Based on a constructed analog combining optimum climate normal and ENSO analog years the upper air pattern for North America for each month of meteorological winter 2024-25 is projected. Revealed is low risk of a “polar vortex” pattern during December or January. However, a broad polar vortex pattern is forecast across Southern Canada during February.

Majority of forecast models are indicating La Nina development by early-to-middle quarter 4 of 2024. Some models are maintaining neutral ENSO. Current diagnostics favor neutral ENSO. Forecast models are more agreeable to the presence of -IOD. The comparison between -IOD/weak ENSO and La Nina coupled with -IOD yield differences but nothing profound. In general, the -IOD/LA Nina regime offers a wetter solution for Brazil.

An area of light and variable wind flow resting in-between high-pressure centers is known in meteorology as a “col”. When located in regions where tropical cyclones are tracking, storms slow down and sometime become stationary. Intensification occurs if tropical systems are offshore. If a tropical cyclone moves into a “col” along or just inland the coastline, stalled systems can wring-out excessive rainfall causing substantial flooding.

ECMWF reported back-to-back global record hot days (Fig. 1) earlier this week (July 21-22). The climatology used extends back to 1940. On Sunday, July 21, the global temperature reached a record 17.09C and was broken the following day at 17.15C. The previous record was observed in early July of last year.