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Summary
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Tornadoes
Magnolia EF2
Summary: Between approximately 810 pm and 835 pm on June 5, an EF2 tornado moved across areas from about 2.75 miles east northeast of Henry, IL, through Magnolia, IL, into western La Salle County about 3 miles east of Magnolia, IL. Wind speeds were estimated to be 135 mph. The tornado touched down at the shore of Sawmill Lake with a width of about 0.5 miles. Numerous trees were snapped off and shredded, laying in scattered directions. Extensive tree damage and some structural damage was observed toward Taylor Rd. Along County Road 150 N and Highway 18 west of Magnolia, several farm outbuildings including a large barn and steel shed were destroyed. A 400 to 450 foot tall cell phone tower was completely destroyed. In Magnolia, IL, the tornado caused extensive tree damage across the northern two thirds of town with minor damage to numerous residences. On the north side of town, the tornado ripped the roofs completely off of four structures. The tornado weakened to an EF0 rating as it crossed into La Salle County. Intermittent damage was then noted from the Putnam County line to just east of East 1st Road, about one half mile south of IL-18. The damage consisted primarily of tree and minor structural damage to farm buildings. |
Naplate EF0
Summary: A tornado briefly occurred just west of Ottawa and just north of Starved Rock State Park. A damage survey conducted by the National Weather Service found some minor damage in the area with a couple large trees downed along with several other branches of varying sizes downed. |
Streator EF2
Summary: Shortly after the Magnolia, IL tornado lifted, the same supercell thunderstorm went on to produce another tornado near the Marshall and LaSalle County line. National Weather Service damage survey teams found the damage from this tornado began just west of 2900 E Road and about one quarter mile south of 1250 N Road, or N 12th Road, which is the road that marks the county line. The tornado crossed north of 1250 N Road at Interstate 39. See Stormdata for Illinois, Central for the beginning of this tornado. |
Streator EFU
Summary: Spotters and chasers witnessed a brief secondary tornado near Streator, in a field just south of Illinois Route 18, between County Roads 14 and 15, about 1/2 mile north of the main Streator tornado track. They observed a brief dust whirl on the ground beneath the funnel cloud, but it was over an open field and there was no damage. |
Ransom EF3
Summary: Very quickly after the tornado that hit Streator lifted, yet another tornado touched down over extreme northern Livingston county approximately one quarter mile south of the county line and about a half mile west of 1100 E Road. Shortly after touching down, this tornado caused severe damage to homes on 1100 E Road and destroyed a barn as well. There were also several large trees downed in this location. As the tornado continued eastward, it completely collapsed a metal truss high tension electrical tower and bent over several other metal truss electrical towers in its path, which is consistent with low end EF3 damage. At this time the tornado was moving through an extremely rural area, however there was also a lone hardwood tree in its path that was debarked, with only large de-leafed branches remaining. |
Dwight EF2
Summary: The beginning of the Dwight tornado occurred about 6 miles west of Dwight and about a quarter mile south of IL Route 17. On N 2200 E Road, 0.3 miles south of IL Route 17, a farm house sustained damage to windows, siding, and shingles, with many trees uprooted or damaged. Outbuildings were also damaged. The tornado at this point was rated EF1, with a path width of 70 yards. Debris from this farm was spread 200 yards wide across the field at N 2300E Road. |
Dwight EF0
Summary: A secondary tornado occurred 3 miles northwest of Dwight in northern Livingston County. The tornado began near the intersection of Rd 3300N and 2300E, where it caused minor damage to a home and surrounding trees. The tornado continued to the southeast where it derailed a train off its tracks near 2400E Road. At this point, the tornado moved east causing minor damage to some area trees before crossing Interstate 55, where it then lifted. The tornado was rated EF0 with winds estimated at around 80 mph and a path width of 20 yards. |
Reddick EF0
Summary: A tornado formed along the north side of 3100 N Road, between 3100 E Road and 3200 E Road, for one quarter of a mile. The tornado was rated EF0 here. There was additional minor damage to tree limbs and a metal farm outbuilding for about half a mile along the north side of 3100 N Road, between 3400 E Road and 3500 E Road. The tornado here was rated EF0 with a path width of 20 yards. |
Forrest EF0
Summary: A very brief and weak tornado occurred 6 miles northeast of Fairbury in southern Livingston County. There was damage to a barn and corn crop. Vents on this barn were torn off with the corn crop flattened and twisted throughout the field. The tornado was rated EF0 with winds estimated at around 70 mph. |
Limestone EF1
Summary: A brief tornado developed about 5 miles southwest of Kankakee, or 3 miles south of Limestone, in southern Kankakee County. This brief tornado caused damage to a farm just north of the intersection of 5000W Road and 3000S Road. Several trees were uprooted or snapped. A machine shed on the property was destroyed, along with farm equipment and vehicles. A quonset building was damaged, and a fence was blown over. The tornado was rated EF1 with winds estimated at around 100 mph. |
St. Anne - Hopkins Park EF3
Summary: The tornado began 3 miles northwest of St. Anne in Kankakee county. The tornado developed just west of 6000E Road and tracked to the east, where it produced damage to a home and a garage along the road. At this location, a single family home collapsed upon itself, leaving it inhabitable. The garage sustained damage to its roof and exterior walls. The tornado was rated EF2 with winds estimated at around 113 mph. |
Wichert EF1
Summary: Spotters witnessed a brief secondary tornado to the north of the primary St. Anne tornado. This tornado touched down in a farm field near a creek, about 1/4 mile north of County Road 3500 S, and one quarter mile west of Illinois Route 1. It destroyed a machine shed and flipped over a large grain trailer. The tornado also blew down large tree limbs. |
The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:
EF-0 Weak 65-85 mph |
EF-1 Moderate 86-110 mph |
EF-2 Significant 111-135 mph |
EF-3 Severe 136-165 mph |
EF-4 Extreme 166-200 mph |
EF-5 Catastrophic 200+ mph |
Environment
Showers and thunderstorms had moved east across portions of central and northern Illinois during the overnight and early morning hours of Saturday morning. This left much of northern Illinois cloudy and somewhat rain-cooled after sunrise, which inhibited development of storms for a good portion of the day. However, clouds began to thin by mid-day across parts of north central Illinois, which allowed temperatures to climb into the lower 80’s during the afternoon hours. Around 2:00 PM, clouds were thinning over LaSalle and Livingston counties. There was also a band of clouds extending from central Illinois west into northern Missouri, which likely likely enhanced low level cloudiness along the outflow boundary from the morning showers and storms.
During the afternoon, temperatures in the lower 80s combined with dew points in the lower 70s created very warm, humid, and unstable conditions. Meteorologists measure instability in the form of Convective Available Potential Energy, or CAPE. At 8:00 PM, surface-based CAPE was near 2000-3000 j/kg over north central Illinois.
At the same time, a mid level disturbance was approaching from the west. This disturbance was helping to increase mid level winds to 60-70 knots across the Midwest, resulting in strong deep layer wind shear, which would result in rotating storms to develop, which are known as supercells.
While increased deep layer shear supported the development of rotation within thunderstorms, low level shear was also increasing, which supported the potential for these storms to produce tornadoes. The outflow boundary which was lifting north from central Illinois likely aided in increasing low level shear and helicity, which led to an environment supportive of tornadic supercells across the area by the evening hours. Values of Storm-Relative Helicity (SRH) were approaching 400 m2/s2 at 8:00 PM CDT, which were more than sufficient for tornado development.
The Storm Prediction Center (SPC) produces a “Significant Tornado Parameter” which combines instability, deep and low level shear, and low level moisture in addition to a couple of other parameters favorable for tornado development. At 8:00 PM CDT, values neared 7 just southwest of LaSalle County, indicator an environment favorable for tornadoes and even a few stronger tornadoes.
Within this environment supportive of producing tornadic supercells, thunderstorms indeed developed across western Illinois around 7:00 pm CDT. These storms developed ahead of a cold front approaching from the west.
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