By Mary O’KEEFE

California has recently been affected by tropical storms. On Sept. 17 and Sept. 18 Tropical Storm Mario brought to the area humid conditions, lower temperatures and thunderstorms. Then earlier this month Hurricane Priscilla affected our area with rain and thunderstorms. This brought some unusual weather our way.

“September 2025 was yet another ‘strange’ weather month along the Pacific Coast. In California, multiple episodes of precipitation (and a fair bit of thunderstorm activity) brought wetter conditions to much of the state – particularly across central and southern California. Serious, even deadly, flash flooding and debris flows occurred in the lower deserts of [southeast California] and the San Bernardino Mountains when remnant moisture and instability from Tropical Storm Mario produced locally torrential thunderstorm downpours; while rain elsewhere was (thankfully) much less dramatic, it was nonetheless unusual for September,” according to an article published on Oct. 8 on weatherwest.com.

When you think of hurricanes we normally think of the Atlantic Ocean and the East Coast. However, the Pacific does have an active hurricane/tropical season that runs from May 15 to Nov. 30. We don’t hear about these storms coming onshore on the West Coast due, in part, to two factors that are needed to form a hurricane: ocean temperature and upper-level wind flow, according to compuweather.com.

The recipe for making a hurricane requires ocean water temperatures of about 80 degrees Fahrenheit or warmer. The average temperature off the coast of California is in the upper 60s. 

“Once a hurricane develops, it tracks generally where the upper level wind flow pattern steers it over the tropical regions of the Pacific and Atlantic Oceans. The trade winds prevail with a general east-to-west flow. This wind flow tends to steer Atlantic hurricanes on a general motion towards the Caribbean and eastern U.S. Meanwhile, over the Pacific Ocean, this east-to-west flow tends to steer most hurricanes out into the open ocean, away from the mainland. On occasion, an eastern Pacific hurricane will break away from the trade winds and track northwestward along or near Baja California and toward the state of California. However, once the hurricane tracks north of Cabo San Lucas, it encounters the much colder ocean waters. This causes the hurricane to weaken before getting close to California,” according to compuweather.com.

But climate change is affecting everything so although NOAA does not state that tropical cyclones would make landfall in California, it could increase the intensity of the storms that develop and therefore lead to more destruction as they do affect the weather in our area. And if you factor in increasing sea rise levels, the storms could become worse. 

“From 1980-2024, there were 46 confirmed weather/climate disaster events with losses exceeding $1 billion each to affect California. These events included 14 drought events, six flooding events, three freeze events, four severe storm events and 19 wildfire events. The 1980–2024 annual average is 1.0 event (CPI-adjusted); the annual average for the most recent five years (2020–2024) is 1.6 events (CPI-adjusted),” according to National Centers for Environmental Information/NOAA. 

And now we have a familiar visitor to California – La Niña is back. 

In September La Niña conditions appeared with the expansion of below-average sea surface temperatures and La Niña is expected to affect the Northern Hemisphere winter (2025-2026), according to NOAA’s Climate Prediction Center. 

La Niña means little girl in Spanish … During La Niña events, trade winds are even stronger than usual, pushing more warm water toward Asia. Off the west coast of the Americas upwelling increases, bringing cold, nutrient-rich water to the surface. These cold waters in the Pacific push the jet stream northward. This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada. During a La Niña year, winter temperatures are warmer than normal in the south and cooler than normal in the north. La Niña can also lead to a more severe hurricane season, according to NOAA’s Ocean Service. 

Normally La Niña means dryer conditions; however, nothing is normal anymore and during the 2022-2023 La Niña California saw above average rainfall in Southern California and a record snowpack in the Sierra Nevada, according to NOAA.

Okey dokie – so we are seeing a La Niña, which should bring us drier weather –but maybe not because nothing is as it was in the world of changing climate. 

“Water can store a lot of heat (compared to the air), which means the ocean can absorb excess heat from a warming atmosphere. About 90% of the excess heat from planetary warming over the past century has been absorbed by the ocean, causing ocean temperatures to rise. Modern record keeping for ocean temperatures began in 1955,” according to NOAA.

And if you look at graphs from NOAA you will see the ever-increasing heat, measured by a unit called zettajoules. 

According to Woods Hole Oceanographic Institute, even a slight increase of 1.5 degrees Fahrenheit in ocean temperature equals a lot of heat. 

“[Heat increases can be] large enough to transform marine biodiversity, change ocean chemistry, raise sea levels and fuel extreme weather. Earth is already experiencing the consequences of these changes impacting property, lives and livelihoods – and not just in coastal areas. Rising ocean temperatures are connected to some weather extremes and can lead to more intense hurricanes, heavier rainfall and snowstorms. Warmer sea surface temperatures influence weather patterns and shift precipitation, causing some regions to experience intense rainstorms and flooding and exacerbating drought conditions and wildfire risks in others,” according to Woods Hole Oceanographic Institute.

So bottom line: the weather is changing at an accelerated rate because we have changed it, and now we may be at the “tipping point” of no return for at least one part of our planet – coral reefs. 

Next week I will cover the newly released information about the “reef death tipping point.”

This week we will see the type of weather that makes people envy California. Temperatures will be in the mid 70s to low 80s. No rain is in sight and winds, if any, are predicted to be calm.