SR SSD 2000-21

Technical Attachment

The Mesoscale Verification Program in East-Central Florida

Timothy W. Troutman
WFO Melbourne, Florida

1. Introduction

The need to improve the spotter network and severe weather verification contacts in the WFO Melbourne county warning area (CWA) led to the development of several initiatives to further this task. The Melbourne CWA comprises ten counties in east-central Florida (Fig. 1), extending southeast and south from Lake and Volusia counties to Okeechobee and Martin counties. Compared to the main population centers at Orlando, Daytona Beach, Melbourne and Vero Beach, parts of Lake, Seminole, Orange, Osceola, St. Lucie and Okeechobee counties are relatively population-sparse. The importance of timely severe weather reports during the wet season, which is typically from early June through mid-October, and also during the hurricane season, has led to the development of a mesoscale verification program (MVP) in east-central Florida. This paper will elaborate on the steps taken to significantly increase the spotter network, verification resources, and other improvements to severe weather operations and disaster mitigation across east-central Florida.

2. Mesoscale Verification Program

The Mesoscale Verification Program (MVP) concept was developed gradually at WFO Melbourne beginning in 1997. The first goal was to recruit 100 rainfall and severe weather storm spotters scattered strategically throughout the ten-county CWA, to provide an excellent spatial distribution of precipitation and severe weather reports for WFO Melbourne. By early summer 1999, 105 rainfall/severe storm spotters had been recruited. These spotters were recruited by advertising in local central Florida newspapers and on the WFO Melbourne home page.

After the spotters were identified and had agreed to measure daily rainfall amounts, an eleven-inch rain gauge was delivered to each spotter, with instructions on where to place the gauge for optimal rainfall measurement. The latitude and longitude was precisely determined using the standard GPS (Global Positioning System), so the data could be accurately correlated with the WSR-88D to determine the accuracy of rainfall estimation by the WSR-88D at WFO Melbourne. Plans are underway to add an additional 100 rainfall/severe storm spotters so that each county will have at least 20 strategically located spotters.

a. Applications of Rainfall/Severe Storm Spotter Reports

Information from spotters is used in several ways at WFO Melbourne. Rainfall reports are used operationally by forecasters when heavy rains occur throughout the wet season, during tropical storms, and in winter synoptic precipitation events. Aside from the obvious benefit of the observations in real-time, the reports facilitate work to determine the rainfall estimation accuracy of WSR-88D 1-hr, 3-hr, storm total and User Selectable Precipitation algorithms. They also contribute to development of a heavy precipitation climatology for east-central Florida. The precipitation data are published locally on the WFO Melbourne Intranet (LANTERN- Local Area Training and Educational Resource Navigator). The additional precipitation data have given the WFO Melbourne staff additional information for the more sparsely populated areas which do not have nearby official observing sites.

b. Further MVP Network Initiatives in East-Central Florida

Paxton and Nash (1997) developed the Florida MesoNetwork, with a total of 603 observation sites in central and west-central Florida. WFO Melbourne has developed the MVP program for east-central Florida. Similar efforts in other states (with fewer sites) were made by Kirkwood et. al. (1996) at WSO Concordia and WFO Wichita, Kansas - the Algorithm Ground Truth Acquisition Program (AGTAP), and by Riddle et al. (1997) at WFO Springfield, Missouri.

The first step at Melbourne was to determine which portions of the county warning area were void of spotters, and for which counties the WFO had the lowest warning verification scores. After determining which areas/counties were most in need of spotters, the spotter contacts were established throughout east-central Florida. These contacts were found by obtaining current telephone books for each of the WFO's ten counties from local law enforcement agencies and emergency managers. Then, a search was done of both the yellow and white pages to determine possible MVP participants. Other resources included the Internet Yellow Pages within the YAHOO search engine at The resulting MVP network consists of:

1. Electric cooperatives
2. Marinas
3. RV parks
4. Large farms, ranches and dairies
5. Golf courses
6. High schools
7. Small airports
8. State and county Department of Transportation maintenance facilities
9. Newspapers
10. Municipal water treatment plants
11. Toll booths
12. Convenience stores
13. Orchards and groves
14. Post offices
15. Bell South Service employees

This comprehensive initiative led to the development of over 1,500 contacts throughout the ten-county CWA, an average of around 150 additional verification contacts per county since 1999. Some overlapping reports have occurred, but the increased number of verification locations in rural areas has already contributed to an approximate 20 percent improvement in warning verification in our CWA since January 2000. Of the above severe weather contacts, most are used for near real-time verification reports during severe weather events. Contacts made primarily after severe weather events for post-storm verification are the electric cooperatives, state and county Department of Transportation maintenance facilities, newspapers, convenience stores and post offices.

Another source for improving severe storm warning verification has been an agreement reached with the State Farm, AllState, Nationwide and Farm Bureau insurance companies. After severe weather has occurred, and after a damage investigation has occurred, these companies now allow WFO Melbourne access to damage claims due to severe weather. These reports have been especially helpful in rural areas of east-central Florida.

3. Web-Based Spotter Training

The need to add as many trained weather spotters as possible to increase the spotter density across east-central Florida has led to the development of Web-based spotter training on the WFO Melbourne home page ( This spotter training session is a combination of the excellent on-line information and graphic spotter guide developed by the University of Illinois Urbana-Champaign, and the on-line spotter guide developed in conjunction with NSSL and available from the Southern Region Web site at ( The graphics in these two spotter guides were combined with local WFO Melbourne preparedness information to provide the public and emergency managers in the Melbourne CWA with spotter training materials which could be easily downloaded for local presentation by emergency managers, and for persons unable to attend the annual severe storm spotter training.

A severe weather spotter test at the end of the Web-based spotter training session is completed by each participant. E-mail addresses of the WFO Melbourne WCM and Severe Local Storms program manager, and the WFO Melbourne mailing address, are provided at the end of the test so it can be mailed in and graded. Upon successful completion of the test, each spotter is scheduled to visit our office to complete their formal training. During this visit, the spotter is trained on severe weather reporting procedures and given our toll-free unlisted spotter number for reporting severe weather. Each spotter gained from the Web-based spotter training sessions is also given printed instructions explaining how to report severe weather, who to report it to, and their county spotter number.

This Web-based spotter training resulted in about 30 new weather spotters who supplied timely severe weather reports on at least ten occasions since the program was implemented in June, 1999.

4. Integrating the MVP Concept into Severe Local Storms Operations

As part of the WFO Melbourne strategic plan (Vision 2005), the spotters were recruited to improve the accuracy and reliability of local severe weather operations by providing timely and accurate information for the warning process. Spotter locations were precisely determined by using GPS to calculate the specific latitudes and longitudes to five decimal places, so the spotter locations could be integrated into AWIPS.

The MVP contacts and telephone numbers have been added to the local WFO Intranet (LANTERN) under the severe weather operations section. In this section of LANTERN, each county has a map on which is highlighted specific contact location within that county. Telephone numbers have been added as a link on the map for quick access during severe weather.

5. Conclusions

The development of the Mesoscale Verification Program (MVP) at WFO Melbourne resulted in improved severe weather and rainfall reports during the 1999 wet season and hurricane season, through the present. The MVP was developed to improve severe weather operations and verification statistics. (A key to improved verification scores is more - and more reliable - ground truth information during severe events.) Preliminary results show improvement of between 10 to 20 percent over the statistics prior to 1999. This year, the MVP severe weather reports have improved statistics around 20 percent, compared to scores based on data from the pre-existing network. The use of technology such as ARCVIEW involving specialized map generation, the local WFO Intranet, and AWIPS have made the severe weather spotter and severe storm verification program at WFO Melbourne more efficient.

It is hoped the preparedness initiatives described here will encourage other offices to use similar ideas to improve their spotter networks and severe weather verification programs.

6. Acknowledgments

The author would like to thank WFO Melbourne HMT Jacquelyn R. Cartwright for her research, input and contributions in producing this manuscript.

7. References

Kirkwood, P., D. Reno, and L. Ritter., 1996: Establishing an AGTAP Spotter Network. Central Region TechnicalAttachment. NWS Central Region Scientific Services Division, Kansas City, MO. 7pp.

Paxton, C., and A. Nash., 1997: The Florida MesoNetwork: High Resolution Meteorological Observations in Florida. Southern Region Technical Attachment 97-51. NWS Southern Region Scientific Services Division, Fort Worth, TX. 5pp.

Riddle, D., D. Schmidt, A. Drew, J. Gordon, and B. Davis, 1997: Community Weather Involvement Program (CWIP): A Link Between the National Weather Service and the Community. Central Region Technical Service Publications NWS CR-01. Central Region Scientific Services Division, Kansas City, MO, 6pp.

Figure 1. WFO Melbourne, FL County Warning Area.