Operational models (GFS and ECM) are remarkably similar with the extended range (days 6-10) forecast of Tropical Disturbance 97L. NOAA/NHC indicates a high probability of a named storm within 48 hours, and tropical cyclone models indicate a steady westward track with intensification to a hurricane in 4-5 days.

The temperature forecast bias among two leading “weeklies” forecast models is clearly too hot in the 16-30-day period across the West and Central U.S. The explanation for the warm (ECM) bias is presence of an unusually strong summertime polar vortex over Greenland with a southward extending upper trough occasionally visiting the West U.S.

The 12-week Evaporative Drought Demand Index (EDDI) reveals U.S. areas most susceptible to fire risk for late meteorological summer/early autumn. The highest alert, ED3/ED4 is spread across central and southern California, much of the Great Basin, and Arizona.

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.