SCIENCE: El Nino is Fading, La Nina is Waiting : What it Means for the U.S.

The El Nino we have been experiencing over 2023 and 2024 is finally fading. Climatologists and oceanographers expect a transition to neutral conditions for a time, before we likely flip over to a La Nina influenced period. Today's blog will explain both El Nino and La Nina and their effects on seasonal weather in the U.S.

 

SCIENCE: El Nino is Fading, La Nina is Waiting : What it Means for the U.S.

Source: NOAA

WHAT IS EL NINO? - It is a warming of the ocean surface, or above-average sea surface temperatures, in the central and eastern tropical Pacific Ocean. El Niño can affect our (U.S.) weather significantly. The warmer waters cause the Pacific jet stream to move south of its neutral position. With this shift, areas in the northern U.S. and Canada are dryer and warmer than usual. During an El Nino pattern, winter means the chances for warmer-than-average temperatures across the northern states increase, while conditions in the Northeast will be wetter (and they were!) than in the West and Midwest. In Southern states, El Nino increases the chance of flooding and wild storms. El Niño also has an impact on ocean temperatures, the speed and strength of ocean currents, the health of coastal fisheries, and local weather from Australia to South America and beyond. El Niño events occur irregularly at two- to seven-year intervals.

LOCAL SOAKER - Here in southern Maine/eastern New Hampshire, we had one of the wettest winters on record with 7" Over average rainfall from January to mid-April.

WHAT'S HAPPENING NOW - The El Niño of 2023–24 is weakening. Forecasters estimate an 85% chance that El Niño will end and the tropical Pacific will transition to neutral conditions by the April–June period. There’s a 60% chance that La Niña will develop by June–August. Overall, the forecast this month is very similar to last month, and we continue to expect La Niña for the Northern Hemisphere fall and early winter (around 85% chance). CLICK FOR FULL EXPLANATION

WHAT IS LA NINA? -La Nina refers to the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. La Niña causes the jet stream to move northward and to weaken over the eastern Pacific. The La Niña phase typically correlates to dry weather in the southern U.S. and cooler, wetter weather in the Pacific Northwest and parts of the North. During La Niña winters, the South sees warmer and drier conditions than usual. The North and Canada tend to be wetter and colder. During La Niña, waters off the Pacific coast are colder and contain more nutrients than usual.

VIDEO EXPLANATION: https://youtu.be/fAvk4RXrW_E