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Severe Storms Forecasting
anticipating the danger

Severe storms modelers have performed many simulations over the years with the intention of helping to make more accurate forecasts.

Modelers can alter the environment that a storm starts and evolves in. Changes in storm behavior can then be assessed. An important characteristic of the atmospheric environment is vertical wind shear, a measure of the change in horizontal wind speed and direction with height. Researchers have found that different vertical distributions of wind speed and direction can make the difference between whether a storm becomes a harmless shower or a tornado producing supercell seen below. The time animation was created from a severe storm simulation by creating a "radar" view typical of the ones shown on television.

[Embedded Object: animation (697K)]

The original source of this image is the Cooperative Program for Operational Meteorology, Education and Training (COMET®) of the University Corporation for Atmospheric Research. Copyright © 1996 University Corporation for Atmospheric Research. All Rights Reserved

As a result of all of these studies, the research community has provided forecasters with information on the relationship between the storm environment and the type and behavior of storms that could possibly develop.

In addition, severe storm modelers have begun using high-resolution forecast models to predict severe weather. These models are initialized with a wide variety of observational data that reflect the character of the current atmosphere. Data includes surface and balloon data, aircraft data, and recently Doppler (NEXRAD) radar data. The benefits of this new direction in severe storm forecasting has already been demonstrated. Below is a forecast for the devastating tornadic storm in Oklahoma on May 3rd, 1999. The improvement in predicted storm location using NEXRAD data is seen.

[Image: (57K)]
Image by CAPS

Convective Lines
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

forecast matrix