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11/27/2018, 10:17 am EST

U.S. Soil Moisture Outlook

Highlight:  Unusually wet soils Texas, Midwest and East. Fig. 1: Palmer Drought Severity Index identifies excessive wet zones. Fig. 2: U.S. soil moisture ranking on Nov. 25, 2018. Fig. 3: Soil moisture change across the U.S. since Aug. 31, 2018 Fig. 4: NCEP CAS soil moisture forecast for end of February 2019. Fig. 5: NCEP CAS soil moisture forecast for end of May 2019. Fig. 6: A collection of all dynamic and statistical ENSO phase forecast models through JUL/AUG/SEP 2018 by the International Research Institute for Climate and Society. Discussion: Palmer Drought Severity Index (PDSI) has reached or surpassed the upper wet limit of the index (>+4 or “extremely wet”) in many regions of the U.S. including Texas, The Midwest and Northeast U.S. Corridor (Fig. 1). The wet signature is somewhat unprecedented in this century primarily due to the general drier-than-normal U.S. climate produced by the long-term warm cycle of the Atlantic multi-decadal oscillation (a warmer-than-normal North Atlantic). In 2018 the AMO was near neutral due to BOTH warm and cool regions of the surface in this ocean basin. In recent years there has been mention of a possible change in the long-term AMO cycle away from the positive phase. Of course U.S. soil moisture rankings are in the upper wet limit where the +4 (or greater) PDSI are located (Fig. 2). The seasonal U.S. soil moisture change has been El Nino-like showing a dramatic wet change in the southern U.S. centered on Texas (Fig. 3). Interestingly (and unusual) the state of Florida has trended drier during autumn and a drought condition is present. An older model provided by NOAA forecasting monthly soil moisture projects the wet condition now in-place across much of the U.S. east of the Continental Divide to remain in-place through the end of February (Fig. 4) and May (Fig. 5). The most consistent wet soil moisture (forecast) is across Iowa and Texas. The wet soil forecast is based on extreme current conditions and a wetter than normal climate produced by an evolving and persistent El Nino climate. A collection of ENSO phase forecast models by the International Research Institute for Climate and Society indicates a consensus of both dynamic and statistical forecast models maintain El Nino through the 2019 warm season (Fig. 6). Agriculture implications are wet soils for spring for planting. Implications for energy is the tendency for suppressed heat risk across wet soil moisture regions as the 2019 warm season begins.