Past IEM Features tagged: outbreak
The tornado outbreak of yesterday may go down in the record books as the largest in US history. The featured chart displays, at five minute intervals, the total number of active tornado warnings and areal coverage of these warnings expressed in square kilometers. Since 3 PM on Tuesday, there has been at least one active tornado warning making for a streak of 39 straight hours (at the time of this writing). At its peak yesterday evening, the areal coverage of would have been large enough to cover roughly one third of Iowa. I'll update this chart once the streak ends and post the final duration number.
Iowa was impacted by a major storm system dumping over a foot of snow near Davenport on the 5th and 6th. The southern end of this powerful storm system brought devastating tornados to Arkansas, Tennessee, Kentucky, and other states. Wikipedia has an excellent summary of this sad event which ranks as the deadliest outbreak during the modern NEXRAD era. The featured animation shows a composite of maximum NEXRAD reflectivity for the event along with maps of local storm reports. You can see the SW to NE oriented streaks in the composite as the strong supercells track along with the mean upperlevel flow. You can also see how the snowfall reports coincide with the lighter areas of reflectivity.