Besides the commonly displayed reflectivity and velocity presentations of RADAR, the NWS NEXRAD system is also running algorithms on this data attempting to identify and track storms. This information is disseminated as a product called Storm Attributes Table and comes with every volume scan. The IEM archives this product and the featured chart presents a summary of this information from the Des Moines NEXRAD. The histogram presentation shows the most common combinations of storm speed + motion and motion + day of the year. The vast majority of storms have a motion from the southwest moving to the northeast at a speed around 20-40 mph. The bottom chart shows the annual cycle of storm motion in Iowa. Storms transition from coming mostly from the WSW to WNW by late July and then back to mostly WSW. The physical reason is due to the synoptic scale flow patterns that change with the seasons.

Voting:
Good = 175
Bad = 22

Tags:   nexrad   storms