Abstract
The National Severe Storms Forecast Center in Kansas City, Missouri, is composed of several operational forecasting units, all national in scope. It includes the Severe Local Storms Unit (SELS), the National Aviation Weather Advisory Unit (NAWAU), and a Techniques Development Unit (TDU). Within SELS there is a synoptic interpretation message (SIM) section and a mesoscale discussion (MD) section.
The SELS Unit has been in Kansas City since 1954 and is responsible for providing a wide array of products related to severe weather: convective outlooks, public weather statements, mesoscale discussions, status reports, and tornado and severe thunderstorm watches for the 48 conterminous states. SELS is also responsible for preparing a national weather summary. NAWAU provides alerts, nationally, of hazardous weather, known as AIRMETs and SIGMETs, and convective SIGMETs to aviation interests. NAWAU also issues aviation area forecasts. The SIM section prepares a diagnostic interpretative message that incorporates satellite and other information and relates them to model trends. The MD section supports the SELS program by providing short-range updates on developing mesoscale systems.
The Techniques Development Unit has been responsible for working hand in hand with SELS to reap the benefits of applying interactive computer-processing technology, progressively giving the forecaster more effective means to provide improved services. Illustrating these improvements is the fact that severe weather watches have significantly increased in accuracy, especially in handling violent death-dealing tornado situations.
An illustrative example of SELS products is shown for the severe weather outbreak of 15–17 June 1992. The example shows how skillfully this episode, producing 172 tornadoes and 462 other reported severe weather events, was forecast. Emphasis is made of the need for consistent and well-coordinated watches and other advisories when dealing with widespread, rapidly moving, severe weather-producing systems.
