During the late afternoon of Thursday, July 7th, scattered storms developed across northern Illinois and slowly moved east-northeast. As the storms grew, their slow movement helped to produce locally heavy rainfall.
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 LOT wrote it up.
During the late afternoon of Thursday, July 7th, scattered storms developed across northern Illinois and slowly moved east-northeast. As the storms grew, their slow movement helped to produce locally heavy rainfall. The Doppler Radar estimated rainfall maps show the localized nature of the heavy rainfall. In addition, there were a handful of funnel cloud reports from the storms due to large scale rotation in the atmosphere. Concentrated storm rotation for tornadoes was not favored.
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 Chicago, IL wrote its last area forecast discussion before the first event at Jul 7, 12:12 PM CST, 1 hour 43 minutes earlier.
Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 112 PM CDT THU JUL 7 2016 .UPDATE... 1050 AM CDT A continued challenging forecast continues though some aspects are starting to emerge to focus the forecast. The primary changes were to note a higher likelihood of scattered storms during the mid-late afternoon from remnant/potential re-enhancing convection moving in from western Illinois. The influence of this convection going forward could very well warrant lower chances of storms this evening /7p-12a/, but with still the potential of a line of gusty storms overnight. Persistent storms across western Illinois have been generally showing a slight weakening over the past couple hours in cloud top and lightning characteristics. Per radar and satellite imagery there is one, possibly two, convectively-enhanced vorticity centers assisting these storms. Would expect a steady convective state for another couple hours and maybe a slight weakening but do not see a complete fizzling out. In fact, as we get into peak heating, the vort centers will be traversing over the forecast area and could promote a re-intensification of isolated to scattered storms. A concentrated area of 20-30 kt 925-850mb flow is sampled by the ILX VWP and this may continue to saturate the level just below steep lapse rates advecting over the area. The limiting factor is that the 12Z ILX sounding and continued RAP analyses indicate a fairly steep CAP to overcome so would not expect immediate surface based convection if storms can continue to fester or redevelop. If storms do fester long enough though a scattered wind threat could develop from any more intense clusters due to high DCAPE and precipitation loading. This may be a little more favored south of I-80 and east of I-55 where low clouds have not hindered heating and destabilization as much. In addition, any scattered storms this afternoon will have a slower movement as the driving MCVs are moving slowly. With PWATs near or exceeding 1.50 inches, any storms would have a localized flood threat. In the wake of this convective short wave disturbance this afternoon, one trait of the high-resolution guidance is a lull in amount of convection during the evening hours. This would conceptually make sense and may steer the forecast drier during that time in a couple hours, but at this point have only made gradual adjustments in this period to see observational trends. On the synoptic scale, afternoon activity would not necessarily work over the atmosphere for more convection later tonight, especially with the magnitude of trough moving in from the Upper Plains and the degree of column and low-level moisture present. However, any organized storms that do develop over the IA/MN area this evening do not look to arrive until late, and there is high uncertainty on just how well-organized the storms will be and likewise high spread in model guidance. We will continue to assess this as we head into this afternoon. MTF && .SHORT TERM... 355 AM CDT Today and Tonight... Complex forecast for the next 18-24 hours, with the main concern being trying to time periods of greater thunderstorm threat. Severe weather potential ramps up across the region by this evening as well as large scale synoptic forcing strengthens wind fields at/just beyond peak diurnal instability. A strong short wave trough was noted emerging from the northern Rockies across Montana early this morning. This trough will move east across the northern plains today, and deepen as it reaches the upper Midwest tonight. In response, a broad region of weak surface low pressure over the Plains will spread northeastward, and will consolidate across the northern Great Lakes by early Friday morning. As this occurs, a very warm and moist low level air mass in place across much of the Missouri/Mississippi river valleys will also spread northeast, ahead of a weak cold frontal boundary which will trail the low and push across the forecast area early Friday morning. While convective trends may be complicated by ongoing complex upstream across the mid-Missouri Valley, large scale forcing will increase ahead of the aforementioned strong short wave late today and tonight as strong height falls develop across the upper Midwest and wind fields strengthen in response. The combination of a very warm/moist and conditionally unstable air mass and increasing mid-upper level wind fields (and deep layer bulk shear) will set the stage for organized severe thunderstorm development, which may potentially affect the WFO LOT forecast area. In the near term, convection-allowing models have continued to struggle with the large thunderstorm complex over the mid-Missouri Valley overnight. Overall however, the expectation over the next several hours is that the strongest convection will propagate southeastward in roughly an Omaha-St Louis axis along the remnant outflow boundary/pseudo warm front from Wednesday's MCS. Farther north, a small-amplitude short wave or MCV over northern Iowa and southern Minnesota will continue to track east toward southern Wisconsin this morning. Recent radar, satellite and lightning data seems to support this scenario with rapid erosion of convection over central Iowa. Residual cloud cover and perhaps some showers or even isolated embedded thunder could work its way east into northern IL after sunrise, though it appears the focus for precip/convection through midday will remain largely northwest and southeast of the cwa. If the portion of the MCS southeast of Omaha persists as expected, it will likely reinforce the old outflow boundary/warm front to our south as will residual cloud cover from activity farther north. The question then becomes how much destabilization occurs farther north across the region by late afternoon/evening, and where focusing boundaries will be at that time. The increase in the synoptic wind field should help lift things northeast with time into this evening, though details of convective initiation and evolution remain somewhat low confidence with respect to direct impact on the local area. Newly arriving 06z 4km WRF output suggests redevelopment occurs later this afternoon near the Sioux Falls area (southwest MN/northwest IA/southeast South Dakota), and eventually grows upscale into a potentially severe forward propagating MCS which moves into our area late evening/overnight. Based on this reasonable scenario have generally gone with slight/low chance pops here during the day with potentially little occurring until this evening when have carried likely pops into the overnight. Severe threat should diminish quickly pre-dawn Friday as the MCS exits and the cold front finishes its transit of the cwa. SPC's new day 1 outlook fits this scenario as well, with an enhanced severe outlook from IA southeast into central IL and far west-central Indiana. This axis likely to be near aforementioned reinforced outflow boundary or pseudo warm front. Ratzer && .LONG TERM... 405 AM CDT Friday through Wednesday... Weak cold front clears the southeastern portion of the forecast area early Friday as deepening low pressure pulls slowly away to the northeast across the northern Lakes. Forecast soundings depict drier thermodynamic profiles with breezy west winds, supporting high temperatures in the mid-upper 80s but with decreasing humidity from the west. Have maintained a brief low chance pop in the morning across the southeast before ending the precip threat for good. As the upper trough amplifies off to our east Friday night into Saturday, a secondary cold front will push south from Wisconsin early saturday, after which surface high pressure will build across the area and linger through the weekend. This should make for a pleasant weekend, with temperatures in the upper 70s to low 80s and noticeably lower humidity. Anticyclonic flow around the high will also support lake breeze cooling with east-northeast winds both Saturday and Sunday. Heading into next week, longer range model solutions depict an amplifying upper pattern with ridging developing across the Midwest downstream of a deepening upper trough over the northern Plains. This will nudge the surface high off to the east and allow south winds to become reestablished across the region, allowing a return of warmer and more humid weather again by mid-week. Ratzer && .AVIATION... For the 18Z TAFs... The concerns with the Chicago area airports are: - Potential for scattered storms from mid-afternoon through early evening, and then a chance of storms the remainder of the night. - South-southeast winds potentially becoming more easterly, although speeds likely to remain primarily below 10 kt. - Possibility of temporary MVFR cigs. A decaying area of showers is moving across northern Illinois early this afternoon and should continue to fade but may bring brief light rain to the airports prior to 19Z-20Z. There is an upper disturbance associated with these showers drifting over the region that could help spark scattered storms during the afternoon. The confidence on this is low-medium, and coverage may only be isolated across northern Illinois. Any storms will have the ability to influence the winds. On the topic of winds, confidence is low on specific direction after 21Z. Believe the wind direction will be 120 to 170 degrees ahead of that time due to the influence of multiple low pressure centers in southern Wisconsin and along the IA/IL border. Confidence is a tad higher that speeds will remain less than 10 kt most of if not the entire afternoon. If scattered storms can develop this afternoon they may linger into the early to mid evening before departing east or weakening. Larger storms are expected to develop across the IA/MN border region this evening and progress east-southeast. This could become an organized area of storms although a gradual weakening is possible. Friday will see gusty westerly winds develop behind the low. Any morning clouds should lift and scatter by afternoon. MTF && .MARINE... 230 am...One area of low pressure north of Lake Ontario will continue moving east today. A trailing cold front from this low extends southwest across central portions of Lake Michigan. This front will remain generally stationary into tonight as low pressure deepens over the upper midwest and western lakes region this evening. The gradient will strengthen with increasing southerly winds over southern parts of the lake and increasing easterly winds over northern parts of the lake. This low will continue deepening as it reaches Lake Huron Friday afternoon. Winds will shift westerly from south to north on Friday with increasing speeds. Wind directions are more uncertain across the far northern part of the lake due to the proximity of the surface low. Eventually winds will shift to the northwest Friday evening and speeds will increase to 30 kts as a tight gradient moves across the lake. High pressure will build across the western lakes Saturday with speeds gradually diminishing Saturday afternoon into Saturday evening. The high will cross the lake Sunday with southerly winds developing Sunday night into Monday as the high departs. cms && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1111 AM CDT THU JUL 7 2016
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
081615-
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-
1111 AM CDT THU JUL 7 2016 /1211 PM EDT THU JUL 7 2016/
THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...THIS AFTERNOON AND TONIGHT.
WEATHER HAZARDS EXPECTED:
ELEVATED THUNDERSTORM RISK...WITH AN ASSOCIATED:
ELEVATED THUNDERSTORM WIND DAMAGE RISK.
LIMITED HAIL RISK...UP TO QUARTER SIZE.
LIMITED FLOODING RISK.
LIMITED EXCESSIVE HEAT RISK.
DISCUSSION:
SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON ACROSS AT
LEAST PART OF THE AREA. A FEW OF THESE MAY BECOME SEVERE WITH THE
MAIN THREAT BEING STRONG WINDS AND HEAVY RAIN WITH A CHANCE FOR
SOME HAIL. THE MORE FAVORED POTENTIAL IS SOUTH OF INTERSTATE 80
AND EAST OF INTERSTATE 55.
THERE IS A CHANCE FOR STORMS THIS EVENING WITH THE POSSIBILITY OF
AN ORGANIZED LINE OF STORMS OVERNIGHT. CONFIDENCE IN THIS IS QUITE
LOW THOUGH AS THESE STORMS WOULD DEVELOP OVER MINNESOTA AND IOWA
AND MAY GRADUALLY WEAKEN BEFORE THEY ARRIVE. IF THESE STORMS CAN
MAINTAIN THEMSELVES THEY WOULD POSE A DAMAGING WIND THREAT.
.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
FRIDAY...
LIMITED MORNING THUNDERSTORM RISK.
HIGH SWIM RISK FOR NORTHWEST INDIANA LAKE MICHIGAN BEACHES.
SATURDAY...
HIGH SWIM RISK FOR LAKE MICHIGAN BEACHES.
TUESDAY...
LIMITED THUNDERSTORM RISK.
WEDNESDAY...
LIMITED THUNDERSTORM RISK.
LIMITED EXCESSIVE HEAT RISK.
DISCUSSION:
THUNDERSTORMS WILL EXIT THE AREA EARLY FRIDAY MORNING AS A
WEAK COLD FRONT MOVES THROUGH THE AREA.
A PERIOD OF GUSTY NORTHERLY WINDS WILL PRODUCE HIGH WAVES AND
CREATE A HIGH SWIM RISK FOR LAKE MICHIGAN BEACHES SATURDAY INTO
SUNDAY.
THERE IS ANOTHER CHANCE OF THUNDERSTORMS TUESDAY AND WEDNESDAY.
.SPOTTER INFORMATION STATEMENT...
SPOTTERS MAY BE NEEDED THIS AFTERNOON AND EVENING.
GENERAL STORM MOTION OF THE DAY:
MOVING FROM THE SOUTHWEST TO THE NORTHEAST AT 35 MPH.
&&
LMZ740>745-081615-
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-
1111 AM CDT THU JUL 7 2016
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE
MICHIGAN.
.DAY ONE...THIS AFTERNOON AND TONIGHT.
SCATTERED THUNDERSTORMS ARE EXPECTED THIS MID TO LATE AFTERNOON
WITH POSSIBLY ANOTHER ROUND OF THUNDERSTORMS LATER TONIGHT. SOME
THUNDERSTORMS MAY HAVE WIND GUSTS IN EXCESS OF 50 KNOTS.
.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
WIND AND WAVES HAZARDOUS TO SMALL CRAFT ARE EXPECTED LATE
FRIDAY NIGHT THROUGH SATURDAY NIGHT.
THERE IS A CHANCE OF THUNDERSTORMS TUESDAY AND WEDNESDAY.
&&
LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-081615-
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-
1111 AM CDT THU JUL 7 2016
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE
MICHIGAN.
.DAY ONE...THIS AFTERNOON AND TONIGHT.
AREAS OF DENSE FOG WILL BE SEEN ACROSS THE NORTHERN PART OF THE
LAKE THIS AFTERNOON.
SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING.
ANOTHER ROUND OF STORMS IS POSSIBLE LATER TONIGHT ESPECIALLY OVER
THE NORTHERN END OF THE LAKE. SOME THUNDERSTORMS MAY BE SEVERE
WITH STRONG WIND GUSTS IN EXCESS OF 50 KNOTS...MAINLY OVER THE
CENTRAL AND SOUTHERN PART OF THE LAKE.
.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
THERE IS A CHANCE OF THUNDERSTORMS OVER NORTHERN PARTS OF THE
LAKE FRIDAY AND FRIDAY EVENING.
THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS TUESDAY AND
WEDNESDAY.
&&
JEE/MTF
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGOThe Chicago radar (KLOT), 32 km away, was scanning. The volume nearest the first event began at 19:54 UTC.
2 flood, 2 funnel cloud. Local standard time, as filed.
Street flooding at Kirk Rd and Wilson. Water up to the tops of tires on turning lanes.
Funnel cloud lasted a few minutes and extended about half way to the ground.
About a foot of standing water on some streets near Damen Ave and Melrose St.
Near LaSalle/DeKalb county line.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2016Every state in 2016This day in weather historyWarnings in Illinois, July 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: 648409, 648400, 649353, 648404.