Comparing February 2012 EDDI to Now

Fig. 1-3: The EDDI for NOW and the same time in 2012 and the harsh drought zones of summer 2012.

EDDI discussion: The evaporative drought demand index (EDDI) considers both long-term climate and short-term weather including soil moisture conditions to establish how susceptible an area is to drought. Right now, the strongest dry EDDI drought condition (ED4) is in-place across the central Great plains (Fig. 1). This zone, given anomalous warmth and dryness once spring/summer arrives is susceptible to a rapid shift into drought. If an unseasonably hot and dry regime were to occur, any part of this zone is susceptible to flash drought. Close monitoring of this region which stretches across the southwest Great Plains wheat-growing region to the western corn belt is required. In a comparison with February 2012 (Fig. 2) which was followed by historic drought in the North-central to Midwest U.S. the following summer (Fig. 3), the current ED4 conditions are not nearly as widespread. However, note that ED4 in the northern half of the Great Plains in February 2012 foreshadowed the harsh drought that was ahead. Summer tropical showers doused the Southern U.S. ED4 conditions in 2012.

In the current 15-day outlook, the Canadian Ensemble most clearly identifies what to expect (Fig. 4). A wetter/whiter regime is ahead. Heavy precipitation affects the Ohio and Missouri Valley(s). Kansas and Nebraska are mostly dry. The Oklahoma precipitation is not particularly effective at easing dry soils. The southern Canadian Prairies are snowy.

Fig. 4: The Canadian Ensemble best depicts the expected 15-day precipitation amount pattern across North America.