During the past 2-3 weeks the convective phase of the Madden Julian oscillation (MJO) has dominated the eastern Indian Ocean/West Indonesia tropics. The general rising air induced by convection along this stretch is replaced by increasing easterly trade winds arriving from the central/eastern equatorial Pacific. The trade wind increase in the central/eastern equatorial Pacific has caused up-welling of cool subsurface water to cause La Nina to gain some strength.

Heavy rain and snow events are ahead in the 6-10 and 11-15-day forecast for the Central and East-central U.S. Included is projections of 5+ in. of rain centered on the western Tennessee Valley in the 11-15-day period.

A pattern change toward a colder regime is indicated in the 8-14/11-15-day period for Western Russia and the Black Sea region likely stretching westward into Europe. The culprit is an elongating longwave upper trough. Precipitation increases beneath the upper trough and is mostly snow due to the colder weather.

Last week, the Nino 12 SSTA region cooled to -1.7C which ties a week last December for the coolest signature of La Nina 2021-22. Indicated are trade winds are increasing and up-welling cold subsurface water off the northwest coast of South America. Not a sign of La Nina weakening.

Based on the potential for widespread dryness across the Great Plains identified by Evaporative Drought Demand Index (EDDI), Climate Impact Company is concerned that drought risk is farther east than indicted by NOAA/CPC in their updated long-lead forecasts issued earlier today.

The Evaporative Drought Demand Index (EDDI) remains in the driest (ED4) condition across the central and southern Great Plains. If the climate pattern leading to this condition continues a drought develops quickly in the Great plains during the warm season. The current ED4 conditions are not as widespread as the February 2012 condition ahead of the Midwest drought of summer 2012.