Fig. 1: Latest U.S. Evaporative Demand Drought Index (EDDI) analysis identifies extreme ED4 conditions across the Central U.S. and into the Ohio Valley. Note the change from the analysis of one month ago (right).
Discussion: According to NOAA/PSL, ED4 is a drought condition previously observed <2% of the time in the 1979-2016 climatology. The ED4 classification across the Great Plains and stretching east to parts of the Ohio Valley (Fig. 1) is impressive. What the EDDI indicates for these regions is that the atmosphere is extremely thirsty partly due to current conditions and also due to time of year. Represented by the widening ED4 regions are large areas of potential drought conditions which could develop quickly given extended periods of lack of precipitation and further aggravated by anomalous heat once spring arrives or high wind over the next 2-3 months.
The most recent NCEP/CAS soil moisture anomaly outlook indicates drought development in March which follows the ED4 guidance extending from Texas to the central Great Plains and touching the Midwest U.S. (Fig. 2). In April, the drought area weakens slightly (Fig. 3) followed by enhancement over southwest Oklahoma by May (Fig. 4). During early summer the drought pattern should be locked-in across the southern half of the Great Plains and Texas to the 4-Corners region (Fig. 5).
Fig. 2-5: NCEP/CAS soil moisture anomaly forecast for MAR-22 to JUN-22.
NOAA probabilistic forecasts extending to May 2022 are agreeable to the NCEP/CAS forecast identifying the central and southern Great Plains into Texas with drought certainty with risk of dangerous D4 drought in northwest Texas to Kansas (Fig. 6). The NOAA probabilistic forecast also implicates Florida for harsh drought!
Fig. 6: NOAA probabilistic drought forecast for May 2022.