The wet forecast bias by all models across Brazil is worsening. The maximum error for the 1-5-day, 6-10-day, and 11-15-day period from the past 30 days is 3+ in. of rain. The ECM is cited due to the worst verification although other models are very close, including GFS.

Taking a look at the 11-15-day East U.S. temperature anomaly outlook reveals lingering cold when combining the GFS and ECM forecasts. However, AI models offer wildly different projections (colder or warmer). So...a look at climate diagnostics reveals what direction to rely.

The updated month 1-4 climate outlook for the U.S. features increasing forecast confidence based on the influence on North America climate by dramatic cool phase of the Pacific decadal oscillation and warm phase of the Atlantic multi-decadal oscillation. A weak ENSO regime has limited influence.

During September 2024 the sea and ice concentration within the polar ice cap is 4th lowest in the 1978-2024 climatology. By comparison, the polar ice cap is considerably smaller than typical of 40+ years ago. The modern-day constricted polar ice cap has contributed to a recent trend of above normal snow cover developing early in the northern hemisphere cold season.