California — A developing El Niño event could influence winter weather across much of the United States, with the West Coast and southern states potentially facing stronger storms, periods of heavy rain and mountain snow, according to the National Oceanic and Atmospheric Administration (NOAA).
In its winter outlook released Thursday, NOAA said the climate pattern is expected to strengthen and could reach its peak intensity in December. Its effects may extend across the Lower 48 states during the winter months, influencing storm tracks, temperatures and precipitation.
Forecasters caution that no two El Niño winters are exactly alike. However, the developing pattern could increase the likelihood of wetter conditions across parts of the southern United States while bringing milder and potentially drier weather to some northern states.
What NOAA’s Winter Outlook Says About El Niño
El Niño occurs when sea surface temperatures in the central and eastern tropical Pacific Ocean become warmer than average. These changes can influence atmospheric circulation and shift weather patterns far beyond the Pacific.
According to NOAA’s outlook, the current event could help steer storms toward the southern tier of the United States during the coming winter.
The jet stream, a fast-moving current of air that generally travels from west to east, plays an important role in this process. Its position helps determine where weather systems travel and which regions receive the greatest amounts of precipitation.
When El Niño influences the jet stream, parts of the southern United States can experience more frequent storms and wetter-than-normal conditions. Northern areas, meanwhile, can see milder temperatures and reduced precipitation.
These are broad climate tendencies, not guarantees for individual cities or states.
West Coast and Southern States Could See Strong Storms
The West Coast and the southern half of the country are among the regions to watch as the winter pattern develops.
A storm track that favors the southern United States could bring repeated rounds of rain to parts of California and other areas along the West Coast. Depending on the location and intensity of individual storms, some systems could produce substantial rainfall and mountain snowfall.
NOAA’s outlook also points toward the possibility of wetter conditions across parts of the South.
The potential impacts will depend on how individual storms develop, how much moisture they carry and where they make landfall. Even during a strong El Niño, rainfall totals can vary considerably from one region to another.
The combination of unusually warm ocean temperatures worldwide and a strong El Niño could also contribute to significant precipitation events. However, the amount of rain or snow from any particular storm cannot be determined from the climate pattern alone.
Heavy Rain Could Raise Flooding and Landslide Concerns
Periods of heavy rainfall can create risks for communities across the West Coast, particularly in areas vulnerable to flooding, erosion and landslides.
Saturated soil can become unstable during prolonged or intense rain, increasing the potential for hillside failures. Rapid runoff can also overwhelm drainage systems and cause flooding in low-lying locations.
California officials are preparing for the possibility of hazardous winter weather.
On Monday, Gov. Gavin Newsom announced a state of emergency ahead of the El Niño season. The declaration is intended to support early statewide preparations for potential winter storms and related hazards, including flooding and landslides.
The announcement highlights the importance of preparing before severe weather develops rather than waiting until a storm reaches the state.
Residents should monitor local forecasts, pay attention to evacuation warnings where applicable and review plans for periods of heavy rain.
Will El Niño Bring More Snow This Winter?
Despite the possibility of warmer temperatures in some regions, El Niño does not automatically mean a snow-free winter.
Mountain communities could still experience substantial snowfall when storms bring sufficient moisture and temperatures remain cold enough. Some storms may produce heavy rain at lower elevations while delivering snow in the mountains.
NOAA’s outlook indicates that the overall winter pattern may be milder across much of the country, but local snowfall will depend on storm timing, elevation and temperature conditions.
The Southeast and parts of the Southern Plains could also see frozen precipitation if cold air arrives at the same time as a storm system.
That timing is difficult to predict far in advance. A storm passing through a region without sufficiently cold air may bring rain instead of snow, while a colder setup could produce winter weather.
Which Parts of the US Could Be Wetter or Drier?
The broad pattern described in NOAA’s outlook suggests different conditions across the country.
- West Coast: Potential for strong winter storms, heavy rainfall and mountain snow in some areas.
- Southern United States: Increased chances of wetter and cooler conditions in parts of the region.
- East Coast: Precipitation is expected to be above average, according to the outlook.
- Northern states: Some areas could experience milder temperatures and drier-than-normal conditions.
- Southeast and Southern Plains: The possibility of snow or other frozen precipitation will depend on the availability of cold air during storms.
These regional expectations do not mean every location will experience the same conditions. Short-term forecasts will be more useful for determining specific rainfall totals, snowfall amounts and storm impacts.
Are you expecting a wetter or colder winter where you live? Share your state and winter weather expectations in the comments below.
