A weak disturbance ahead of a storm system in the southern plains spawned a couple of brief, weak tornadoes with an area of showers and thunderstorms in west central Illinois.
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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 DVN wrote it up.
A weak disturbance ahead of a storm system in the southern plains spawned a couple of brief, weak tornadoes with an area of showers and thunderstorms in west central Illinois.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at May 9, 2:28 PM CST, 1 hour 47 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 328 PM CDT MON MAY 9 2016 .SYNOPSIS... ISSUED AT 327 PM CDT MON MAY 9 2016 WIDESPREAD LOW STRATUS WAS KEEPING INSTABILITY MINIMAL AND DEEP LAYER SHEAR WAS RATHER WEAK. A FEW THUNDERSTORMS WERE NOTED IN THE SOUTHWEST HALF OF THE CWA BUT WERE WELL BELOW SEVERE LEVELS. THE STORMS WERE IN AN INCREASING AREA OF SHOWERS AHEAD OF A STRONG SHORT WAVE LIFTING NORTHEAST ACROSS MO. STRONGER STORMS WERE BEGINNING TO FIRE ACROSS THE PLAINS WHERE SBCAPES WERE 3000+ J/KG. 3 PM TEMPERATURES ACROSS THE CWA WERE IN THE 60S. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 327 PM CDT MON MAY 9 2016 FORECAST FOCUS ON SHOWERS AND THUNDERSTORMS. TONIGHT...NUMEROUS SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL OCCUR ACROSS MUCH OF THE CWA THROUGH THE EVENING HOURS. WITH A SATURATED AIRMASS AND PWAT'S 1.50 INCHES THE THREAT OF LOCALLY HEAVY RAINFALL WILL EXIST IN ANY THUNDERSTORM. THE RAIN WAS BEING ENHANCED BY MODERATE TO STRONG FORCING AHEAD OF A DECENT SHORT WAVE LIFTING NORTHEAST ACROSS MO...AHEAD OF THE MAIN UPPER LEVEL TROUGH STILL BACK IN THE PLAINS. AS THE WAVE PUSHES TO OUR EAST LATE THIS EVENING AND OVERNIGHT THE RAIN CHANCES WILL DIMINISH SO WILL HAVE DECREASING POPS. MINIMUM TEMPERATURES SHOULD RANGE FROM THE LOWER 50S FAR NORTH TO THE UPPER 50S FAR SOUTH. TUESDAY...THE MAIN TROUGH WILL COME ACROSS THE AREA SO WILL HAVE CHANCE POPS IN THE MORNING...BUT THEN AS HEATING TAKES PLACE THE SHOWERS AND STORMS WILL BECOME MORE NUMEROUS IN THE AFTERNOON. SBCAPES WILL PUSH TO 2000+ J/KG BUT THE DEEP LAYER SHEAR WILL BE EVEN WEAKER...SO NOT EXPECTING ANY STRONG STORMS. WITH THE WARM FRONT LIFTING NORTH OF THE CWA WE WILL HAVE SOUTHERLY WINDS AND SOME SUNSHINE TO PUSH AFTERNOON TEMPERATURES INTO THE 70S AT MOST LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 327 PM CDT MON MAY 9 2016 TUESDAY NIGHT...SLIGHT CHANCES FOR A SHOWER AREA-WIDE...OR A VERY ISOLATED STORM SOUTH OF I-80. MAJORITY OF THE CWA WILL MORE THAN LIKELY STAY DRY THROUGH THE NIGHT AS A COMPACT 500MB RIDGE DEVELOPS AND MID-LEVEL HEIGHTS RISE OVER THE UPPER MISSISSIPPI RIVER VALLEY. PARTLY TO MOSTLY CLOUDY SKIES SHOULD HOLD TEMPS IN THE 50S. WEDNESDAY...SE SFC WINDS TO ADVECT LOWER TO MIDDLE 60 DEWPOINTS INTO E IOWA/W ILLINOIS DOWNSTREAM OF APPROACHING 500MB POSITIVE VORTICITY LOBE AND LOW-LEVEL AXIS OF DILATATION. HIGHS IN THE MID 70S FAR NORTH TO AROUND 80 F ELSEWHERE WOULD YIELD MUCAPES OF 1000-2000 J/KG. SHEAR IS WEAK THROUGH THE DAY BUT DOES INCREASE DURING THE EARLY EVENING TO ABOUT 40 KTS. CONDITIONALLY...THE POTENTIAL EXISTS FOR STRONG OR SEVERE CONVECTION. SPC IS OUTLOOKING THE SOUTHERN TWO- THIRDS OF THE FORECAST AREA WITH A SLIGHT RISK FOR SEVERE STORMS. THE GREATEST LIMITING FACTORS ARE... 1. EXTENT OF CLOUDS LIMITING INSTABILITY 2. LATE ARRIVAL OF THE LOW-LEVEL BOUNDARY AFTER PEAK HEATING NONETHELESS SHOWERS AND THUNDERSTORMS ARE LIKELY WEDNESDAY EVENING INTO WEDNESDAY NIGHT PRODUCING MODERATE TO HEAVY RAIN AS THEY UTILIZE THE MOIST 1.40 INCH PWAT AIR...BUT AGAIN SEVERE POTENTIAL IS UNCERTAIN. THURSDAY...MODEL CONSENSUS IS DRY WITH TEMPS IN THE UPPER 60S. THE NAM IS AN OUTLIER SENDING ANOTHER VORT. MAX UP ALONG THE LOW-LEVEL BOUNDARY WHICH WOULD RESULT IN MORE SHOWERS. CURRENT FORECAST IGNORES THIS SOLUTION. FRIDAY...MODELS AGREE THAT A SIGNIFICANT PATTERN CHANGE WILL TAKE PLACE TOWARD THE END OF THIS WEEK AND LAST INTO EARLY NEXT WEEK. A LARGE TROUGH IS FORECAST TO DEVELOP ACROSS THE NORTH-CENTRAL PORTION OF NORTH AMERICA WITH THE MAIN UPPER LOW POSITIONED OVER ONTARIO. GFS AND ECMWF ARE EVEN ADVERTISING 850MB TEMP DROPPING TO SEVERAL DEGREES BELOW ZERO CELSIUS. AN ALBERTA CLIPPER SYSTEM EMBEDDED WITHIN STRONG FLOW ALOFT WARRANTS 20-40 POPS AS LOW-LEVEL FRONTOGENESIS STREAKS THROUGH THE REGION. THE POPS MAY HAVE TO BE INCREASED FOR PORTIONS OF THE CWA. SATURDAY THROUGH MONDAY...CONSENSUS TEMPS ARE IN THE LOWER 60S FOR HIGHS AND LOWER 40S FOR LOWS. IF WE GET THE RIGHT SET UP...CLEAR SKIES AND LIGHT WINDS...MAY HAVE PATCHY FROST ACROSS THE FAR NORTH FRIDAY NIGHT OR SATURDAY NIGHT...SOMETHING TO MONITOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 113 PM CDT MON MAY 9 2016 MVFR/OCNL IFR CONDS IN WIDESPREAD SHOWERS AND A FEW EMBEDDED THUNDERSTORMS THIS AFTERNOON AND EVENING...DIMINISHING FROM SOUTH TO NORTH AFTER 05Z/10. CONDS SHOULD BECOME MVFR POSSIBLY VFR TUESDAY MORNING. EAST TO SOUTHEAST WINDS 15 TO 25 KNOTS THIS AFTERNOON DIMINISHING TO AROUND 10 KNOTS TONIGHT. WINDS BECOMING SOUTH AROUND 10 KNOTS ON TUESDAY. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && SYNOPSIS...HAASE SHORT TERM...HAASE LONG TERM...UTTECH AVIATION...HAASE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 324 PM CDT MON MAY 9 2016 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-102030- BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON- CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON- HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL- WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON- WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK- 324 PM CDT MON MAY 9 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL ILLINOIS...NORTHWEST ILLINOIS...WEST CENTRAL ILLINOIS...EAST CENTRAL IOWA...NORTHEAST IOWA...SOUTHEAST IOWA AND NORTHEAST MISSOURI. .DAY ONE...THIS AFTERNOON AND TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS WILL BE ACROSS THE AREA THIS AFTERNOON AND EVENING BUT SEVERE WEATHER IS NOT EXPECTED. HOWEVER... A FEW STRONGER STORMS MAY PRODUCE GUSTY WINDS...SMALL HAIL AND HEAVY RAINFALL. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS ARE LIKELY ON TUESDAY...ESPECIALLY IN THE AFTERNOON BUT SEVERE WEATHER IS NOT EXPECTED. THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS WEDNESDAY AFTERNOON AND EVENING...MAINLY SOUTH OF HIGHWAY 30. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS...ALTHOUGH ISOLATED TORNADOES ARE POSSIBLE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THIS AFTERNOON OR TONIGHT. HAASE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE QUAD CITIES IA IL 416 PM CDT MON MAY 9 2016 IAZ040-041-051-052-063-064-076-077-087-088-098-099-092330- BUCHANAN-DELAWARE-BENTON-LINN-IOWA-JOHNSON-KEOKUK-WASHINGTON- JEFFERSON-HENRY IA-VAN BUREN-LEE- INCLUDING THE CITIES OF...INDEPENDENCE...MANCHESTER...VINTON... CEDAR RAPIDS...MARENGO...IOWA CITY...SIGOURNEY...WASHINGTON... FAIRFIELD...MOUNT PLEASANT...KEOSAUQUA...FORT MADISON 416 PM CDT MON MAY 9 2016 ...LOCALLY HEAVY RAINFALL IN EASTERN IOWA... DOPPLER RADAR INDICATED AN AREA OF THUNDERSTORMS MAINLY WEST OF A MANCHESTER TO DONNELLSON LINE IN EASTERN IOWA. THE STORMS WERE MOVING NORTHWARD AND WERE REPEATING OVER SOME OF THE SAME LOCATIONS. RADAR INDICATED RAINFALL AMOUNTS OF OVER AN INCH PER HOUR. SOME LOCATIONS MAY RECEIVE 2 INCHES OF RAIN LATE THIS AFTERNOON WHICH MAY CAUSE PONDING OF WATER AND SOME RISES IN LOCAL CREEKS AND SMALL STREAMS. THE STORMS SHOULD DIMINISH TOWARDS EVENING. WHEN THUNDERSTORMS ARE OCCURRING MOVE INDOORS. DO NOT STAND BY WINDOWS. AVOID USING TELEPHONES AND ELECTRICAL APPLIANCES UNTIL THE STORM HAS PASSED. MOTORISTS SHOULD SLOW DOWN DUE TO PONDING OF WATER ON ROADWAYS AND REDUCED VISIBILITY IN HEAVY RAIN. HAASE
The Lincoln radar (KILX), 106 km away, was scanning. The volume nearest the first event began at 22:12 UTC.
2 tornado. Local standard time, as filed.
The tornado width was 25 to 50 yards, and on the ground for about 2 minutes with no damage.
There was a brief tornado touchdown with no damage.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2016Every state in 2016This day in weather historyThe tornado archive for Illinois, 2016Warnings in Illinois, May 2016
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: 636844, 636845.