Searing heat dominated East China and Japan beneath intense subtropical high pressure during July 2025. The latest week 2-4 outlook regenerates additional late summer excessive heat for the region.

The 12Z GFS is hot in the Southwest during the 6-10-day period and trending warmer from the eastern Canadian Prairies to Quebec. In the 11-15-day period, the 12Z GFS explodes hotter into the Northeast U.S. causing 106 CDD for Aug. 8-14 which would easily exceed the current week.

The ITCZ in the outer tropical North Atlantic is becoming very impressive. The beginning of real tropical cyclone season (August 1st) is vividly approaching! Forecast models indicate potential for 2 tropical waves to emerge in the east-central tropics midweek and track west or west to northwest but, due to dry air, unlikely to develop into a tropical system.

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.