By Zach Butler, Meteorologist Posted 2 months ago December 22, 2023
Winter is underway across North America and much of the weather pattern and snowfall totals thus far have been affected by El Niño. El Niño will continue for the 2023-2024 winter as expected. Let’s take a look at where we are with El Niño, what we can expect for the rest of the winter, and how El Niño has affected the weather thus far.
Where We Are With El Niño
El Niño is expected to continue through the 2023-2024 winter as a ‘strong’ El Niño with an average sea surface temperature (SST) anomaly of 1.8°C since September. We are nearing the peak El Niño SSTs across the equatorial Pacific Ocean with a 54% chance of a "historically strong" El Niño during the November-January season.
A “historically strong” El Niño means SSTs would be ≥ 2.0°C in the Niño-3.4 region during November-January. If we end up in the historically strong El Niño, we could move into the top 5 of El Niño events since 1950.
Below is a look at the latest NOAA forecast on ENSO conditions, showing El Niño continuing until about April 2024. There are some early indications we could transition into La Niña for the summer, although it is too early to have confidence in this.
More information on El Niño and other ENSO data can be found from the Climate Prediction Center (CPC) here.
What We Can Expect This Winter
The current “strong” and potential to move into a “historically strong” El Niño are forecasted to bring increasing chances of precipitation to California, the Southwestern US, a few areas in the Interior West, and the Southeastern US.
While this forecast for above-normal precipitation has not been validated yet through California and the Southwest, we are just getting underway this winter, with a long way to go. The long-range numerical model guidance is still showing a favorable chance of above-normal precipitation for much of the southern half of the US.
Below is a look at the Climate Prediction Center’s (CPC) probability outlook of temperatures (top) and precipitation (bottom) for January, February, and March of 2024.
The areas that have an increased chance of above-normal precipitation do not always equate to above-normal snowfall. Temperatures during El Niño can be above-normal, which raises snow levels and does not always mean more snow.
El Niño Affects Thus Far
We have seen a few effects from El Niño thus far in the early winter season. The Pacific Northwest and the Midwest have seen below-normal snow due to warmer temperatures. Precipitation amounts have been near normal, but increased temperatures have caused most precipitation to fall as rain.
California, the Southwest, and the Interior West have also seen near-normal precipitation, but above-normal temperatures are causing a larger fraction of the precipitation to fall as rain than snow. Below is a look at the average snow conditions across the Western US, highlighting the below-normal snowpack.
Below is a look at the temperature (top) and precipitation (bottom) anomalies over the past 60 days, since late October. It shows above-normal temperatures across the US and near-normal precipitation.
The highest snow-producing months are still ahead of us into 2024 and the forecast continues to show increased chances of improving the snowpack across much of the West. The PNW and Midwest might not be so fortunate though, with a potentially tough winter ahead.
Stay posted on your favorite Daily Snow for when the best skiing and riding will come to your area.
Thanks for reading!