A weak upper-level disturbance interacting with a very warm and humid airmass triggered isolated thunderstorms during the morning of July 11th. The storms produced wind damage across parts of southern and eastern Fulton County before dissipating as they tracked further eastward.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS ILX wrote it up.
A weak upper-level disturbance interacting with a very warm and humid airmass triggered isolated thunderstorms during the morning of July 11th. The storms produced wind damage across parts of southern and eastern Fulton County before dissipating as they tracked further eastward.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Lincoln, IL wrote its last area forecast discussion before the first event at Jul 11, 4:53 AM CST, 1 hour 22 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 553 AM CDT MON JUL 11 2011 .DISCUSSION... ISSUED 300 AM CDT MON JUL 11 2011 MAIN WEATHER STORY IN THE IMMEDIATE SHORT-TERM WILL BE THE HEAT AND HUMIDITY TODAY...AS AFTERNOON HEAT INDEX VALUES RISE WELL ABOVE 100 DEGREES. FURTHER OUT...ATTENTION TURNS TO CONVECTION CHANCES AND COOLER TEMPS AS FRONTAL BOUNDARY DROPS SOUTHWARD INTO CENTRAL ILLINOIS. SHORT TERM...TODAY THROUGH WEDNESDAY SEVERAL CLUSTERS OF THUNDERSTORMS HAVE DEVELOPED ALONG SYNOPTIC COLD FRONT STRETCHING FROM MINNESOTA TO NEBRASKA EARLY THIS MORNING. THIS CONVECTION IS BEING AIDED BY A VIGOROUS SHORT-WAVE TRACKING ACROSS THE NORTHERN PLAINS AND A 35 TO 40KT LOW-LEVEL JET. MODELS ARE NOT HANDLING THE CURRENT SCENARIO PARTICULARLY WELL...SO SHORT-TERM FORECAST WILL BE BASED PRIMARILY ON LATEST SATELLITE/RADAR TRENDS AS WELL AS BASIC CONCEPTUAL MODELS. 00Z UPPER AIR ANALYSIS CONTINUED TO SHOW A STRONG RIDGE OF HIGH PRESSURE SPRAWLING FROM THE CENTRAL PLAINS EASTWARD INTO THE OHIO RIVER VALLEY. VERY WARM/SUBSIDENT AIR BENEATH THIS RIDGE HAS CREATED A HEALTHY CAP...CHARACTERIZED BY 700MB TEMPS OF 14 TO 16C. CAP IS WEAKER FURTHER NORTH FROM MINNESOTA E/SE INTO THE GREAT LAKES AND THINK THIS WILL BE THE PRIMARY ZONE OF CONVECTION TODAY. EARLY MORNING STORMS CURRENTLY OVER WESTERN IOWA WILL LIKELY TRACK EASTWARD ACROSS NORTHERN ILLINOIS BETWEEN 12Z AND 18Z...POSSIBLY BRUSHING THE FAR NORTHERN KILX CWA. AFTER THAT...ADDITIONAL CONVECTION MAY BE HARD TO COME BY TODAY AS AIRMASS REMAINS CAPPED. THINK MOST LOGICAL MODEL APPEARS TO BE THE LOCAL WRF...WHICH KEEPS CENTRAL ILLINOIS DRY FOR MUCH OF THE DAY UNTIL COLD FRONT SAGS SOUTHWARD DURING THE MID TO LATE AFTERNOON. GIVEN DECENT CONVERGENCE ALONG THE FRONT...SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP IMMEDIATELY ALONG THE BOUNDARY ACROSS NORTHERN ILLINOIS AFTER 18Z. SOME OF THESE STORMS MAY DROP INTO NORTH-CENTRAL ILLINOIS AS THE DAY PROGRESSES. HAVE ADJUSTED POPS ACCORDINGLY...MAINLY TO FOCUS HIGHEST RAIN CHANCES ALONG AND NORTH OF I-74. HAVE BROUGHT SLIGHT CHANCE POPS AS FAR SOUTH AS I-70 DURING THE AFTERNOON...BUT HAVE MAINTAINED DRY CONDITIONS FURTHER SOUTH. BIG STORY TODAY WILL BE THE HEAT...AS HIGH TEMPERATURES SOAR INTO THE LOWER TO MIDDLE 90S. DEWPOINTS REACHED THE UPPER 70S TO AROUND 80 DEGREES YESTERDAY AFTERNOON IN THE VICINITY OF AN ADVANCING WARM FRONT...AND EXPECT SIMILAR READINGS TODAY. THIS WILL PRODUCE HEAT INDEX VALUES OF 105 TO 110 ACROSS THE BOARD...WITH POTENTIALLY HIGHER NUMBERS IN EXCESS OF 110 SOUTH OF I-70. WILL THEREFORE EXTEND THE HEAT ADVISORY TO COVER THE ENTIRE AREA...INCLUDING PEORIA/GALESBURG WHICH HAD PREVIOUSLY BEEN LEFT OUT DUE TO UNCERTAINTIES CONCERNING POTENTIAL OUTFLOW FROM OVERNIGHT STORM COMPLEX ACROSS NORTHERN ILLINOIS. DAY SHIFT WILL NEED TO MONITOR AREAS SOUTH OF I-70...AS THE ADVISORY MAY NEED TO BE UPGRADED TO A WARNING THERE. COLD FRONT WILL DROP INTO CENTRAL ILLINOIS AND REMAIN IN THE VICINITY TONIGHT THROUGH WEDNESDAY. AS SUCH...WILL FEATURE CHANCE POPS THROUGH THE ENTIRE PERIOD. SPC HAS INDICATED SLIGHT RISK FOR SEVERE ON TUESDAY...HOWEVER THINK MAIN THREAT FROM STORMS WILL BE LOCALLY HEAVY RAINFALL DUE TO HIGH PRECIPITABLE WATER VALUES IN EXCESS OF 2 INCHES. MAY ALSO SEE SOME GUSTY WINDS WITH A FEW OF THE STORMS...BUT OVERALL AREAL COVERAGE WILL LIKELY NOT BE THAT GREAT. FRONT WILL GET PUSHED FURTHER SOUTHWARD BY WEDNESDAY NIGHT...RESULTING IN AN END TO THE RAIN CHANCES. LONG TERM...THURSDAY THROUGH SUNDAY HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES ON THURSDAY...PROVIDING A COOLER/LESS HUMID E/NE FLOW ACROSS CENTRAL ILLINOIS. HIGH TEMPS WILL REMAIN IN THE LOWER TO MIDDLE 80S. AFTER THAT...UPPER RIDGE WILL BUILD BACK EASTWARD INTO THE MIDWEST WITH GUSTO OVER THE WEEKEND...WITH THE LATEST ECMWF SHOWING A 599DM HIGH CENTERED OVER NORTHERN MISSOURI BY SUNDAY EVENING. AS HEIGHTS RISE AND THE FRONT GETS PUSHED BACK NORTHWARD...MAY SEE A FEW ISOLATED SHOWERS/STORMS ON FRIDAY...FOLLOWED BY INCREASING HEAT AND HUMIDITY FOR SATURDAY AND SUNDAY. && .AVIATION... ISSUED 550 AM CDT MON JUL 11 2011 MAIN FORECAST CONCERN WILL BE COVERAGE OF CONVECTION THIS MORNING ACRS THE NORTH...AND OVER THE ENTIRE AREA LATER THIS AFTERNOON AND EVENING AS A WEAK COOL FRONT EDGES CLOSER TO CENTRAL IL. CONVECTION CONTINUES TO TRACK ENE ACRS EASTERN IOWA WITH THE BULK OF THE ACTIVITY EXPECTED TO REMAIN TO THE NORTH OF THE TAF SITES THIS MORNING. HOWEVER...WILL INCLUDE A VCTS AT PIA AS THEY WILL BE THE CLOSEST TO THE ACTIVITY AND MAY BE AFFECTED BY THE OUTFLOW BOUNDARY IN THE 12Z-14Z TIME FRAME. FURTHER SOUTH...THE ATMOSPHERE IS FAIRLY WELL CAPPED WITH A SIGNIFICANT WARM LAYER FROM 850-700 MB. LOCAL MVFR VSBYS IN FOG AND HAZE SHOULD GIVE WAY TO VFR CONDITIONS OUTSIDE ANY TSRA TODAY. AFTR 20Z ACRS THE PIA AREA...IT APPEARS ENOUGH LOW LEVEL CONVERGENCE AHEAD OF THE FRONT MAY BE ENOUGH TO BREAK THE CAP AND BRING AT LEAST WDLY SCT TSRA TO THE AREA. FOR NOW WILL INCLUDE A VCTS AT PIA AND BMI AFTR 19Z TO ACCOUNT FOR THIS POSSIBLE DEVELOPMENT ALONG THE AFOREMENTIONED BOUNDARY. SCATTERED TSRA PSBL INTO THIS EVENING WITH A DIURNAL WEAKENING TREND EXPCTD AFTR 03Z. MVFR VSBYS PSBL AGAIN LATE TNT IN FOG/HZ. SFC WINDS WILL BE FROM THE SOUTH THIS MORNING AT AROUND 10 KTS AND THEN BEGIN TO VEER MORE INTO THE SOUTHWEST THIS AFTN AT 10 TO 15 KTS. WINDS TONIGHT WILL TREND MORE TOWARDS A WESTERLY DIRECTION AT LESS THAN 10 KTS. SMITH && .ILX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-040>057-061>063-066>068-071>073. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LINCOLN IL 500 AM CDT MON JUL 11 2011 ILZ027>031-036>038-040>042-047>051-121100- CASS-FULTON-KNOX-LOGAN-MARSHALL-MASON-MCLEAN-MENARD-MORGAN-PEORIA- SANGAMON-SCHUYLER-SCOTT-STARK-TAZEWELL-WOODFORD- 500 AM CDT MON JUL 11 2011 ...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 7 PM CDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS. .DAY ONE...TODAY AND TONIGHT HEAT INDEX VALUES WILL CLIMB TO BETWEEN 105 AND 110 DEGREES THIS AFTERNOON. SCATTERED THUNDERSTORMS WILL BE POSSIBLE THIS MORNING...MAINLY ALONG AND NORTH OF INTERSTATE 74. A FEW OF THE STORMS WILL BE CAPABLE OF PRODUCING GUSTY WINDS AND HEAVY RAINFALL. LATER THIS AFTERNOON AS A COLD FRONT EDGES CLOSER TO THE AREA...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE ENTIRE AREA. A FEW OF THE STORMS THIS AFTERNOON INTO THIS EVENING MAY PRODUCE DAMAGING WIND GUSTS ALONG WITH HEAVY RAINFALL. FOR INTERESTS ALONG THE ILLINOIS RIVER FROM HAVANA DOWNSTREAM WILL REMAIN IN FLOOD FOR THE NEXT DAY OR TWO. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY SLIGHTLY COOLER WEATHER WILL PUSH IN FROM THE NORTHWEST ON TUESDAY WITH HEAT INDEX VALUES RANGING FROM 92 IN THE NORTH TO NEAR 102 IN THE SOUTH. SCATTERED THUNDERSTORMS WILL BE POSSIBLE AGAIN TUESDAY AND WEDNESDAY. A FEW OF THE STORMS TUESDAY AFTERNOON AND EVENING MAY BE SEVERE...WITH THE PRIMARY THREAT BEING FROM DAMAGING STRAIGHT LINE WINDS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED...MAINLY THIS AFTERNOON AND EVENING...FROM 300 PM UNTIL 900 PM. ILZ043>046-052>057-061-121100- CHAMPAIGN-CHRISTIAN-COLES-DE WITT-DOUGLAS-EDGAR-MACON-MOULTRIE- PIATT-SHELBY-VERMILION- 500 AM CDT MON JUL 11 2011 ...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 7 PM CDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS AND EAST CENTRAL ILLINOIS. .DAY ONE...TODAY AND TONIGHT HEAT INDEX VALUES WILL RISE TO 105 TO 110 DEGREES THIS AFTERNOON. SCATTERED THUNDERSTORMS WILL BE POSSIBLE TODAY...ESPECIALLY DURING THE MID AFTERNOON THROUGH EARLY EVENING HOURS. A FEW OF THE STORMS WILL BE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS ALONG WITH HEAVY RAINFALL. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY SLIGHT COOLER AIR WILL FILTER SOUTH INTO THE AREA ON TUESDAY WITH AFTERNOON HEAT INDEX VALUES OF BETWEEN 96 AND 102 DEGREES. SCATTERED THUNDERSTORMS WILL BE POSSIBLE AGAIN ON TUESDAY AND WEDNESDAY AS THE WEAK COOL FRONT WILL BE SLOW TO PUSH SOUTH OF THE AREA. A FEW OF THE THUNDERSTORMS TUESDAY AFTERNOON AND EVENING MAY BE SEVERE WITH THE PRIMARY THREAT BEING FROM DAMAGING STRAIGHT LINE WINDS. SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING... PRIMARILY FROM 400 PM UNTIL 10 PM. ILZ062-063-066>068-071>073-121100- CLARK-CLAY-CRAWFORD-CUMBERLAND-EFFINGHAM-JASPER-LAWRENCE-RICHLAND- 500 AM CDT MON JUL 11 2011 ...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 7 PM CDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL ILLINOIS AND SOUTHEAST ILLINOIS. .DAY ONE...TODAY AND TONIGHT HEAT INDEX VALUES THIS AFTERNOON WILL RANGE FROM 106 TO 111 DEGREES. A FEW THUNDERSTORMS MAY DEVELOP DURING LATE AFTERNOON AND EVENING HOURS. A SEVERE STORM WILL BE POSSIBLE WITH THE MAIN THREAT BEING FROM DAMAGING STRAIGHT LINE WINDS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY HOT AND HUMID WEATHER WILL PREVAIL ACROSS THE AREA AGAIN ON TUESDAY BUT BY WEDNESDAY...A COOL FRONT MAY BRING SOME TEMPORARY RELIEF TO THE AREA. HEAT INDEX VALUES TUESDAY AFTERNOON WILL RANGE FROM 105 TO 110 DEGREES. SCATTERED THUNDERSTORMS WILL BE POSSIBLE ON TUESDAY AND WEDNESDAY AS A WEAK COOL FRONT EDGES SOUTH INTO OUR AREA. A FEW OF THE THUNDERSTORMS ON TUESDAY AFTERNOON AND EVENING MAY BECOME SEVERE WITH THE PRIMARY THREAT BEING FROM DAMAGING STRAIGHT LINE WINDS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED AFTER 600 PM CDT THIS EVENING. SMITH
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
653 AM CDT MON JUL 11 2011
ILZ036-040-041-047-111245-
CASS-FULTON-MASON-SCHUYLER-
653 AM CDT MON JUL 11 2011
...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN CASS...SCHUYLER...
SOUTHWESTERN FULTON AND SOUTHWESTERN MASON COUNTIES UNTIL 745 AM
CDT...
AT 649 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 7 MILES SOUTHWEST OF RUSHVILLE...MOVING EAST AT
35 MPH.
WINDS UP TO 50 MPH ARE EXPECTED WITH THIS STORM.
LOCATIONS IMPACTED INCLUDE...
RUSHVILLE...
BROWNING...
ASTORIA...
OTHER LOCATIONS AFFECTED INCLUDE...FREDERICK...SNICARTE AND BLUFF
CITY.
PEOPLE NEAR THESE LOCATIONS SHOULD MONITOR THE WEATHER SITUATION
CLOSELY. LISTEN FOR POSSIBLE WARNINGS...AND BE PREPARED TO TAKE
APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN.
LAT...LON 4034 9025 4006 9015 3999 9061 4002 9062
4005 9068 4007 9068 4008 9071 4010 9071
4010 9077 4015 9078
TIME...MOT...LOC 1152Z 262DEG 32KT 4008 9064
SMITHSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LINCOLN IL 715 AM CDT MON JUL 11 2011 ILZ036-041-111315- FULTON-MASON- 715 AM CDT MON JUL 11 2011 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN MASON AND SOUTHERN FULTON COUNTIES UNTIL 815 AM CDT... AT 712 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 6 MILES SOUTHEAST OF IPAVA...OR 8 MILES SOUTHWEST OF LEWISTOWN...MOVING EAST AT 35 MPH. WINDS AROUND 50 MPH ARE EXPECTED WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... LEWISTOWN... HAVANA... OTHER LOCATIONS AFFECTED INCLUDE...DUNCAN MILLS...CHATAUQUA PARK... LITTLE AMERICA...LIVERPOOL...TOPEKA AND GOOFY RIDGE. PEOPLE NEAR THESE LOCATIONS SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS...AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN. LAT...LON 4047 8997 4033 8984 4022 9029 4036 9034 TIME...MOT...LOC 1215Z 251DEG 31KT 4031 9020 SMITH
The Lincoln radar (KILX), 73 km away, was scanning. The volume nearest the first event began at 12:17 UTC.
2 thunderstorm wind. Local standard time, as filed.
Numerous trees and tree branches were blown down near Duncan Mills. A semi trailer was tipped over and about 2 acres of corn were flattened in the area.
A power pole was blown down near Ipava causing a few power outages.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2011Every state in 2011This day in weather historyWarnings in Illinois, July 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 333412, 333416.