NOAA’s winter outlook for December through February favors a wetter-than-average southern tier of the country and warmer-than-average conditions across the Midwest, the Mississippi Valley and much of the East. The agency ties the pattern to a strong El Niño that its Climate Prediction Center says is still building.
What NOAA Forecast for December through February
NOAA released the outlook on Oct. 15. For temperature, it favors warmer-than-average conditions in northern California, the Pacific Northwest, the Midwest, the Mississippi Valley, much of the East, Alaska and Puerto Rico and the U.S. Virgin Islands. Near-normal temperatures are most likely in parts of the Southeast, including Florida. Hawaii and much of the Southwest have equal chances of below-, near- or above-average temperatures.
For precipitation, wetter-than-average conditions are most likely across the southern tier from the Southwest to the Southeast and along the East Coast. Drier-than-average odds are elevated in Hawaii, much of Alaska, the northern Mountain West, parts of the Great Lakes and the western Pacific Islands. The Intermountain West, the northern Plains, the Ohio Valley and Puerto Rico and the U.S. Virgin Islands have equal chances of a wet, dry or normal winter. The outlook uses the terms “favored,” “most likely” and “equal chances,” and the release gives no numeric probabilities. It does not project snowfall totals.
How Strong the El Niño is
The Climate Prediction Center’s Oct. 8 discussion keeps an El Niño Advisory in effect and says a strong-to-very-strong event is likely through January to March 2027. The Niño-3.4 region, the standard measure, ran +2.1 degrees Celsius above average that week. Niño-3 ran +3.0 degrees and Niño-1+2, nearest South America, ran +3.9 degrees. Sea surface temperatures exceeded +4.0 degrees in parts of the eastern equatorial Pacific, and temperatures at depth in the eastern Pacific remain above +10.0 degrees.
The center gave probabilities that the three-month average in a relative index reaches +2.5 degrees or higher, a level it said would exceed every El Niño since 1950. It put the chance at 54% for September to November, 83% for October to December and 70% for November to January. The 83% figure is 29 points above the 54% figure, a calculation from the center’s numbers. The Oct. 8 Niño-1+2 reading is about 1.9 times the Niño-3.4 reading, also a calculation.
Convection and rainfall are enhanced from the central to the eastern Pacific and suppressed over Indonesia, the center said, and both Southern Oscillation indices are significantly negative. It expects El Niño to keep strengthening through the end of 2026 and said an event of this size makes El Niño-consistent impacts more likely, though not guaranteed.
What the Oct. 15 Climate Prediction Center Discussion Added
The center’s prognostic discussion, issued the same day as the NOAA outlook, lists newer weekly readings of +2.4 degrees for Niño-3.4, +3.4 for Niño-3 and +4.4 for Niño-1+2. Those are 0.3, 0.4 and 0.5 degrees higher than the Oct. 8 readings, calculations from the two discussions. The center said the atmosphere has responded, with enhanced convection over the central and eastern Pacific and weakened trade winds.
The center’s models project the peak in the November to January period. Its official outlook gives 80% odds that at least a strong El Niño continues through January to March 2027. It then favors neutral conditions from May to July 2027 and a possible La Niña in autumn 2027. The discussion cites the very strong 1997-98 and 2015-16 events as reference points. Both occurred while the Pacific Decadal Oscillation was in its positive phase, and the current phase is negative, which the discussion says makes the comparison harder. It judges the oscillation’s influence this winter to be likely minimal.
On precipitation, the discussion says a southward and eastward-shifted Pacific jet supports wetter conditions along the West Coast, north to the Oregon coast. Odds of a wetter-thanaverage winter exceed 70% in parts of the extreme Southeast and northern Florida through January to March. For temperature, it puts the highest odds of above-normal readings in
Southeast Alaska, the Pacific Northwest to the northern Plains, the Great Lakes and the interior Northeast. It notes that some models may overstate cooling in the Southeast and Florida, while statistical guidance there favors near- to above-normal temperatures. The discussion covers November to January, not the December to February period in the NOAA release, so the regional maps differ at the edges.
Why a Strong El Niño Matters for Flooding
Ken Graham, the director of the National Weather Service, said in the release that a very strong El Niño will likely shift the jet stream south and east. He said “too much precipitation on dry soil can fuel destructive flash floods and mudslides.” The wet signal falls on the Southwest, where the drought outlook below calls for improvement. Dry ground absorbs less water, and fast runoff is the hazard Graham described.
Drought Outlook through January 2027
The release’s drought forecast covers Oct. 15 through January 2027. Drought is forecast to improve or end in the Southwest, the southern Great Plains, the Southeast and parts of the East Coast. It is favored to develop or worsen in parts of the northern Rockies, northeastern Oregon and eastern Washington. The precipitation outlook also tilts dry in the northern Mountain West.
New Tools for Flood and Winter Storm Warnings
NOAA said its Probabilistic Precipitation Portal is now operational. The portal shows low-end, expected and high-end amounts of snow, ice and rain, along with the probability that precipitation crosses chosen thresholds. NOAA also said select Blizzard Warnings and Ice Storm Warnings may use “Particularly Dangerous Situation” wording this season for high-confidence, historically severe events. Graham said in the release that now is the time for communities and individuals to plan ahead for winter.
Dates to Watch
The Climate Prediction Center will issue its next El Niño discussion Nov. 12, 20 days after Oct. 23, and NOAA will update the three-month outlook Nov. 19, 27 days after Oct. 23. Both counts come from the published dates. The seasonal outlook describes odds for a three-month average, so a single storm or cold snap can fall outside it.
