The Pacific is running hot right now, and it isn’t a small signal. El Niño has strengthened quickly this fall, and the latest model runs take it to a level we’ve never measured before by December. That matters for Texas. It means better odds of rain for a big part of the state this winter, a colder second half of the season, and more snow chances up north than we usually see.
Meteorologist Trey Greenwood with Convective Chronicles put together a full breakdown for us. The video is below, and here’s the short version.
What El Niño actually is
El Niño is the warm side of what forecasters call ENSO, the El Niño–Southern Oscillation. When the water along the equator in the Pacific stays warmer than normal for months at a time, that’s El Niño. When it stays cooler than normal, that’s La Niña. We were in a weak La Niña last winter. Since spring, the Pacific has swung hard the other way, and the warm water now stretches across the entire area forecasters use to track it.
This one could set a record
The number to watch is the Relative Oceanic Niño Index, or RONI. A reading of +0.5 or higher means El Niño. Anything above +2.0 is what people mean when they say Super El Niño. The July through September reading came in at +1.7, and both the NMME and CFSv2 forecasts push it to around +3.0 by December. The highest reading since 1950 is +2.4, from the winter of 1982–83. Even if the models are running a little hot, we’re still looking at a strong to very strong El Niño through the end of winter.
Why it matters for Texas
El Niño doesn’t send storms to Texas on its own. What it does is shift the jet stream, and the jet stream is what steers storm systems across the country. In a typical El Niño winter, the jet sets up farther south, right across Texas and the Gulf Coast states. That puts us in the path of more systems, which is why El Niño winters tend to run cooler and wetter here while the northern U.S. runs drier and warmer.
The wild card this year
One thing makes this winter harder to call. Most of the strong El Niño winters on record happened while the Pacific Decadal Oscillation, or PDO, was positive. The PDO is a slower pattern of ocean temperatures in the North Pacific, and right now it’s negative. Only six past winters line up well with what we have this year. Those winters still ran wetter than normal across Texas, just not by as much as the classic El Niño years.
What to expect across Texas
Rain
Most of Texas leans wetter than normal this fall and winter. The best odds are in Central and East Texas, especially early in the season. NOAA’s official November through January outlook gives most of the state a 33 to 40 percent chance of above-normal precipitation.
Temperatures
Overall, this looks like a colder than normal winter. It may start out near normal before the pattern turns colder after the new year. By January through March, the NMME model blend runs about 1.2 degrees below normal statewide.
Snow and ice
Snow chances look better than usual, mainly across the northern half of the state. December through February is the window to watch, and the Panhandle and Northwest Texas have the best odds from January into February. If you travel up that way this winter, plan on more winter weather days than normal.
Severe weather
Tornado activity looks close to normal. North and East Texas are favored, with some activity possible out west, and more of it may come early in the season. For context, Texas averages about 28 tornadoes from October through February. Past El Niño winters with a positive PDO averaged 31, and the ones with a negative PDO, like this year, averaged 24.
One last thing
This is a seasonal outlook. It tells you which way the odds lean for the season as a whole, not what will happen on a given day or with a given storm. We’ll be tracking each system as it comes and keeping you updated along the way.
You can get every forecast update free in the Texas Storm Chasers app, and our live radar is always running.