Using the Memphis ARTCC zoom, the image above shows the storm detection shapes produced by the Thunderstorm Identification Tracking and Nowcasting (TITAN, Dixon and Wiener 1993) algorithm which is run on the elliptical-filtered field. TITAN is tuned to detect areas of 520 square km or greater that are filled with VIP level 3 or higher. TITAN uses these shapes to determine speed and direction of the convection. Click on the image to see the detection shapes from 20 minutes prior. A detection needs a history of 1 prior time (20 minutes) or be near-by a storm with history in order for a extrapolation forecast to be issued. Although forecasts are issued every 5 minutes, the speed and direction change every 10 minutes. This helps to smooth out erratic motions of the convection. Surrounding storm motions are also considered when applying speed and direction to any one detection. This is done using a distance weighted mean. Another feature of TITAN is the ability to use a second level threshold to break up detections that are very large. See "Dual TITAN" for example/benefits of this feature.

Click "Next" to go to Applying tops value.

Click "Back" to return to Elliptical filter.