As a follow-up to the last posting on the heat dome in the central US, Bob Henson of Weather Underground posted this lengthy article about how a heat spell like the one that is coming can trigger the development of a “flash drought”, in this case most likely in the Corn Belt region, although it could affect other areas too. He compares this event to the 2012 heat wave which set off a previous drought in the region. He also discusses the impacts of the heat wave on corn and soybean production in the Midwest and elsewhere.
What’s a flash drought? Here’s his explanation: “While long-term drought can emerge simply through a lack of precipitation, a flash drought is closely linked to hot summer weather. The type of flash drought most often observed in the Midwest develops as a torrid air mass sweeps in for a period of a few days to several weeks. At first, the landscape may not be particularly dry, in which case large amounts of water vapor flow from vegetation and soils into the scorching surface air (as is expected later this week). If the heat is strong and sustained enough, the landscape quickly dries out and a flash drought takes hold.” Note that flash droughts are most likely in the Midwest and less frequent in the Southeast, although they still do occur.
