A Model for a Multi-County Severe Weather Warning System
Submitted for the Symposium on Weather Analysis and Forecasting, January 1994

Paul L. Sirvatka Division of Natural Sciences College of DuPage 425 22nd Street Glen Ellyn, IL 60137 (630) 942-2118; (630) 942-2590 Fax: (630) 858-9399 E-Mail: sirvatka@weather.cod.edu

Thomas O. Mefferd DuPage County Office of Emergency Management 136 North County Farm Road Wheaton, IL 60187 (630) 682-7925 Fax: (630) 682-7931

1. INTRODUCTION

On August 28, 1990, a devastating tornado ripped through Will County Illinois, killing 29 and injuring over 300. The lack of adequate warning for the public prompted an investigation of the state of preparedness in the Chicago area. The National Disaster Survey Report (1991) concluded that there was a "lack of coordinated, comprehensive, or integrated county-wide procedures or structures for, or dealing with, possible severe weather occurrences within the counties struck by the tornado." While a number of other factors contributed to the low state of readiness on that fateful August day in 1990, the underlying meaning was clear. Northeast Illinois was prone to the occurrence of devastating tornadoes and was not ready to adequately provide the public with sufficient procedures to insure the highest state of protection and emergency response.

A concerted effort was made to rectify the situation in the Fall of 1990. As a result of combined efforts of the DuPage County Office of Emergency Management (OEM), the College of DuPage and the Chicago National Weather Service Forecast Office (WSFO), a plan was devised to create a multi-county severe weather warning network. In addition to suburban DuPage County, the network would include 10 other counties in Northeast Illinois. Today, with the restructuring of the NWS and the change in each one's areas of warning responsibility, over three thousand trained volunteer spotters in a total of fifteen counties are part of the system. The DuPage County Board has passed a resolution making the communications center of the Multi-County Severe Weather Warning System part of the job requirements of the DuPage OEM. The multi-county network provides spotter information to the NWS and Emergency Operating Centers (EOC's) that affect over 8 million people. In addition, advanced spotter training and community education are among other ongoing activities of the multi-county network.

2. OBJECTIVES

The goal of the multi-county severe weather network is to provide the most rapid communications possible among all branches of the network. As has often been commented, the average tornado is on the ground for a period shorter than the time it takes for the weather service to issue a warning. Whether or not this is true, it underscores the need for a rapid relay of information to and from the weather service. As important as the flow of information is to the weather service to offer ground truth to their interpretation of radar signatures, the return flow of information to an affected municipality and the municipalities downstream of an event is just as vital. The communications center at the DuPage County EOC acts as a hub to maintain a rapid and redundant flow of weather reports and significant events that affect the counties in the network.

In order to achieve the goal of the network, communications needed to link as many segments of the network as possible, without delaying information to the needed areas and over-burdening the Chicago WSFO located in suburban Will County. Although redundancy is imperative, unneeded repetition must be limited. It was decided that each county was to coordinate its own municipalities and each municipality would oversee its own spotters. The main framework of the communications network would be among the counties. In addition, there would be some spotters that would report directly to the each county's EOC to supplement areas that may have few spotters. As a county received a report, the information would be simultaneously passed on to all of counties' municipalities as well as the DuPage EOC. DuPage would then pass on information to all the other counties via VHF radio and at the same time pass on the report to the Chicago National Weather Service Forecast Office via the National Warning System (NAWAS). Because of the importance of area ham nets that operate under the net control of Chicago Area Skywarn, any information received or transmitted would be paralleled on the ham frequency as well. Information from the NWS would likewise travel in the opposite direction. Public statements (i.e., warnings, severe weather statements, and radar summaries) from the NWS are received on the weather wire and broadcast to all counties.

In order to coordinate activities of all people involved in the system, it was decided that a four-color level of readiness be adopted. Although not intended to replace the weather service's watch and warning terminology, the colors provide an easy-to-reference list of activities when each color level is reached. To best describe the different levels of readiness, a typical day will be described, listing the initiating action and the general response.

Mnemonically, the sky is blue but there is a threat for severe weather later in the day. Keep one's eye to the sky.

Twice a day, at 7:00 and 11:00 local time, the Chicago WSFO issues a severe weather outlook, reflecting the potential for severe weather in Illinois. On the basis of the risk as issued by the Storm Prediction Center (SPC), a moderate risk or higher will bring the network to condition blue. Although a slight risk of severe weather may exist, the system does not automatically implement to condition blue. However, upon recommendation by the NWS or the College of DuPage Weather Office, condition blue will be initiated. The reason a slight risk does not force a response to condition blue is to avoid bringing the network up too often, as is the case frequently in the summer. If a watch is issued close to the area, and appears that the activity will move into the network's jurisdiction, or if a mesoscale discussion indicates the possible issuance of a weather watch, the network will be activated. At this time, the statement as issued by the NWS will be transmitted on radio to each county on ESMARN (Emergency Services Mutual Aid Radio Network) and IEMA (Illinois Emergency Management Agency radio network) and to each municipality in DuPage County on DCERN (DuPage County Emergency Radio Network). Each county has similar ways to contact its municipalities. In addition, a faxed copy of the condition blue statement will be sent to all counties. This will provide a hard copy of the activation to allow for county-wide re-broadcast and to serve as a redundancy in case of radio problems. Condition blue is designed to give notice to all people concerned that severe weather may threaten the area and people should arrange their plans as necessary. Each county and municipality is advised to notify their weather spotters of possible activation later in the day. Municipalities are also advised to review their calendars to be aware of any special events where are large number of people may be affected.

Information is sent to each county describing the potential threat and timing of the severe events. Statements of a limited technical nature are included to help advanced spotters understand the cause of severe weather and to help validate the outlook. Since the network is also involved in training of spotters, it is believed that additional information can be helpful to increase the scientific literacy of the network's participants and to combat waning interest. (Moller, et al., 1993)

Mnemonically, green means go. Time for action.

When SPC issues a severe weather watch, condition green is implemented. It is strongly believed that equal consideration be given to both a tornado watch and severe thunderstorm watch. As a result, identical procedures are followed regardless of the type of watch. The weather watch is transmitted similarly as described in condition blue. At this point, all affected counties are to staff their EOC's and deploy their watch spotters. These spotters are primarily composed of full-time employees who, by nature of their occupation, are able to watch the sky. These include, but are not limited to police officers, fire fighters, public works employees, utility workers and other volunteers. It is felt, because of the high number of weather watch hours, that all spotters do not need to be activated during the entirety of the watch. However, as the weather situation deteriorates, alert spotters, who have been placed on standby, are called into action during the following condition yellow. Notification of recreational and civic events being conducted in the county is done by phone. All municipalities are contacted similarly.

Mnemonically, yellow means that red is soon to follow. Yellow indicates extreme caution.

Condition yellow is an intermediate step to insure the highest state of readiness to issue spotter reports and deal with a warning. This is the only condition that is not initiated directly by actions of the NWS. Since no criterion has been met for the weather service to issue a warning, each county is responsible for this heightened state of readiness. Usually, an initiating event is the approach of a thunderstorm in the county as reported by a watch spotter. Condition yellow may also be declared as a result of rapid cumulus development observed during the early stages of a watch. The NWS may request a county move to a higher state of readiness, or DuPage County EOC may recommend the same if radar indicates an approaching cell. However, each county is ultimately responsible for the deployment of their spotters. Notification of condition yellow will be transmitted to each county via IEMA and ESMARN and to the NWS via NAWAS.

In addition to the above responsibilities, a municipality in the path of the storm should review the "Guideline for the Activation of Outdoor Warning systems", as prepared by the DuPage OEM (1991). Since each municipality is ultimately responsible for its own sirens, sounding criteria may vary. An Attention or Alert Warning signal is a 3 to 5 minute steady signal from sirens, horns, or other devices. This signal may be used as authorized by local government officials to alert the public of peacetime emergencies. This may result in some unwarranted sirens, but it also gives a municipality the ability to sound the sirens before a warning is officially given. This is true if there is a spotter report of a tornado on the ground, a funnel or wind damage. Since this report is passed on to the weather service and over the radio simultaneously, communities may respond minutes before a warning is issued. Each county may apply different procedures to the individual citizens in charge of activating the sirens. Unfortunately, this leads to confusion by the public when the siren is sounded. Many false alarms lead to a general disbelief of the impact of severe weather and therefore may not provide a strong enough call-to-action. It is believed by the authors that unified criteria should be adopted by all participating communities. However, politics may limit the success of this goal.

Mnemonically, red means warning.

Condition red is initiated when the NWS issues either a tornado or severe thunderstorm warning. That warning will be reported to each county over IEMA and ESMARN and to each municipality over DCERN. Procedures call for sirens to be sounded in DuPage County municipalities when a tornado, or funnel cloud aloft, is reported within 5 miles of the community. As is done in previous conditions, spotter reports are actively solicited by the communications team at the DuPage EOC in regions affected by a storm. These are done either at the request of the NWS, or as a result of potentially significant radar signatures as detected on the Kavouras radar display. The radar display is not used to broadcast information to others on the network, but is used to monitor a storm's progress and deploy spotters where the most useful information can be obtained. It is also used to identify areas that can provide verification of a sighting and prepare for emergency response. Reports of damage, confirmation or lack of the aforementioned are sent to the NWS via NAWAS. Investigating the extent of the situation assists the NWS in making accurate local storm reports. In the extreme case of a significant severe weather event (i.e., a large tornado, wide-spread wind damage or street and river flooding), information can be given to the Illinois Emergency Management Agency to assist in disaster relief efforts.

A unique component of the weather warning system is the incorporation of chase teams from the College of DuPage. The College has a full-functioning weather office, where students and faculty monitor the threat for severe weather potential. Advising of the situation occurs on the day prior to the development of severe weather. The College of DuPage can interpret information from the NWS, including information on the expected type of severe weather and the timing of the system. This information can be used to help prepare the DuPage officials prepare for condition green. Students have access to domestic data, DIFAX and McIDAS products along with other information available via the Internet. Courses in weather forecasting focus on the development of severe weather in real time when the situation arises.

When a watch is issued, storm chase teams can be deployed to offer mobile information on the development and evolution of thunderstorms. The students must complete a course in severe weather and storm chasing before being allowed to chase. Video tape collected by students is reviewed and discussed to further train the student on severe weather spotting. Students also volunteer time working at the DuPage EOC during a weather watch. The combination of participating in community service while applying their education gives students a rare experience to explore meteorology in the field. Students also use this experience to pursue further educational goals. In addition to the College of DuPage, students at Northern Illinois University in DeKalb are also becoming active in the spotter network.

Along with the activities listed above on the day of severe weather, the network is also involved in other activities concerning weather and the state of readiness of citizens in the network area of responsibility. During the winter months, the network has taken on responsibilities for issuing advisory statements for significant winter weather. Information is relayed from the WSFO for use by municipalities, schools, hospitals and others, and, in return, snowfall amount and street condition reports are given to the NWS.

Efforts continue to educate and organize spotters. Yearly, the DuPage County Office of Emergency Management and the College of DuPage co-sponsor an advanced spotter training workshop. The number in attendance has grown from 125 to well over 300 in the last three years. In addition to local speakers, a nationally recognized expert in severe thunderstorms has come in to be the keynote speaker. Similarly, the DuPage OEM also sponsors a tornado shelter workshop to help institutions identify potentially dangerous situations and offer solutions to finding safe tornado shelters.

Further education is also being accomplished with 911 operators and emergency response personnel. The course was developed to assist local, county and state government communicators as well as amateur radio operators understand the unique attributes of severe weather communicators. It also familiarizes all these operators with the color-code scheme to unify the understanding of network-wide responsibilities. Communicators are a vital component to the success of the network in relaying timely information to both the operations center and the NWS. Future plans include adding a redirection of public reports of severe weather events directly to the EOC.

The success of the network ultimately rests on the public in responding to potentially dangerous weather situations. Recognition of tornado look-alikes, supplying ample coverage of spotters and public apathy continues to be problems in giving the weather service timely, accurate and helpful information. However, the state of preparation to respond to significant weather situations has never been higher in Northeast Illinois. Tornadoes will strike Northern Illinois. Next time, the Multi-County Severe Weather Warning Network is prepared to stand ready.

The authors wish to thank the representative of the counties involved in the Weather Warning Network and Paul Daily and Jim Allsopp of the Chicago WSFO for their helpful input in developing this network. The Weather Office at the College of DuPage and this material is based upon work supported by the National Science Foundation under Grant No. DUE-9351390.

DuPage County - Office of Emergency Management, Guidelines for the Activation of Outdoor Warning Systems. DuPage County, IL, 1991

Moller, A. R., Foster, M. P., and Doswell, C. A., 1993: Some Considerations of Severe Local Storm Product Dissemination in the Modernized and Restructured National Weather Service. Preprints, 17th Conference on Severe Local Storms (St. Louis, MO), American Meteorological Society, 375-379.

National Disaster Survey Report, The Plainfield/Crest Hill Tornado. U.S. Department of Commerce, 1991

*Corresponding author address: Paul L. Sirvatka,

College of DuPage, Glen Ellyn, IL 60137