunderstorm WarningLOTLaSalle50 min
May 22, 8:15 PM CDTSevere Thunderstorm WarningLOTBoone, DeKalb, McHenry60 min
May 22, 8:17 PM CDTSevere Thunderstorm WarningLOTLake, McHenry58 min
May 22, 8:22 PM CDTSpecial Marine WarningLOT113 min
May 22, 8:51 PM CDTSevere Thunderstorm WarningLOTCook, DeKalb, Kane26 min
May 22, 9:32 PM CDTAreal Flood WarningLOTIroquois3 hr
May 22, 9:38 PM CDTSevere Thunderstorm WarningLOTDeKalb, Lee, Ogle52 min
May 22, 9:50 PM CDTSevere Thunderstorm WarningLOTLaSalle, Lee37 min
May 22, 10:24 PM CDTSpecial Weather StatementLOTDeKalb, DuPage, Kane, Kendall, McHenry66 min
May 22, 10:25 PM CDTSpecial Marine WarningLOT59 min
May 22, 11:07 PM CDTSpecial Weather StatementLOTDuPage, Kane, Kendall, Lake53 min
May 23, 9:53 AM CDTSmall Craft AdvisoryLOT9 hr

Nearby

Flash Flood Warnings in Illinois, 2011Every flash flood warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.