An unseasonably strong storm system impacted the region January 10-11. Heavy rainfall, flooding, isolated damaging winds, a brief tornado, and gusty non-thunderstorm winds impacted southern Illinois during this time. The bulk of the event occurred overnight and into the morning hours on the 11th. Rainfall totals ranged from 2 to 5 inches, which resulted in widespread areal flooding and isolated flash flooding across the region. Smaller rivers such as the Little Wabash and the Skillet Fork went into moderate to major flooding. Strong to severe convection over the Ozark Mountains moved east into an environment of very strong wind shear over southeast Missouri, with 850 mb winds near 60 knots. Tremendous wind shear (winds of 50 knots down to 1500 feet above ground level) and strong forcing associated with a potent 500 mb shortwave compensated for weak instability. The convection weakened after it crossed the Mississippi River during the early morning hours. Some of the strong winds aloft reached the surface as gradient gusts from 40 to 49 mph, mainly along and south of a Carbondale to Harrisburg line. A weak surface low formed along a cold front over southwest Arkansas, then deepened as it tracked northeast across the Missouri Bootheel and into the lower Ohio Valley on the morning of the 11th.

Strong Wind in ALEXANDER, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in PULASKI, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in MASSAC, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in HARDIN, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in POPE, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in JOHNSON, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in UNION, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in GALLATIN, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in SALINE, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in WILLIAMSON, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in JACKSON, ILLINOIS
From 10-JAN-20 22:00:00 to 11-JAN-20 03:00:00 (CST-6)
Magnitude: 43.00 MG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: ASOS

Flood in WAYNE, ILLINOIS
From 11-JAN-20 13:30:00 to 14-JAN-20 14:30:00 (CST-6)
Location: WAYNE CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Major flooding occurred on the Skillet Fork River. The river crested at 20.91 feet on the evening of the 12th at the Wayne City river gage. Major flooding begins at 20 feet. Numerous county roads were flooded, some of which were impassable. There was widespread flooding of low-lying fields and woodlands.

Flood in JACKSON, ILLINOIS
From 12-JAN-20 09:00:00 to 25-JAN-20 13:30:00 (CST-6)
Location: MT CARBON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Moderate flooding occurred on the Big Muddy River. The river crested at 29.92 feet on the evening of the 15th at the Murphysboro river gage. Moderate flooding begins at 28 feet. There was considerable flooding of low-lying woods and fields. Parts of a city park were flooded.

Flood in FRANKLIN, ILLINOIS
From 12-JAN-20 16:00:00 to 18-JAN-20 04:00:00 (CST-6)
Location: PLUMFIELD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Minor flooding occurred on the Big Muddy River. Low-lying woods and fields near the river were inundated.

Flood in WHITE, ILLINOIS
From 11-JAN-20 08:00:00 to 31-JAN-20 23:59:00 (CST-6)
Location: BROWNSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Moderate flooding occurred on the Little Wabash River. The river crested at 34.64 feet on the afternoon of the 20th at the Carmi river gage. Moderate flooding begins at 32 feet. Areas near Routes 1 and 14 in Carmi flooded. County roads were inundated. The river remained above flood stage into February.

Tornado in UNION, ILLINOIS
From 11-JAN-20 02:02:00 to 11-JAN-20 02:03:00 (CST-6)
Location: WARE
Tornado F-scale: EF1
Property damage: 80.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado snapped large tree branches in the town of Ware. Metal roofing was removed from a farm outbuilding. A large open storage building was overturned and destroyed. Shingles were removed from the roof of a hunting club. Another home had its roof lifted slightly by the tornado, causing water damage. The roof of a metal storage building was lofted and overturned. Hundreds of decoy ducks were tossed and broken near the hunting club. Numerous trees were snapped or uprooted along the path of the tornado. Peak winds were estimated near 100 mph.

Thunderstorm Wind in WILLIAMSON, ILLINOIS
From 11-JAN-20 02:38:00 to 11-JAN-20 02:38:00 (CST-6)
Location: HERRIN
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

Small tree limbs were broken. The report was received via the mping (Meteorological Phenomena Identification Near the Ground) app.

Thunderstorm Wind in JACKSON, ILLINOIS
From 11-JAN-20 02:01:00 to 11-JAN-20 02:01:00 (CST-6)
Location: (MDH)CRBNDL/MRFYSBRO
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A wind gust to 70 mph was measured by the automated weather observation system at the Carbondale airport.

Flash Flood in PERRY, ILLINOIS
From 11-JAN-20 07:00:00 to 11-JAN-20 11:00:00 (CST-6)
Location: PINCKNEYVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Three inches of rainfall reportedly caused flooding.

Flash Flood in MASSAC, ILLINOIS
From 11-JAN-20 07:15:00 to 11-JAN-20 09:15:00 (CST-6)
Location: METROPOLIS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Six to eight inches of water was flowing over a 30 to 40 foot section of road at the entrance to a subdivision.

Flash Flood in WABASH, ILLINOIS
From 11-JAN-20 06:00:00 to 11-JAN-20 09:30:00 (CST-6)
Location: MT CARMEL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Highway 1 south of Mount Carmel was impassable due to flooding.

Flash Flood in UNION, ILLINOIS
From 11-JAN-20 06:00:00 to 11-JAN-20 11:15:00 (CST-6)
Location: SARATOGA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Lick Creek Road was flooded close to the Johnson County line. A few other county roads were covered with water.