La Nina Modoki is rare! The last fortified La Nina Modoki occurred during quarter 1 of 1989. The climate patterns for quarter 1 of 1989 associated with this ENSO regime were generally much different from conventional La Nina. The La Nina Modoki favors a drier climate in South America and Australia and shifts typical storm tracks for mid-to-late winter across the U.S. while favoring a colder climate. The La Nina Modoki climate anomalies identified may not be exactly as indicated given the much warmer global oceans of the modern-day climate.

A leading catalyst for wet climate forecasts across parts of Brazil during spring 2021 is a projected westward shift of warmer than normal SSTA in the South Atlantic tropics toward the Northeast Brazil coast indicated by most SSTA models. During the past several weeks this previously robust warm SSTA region has trended cooler and is not showing the westward shift as previously indicated. The wet spring forecasts remain but confidence has lowered.

From a climate perspective, the accelerant of anomalous heat which is currently at record levels for California for summer 2021 so far is a semi-permanent upper-level high-pressure ridge present much of the time since 2013 and associated with reginal warming of the northeast Pacific Ocean.

A stronger-than-normal Bermuda high-pressure system is contributing to the lack of relative humidity in the middle atmosphere across the tropical/subtropical North Atlantic basin. The lack of RH in the mid-level atmosphere is well-correlated to lack of tropical cyclone activity since Elsa earlier this month.