SVRGIS

Geographic Information System (GIS) Graphical Database of Tornado, Large Hail, and Damaging Wind Reports in the United States (1950-2006).

The United States' severe weather report database (tornadoes 1950-2006, hail/wind 1955-2006) is now available in shapefile (.shp) format. The data can be viewed in graphical, tabular, and statistical formats depending on user programs. The NOAA/NWS Geodata page has links that are directed to free, easy-to-use GIS viewing programs.

More information about SVRGIS's previous methodology and application can be found by examining the project's extended abstract and poster (3MB file) that were presented at the American Meteorological Society's 23rd Severe Local Storms conference. Despite a change in the data's final source (i.e. SPC's severeplot program) before shapefile conversion, the data application remains the same.

METADATA

The data was obtained from the SPC severeplot program. Per communication with John Hart (severeplot developer), the severe reports came from NWS headquarters, which in turn came from each forecast office's final monthly list that was prepared by each office’s Warning Coordination Meteorologist. The reports should match the reports in the National Climatic Data Center ’s (NCDC) StormData, except for tornadoes. The SPC (severeplot) matches up and concatenates the tornado segments that are listed to determine total path lengths, while other groups (e.g., NCDC) leave the segments separated.

The data was prepared in a USA Contiguous Lambert Conformal Conic projection with North American Datum 1983 as the data’s geographic coordinates.

Cost:

The data is available free of charge.

UPDATES:

Yearly updates will be available around the end of May each year.

The data below are in zip files and can be quite large, up to around 50MB, e.g. Cities.zip and topo.zip files. The 2007 update also includes a prepared .mxd file as a base template for users with programs capable of viewing .mxd files. An instructional manual is now provided on how to build and develop a basic severe weather report GIS database in ArcGIS.

Available Data: