The National Weather Service’s forecast for precipitation through June 20. (Pivotal Weather) An upper-level “cutoff” low is seen swirling over the eastern United States on June 15 in this water vapor satellite image captured by the GOES East weather satellite. (College of DuPage) A “cutoff low” with cold air aloft whirls over the southeastern United States on June 16 in this European model simulation. (WeatherBell) The National Weather Service’s forecast for precipitation through June 18. Realized rainfall totals, especially in the heavier bands, could be markedly higher. (WeatherBell) Matthew Cappucci is a meteorologist for Capital Weather Gang. He earned a B.A. in atmospheric sciences from Harvard University in 2019, and has contributed to The Washington Post since he was 18. He is an avid storm chaser and adventurer, and covers all types of weather, climate science, and astronomy.