The ECMWF and AI 4Cast Net V2 ECM ENS are in excellent agreement on regenerating significant heat for Mid-August this time affecting the West/Northwest U.S. while excessive heat regenerates in the Northeast U.S.

The latest global sea surface temperature anomaly analysis reveals the presence of intense marine heatwaves off the East Asia Coast extending eastward past the Dateline. The MHW is linked to recent heat in Japan and East China. MHW's in the western North Atlantic is linked to the East U.S. current heatwave. MHW's in the Mediterranean Sea and west of Europe contributed to extreme heat in June across Europe and a much wetter regime in July. MHW's are also influencing Australia climate.

The hot weather is impressive through the weekend focused on the Ohio Valley today and Northeast/Mid-Atlantic tomorrow, but extreme alert-4 conditions for dangerous heat emerge Sunday and Monday (Fig. 2) in the Southeast U.S. On Tuesday and Wednesday of next week, extreme alert-4 conditions widen across the Southeast U.S. where this heatwave is most intense.

The upper ocean temperature anomaly structure in the eastern equatorial Pacific indicates a new moderately deep cool layer. The warm layer just beneath the surface is beginning to weaken. The long-term ENSO outlook for later in 2025 remains in the neutral phase. However, as observed all of 2025, some models are indicating La Nina development, and a slight cooler trend has developed supportive of the La Nina outlier forecasts.