The United States is set to experience its second consecutive La Niña winter, increasing the chances of warm and dry temperatures in the south, cool and wet conditions in the Pacific Northwest, and damp weather around the Great Lakes.
Watch the video to know more.
The Meteorological Spring season lasts three months, from March to May. This year, La Nina, which has a long history of influencing spring weather, will be a crucial factor.
What is La Nina, and how does it affect our weather seasons?
La Nina is a chilly phase of El Niño Southern Oscillation (ENSO), a huge and intense oceanic oscillation. This is an area of the tropical Pacific Ocean that swings between cold and warm periods. Tropical trade winds that circle the Earth around the equator frequently start or halt a phase by mixing the ocean surface waters and changing the ocean currents.
ENSO significantly influences tropical rainfall and pressure patterns, affecting the highly fragile ocean-atmosphere feedback system. ENSO’s effect is spread globally through this ocean-atmosphere interaction system.
We often see a worldwide shift in pressure patterns during the onset and longevity of ENSO phases. During the shifting seasons, each phase has a distinct influence on the tropics and (with some delay) on our weather. A specific phase (warm/cold) starts typically in late summer or early autumn and can last until the following summer, or even up to two years in extreme situations.
Spring weather summary
We are now halfway through the meteorological winter. Looking forward, early indicators for Spring reveal the existence of La Nina in weather patterns. This implies that we must keep a close check on the coming months, as La Nina often leads to more severe tornado seasons in the U.S.
U.S. forecasters predict warmer than average conditions across the southwest and drier conditions in the region. The central and eastern U.S. is also expected to have a warmer than usual Spring on average, while northern and northeastern states can expect mostly neutral to wetter weather.
Cooler and wetter weather is expected in the northwestern United States, as a low-pressure area originating over western Canada brings in its northwesterly flow.
People living in the south-central U.S. can expect more severe weather in mid to late Spring, with the heightened threat of severe weather occurring over the Tornado Alley in April, May, and June.
The North American winter forecast looks solid for a cold spring. Temperatures in western Canada will likely stay below normal, extending the winter season into Spring.