Pacific marine heatwave could influence U.S. weather into winter

An expansive marine heatwave stretching across much of the Pacific Ocean could shape weather patterns across the United States for months, increasing the potential for extreme heat, heavier rainfall, stronger storms, and coastal flooding later this year.

The marine heatwave now covers an area extending from the Philippines to Peru and north toward Hawaii and the California coast. Marine heatwaves are prolonged periods of unusually warm ocean temperatures that can significantly influence weather patterns, according to the National Oceanic and Atmospheric Administration.

The current event developed after two smaller areas of unusually warm water in the North Pacific and along the equator merged into one larger system.

Scientists say the warmer-than-normal ocean waters are already contributing to weather changes. A super typhoon in the western Pacific and the potential development of a heat dome across the western United States later this month are among the impacts being monitored. The excess ocean heat released into the atmosphere could also contribute to more intense thunderstorms and flooding across parts of the southern and eastern United States during the coming months.

California’s coastline may also experience higher sea levels this winter, raising the risk of coastal flooding during powerful storms and seasonal king tides. Researchers say the warmer ocean temperatures increase the likelihood of unusually wet and stormy conditions along parts of the West Coast during the upcoming winter.

While the greatest impacts are expected in western and coastal states, changing Pacific weather patterns can influence conditions across much of the country. In Pennsylvania and the Mid-Atlantic, any long-range effects remain uncertain, but forecasters will continue monitoring whether the warmer Pacific contributes to a wetter or more active storm pattern later this fall and winter.

Marine heatwaves have become increasingly common in recent decades. Scientists report that the share of the global ocean experiencing these unusually warm conditions has risen dramatically since the 1980s. At present, more than one-third of the world’s oceans are experiencing marine heatwave conditions, reflecting a broader warming trend that researchers say can have lasting effects on weather, marine ecosystems and coastal communities.

Source: Yahoo!News