In the weekly ENSO diagnostics report we take a look at the continued cooling in the subsurface equatorial Pacific Ocean signaling La Nina onset for Q4 of 2021.
The warm SSTA pattern in the northern Gulf of Mexico just-prior to Ida's passage and off the U.S. East Coast as the remains of Ida traversed the northern Mid-Atlantic States provided a significant contribution to the storms unprecedented intensity over such a large (inland) stretch.
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.
Hurricane Larry is forecast to reach category-3 major hurricane intensity BEFORE reaching 84-85F water surface in the western North Atlantic basin. The concern is a larger and more intense storm may resist (initially) a north to northeast turn leaving the U.S. East Coast at risk of a nearby major hurricane.