Warmest, Second Wettest December in IL

flood1

Flooded park in Champaign, IL.

Looking at the preliminary numbers, Illinois has experienced its warmest, and second wettest December on record. Statewide records go back to 1895.

Precipitation: the statewide average precipitation was 6.70 inches, 4.01 inches above average and the second wettest December on record.

The wettest December on record was in 1982 with 7.17 inches. Like this year, that was also during a major El Niño event.

Temperature: the statewide average temperature for December is 40.6 degrees, an incredible 10.7 degrees above average and the warmest December on record. This December beat the old record by 1.7 degrees that was set in 1923 with 38.9 degrees.

[this posted was updated on January 2, 2016, to reflect the latest information for December 2015]

Posted in Climate Monitoring | Tagged , , | 1 Comment

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
Posted in Climate Monitoring | Tagged , | Leave a comment

Heavy Rains Hit Illinois

A large, slow-moving winter storm has dropped considerable rainfall across Illinois in the last few days. Here is the map of the amounts in the last 7 days, through this morning (12/28). Areas in shades of red are 5 to 8 inches, and follow Interstate 70 across Illinois. Areas in shades of yellow to light brown are 2 to 5 inches. I’ll post more when the rain finally ends.

AHPS Precipitation Analysis

And it’s still raining. There is the potential for another 0.75 to 1.25 inches expected in southern and central Illinois. Another 1.25 to 1.75 inches is expected in parts of northern and western Illinois before this system moves on.

Is this El Niño?

Continue reading

Posted in Climate Monitoring | Tagged , | Leave a comment

Warm, Nearly Snowless December in Illinois

The first 17 days of December in Illinois has been nearly 11 degrees above average, with plenty of rain and a little snow in northern Illinois.

Temperature

Here are the temperature departures for December 1-17. The statewide average temperature was 43.0 degrees, 10.8 degrees above average. The light to dark pink in southern and central Illinois represents a 9 to 11 degree departure from average. The shades of red north of Interstate 72 represent an 11 to 13 degree departure from average. The departures get even stronger in Iowa, Minnesota, and Wisconsin.

map1

Snow

Continue reading

Posted in Climate Monitoring | Leave a comment

Latest Seasonal Outlook for IL

Illinois has higher odds of being both warmer and drier than average though June, according to the newly released NWS Climate Prediction Center outlooks.

The main driver of the forecast continues to be the strong El Niño event in the Pacific Ocean. El Niño is expected to go away by late spring or early summer. The increased odds of drier conditions through June could be a concern. However, I am more confident in the temperature forecasts from CPC than I am of the precipitation forecasts.

January:

(click on any map to make it bigger)
Illinois has higher odds of being both warmer and drier than average.

January – March:

Illinois has higher odds of being both warmer and drier than average.

April – June:

Continue reading

Posted in Seasonal Forecast | Leave a comment

Chance of a White Christmas in Illinois

I just heard “Let It Snow” on the radio and it reminded me that it’s time to do the annual post on …

What are the historical chances of a White Christmas?

We define a “white Christmas” as having at least an inch of snow on the ground on December 25. The map below shows the odds across the state. It should come as no surprise that the highest odds are in northern Illinois.  In general, the odds are about 40-60 percent in the northern third of Illinois, 20-40 percent in central Illinois, and 0-20 percent in southern Illinois.

There can be large differences between nearby sites. Snowfall is notoriously difficult to measure with blowing, drifting, and melting. Two nearby sites may have different results due to exposure to the sun and the wind as well as the dedication of the observer to report on Christmas Day.

WC_Chance_8110

What happened last year?

We had just a little bit of snow on the ground in parts of the northern half of Illinois on December 25, 2014 – hardly impressive. dec25-2014

What is the most snow on Christmas Day?

Here are the largest snow depths on Christmas Day (12/25) for selected locations around the state:

  • Chicago, 17 inches in 1951
  • Rockford, 14 inches in 1951 and 2000
  • Quad Cities, 12 inches in 1909
  • Peoria, 10 inches in 1909
  • Springfield, 10 inches in 1915
  • Champaign-Urbana, 9 inches in 1983
  • Carbondale, 9 inches in 2004

What are the odds this year?

What are the odds this year? They may be a little better than you think. While December has been incredibly mild so far, 10 degrees above average, that could change for short periods of time. Keep an eye out for developing storms as we get into Christmas week.

[An earlier version of this post had an interesting run from the GFS model showing a potential for snow around Christmas, but subsequent model runs did not support this. ]

Posted in Climate Monitoring | Tagged , | 2 Comments

Fifth Warmest Fall in Illinois

The average temperature for fall in Illinois (September-November) was 57.4 degrees, 3.0 degrees above average. As a result, it is the 5th warmest fall since 1895, based on preliminary data.

The top five warmest falls in Illinois:

  1. 1931 with 59.8 degrees
  2. 1963 with 58.0 degrees
  3. 1998 with 57.7 degrees
  4. 1971 with 57.5 degrees
  5. 2015 with 57.4 degrees

Here are the monthly departures of temperature in Illinois through the end of November for 2015. All three fall months were warmer than average. September was 4.6 degrees above average, October was 1.7 degrees above average, and November was 4.5 degrees above average.

image019.png

Monthly precipitation for 2015 shows the near-average September, the dry October, and the wet November. The 3-month total was 10.44 inches, 0.5 inches above average. Of course, this was overshadowed by the wet spring, especially June. In face, Illinois has already reached 41.79 inches of precipitation in 2015, 1.35 inches above the 12-month average.

image021.png

Posted in Climate Monitoring | Tagged , | Leave a comment