WEATHER CURRENTS
National Weather Service, Chicago
Winter 2006 Volume 4 Issue 4
Serving the people of north central and northeast Illinois, northwest Indiana, and the boaters of
Lake Michigan
In this issue:
Top Weather Events of 2006 for North Central and Northeast Illinois and Northwest Indiana
40th Anniversary of the January, 1967 Blizzard
El Nino Winters vs. Chicago and Rockford Snowfall
Skywarn Recognition Day 2006
The Importance of NOAA Weather Radio – All Hazards, Your First Source for Critical Weather Information
January 20-21 Winter Storm
A band of heavy snow fell across De Kalb, Kane, southeast McHenry, northwest Cook and Lake Counties in northern Illinois from late afternoon Friday January 20 through early Saturday morning the 21st. Some of the heaviest snowfall totals were 12.0 inches at Elgin, 11.7 at Grayslake, 11.5 at Shabbona, and 11.0 at Barrington. Snow tapered off north and south of this area. Only 4.7 inches fell at O’Hare and 5.0 inches at Rockford.
February 18 Extreme Cold
February 18 was the coldest day of 2006. An arctic air mass accompanied by strong winds blasted the area. O’Hare had a low of 7 below zero and a high of 8 above, and Rockford had a low of 11 below and a high of only 3 above. Wind chills were as low as -30 to -35. A couple days before the arctic air hit, temperatures were in the 50s and heavy rain and a few thunderstorms occurred.
March 12 Severe Storms
An early season severe weather outbreak hit the Midwest. Severe storms affected areas from the southern plains through the Great Lakes. One supercell formed in eastern Kansas in the afternoon, traversed all of Missouri, and Illinois before dissipating in northern Indiana that evening. The storm clipped Ford and Iroquois Counties with downburst winds and a weak tornado. The storm also produced tornadoes in Springfield. Another storm produced an intense microburst in Bridgeview, which unroofed an apartment building and damaged garages and trees. There were many reports of hail to up to the size of golf balls, especially across LaSalle, Grundy, and Will counties.
March 31 High Winds
Winds gusted as high as 60 to 65 mph across the Chicago area and Gary Indiana. A small boy was injured by a falling tree branch in Chicago. A building façade fell onto Irving Park Road and a pedestrian was injured by flying debris. A car wash was partially unroofed, injuring another person. A roof was also damaged at a recreational center in south suburban Thornton. The City of Chicago reported 107 calls about tree damage. A billboard was blown down in west suburban Addison. Peak wind gusts included 67 mph at Gary, and 60 mph at Lansing.
April 13-14 Big Hail, Small Twisters
Supercells produced the biggest hail of the season over parts of northern Illinois and northwest Indiana. Hail was up to baseball size in Dixon, golf ball and bigger in Rockford, tennis balls in Milford (Iroquois County), and golf balls at Boswell and Remington Indiana. There were also several funnel cloud reports. Brief, weak F0 tornadoes occurred near Ambia in Benton County, Indiana, and near Grand Ridge in LaSalle County.
July 15-17 and July 28-August 2 Heat Waves
A heat wave developed in mid July. Highs were in middle 90s for three straight days. The highest temperature at O’Hare was 97 on the 15th. The Heat Index peaked at 108 at O’Hare and 117 at Northerly Island in Chicago on the 17th. Overnight low temperatures were in the middle to upper 70s during the period. There were 9 heat related deaths in Cook County. Later in the month, the area sustained 6 straight days in the 90s. The highest temperature at O’Hare was 99 on July 31st and again on August 1. The Heat Index peaked at 107 at O’Hare on the 31st and 1st. There were 28 heat related deaths in Cook County from the late July-early August heat wave.
August 23 Downburst near Michigan City
A supercell thunderstorm formed over southern Lake Michigan. Waterspouts were witnessed by pilots over the Lake. The powerful storm hit Michigan City and Town of Pines with winds 80 to 110 mph, downing many trees and limbs. One tree fell on a trailer, other trees and limbs fell on cars and roofs. A wind gust to 106 mph was recorded at Michigan City.
September 4 Labor Day Flash Flood in Rockford
A slow moving low pressure system triggered scattered thunderstorms across eastern Iowa, southern Wisconsin and northern Illinois during the afternoon of September 4. A series of slow moving storms moved into and sat over the east side of Rockford. As much as 5 to 10 inches of rain fell in a localized area, while less than three quarters of an inch fell nearby at the airport. The heavy rain produced severe flooding of Keith Creek in the late afternoon and early evening. Hundreds of basements were flooded and fifteen homes were left uninhabitable. Streets and parking lots were flooded and cars were submerged in water. Damage was estimated at about 20 million dollars.
September 13 Highland, Indiana Flash Flood
Heavy rain fell over northwest Indiana during the morning hours of September 13, which caused severe flooding in Highland and East Chicago. As much as 4 to 8 inches of rain fell in a couple hours. At one point 90 percent of the streets in Highland were flooded and 70 percent of the homes were affected. Fourteen homes were condemned due to flooding. Total damage was about 8 million dollars.
September 22 Supercells - Tornado at Loyola, Near Miss at O’Hare
A series of strongly rotating supercell thunderstorms developed and moved across parts of DeKalb, Kane, DuPage, and Cook Counties. A well developed funnel cloud was observed near Waterman in DeKalb County and wind damage occurred to power poles, trees, crops and outbuildings. A tornado occurred briefly at Loyola University on the north side of Chicago before moving out over Lake Michigan as a waterspout. One of the supercells produced a well formed “hook” over O’Hare Airport near I-90 and I-294 at the peak of rush hour. The hook echo is a classic tornado signature sometimes seen on radar. Fortunately no tornado occurred.
October 2 Severe Storm Outbreak
Unseasonably warm and humid air moved into the region. Some locations in downstate Illinois had record highs in the 90s. Severe storms broke out in the afternoon producing heavy rain across Kendall and Will Counties, and large hail at many locations. Storms redeveloped in the evening with more heavy rain and flooding in parts of the Chicago metro area. A total of 4 to 5 inches of rain fell in some areas. A squall line moved north to south across the Chicago metro area producing widespread wind damage. The hardest hit areas were Hickory Hills, Bridgeview, and Palos Hills in southern Cook County. A large section of a gymnasium roof was blown off a junior high school. Debris fell on a van injuring two passengers. Warehouse buildings had walls blown out in an industrial complex.
November 30-December 1 Snow and Ice Storm
After four straight days in the 60s, late November turned sharply colder as a cold front slipped east across northern Illinois before stalling out in Indiana. A strong low pressure system rode up the stationary front Thursday night November 30 and Friday morning December 1. The storm brought a mix of freezing rain and sleet to parts of central and northern Illinois which eventually changed to snow. Snow became heavy with lightning and thunder in the early morning hours. The heaviest snow fell in a corridor from LaSalle-Peru north to Rockford and the north suburbs of Chicago. Some snowfall totals included 17.3 inches at Peru, 14 inches at Rockford, 13.5 inches at Dixon and Rochelle, and around a foot at DeKalb, Palatine, Woodstock, and Beach Park.
The Event
Forty years ago, on January 26 and 27, 1967, Chicago endured its worst snowstorm ever. The snow started at 502 AM on the 26th, and by 1010 AM of the 27th a record 23 inches of snow crippled the city. The previous record snow for the city was 19 inches on March 25th and 26th, 1930. During the storm winds gusted to 53 mph at Midway Airport. The high winds caused considerable blowing and drifting. Drifts 4 to 6 feet high were widespread throughout the area.
The heaviest snow fell in the morning and early afternoon of the 26th with the maximum rate of accumulation 2 inches per hour during the late morning. A thunderstorm was reported at Meigs Field. Snow tapered off by evening but intensified again overnight.
Two days before the blizzard, on January 24th, the high temperature was 65 degrees and the low was 44, both records that still stand today. Thunderstorms occurred in the evening of the 24th. There were reports of wind damage, and funnel clouds were spotted in the southwest section of the city. The wind gusted to 48 mph at Midway. The wall of a building under construction at 87th and Stony Island toppled, killing one man and injuring four others.
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The Impact
Snow began on Thursday morning, January 26th but most people made it to work and school without much trouble. But by noon about 8 inches was already on the ground and O’Hare Airport was shut down. Some businesses and schools released employees and students early. The commute home, even for those who started early, was a nightmare. Many workers did not get home, or arrived very late. Many stayed at work or in hotels. By Friday morning the city was at a standstill. The airports and local transportation were shut down. In the city of Chicago 20,000 cars and 1,100 CTA buses were stranded in the snow. People walked to stores to clear the shelves of bread and milk. Helicopters were used to deliver medical supplies to hospitals, and food and blankets to stranded motorists. Expectant mothers were taken to hospitals by sled, bulldozer and snow plow. At least a dozen babies were born at home. Looting became a problem on the west and near south sides of the city. Another problem in the aftermath of the storm was low supplies of heating oil. Trucks couldn’t get access to buildings.
By Saturday the 28th, Chicago was beginning to dig itself out. Commuter trains were running and CTA buses were operating most lines. The city sent a workforce of 2,500 people with 500 pieces of equipment out to clear the streets. Iowa, Wisconsin and Michigan sent heavy equipment to help with the snow removal. But the thousands of abandoned vehicles hampered the clean up. Snow was hauled by dump truck to the Chicago River. O’Hare finally opened around midnight Monday, allowing people who had been stranded for days to finally get home. Most schools didn’t reopen until Tuesday. By then most transportation was back to normal.
By the time it was over, 60 people were dead and there was an estimated $150 million in business losses (about $904 million in 2006 dollars). The 1967 snowstorm probably caused the biggest disruption to the commerce and transportation of Chicago of any event since the Great Chicago Fire of 1871.
O'Hare Airport
The Meteorology
On Wednesday January 25 a cold front had moved through the upper Midwest replacing the balmy 60 degree weather of the previous day with more seasonal readings. A strong 1032mb (30.48 in) high pressure center was over the prairie provinces of southern Canada. A vigorous upper level trough was moving across the southern Rockies causing a low pressure area to form at the surface near the Texas Panhandle. By midnight of Thursday January 26 the high was building into the northern plains states while the low, now at 1008mb (29.77 in) continued to develop and move east to Oklahoma. During the day Thursday the upper trough moved through the mid and lower Mississippi Valley and an upper level low began forming near the Missouri/Arkansas border. The surface low moved through Arkansas and western Tennessee and Kentucky, reaching south central Indiana by midnight Friday. The low deepened rapidly to 997mb (29.44 in) as it moved to Indiana.
Dew points in the 50s to lower 60s over the southern plains and Gulf Coast states fed the storm with ample moisture while the Canadian high pressure, now centered over Lake Superior and southern Ontario, kept cold dry air pouring into the Great Lakes. The strong pressure gradient between the high over the upper Lakes and the deepening low over the Ohio Valley caused winds to howl off Lake Michigan. This produced severe blowing and drifting of snow as well as causing lake effect enhancement of the snowfall.
On Friday the upper low continued to form and move northeast to northwest Ohio. The surface low occluded and deepened to 990mb (29.23 in) as it lifted northeast across Lake Erie and into southeast Ontario, Canada by Friday night. By this time the snow had ended in Chicago and winds shifted to north northwest and began to subside.
Map 1: Midnight CST Jan 26, 1967
Map 2: Midnight CST Jan 27, 1967
Map 3: Midnight Jan 28, 1967
To view high resolution images of these maps go to: http://docs.lib.noaa.gov/rescue/dwm/data_rescue_daily_weather_maps.html
The Forecast
Issued at 945 AM Wednesday January 25th
Thursday...Cloudy with a chance of snow especially in the afternoon. High near 30. Northeast winds 8 to 15 mph. Chance of precipitation 50 percent.
Issued at 345 PM Wednesday January 25th
Thursday...Cloudy with rain or snow likely. High in the 30s. Northeast to east winds 10 to 18 mph. Chance of precipitation 50 percent.
Thursday Night...Rain or snow likely. Low in the lower 30s. Chance of precipitation 50 percent.
Friday...Rain or snow ending.
Issued 945 PM Wednesday January 25th
...Hazardous Driving Warning late tonight and Thursday...
Remainder of tonight...Cloudy and colder with snow possibly mixed with freezing rain beginning late tonight. Low in the upper 20s. Chance of precipitation 50 percent.
Thursday...Snow mixed with freezing rain likely. High in the lower 30s. Northeast to east winds 10 to 20 mph. Chance of precipitation greater than 90 percent.
Thursday Night...Snow or rain changing to snow and turning colder. Low near 20. Chance of precipitation greater than 90 percent.
Friday...Partly cloudy and colder.
Issued at 345 AM Thursday January 26
...Heavy Snow Warning...
Today...Snow with accumulations of 4 inches or more by this afternoon. High in the lower 30s. Northeast winds 15 to 25 mph. Chance of precipitation greater than 90 percent.
Tonight...Snow diminishing or ending. Colder with the low near 20. North to northeast winds 15 to 25 mph. Chance of precipitation 80 percent.
Friday...Partly cloudy and colder. High in the mid 20s. Chance of precipitation 20 percent.
Issued at 945 AM Thursday January 26
...Heavy Snow Warning...
Today...An additional 4 to 8 inches. Windy with steady temperatures. Northeast winds 25 to 35 mph. Chance of precipitation 100 percent.
Tonight...Snow diminishing and ending. Colder with the low 10 to 15. North to northwest winds 15 to 30 mph. Chance of precipitation 50 percent.
Friday...Partly cloudy and colder. High in the middle 20s. Northwest winds 12 to 22 mph. Chance of precipitation 20 percent.
Over the last 40 years, the advent of high resolution numerical weather prediction models, advanced GOES satellite technology, Doppler radar, and a dense network of automated surface observations has allowed forecasters to give much more accurate warnings of snow storms with much greater lead time.
The Record Book
- Greatest snowfall in a calendar day - 16.4 inches on January 26, 1967 (this was surpassed when 18.6 inches fell on January 2, 1999)
- Greatest snowfall in a 24 hour period - 19.8 inches January 26-27, 1967
- Greatest snowfall from a storm - 23.0 inches January 26-27, 1967
- Greatest snow depth - Additional snows brought the snow depth to 27 inches by February 6, 1967. (This was surpassed when 29 inches covered the ground January 14, 1979.) A total of 36.5 inches of snow fell on the city during the 11 day period from January 26 through February 5, 1967, which is close to normal snowfall for an entire season! Snow covered the ground until March 10.
- Greatest snowfall for a season - The winter of 1966-1967 set the record for Chicago with a total of 68.4 inches. (The record was surpassed in 1969-1970, 1977-1978, and 1978-1979.)
Tell Us Your ’67 Blizzard Story!
Do you have a unique or interesting memory of the January 1967 snow storm? Did you have an eight hour commute home? Did you spend four days stranded at O’Hare? Were you born on the 27th of January and was your mother taken to the hospital by bulldozer or toboggan? We will post the best stories in a future web article at weather.gov/chciago. Send your story to jim.allsopp@noaa.gov.
The Climate Prediction Center (www.cpc.ncep.noaa.gov) recently came out with an update on El Nino and the resulting impacts that it will have across the lower 48 states. The forecast for the strength of the El Nino in the eastern Pacific is in line with the previous forecasts; to reach “moderate” strength with Sea Surface Temperature anomalies of around 1.5 degrees. This generally means that our temperatures over the winter season will have the best chance of being at or above normal. In terms of precipitation, it tends to lead to drier conditions for portions of the Midwest. The main question that everyone asks is, “Well, does that mean that we’re not going to have a snowy winter?” Recent trends during El Nino years say that we won’t have a snowy winter. Here are some statistics at the two primary climate sites in northern Illinois, Chicago and Rockford, that show how much snow they’ve received in past El Nino winters.
| Year |
ORD
|
RFD
|
|
Average
|
36.6
|
32.7
|
|
1941
|
29.8 (-6.8)
|
36.5 (+4.2)
|
|
1957
|
20.0 (-16.6)
|
19.3 (-13.4)
|
|
1963
|
35.2 (-1.4)
|
39.8 (+7.1)
|
|
1965
|
24.9 (-11.7)
|
18.9 (-13.8)
|
|
1972
|
32.9 (-3.7)
|
26.6 (-6.1)
|
|
1982
|
26.6 (-10.0)
|
28.0 (-4.7)
|
|
1987
|
42.6 (+6.0)
|
45.0 (+12.3)
|
|
1991
|
28.4 (-8.2)
|
30.6 (-2.1)
|
|
1994
|
24.1 (-12.5)
|
32.4 (-0.3)
|
|
1997
|
29.6 (-7.0)
|
No Data
|
|
2002
|
28.6 (-8.0)
|
18.3 (-14.3)
|
(Note: Since dealing with a larger dataset than the last 30 years, averages were adjusted to reflect the data from the entire dataset, which means data going back to 1884 for Chicago and back to 1906 for Rockford. The latest 30 year normal may be skewed a bit by the large snowfall seasons of the late 1970s. The overall averages were 1.4" lower for Chicago and 6.0" lower for Rockford when compared to the current 30 year normals provided by NCDC.)
So, it is evident that in this 60+ year sample that an El Nino year tends to translate to below normal amounts of snowfall during the winter, more so for Chicago than Rockford. There are some exceptions, so it isn't entirely impossible to have an above normal season, but it does look rare for Chicago. As of December 19th, Chicago has received 6.5” of snow, which is 0.4” below the normal value of 6.9” for up to this point in the snow season. At Rockford, 10.9” of snow has fallen so far this season, which is 2.2” above the normal value of 8.7”. Although we are above normal for this point in the season at Rockford, the effects from El Nino aren’t typically felt until later in the winter season, so we’ll have to wait and see what happens!
Skywarn Recognition Day is a day set aside for acknowledging and thanking the Amateur Radio operators who perform severe weather spotting and communications. Amateur Radio Operators (Hams) operate radios out of the National Weather Service forecast offices across the United States.
At the Chicago Forecast office Amateur Radio Operators came during the evening of December 1, 2006 and operated radios on most of the Amateur radio bands. The Hams worked contacts for 24 hours until 6 pm Saturday afternoon, December 2, 2006. The Will County Emergency Management Agency provided their emergency communications van for tours and radio operations. A Red Cross communications vehicle was present for tours and communications. The City of Lockport, Illinois provided an aerial lift truck for one of our antennas.
Twenty-six Hams came to the office during the 24 hour period and operated radios. Hams came from many places in northeast and north central Illinois and northwest Indiana. Several Amateur Radio operators spent the night in our office, sleeping on cots and sleeping bags. We made a total of 313 contacts across United States and parts of the world. We contacted at least 40 other National Weather Service Offices. Twenty five visitors came to observe and tour the weather office. We thank all who help in setup and supported this event. We look forward to Skywarn Recognition Day 2007.
For more information on Amateur Radio Operations at NWS Chicago visit http://www.crh.noaa.gov/lot/?n=am_radio
Since the inception of NOAA Weather Radio in Chicagoland in 1960, NOAA Weather Radio has been broadcasting weather information from downtown Chicago for over 45 years. In that time, the NOAA Weather Radio network has grown tremendously not only in northern Illinois and northwest Indiana, but across the country as well. To date there are over 940 NOAA Weather Radio transmitters scattered throughout the U.S., and most places in the U.S. are covered by one or more transmitters. NOAA Weather Radio provides a vital function when threatening weather approaches as regular programming is interrupted each and every time a critical weather message such as a severe thunderstorm or tornado warning is issued.
In northern Illinois and northwest Indiana we are extremely fortunate to have a dense network of NOAA Weather Radio transmitters. The National Weather Service office in Romeoville is responsible for the programming of 11 separate transmitters which serve northeast and north-central Illinois, northwest Indiana, and boaters on southern Lake Michigan. During severe weather episodes, one individual is assigned to the task of manning the NOAA Weather Radio console at the National Weather Service office in Romeoville, and his/her sole responsibility is to ensure that critical products such as severe thunderstorm and tornado warnings are making their way to the weather radio transmitters in a timely manner. In addition, this person ensures that updates to previously issued warnings are also being transmitted over the airwaves.
NOAA Weather Radio is now an “All Hazards” radio. In addition to standard weather information such as seven day weather forecasts, weather synopses, marine weather forecasts for Lake Michigan, and daily and monthly climatological information, other non-weather products are broadcast. NOAA Weather Radio is part of the Emergency Alert System (EAS) and also serves as a method of broadcasting critical information which may not be weather related. For instance, if a child has been abducted and the local or state authorities issue an Amber alert, NOAA Weather Radio is interrupted with the Amber alert bulletin giving the latest information regarding the abduction. Other non-weather hazardous information that may be transmitted over the NOAA Weather Radio includes toxic chemical and oil spills, 911 emergency telephone outages, earthquake information, and information regarding terrorist attacks.
Over the past 45 years, technology for home receivers of NOAA Weather Radio broadcasts has greatly improved. The recent advent of Specific Area Message Encoding (SAME) now gives the radio owner the ability to program a NOAA Weather Radio for a specific location. If, for example, a person lived in Cook County, the NOAA Weather Radio receiver could be programmed with the Cook County SAME code and only warnings affecting Cook County would be alerted by the receiver. SAME coding has now made it possible to leave a radio unattended. When a warning is issued for a specific area the radio was programmed for, the radio will automatically come on with an alarm signal alerting the radio owner of the new warning. This feature has dramatically improved NOAA Weather Radio quality in the fact that the owner can now leave a programmed radio near his/her bed and have confidence that he/she will be woken up in the middle of the night to the alert signal of a new warning.
NOAA Weather Radio continues to be an excellent source for the latest weather information across the U.S. Users of NOAA Weather Radio can take their radios with them as they travel across the country knowing they will always have the latest weather information at their fingertips. The latest information such as severe thunderstorm and tornado warnings automatically gets transmitted over the airwaves as soon as the warnings are issued. Additionally, critical information such as amber alerts and earthquake information is also transmitted over NOAA Weather Radio. Receiving and reacting to the information broadcast over NOAA Weather Radio could save your life!
If you have any questions regarding NOAA Weather Radio, please contact the National Weather Service in Romeoville at 815-834-1435.
NOAA Weather Radio transmitters in Northern Illinois and northwest Indiana:
| KWO-39 |
Chicago |
162.550 MHz |
| KXI-86 |
Crescent City |
162.500 MHz |
| KXI-41 |
Crystal Lake |
162.500 MHz |
| WNG-536 |
DeKalb |
162.550 MHz |
| KZZ-55 |
Dixon |
162.525 MHz |
| WNG-689 |
Hebron, IN |
162.450 MHz |
| KZZ-58 |
Kankakee |
162.525 MHz |
| KZZ-81 |
Lockport |
162.425 MHz |
| WXK-24 |
Odell |
162.450 MHz |
| KXI-58 |
Plano |
162.400 MHz |
| KZZ-57 |
Rockford |
162.475 MHz |
For the most complete marine weather information...tune to KWO-39 Chicago.
For more information on NOAA Weather Radio – All Hazards, visit http://www.crh.noaa.gov/lot/?n=nwr
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