Key Takeaways:

• La Niña has officially started, bringing shifts in winter weather patterns.
• Forecasts indicate warmer, drier conditions across much of the southern U.S.
• The phenomenon is expected to persist mainly as a weak event through April.
• Cooler temperatures and increased precipitation are anticipated in the Pacific Northwest.
• Climate patterns like La Niña could impact hurricane seasons in the Atlantic.

AUSTIN (KXAN) – The Climate Prediction Center announced that La Niña has officially begun, with conditions emerging around December 2024. La Niña represents the cool phase of the El Niño-Southern Oscillation (ENSO), characterized by sea-surface water temperatures in the eastern Pacific dropping approximately 0.5 degrees Celsius (about 32.9 degrees Fahrenheit) below the climatological average. It is associated with significant shifts in weather patterns across the U.S.

According to meteorologists, despite being predicted as a weak event, La Niña is expected to influence winter conditions through April. This phase is typically associated with warm and dry conditions across much of the southern states, while cooler and wetter weather is more common in northern regions. The National Weather Service highlights that overall precipitation and temperature impacts should be less intense compared to previous La Niña events.

The shift in the jet stream caused by La Niña is predicted to decrease precipitation in the southern U.S. while increasing the prospects of heavy rainfall in the Pacific Northwest and the northern rim of the country. Northern states are already showing signs of above-average snow, while areas in the Southeast and Southwest face likely dry spells.

Regions such as Washington, Oregon, and parts of the Midwest are expected to experience above-average precipitation, enhancing snowfall and overall rain levels. Meanwhile, the Southeast, Southwest, and parts of the Central U.S. will likely see increased temperatures and dry conditions.

One notable consequence of La Niña is its potential to contribute to more severe hurricane seasons in the Atlantic by creating an environment favorable for storm development. This trend has been noted by the National Oceanic and Atmospheric Administration (NOAA), which links the phenomenon with shifts in ocean temperatures and atmospheric interactions that play crucial roles in storm activity.

In comparison, last winter was marked by El Niño conditions, resulting in some of the warmest averages recorded in U.S. history. Historically, shifts between these cycles each span about three to five years and can result in varied impacts on temperature, precipitation, and severe weather across North America and beyond.

For further details, refer to the original articles from The Hill and Forbes.