Fig. 1-2: The combination of deep layer soil moisture anomaly deficits and mid-summer harsh heat is the recipe for flash drought in the Central Great Plains.
Discussion: Large regions of deep-layer soil moisture deficits are caused by long-term (usually 9 months or more) precipitation shortages. In the U.S. and generally east of the Continental Divide, presence of large areas of deep-layer soil moisture deficits can foreshadow flash drought risk areas. Right now, a large area of deep layer soil moisture deficit is located across the Great Plains centered on Nebraska and Kansas (Fig. 1). Coincidentally, the GFS forecasts a 15-day departure from normal of >10F in this zone (Fig. 2). Many consecutive days of >100F (and possibly 110F) are ahead for mid-to-late July across the deep layer soil moisture deficit zone (and vicinity). The risk of rapidly intensifying (or developing) drought or flash drought in this zone is increasing rapidly.