During the current warm AMO cycle, hurricanes are observed to intensify more rapidly when crossing over warm water. According to Andra Garner’s white paper “Observed increases in North Atlantic tropical cyclone peak intensification rates” the number of category-1 hurricanes intensifying to a major hurricane within 36 hours has doubled in the modern warming of the North Atlantic era.

NOAA updated the solar cycle 25 forecast late last week. Solar cycle 25 is interesting, beginning much more active than expected and well ahead of the initial forecast. However, recent months have brought a slowdown in solar activity making the over-achieving character of early solar cycle 25 to question. The new NOAA projection is certainly stronger than the initial forecast. Additionally, the arrival of solar maxima 25 is faster.

Overnight “Otis” intensified rapidly to become a category-5 major hurricane just before striking Acapulco on the south coast of Mexico this morning. Former Tropical Depression 21 has crossed Central America and entered the East Pacific and is likely to drift west-northwest and become another hurricane. Hurricane Tammy is forecast to turn northwest and west while transitioning into a powerful extratropical cyclone. An ALERT is issued for the North-central Caribbean Sea for a possible tropical cyclone emerging next week.

Here it comes…early winter weather is organizing over the Interior Northwest to the northwest Great Plains the next 1-2 days as Winter Storm Warnings are issued and will expand. Meanwhile the onset of an extreme rainfall event in the Southern U.S. is showing signs with a Flood Watch posted for southern Oklahoma/northern Texas. Over-achieving morning chill in the East as Frost Advisories are issued for much of the Mid-Atlantic region.

The Climate Impact Company season 1-3 ahead climate forecast for South America is updated. The forecast is based on a constructed analog rooted in regional SSTA regimes and their historical upper air patterns. Highlights include the likely evolution of Central Brazil drought during summer 2023-24 possibly expanding eastward during early autumn. Wet climate shifts into Northeast Argentina easing long-term drought in that region.

Deep layer (10-200 CM) soil moisture deficits are often caused by lack of rainfall over a lengthy (at least 9 months) time-period. This condition generally involves drought development at the surface and potential for flash drought if a dry and anomalous hot weather pattern settles over the area. Dramatic events are inspired by these conditions.