Fig: 1: Leading forecast models and a summary of ENSO phase for 2023.
Discussion: Climate models are increasingly agreeable of a 2023 ENSO transition from La Nina to El Nino. Model consensus suggests El Nino onset by late northern hemisphere meteorological spring and moderate El Nino by August with additional strengthening late in the year (Fig. 1). The latest NCEP CFS V2 JUN/JUL/AUG 2023 forecast indicates the greatest summertime heat risk is across the Northwest and Mid-south States (Fig. 2). If the current Kansas to Texas drought remains intact or strengthens, this area could also be hotter. The precipitation forecast suggests possible early season tropical cyclone issues in the Gulf of Mexico and Western Caribbean Sea (Fig. 3). The summer wet monsoon ignites Continental Divide thunderstorms, and the residual moisture extends across the North-central U.S. Dry risk is not overwhelming in the Missouri/Ohio River Valleys. The NOAA CAS end of April/June soil moisture anomaly forecast projects the Kansas to Texas drought lingering (Fig. 4).
Fig: 2-3: NCEP CFS V2 JUN/JUL/AUG 2023 temperature and precipitation anomaly forecast for the U.S. and Southern Canada.
Fig: 4: NCEP CAS U.S. soil moisture forecast for spring/early summer 2023.
In Europe, the NCEP CFS V2 forecast projects anomalous heat and drought focused on the Eastern Black Sea region with wet climate suppressing heat across Southeast Europe (Fig. 5-6).
Fig. 5-6: NCEP CFS V2 JUN/JUL/AUG 2023 temperature and precipitation anomaly forecast for Europe and Western Russia.
During the peak of tropical cyclone season (September), the rainfall anomaly forecast across the North Atlantic basin suggests potential tropical cyclone tracks on the Southeast U.S. Coast and in the central North Atlantic tropics/subtropics (Fig. 7). Note that, due to El Nino, the western North Atlantic tropics (Gulf and Caribbean) are mostly dry. However, the SSTA forecast indicates prohibitive warming in the Gulf of Mexico and off the Southeast U.S. Coast which indicates September tropical cyclones moving through these waters can strengthen quickly with increased risk of a major hurricane (Fig. 8).
Fig. 7-8: NCEP CFS V2 SEP-23 rainfall anomaly and SSTA forecast across the North Atlantic basin.