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Special Topics for Storm Spotters

Storm-Based Warnings

National Weather Service Storm-Based Warning Webpage
As of October 1, 2007, the National Weather Service began issuing storm-based warnings for severe thunderstorm, tornado and flood hazards. Prior to that, warnings were issued based on geographical boundaries. The storm-based warning technique increases the specificity and accuracy of warnings that are issued now. When severe weather impacts Oklahoma now, you can go the the NWS Norman homepage and instead of entire counties being shaded in for warnings, only the section of the county under a warning will be shaded. For more on storm-based warnings, click on the link above.

Enhanced Fujita Scale

Storm Prediction Center EF-Scale Webpage
Warning Decision Training Branch EF-Scale Webpage
EF-Scale Report (PDF)
As of February 1, 2007, the National Weather Service began rating tornadoes on the "Enhanced Fujita Scale". This scale allows damage surveyors to be more precise and accurate when rating tornado damage. The scale utilizes 28 different "damage indicators" (basically objects or buildings that are commonly damaged by tornadoes) with varying "degrees of damage" and expected wind speeds for each damage indicator. For more information on everything related to the EF-Scale, visit the links above. It is important to note that while tornadoes are now being rated on the EF-Scale, the historical database with tornadoes being rated on the F-Scale has been preserved.

Current Research Projects in Meteorology

NSSL Polarimetric Radar Webpage
NSSL Phased Array Radar Webpage
NSSL Lightning Mapping Array Webpage
Currently, the National Severe Storms Laboratory is undertaking some exciting research here in Oklahoma that could have a major impact in the upcoming years on warnings, warning lead times, forecast accuracy, and so forth - all of which will benefit the public. For more information on these research projects, click on the links above. is the U.S. government's official web portal to all federal, state and local government web resources and services.