KANSAS CITY — Ocean temperatures are in constant flux. Some scientists are still puzzled and frequently amazed at the changes in ocean surface and subsurface temperatures. In recent decades, it has been discovered how important a role the oceans play in world weather and climate and understanding how and why the ocean temperatures’ change could solve one of the largest mysteries in long-range weather forecasting. Perhaps Artificial Intelligence (AI) will provide the help needed to resolve the issue of predicting ocean temperature changes, but that is not coming quite yet.
In recent months, the media and weather service companies around the world have made it clear that the warm ocean water in the Atlantic, Pacific and Indian Oceans will support frequent tropical cyclones. So far, there have been a few bursts of tropical cyclone activity, but the season has not been anomalously active — at least not yet. The warm oceans will continue to provide incentive and support for tropical cyclones to develop in the tropics and subtropics worldwide over the next four to six weeks.
El Niño years — like this one — tend to have a little more wind shear aloft than other years. The wind shear works against tropical cyclone development by inducing more variation in wind direction with altitude and that is just the opposite of what tropical cyclones need for development. A consistent wind from the surface of the ocean up high into the atmosphere is needed to induce a spin in the atmosphere that can take warm and moist air rising above warm ocean water to create an aggressively developing tropical cyclone.
Tropical cyclones are known for their destruction of property and threat to society. Many deaths occur from tropical cyclones and the destructive power in these storms is nothing short of amazing. The storms have some beneficial aspects, though, that many folks do not think much about; however, tropical cyclones transport huge volumes of warm and moist air from the tropics to the middle and sometimes the higher latitudes. That transport of moisture and warmth is essential in times like that of the past few years when drought dominated the higher latitudes.
The past few years of dryness in North America, Europe, Asia, South America and Australia was allowed to fester in some areas much longer than usual because of La Niña, which has a tendency to remove moisture from the middle latitudes and increases rainfall in the lower latitudes. Tropical cyclones attempt to reverse this trend and after multiple years of dryness brought on by La Niña, an increased number of tropical cyclones may be necessary to improve rainfall potential in the coming months. The more numerous tropical cyclone years usually bring greater warmth and moisture to the middle latitudes, and that is exactly what should happen this late summer in the Northern Hemisphere. Frequent tropical cyclones should evolve in the warm tropical and subtropical water of the world and they will transport some of the warm and moist air to the higher latitudes.
This year’s ocean temperature anomalies are not just warm in the lower latitudes, but in the higher latitudes as well. This trend is of great interest for the winter of 2023-24 because of greater moisture becoming available for precipitation events as the atmosphere cools seasonably. Warm and moist air coming off the oceans becomes suspended into the atmosphere. As the air temperatures warm from water vapor coming off the ocean the air will rise, and as it moves higher into the atmosphere it eventually will run into cooler air aloft and that will saturate the air and induce rain and/or snow. So, while the media is concerned over tropical cyclone development others are praying for drought relief.
World Weather, Inc. is observing unusually warm ocean water temperatures in nearly all of the Atlantic Ocean Basin, much of the tropical eastern Pacific Ocean, across the northern Pacific Ocean and in portions of the western Indian Ocean. During the Northern Hemisphere winter season cooler air becomes more available in the atmosphere. If the air is full of moisture when the cooler air masses arrive, it will condense out as notable precipitation events when conditions are just right. This winter could easily become more stormy than usual across Europe (especially the south), North Africa and the Mediterranean Sea region because of the warm ocean temperatures in the central and northern Atlantic Ocean, especially during periods of cool air aloft.
There is also potential that the coast of British Columbia and other coastal areas in the Gulf of Alaska will experience greater-than-usual precipitation this winter because of warm ocean water present today. El Niño also will be present during the winter this year and that should favor a warmer and drier bias in Canada’s Prairies while greater-than-usual precipitation occurs across the southern and east-central United States. Similarly, El Niño will generate greater-than-usual rain in the Mediterranean region and across the Middle East. China’s weather will trend seasonably dry in the north this late autumn and winter while the south is impacted by tropical cyclones.
The tropics eventually will hurt most for rain since the El Niño phenomenon usually creates high pressure aloft over northern South America, Central America and in central Africa reducing rainfall. The same phenomenon occurs in Indonesia, Malaysia and the Philippines as well as northern and eastern Australia and the heart of South Africa. Center south and far southern Brazil should be wetter biased late this year and in early 2024 just like southern Europe, North Africa and the southern United States.
So, not all of the warm water that is present in the world’s oceans should be deemed as a negative. There will be numerous tropical cyclones coming in the balance of this month and possibly into October, but that transport of moisture and heat energy might just be what the doctor ordered to end drought in Canada, the southern US Plains, northern Mexico, southern Europe, North Africa and dryness from eastern Ukraine into western Kazakhstan. Argentina also may get a little relief from drought, but unfortunately for eastern Australia and many areas in Southeast Asia, central Africa, Central America and northern South America drought is likely to evolve because of El Niño’s presence.