A 10-day forecast of synoptic features across the U.S. valid 7PM EST on Monday November 27th was performed using a comparison between GFS, ECM, and Graph Cast AI-generated models. The results were a near perfect forecast by Graph Cast while GFS was out-of-phase with an Upper Midwest storm and attendant cold front while ECM was much too stormy across the Southern States.  

During the past several weeks, a large area of exceptionally warm surface water has developed between 20S and 25S in the South Atlantic Ocean. Initially, the large area of warm sea surface temperature anomalies (SSTA) formed off the Southwest Africa Coast. During the past 30 days the anomalous warmth has surged westward toward the central Brazil Coast.

The rainfall pattern in the tropics across the Pacific Ocean with all El Nino’s since 2000 during AUG/SEP/OCT has produced typical heavy thunderstorm activity and attendant rainfall across the central and east-central Pacific. To compensate, the far western tropical Pacific/Indonesia observes atmospheric subsidence and a dry climate. The vertical air motion difference between the sinking air over Indonesia and rising air near and east of the Dateline drives the El Nino climate. In 2023, the pattern described is not present.

In October 2023, the Nino34 SSTA index was +1.59C which eclipses the +1.50C threshold for strong oceanic El Nino classification. However, the response of the atmospheric climate pattern to the El Nino warming is weak yielding neutral multivariate ENSO index (MEI = +0.3) during SEP/OCT 2023. Preliminary investigation reveals this is a first-time occurrence for a strong oceanic El Nino.