Federal forecasters are no longer just saying a strong El Niño is coming. They are saying there is a better than two in three chance this one beats every El Niño on record.
The Climate Prediction Center's most recent ENSO diagnostic discussion, issued August 13, carries an El Niño Advisory and puts a very strong event during Northern Hemisphere fall and winter 2026 to 2027 at greater than 90 percent probability. More striking is the second number: during the October through December season, the center gives a 69 percent chance of a historic event exceeding the strength of every El Nino dating back to 1950, defined as a three month value of plus 2.5 degrees Celsius or more on the relative oceanic Nino index.
The ocean is already running hot. Sea surface temperature anomalies exceeded plus 2.0 degrees Celsius in the eastern equatorial Pacific during July, and the Southern Oscillation indices sat near two standard deviations negative.
For households, the useful translation is not about snowfall totals. It is about which health risks become more likely, and which preparations are worth making before November.
What a Seasonal Outlook Can and Cannot Tell You
The Climate Prediction Center is explicit about the limits of its own forecast. With an event of this magnitude, the agency notes, the chances of experiencing impacts consistent with El Niño are larger, but they are not guaranteed. Its seasonal outlooks describe probabilities across three-month windows. They do not predict specific storms, snowfall totals, or the temperature on any given day.
Historically, strong El Niño winters tilt the odds toward wetter conditions across the southern tier of the United States and drier conditions across parts of the north, with warmer seasonal averages favored across much of the West and northern states. Those tilts are meaningful for planning and useless for scheduling. Strong events have also produced varied regional outcomes, and the relationship between event strength and any given city's winter is loose. The center maintains a probabilistic strength forecast and updates oceanic and atmospheric conditions weekly.
The Injury and Illness Patterns That Track with Winter Weather
Cold-related risks are not distributed the way most people assume. Hypothermia does not require extreme cold. It develops readily in wet conditions at moderate temperatures, particularly with wind, which is why it turns up in summer flash flood rescues as well as January storms.
Falls rise with ice and reduced daylight, and consequences differ sharply by age. A fall that bruises a 30 year old can fracture a hip in an 80 year old, and hip fracture carries substantial mortality in the following year.
Carbon monoxide poisoning clusters around power outages and the heating season. It comes from generators run too close to a house, charcoal or gas grills used indoors, blocked furnace vents, and cars idling in attached garages. Symptoms mimic the flu: headache, dizziness, nausea, confusion. Because the gas is odorless and the symptoms are unremarkable, poisoning is frequently misattributed until several people in a household are affected at once.
Respiratory illness transmission increases as people spend more time indoors together, which overlaps with peak flu and RSV season regardless of the state of the Pacific. Power outages compound all of these risks at once, removing heat, disabling medical equipment, and pushing households toward the improvised heating and cooking that causes the poisonings described above.
The Households Most Exposed to a Wet Southern Winter
If the wet southern signal verifies, the health consequences concentrate in places with the least cold weather infrastructure. Southern metros including Houston, Dallas, San Antonio, Atlanta, New Orleans and Phoenix have less experience with sustained freezing, fewer well-insulated homes, and grids that have failed under winter stress within recent memory.
Flooding brings its own health problems: contaminated floodwater, mold in structures that stay damp, displacement, and interrupted access to dialysis, oxygen supply, and pharmacies. Mold exposure in particular can persist for months after water recedes and disproportionately affects people with asthma.
The people who absorb the most risk in any severe winter are consistent across regions. They include older adults living alone, people who depend on electrically powered medical equipment, people experiencing homelessness, outdoor workers, low-income households facing heating costs they cannot cover, and people with chronic heart and lung disease for whom cold air and exertion such as snow shoveling raise cardiac risk.
Preparations That Make Sense Now Rather Than in December
Some steps are worth taking before the season regardless of how the forecast verifies.
Test carbon monoxide alarms and replace batteries, and install one if there is none. Alarms belong on every level of a home and near sleeping areas. If a generator is part of the plan, confirm it will run outdoors, well away from windows and doors.
Build a prescription buffer. Ask a pharmacist about extended day supplies for maintenance medications and whether insurance permits early refills ahead of a forecast storm. Households relying on powered medical equipment should register with their utility company, since many maintain priority restoration lists, and should confirm both a backup plan and a warming or charging location.
Older adults and people with chronic conditions should complete seasonal vaccinations on the schedule their clinician recommends. Households facing heating costs should look into the Low Income Home Energy Assistance Program through their state and ask local utilities about winter shutoff protections, which vary by state and often require an application before a crisis rather than during one.
Stockpiling beyond a reasonable buffer, canceling winter travel eight weeks out, or treating a seasonal probability as a specific forecast would all be premature.
The Next Official Update and the Limits of the Forecast
The Climate Prediction Center issues its ENSO diagnostic discussion on the second Thursday of each month, and the next is scheduled for September 10. Seasonal temperature and precipitation outlooks are updated monthly and will incorporate the revised strength assessment. The agency also publishes an alert system explainer describing what an advisory does and does not signal.
The reasonable posture is preparation that would be sensible in any winter, done earlier than usual. Working carbon monoxide alarms, a medication buffer, a plan for powered medical equipment, and updated contact with a utility company cost little and pay off whether or not this winter becomes the record the models point toward.
Key Questions Answered
What did NOAA actually forecast? The Climate Prediction Center's August 13 ENSO discussion carries an El Niño Advisory and puts the chance of a very strong event during fall and winter 2026 to 2027 above 90 percent. It also gives a 69 percent chance that the October through December season exceeds every El Niño on record back to 1950.
Does this mean a specific amount of snow? No. Seasonal outlooks describe probability shifts across three-month periods. They do not forecast individual storms, snowfall totals, or conditions on a specific date, and the agency says El Niño impacts are more likely but not guaranteed.
Which health risks typically rise in winter? Hypothermia, falls on ice, carbon monoxide poisoning during outages and heating season, cardiac events associated with exertion in cold air, and increased respiratory illness transmission indoors.
Why does carbon monoxide deserve particular attention? The gas is odorless and its symptoms resemble flu, so poisoning is often missed until several people in a home are affected. Risk concentrates around generators, indoor grill use, blocked furnace vents, and idling vehicles in attached garages.
What should households do before winter? Test carbon monoxide alarms, ask a pharmacist about extended medication supplies, register powered medical equipment with the utility company, complete recommended seasonal vaccinations, and look into heating assistance programs.
When is the next forecast update? The Climate Prediction Center issues its ENSO diagnostic discussion on the second Thursday of each month, and the next is scheduled for September 10.
