NOAA's Climate Prediction Center released its full package of seasonal outlooks at 8:30 a.m. Eastern on Thursday, August 20, 2026. These are the first long-lead maps issued since the agency raised the odds of a very strong El Niño past 90 percent, and they answer the question the odds never did: which parts of the country actually get the water, and when.
The short version is that the wet signal is real, it is concentrated in two regions, and it shows up later than a textbook El Niño would suggest. If you are in California or the Southeast, your highest-probability window is the middle of winter and especially late winter — not this fall.
The headline change: the rain comes late
The most useful sentence in the CPC's seasonal outlook discussion is about timing. Forecasters write that El Niño impacts are expected to increase "slowly at first before quickly ramping up during the core winter months and especially late winter."
The reason is the flavor of this event. This is an eastern-Pacific-based El Niño, and CPC says the closest historical analogs to that pattern point to a delayed onset of the big southern-tier wet signal. Fall stays muted. Then the map changes quickly.
That timing matters more than it sounds. A lot of people read "super El Niño" and brace for an October that never comes, then relax right before the window that actually matters. The outlook says January through March 2027 is when coverage peaks.
What the fall maps show
For September through November, the wet signal is narrower than the winter maps. Above-normal precipitation is favored from the southwestern U.S. to the central High Plains, with the greatest chances — higher than 40 percent — across much of the Southwest and adjacent parts of the Great Basin and the central and southern Rockies. Parts of the coastal Southeast also carry elevated chances.
Two areas are notable for what they do not show. The Lower Mississippi Valley and the eastern Southern Plains land in "equal chances" for fall, because a strong recent dry trend is fighting the El Niño wet signal to a draw. And a slight tilt toward below-normal precipitation covers much of the Great Lakes and Northeast, plus northern and eastern Washington, northern Idaho, and northwestern Montana.
By October through December, modest above-normal chances — generally 33 to 50 percent — spread across the southern tier, the Southeast, and the central and southern Plains, extending north across much of the Plains. Still modest. Still ramping.
Where the winter signal actually concentrates
This is where the maps get emphatic, and it is worth reading the two regions separately.
- The Southeast. Probabilities of above-normal precipitation exceed 60 percent across parts of the Southeast by November–January, and stay elevated through January–March. That is a strong number for a seasonal outlook. The wet tilt also extends along almost the entire East Coast from November–January through February–April.
- Coastal California and southern Arizona. CPC raised probabilities of above-normal precipitation above 50 percent from December–February through February–April, with coverage peaking in January–March. Forecasters specifically noted that recent eastern-Pacific El Niños produced heavy late-winter precipitation, and that 2024 and 1998 were among the wettest Februaries in the last 100 years for parts of California.
The 1998 reference is not decoration. That was the last comparable event, and it is the reason this outlook reads the way it does. Our Super El Niño 2026-2027 forecast and winter weather map breaks down what the last three very strong events actually cost, region by region.
The dry side of the map
A classic El Niño winter map puts a broad dry signal across the Pacific Northwest and the northern tier. This one mostly does not, and that is a real departure.
CPC kept the dry tilt off the West Coast entirely and restricted it to inland areas — the Northern Rockies and the northern High Plains — during the core winter months. Their reasoning: several of the closest analogs to this event were wet well north along the coast, reaching into much of the southern half of the Pacific Northwest. A slight dry tilt also covers parts of the Great Lakes. The Ohio and Tennessee valleys sit in equal chances for winter, because the analogs do not support a confident dry signal there either.
If you live in Oregon or Washington west of the Cascades, the practical read is that you should not treat this winter as a guaranteed dry one.
What the ocean looks like right now
The outlook rests on an ocean that has kept intensifying. In the latest ENSO diagnostic discussion, sea surface temperature anomalies in the eastern equatorial Pacific have exceeded +3.0°C. The most recent weekly index values are +1.8°C for Niño-3.4, +2.5°C for Niño-3, and +3.2°C for Niño-1+2, with subsurface anomalies reaching +10.0°C at depth.
CPC still puts a greater than 90 percent chance on a very strong event during fall and winter, and gives October–December a 69 percent chance of becoming a historic event exceeding every El Niño back to 1950 — defined as a three-month relative Niño-3.4 value of +2.5°C or higher. The agency's official ENSO probability table shows El Niño continuing to strengthen through the end of 2026. NOAA's Climate.gov ENSO blog is the plainest-English place to follow the monthly updates.
What to do with this if you are in the wet zone
A seasonal outlook is not a forecast of any particular storm. It tells you which way the odds lean over three months. That is still enough to act on, because the useful preparation is the kind that takes weeks and cannot be done the night before.
- Use the timing. If your highest-probability window is January through March, you have four to five months. That is enough time for gutter and drainage work, a roof inspection, and a flood insurance policy — NFIP policies carry a 30-day waiting period, so a January risk means a December decision at the absolute latest.
- Know your actual exposure. Most flood damage in these events is rainfall and drainage, not rivers. Low doors, garage thresholds, basement window wells, and window-level grade are where water gets in first.
- Work out your barrier math once, now. Our sandbag calculator converts an opening width and an expected water height into a bag count, so you are not guessing in a hardware store parking lot.
- Set up alerting. The Flood Watch tool pulls active NWS flood alerts nationwide into one view, so you can see what is live in your area without hunting.
On the equipment side, the reason we suggest sorting this out in advance is simple: StormBags weigh about a pound dry and store flat, so you can stage them in a closet months ahead. Each one absorbs roughly four gallons and expands to about 33 pounds in under three minutes in fresh water, building a six-inch barrier. They are FEMA and DHS approved and made in Chico, California. A 10-pack runs $99.99 and a 25-pack $239.99.
One caveat for anyone on the coast, since this outlook puts heavy precipitation over coastal California and the Southeast: StormBag cannot be hydrated in salt water, but will work to repel salt water once they are hydrated with fresh water. Plan on a fresh water source to set the barrier.
For a full month-by-month sequence, our El Niño 2026-2027 preparation guide lays out what to do and when.
Bottom line
The August 20 outlook turns a probability story into a map. Two regions carry the strongest wet signal — the Southeast, above 60 percent by late fall, and coastal California, above 50 percent through late winter. The usual El Niño dry signal got pulled back off the West Coast and confined to the inland northern Rockies and northern High Plains. And the whole pattern arrives later than the label suggests, peaking in January through March 2027.
The next set of CPC long-lead outlook maps supersedes this one on September 17, 2026, and the next ENSO diagnostic discussion is September 10. We will update this post if the regional picture shifts.
