Late December Heavy Rains, Flooding in Illinois

A large, slow-moving low-pressure system moved through the central US, bringing widespread, heavy rains to Illinois and neighboring state. This resulted in considerable flooding ranging from flooded basements to major flooding on the Mississippi River.

Rainfall Maps for December 26-29, 2015

This first map shows the widespread heavy rains from Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, and Indiana. Areas in the three shades of red represent amounts of 5 to 10 inches. The purple streak from Oklahoma to Missouri represents 10 to 15 inches of rain.

Southern and central Illinois were hardest hit with large areas of 5 to 10 inches of rain, falling on soils that were already saturated. Meanwhile, the northern third of Illinois received 2 to 4 inches of precipitation (rain plus water content of snow), as well as 1 to 4 inches of snow.

map1

This second map zooms in on Illinois, showing the heavy rains across the state more clearly. The lightest shade of red is 5 to 6 inches, the next darker shade is 6 to 8 inches, and the darkest shade of red east of St. Louis and south of Decatur is 8 to 10 inches.

To put this in perspective, the average December precipitation for Illinois ranges from 4.5 inches in southern Illinois to 2 inches in northwest Illinois. So areas in central Illinois, where the average is about 3 inches, received about 3 times that over the course of 4 days.

map2

Flooding

These heavy rains have led to widespread flooding. Here is the NWS map of rivers and streams in various stages of flooding. The purple dots and squares represent areas of major flooding, mostly the Mississippi River from St. Louis southward.

“Major Flooding” means extensive inundation of structures and roads. Significant evacuations of people and property. Red means moderate flooding (some risk of flooding to structures and roads) and tan means minor flooding. 

map3

Here is a NWS river flood forecast at Chester IL on the Mississippi River, showing the impact of the heavy rains upstream. Right now they are expecting a record, or near record, stage at that point of the river.

map4

Rainfall Totals for December 26-29, 2015

Here are some rainfall totals from our volunteer CoCoRaHS network around the state, ranked from highest to lowest, with complete data from December 26-29, 2015. Godfrey IL, near St. Louis, reported the highest 4-day total of 10.03 inches.

 

Station
Number
Station Name Total Precip (inches)
 IL-MD-34 Godfrey 2.5 SSW 10.03
 IL-MD-28 Staunton 4.3 SSW 8.90
 IL-SH-1 Shelbyville 0.5 NE 8.87
 IL-MD-10 Granite City 1.4 ENE 8.57
 IL-EF-13 Effingham 6.7 N 7.61
 IL-CN-3 Pana 6.2 NNE 7.45
 IL-MP-12 Carlinville 1.1 E 7.42
 IL-SC-18 Fairmont City 0.9 ENE 7.05
 IL-MY-1 Nokomis 4.5 NW 6.98
 IL-RH-7 Sparta 1.6 SW 6.74
 IL-CN-7 Taylorville 0.6 ENE 6.73
 IL-DG-12 Camargo 4.5 ESE 6.65
 IL-RH-8 Sparta 1.9 SSW 6.56
 IL-SH-3 Mode 3.7 NW 6.51
 IL-ED-6 Chrisman 3.6 ESE 6.50
 IL-DG-11 Tuscola 0.6 NNE 6.27
 IL-MP-18 Girard 0.1 WSW 6.26
 IL-MA-1 Mount Zion 0.8 ESE 6.22
 IL-CN-4 Edinburg 3.0 W 6.15
 IL-CP-21 Broadlands 0.1 SSW 6.13
 IL-DG-4 Tuscola 0.5 WSW 6.10
 IL-MD-20 Edwardsville 0.9 WSW 6.08
 IL-MD-33 Troy 1.5 SSE 6.04
 IL-WM-4 Bush 2.0 ESE 6.02
 IL-MP-4 Girard 1.2 W 5.97
 IL-SC-11 Centreville 1.9 E 5.87
 IL-WS-3 Okawville 2.3 SW 5.76
 IL-CL-2 Marshall 4.6 W 5.75
 IL-PT-1 Monticello 3.5 NNE 5.72
 IL-CP-14 Philo 0.3 NE 5.68
 IL-SC-9 Belleville 4.5 WNW 5.67
 IL-CP-1 Homer 2.0 N 5.63
 IL-SC-3 Belleville 2.2 SE 5.57
 IL-EF-10 Watson 0.3 NE 5.52
 IL-SC-23 Belleville 2.7 SSE 5.52
 IL-MC-1 Belknap 11.1 ESE 5.45
 IL-JF-4 Mount Vernon 1.3 SW 5.44
 IL-CP-58 Urbana 0.9 SSE 5.43
 IL-VR-19 Danville 7.6 N 5.34
 IL-MG-9 Jacksonville 1.2 SW 5.26
 IL-CP-95 Urbana 4.2 ESE 5.15
 IL-VR-4 Henning 3.4 SSE 5.15
 IL-SG-4 Riverton 1.9 W 5.12
 IL-PT-6 Monticello 6.5 WSW 5.11
 IL-CP-31 St. Joseph 0.9 SSW 5.04
 IL-MG-6 Murrayville 0.4 NE 5.03
 IL-CP-90 Champaign 2.4 S 5.02
 IL-VR-20 Westville 0.6 SSW 4.99
 IL-RC-3 Olney 0.7 E 4.95
 IL-PT-8 White Heath 3.7 NNE 4.94
 IL-VR-14 Danville 0.6 NW 4.94
 IL-CP-37 Sidney 0.9 N 4.93
 IL-CP-59 Mahomet 1.7 NNE 4.92
 IL-CP-92 Mahomet 1.2 S 4.90
 IL-MN-5 Odin 0.5 SSE 4.88
 IL-SG-47 Springfield 6.6 S 4.85
 IL-CP-64 Champaign 2.4 SSE 4.83
 IL-PT-13 Mansfield 3.0 WSW 4.83
 IL-SG-17 Springfield 4.4 W 4.83
 IL-CP-81 Dewey 1.6 NNW 4.75
 IL-LG-36 Lincoln 1.7 W 4.71
 IL-CS-3 Arenzville 5.3 NNE 4.68
 IL-ME-10 Athens 2.4 NNW 4.61
 IL-SG-11 Chatham 1.4 ESE 4.56
 IL-MO-4 Fults 3.7 ENE 4.50
 IL-LG-8 Lincoln 1.4 SE 4.46
 IL-ME-9 Athens 1.0 N 4.46
 IL-LG-13 Lincoln 0.9 NNW 4.38
 IL-LG-22 Lincoln 0.87 SE 4.38
 IL-CK-14 Chicago 5.5 ESE 4.36
 IL-MCL-4 Heyworth 0.6 E 4.35
 IL-MCL-7 Le Roy 4.1 SSW 4.31
 IL-LG-9 Beason 4.0 SW 4.27
 IL-PT-17 Monticello 3.8 NNE 4.25
 IL-VR-17 Hoopeston 0.8 W 4.18
 IL-LG-40 Lincoln 0.4 NE 4.17
 IL-CP-47 Champaign 2.3 NNW 4.15
 IL-FK-5 West Frankfort 0.3 WNW 4.02
 IL-LG-30 Atlanta 7.1 W 4.01
 IL-CP-28 Champaign 1.3 SSW 4.00
 IL-MCL-30 Saybrook 4.3 SSE 3.96
 IL-SG-48 Springfield 2.6 WNW 3.92
 IL-FD-9 Gibson 3.0 WNW 3.86
 IL-CW-3 Hutsonville 0.3 WNW 3.79
 IL-LV-6 Pontiac 1.0 SE 3.71
 IL-GY-2 Dwight 4.1 NNW 3.68
 IL-TZ-26 Pekin 3.6 SSE 3.66
 IL-MCL-23 Normal 1.9 ESE 3.53
 IL-KK-7 Kankakee 4.5 WNW 3.44
 IL-KK-23 Bonfield 4.0 WSW 3.40
 IL-SG-44 Sherman 4.1 N 3.40
 IL-KK-25 Bonfield 4.2 NNE 3.39
 IL-MCL-2 Arrowsmith 1.7 NNE 3.25
 IL-WF-12 Germantown Hills 1.3 NW 3.21
 IL-IR-2 Ashkum 5.6 E 3.19
 IL-LV-7 Chatsworth 0.4 ESE 3.19
 IL-WL-23 Beecher 3.4 SSE 3.15
 IL-CK-145 Oak Park 1.5 S 3.14
 IL-MCL-9 Danvers 1.7 WNW 3.14
 IL-WL-26 Manhattan 0.8 ESE 3.14
 IL-GY-12 Braceville 0.5 SSE 3.12
 IL-WL-131 Homer Glen 0.7 NNE 3.12
 IL-GY-9 Mazon 0.5 ENE 3.10
 IL-CK-82 Burnham-Hegewisch 1.6 NNW 3.09
 IL-PR-9 Dunlap 2.6 S 3.09
 IL-WL-73 Wilmington 2.6 SE 3.09
 IL-WL-20 Manhattan 4.7 ENE 3.00
 IL-CK-152 Chicago Ridge 0.2 WSW 2.99
 IL-CK-206 Park Forest 1.0 SW 2.98
 IL-TZ-14 Morton 1.0 SSE 2.97
 IL-WL-63 New Lenox 1.8 SE 2.96
 IL-CK-154 Worth 0.1 E 2.92
 IL-GY-10 Minooka 0.3 NE 2.88
 IL-WL-118 Elwood 4.6 NE 2.84
 IL-GY-1 Carbon Hill 3.1 N 2.83
 IL-WL-97 New Lenox 3.3 E 2.83
 IL-WL-99 Manhattan 1.9 SE 2.83
 IL-GY-21 Coal City 2.8 N 2.82
 IL-MCD-7 Colchester 3.5 NE 2.80
 IL-CK-253 Midlothian 0.1 SSE 2.79
 IL-WL-67 Channahon 2.5 SSE 2.75
 IL-DP-79 Burr Ridge 1.9 SW 2.73
 IL-LS-33 Streator 3.7 ENE 2.73
 IL-WL-16 Homer Glen 0.8 ENE 2.73
 IL-WL-25 Crete 2.6 E 2.72
 IL-HN-1 Dallas City 3.0 SSE 2.71
 IL-KK-26 Kankakee 3.2 SE 2.70
 IL-GY-16 Morris 6.4 ESE 2.68
 IL-LS-1 Ottawa 1.3 NW 2.65
 IL-CK-50 Palos Park 1.3 SW 2.64
 IL-CK-153 Alsip 0.2 E 2.64
 IL-WL-71 Plainfield 1.1 SW 2.62
 IL-CK-196 Harwood Heights 1.9 NNE 2.61
 IL-CK-211 Oak Lawn 1.6 WNW 2.60
 IL-LS-17 Ottawa 1.6 N 2.58
 IL-CR-4 Chadwick 2.7 WSW 2.56
 IL-DP-127 Downers Grove 0.4 NNE 2.55
 IL-WL-100 Joliet 2.9 WNW 2.54
 IL-CK-180 Park Ridge 0.5 SSW 2.50
 IL-DP-85 Villa Park 1.0 NW 2.50
 IL-KD-24 Oswego 5.0 SSE 2.50
 IL-WL-119 Homer Glen 1.6 NW 2.50
 IL-WL-80 Lockport 1.3 SE 2.48
 IL-CK-106 Hoffman Estates 4.6 W 2.45
 IL-LK-42 Gurnee 1.6 W 2.44
 IL-CK-61 Oak Park 1.0 SW 2.42
 IL-DP-57 Aurora 3.5 NE 2.42
 IL-CK-232 Rogers Park 0.6 ESE 2.40
 IL-CK-98 La Grange Park 0.7 SSW 2.37
 IL-DP-102 Bolingbrook 2.7 NE 2.34
 IL-DP-32 Lisle 1.3 SE 2.32
 IL-LS-7 Sheridan 3.4 SSE 2.32
 IL-LS-56 Ottawa 0.4 N 2.32
 IL-DP-77 Roselle 1.1 W 2.31
 IL-GY-20 Morris 2.5 SSE 2.30
 IL-KN-62 Batavia 1.3 WNW 2.29
 IL-KX-9 Knoxville 0.7 NW 2.29
 IL-GY-11 Morris 4.8 NNW 2.27
 IL-LS-57 Mendota 0.4 ENE 2.26
 IL-CK-75 Elk Grove Village 2.2 WSW 2.25
 IL-CK-149 Oak Lawn 0.5 SSW 2.25
 IL-LE-8 Ashton 0.4 SSW 2.22
 IL-DP-132 Wheaton 2.0 NNE 2.19
 IL-HD-1 Stronghurst 0.4 SSW 2.19
 IL-CK-94 Lincolnwood 1.8 E 2.18
 IL-BU-8 Tiskilwa 2.1 N 2.16
 IL-LK-8 Gurnee 2.5 NE 2.15
 IL-LK-22 Lake Forest 2.1 NNE 2.15
 IL-DP-109 Elmhurst 0.8 ESE 2.14
 IL-KN-51 Sugar Grove 1.4 ENE 2.14
 IL-DP-75 Naperville 1.1 NW 2.13
 IL-LS-34 La Salle 0.1 W 2.11
 IL-KN-4 Sugar Grove 0.7 NE 2.10
 IL-CK-63 Elk Grove Village 0.6 ESE 2.09
 IL-DP-101 Aurora 3.8 SE 2.09
 IL-KD-34 Plainfield 4.8 SW 2.09
 IL-LK-39 Riverwoods 0.4 ENE 2.09
 IL-DP-40 Lombard 1.0 NNW 2.08
 IL-KN-33 North Aurora 1.5 NE 2.08
 IL-LK-69 Highwood 0.9 S 2.06
 IL-KN-63 Geneva 1.7 WSW 2.04
 IL-DP-100 Bartlett 1.1 SE 2.00
 IL-WL-46 Peotone 0.4 ENE 1.99
 IL-LS-11 Mendota 0.9 N 1.98
 IL-DK-24 Somonauk 1.9 NE 1.95
 IL-LK-16 Buffalo Grove 1.5 N 1.95
 IL-DP-16 Aurora 3.6 SE 1.94
 IL-WN-26 Rockford 1.5 ENE 1.92
 IL-KN-23 Batavia 1.5 WNW 1.91
 IL-KN-30 Elburn 0.4 NW 1.90
 IL-KN-64 St. Charles 0.1 E 1.84
 IL-KN-9 Elgin 1.0 S 1.82
 IL-WN-8 Rockford 0.7 NW 1.82
 IL-BN-14 Capron 0.1 N 1.78
 IL-KN-110 Elgin 1.9 NE 1.78
 IL-LE-21 Dixon 5.2 WSW 1.74
 IL-LK-3 Beach Park 1.4 W 1.69
 IL-MCH-43 Algonquin 0.7 N 1.69
 IL-MCH-30 Wonder Lake 0.8 WNW 1.66
 IL-LK-81 Lake Villa 2.3 WSW 1.63
 IL-CK-131 Schaumburg 2.0 E 1.62
 IL-KN-95 Elgin 2.5 W 1.53
 IL-WN-3 Machesney Park 3.1 ENE 1.51
 IL-CR-12 Mount Carroll 6.8 NNW 1.47
 IL-RI-13 Moline 0.7 NNE 1.44
 IL-WN-2 Roscoe 1.6 ESE 1.44
 IL-SP-6 Freeport 2.0 NW 1.43
 IL-RI-3 Moline 0.9 N 1.41
 IL-CK-192 Park Ridge 0.7 WNW 1.38
 IL-SP-7 Davis 0.5 N 1.38
 IL-LE-17 Dixon 1.5 SW 1.32
 IL-OG-4 Byron 3.2 N 1.23
 IL-CR-13 Shannon 0.2 S 1.22
 IL-MCH-66 Harvard 2.8 SSE 1.02
 IL-CK-36 Chicago 4.7 NE 1.01
 IL-SP-8 Winslow 4.3 ESE 0.77
 IL-LE-14 Amboy 0.5 ESE 0.17

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