The 2018 Tornado and Severe Thunderstorm Season (Invited Presentation)

This presentation will survey the 2018 tornado and severe thunderstorm season across the United States, including trends, and a look closely at several significant tornado and severe thunderstorm outbreak days. Through mid October, the 2018 tornado count is once again near a record low. Severe hail reports are also much below normal, which suggests 2018 was characterized by fewer storm environments possessing strong deep layer wind shear, and as a result, fewer long lived supercell thunderstorms. In contrast, 2018 severe convective wind reports are at near normal levels through mid October. The below normal tornado activity during 2018, has contributed to only 5 fatalities directly attributable to tornadoes, which is on pace for 2018 to be a historically low total.

As is typical, 2018 tornado season began slowly, with a relatively quiet January and early February, with a major severe weather event over the central Mississippi River Valley on 24 February, producing approximately 135 severe weather reports, including tornadoes that resulted in 2 fatalities and more than 20 injuries. Around three weeks later on 19 March, strong tornadoes impacted Northern Alabama extending eastward into Central Georgia. Although no fatalities were reported, there was widespread damage in Alabama, in particular near Jacksonville, where there was EF3 damage. On 14 April, widespread severe weather resulted in over 400 severe weather reports across Arkansas, Missouri, Louisiana, and surrounding states. The third tornado fatality occurred on this date with an EF1 tornado southwest of Shreveport, LA. On 28 June, several severe Mesoscale Convective Systems (MCS) produced over 800 severe weather reports along two major swaths across both the Northern Great Plains and across the Central United States. Numerous measured wind gusts to over 90 miles per hour where reported over the Northern Plains. Two significant severe weather episodes struck the the Central United States on 19 July, with a widespread tornado cluster from near Des Moines, Iowa toward southeast IA, and a severe MCS produced damaging winds from North-Central KS, across southwest MO, into Arkansas. Near Branson, MO tragedy struck on Table Rock Lake, when a tourist boat capsized resulting in 17 fatalities. This was the largest direct wind fatality event in US Severe Weather Database (1955 - present) history.