Prognostic Discussion for Long-Lead Seasonal Outlooks 
NWS Climate Prediction Center College Park MD 
830 AM EDT Thu Sep 17 2026 
 
SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS 
 
El Niño conditions are present, as represented in current oceanic and 
atmospheric observations. El Niño is strengthening, with a greater than 90 
percent chance of a very strong event this fall and winter. 
 
The October-November-December (OND) 2026 Temperature Outlook favors above 
normal temperatures for much of Alaska as well as most areas west of the 
Rockies, nearly all areas east of the Mississippi River, and the northcentral 
states in-between. The highest probabilities (greater than 50 percent) of above 
normal temperatures are forecast across Southeast Alaska, the Northern Great 
Basin, and the vicinity of North Dakota and northwestern Minnesota. 
 
The OND 2026 Precipitation Outlook depicts enhanced probabilities of above 
normal precipitation amounts from the southern half of California 
east-northeastward across most of the Four Corners region and Great Plains, 
much of the Mississippi and Tennessee Valleys, the Southeast, and the 
Mid-Atlantic. The greatest chances (higher than 60 percent) for above normal 
precipitation are indicated for parts of the eastern Gulf Coast region and 
Southeast coast. A modest tilt in the odds towards above normal precipitation 
is depicted from portions of southcentral Alaska eastward through much of 
Southeast Alaska. Modest tilts towards below normal precipitation amounts are 
favored over the Aleutians, interior portions of Mainland Alaska, interior 
portions of the northwestern CONUS, and parts of the Great Lakes region. 
 
Equal chances (EC) are forecast for areas where probabilities for each category 
of seasonal mean temperatures and seasonal accumulated precipitation amounts 
are expected to be similar to climatological probabilities. 
 
BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOKS 
Note: For Graphical Displays of the Forecast Tools Discussed Below See: 
http://www.cpc.ncep.noaa.gov/products/predictions/90day/tools/briefing 
 
CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS 
 
El Niño strengthened over the past month, with sea surface temperature (SST) 
anomalies exceeding +3.0°C in the eastern equatorial Pacific. The latest 
weekly Niño index value for Niño-3.4 was +2.0°C, and for Niño-3 the index 
value was +2.8°C. The equatorial subsurface temperature index (average from 
180°-100°W) remained steady during August, reflecting a deeper-than-average 
thermocline. Subsurface temperature anomalies were significant, reaching 
+10.0°C at depth. Low-level westerly wind anomalies and upper-level easterly 
wind anomalies extended from the western to east-central equatorial Pacific. 
Convection and rainfall were enhanced from the central to eastern Pacific and 
were suppressed over Indonesia. The traditional and equatorial Southern 
Oscillation indices were significantly negative. Collectively, the coupled 
ocean-atmosphere system reflected a strengthening El Niño. 
 
PROGNOSTIC DISCUSSION OF SST FORECASTS 
 
The CPC Official El Niño Southern Oscillation (ENSO) Outlook, which 
synthesizes multiple models from North America and abroad, indicates El Niño 
will continue to strengthen through the end of the year. During the 
October-November-December (OND) 2026 season, there is a 75% chance of a 
historic event that would exceed the strength of previous El Niño events 
dating back to 1950 (+2.5°C or more for a 3-month RONI value). With an event 
of this magnitude, the chances of experiencing impacts consistent with El Niño 
are larger, but they are not guaranteed. In summary, El Niño is strengthening, 
with a greater than 90% chance of a very strong event during the Northern 
Hemisphere fall and winter 2026-27. 
 
PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS 
 
Newer RONI ENSO composites derived from the current and forecast state of ENSO 
were strongly utilized due to the magnitude of this El Niño event. Analogs of 
the "Big Three" El Niño's were also considered in making the temperature 
outlooks throughout the fall and winter. Dynamical model forecasts from the 
North American Multi-Model Ensemble (NMME), the Climate Forecast System version 
2 (CFSv2), and the Copernicus (C3S) multi-model ensemble system were also used 
for the first six leads when they are available, as was the objective, 
historical skill-weighted consolidation and Calibration, Bridging, and Merging 
(CBaM) guidance, that combines both dynamical and statistical forecast 
information. Analysis of antecedent conditions such as extratropical SST 
anomalies and sea ice extent were considered where appropriate. At later leads, 
decadal trends  in temperature and precipitation were increasingly relied upon 
in creating the seasonal outlooks. 
 
PROGNOSTIC DISCUSSION OF OUTLOOKS - OND 2026 TO OND 2027 
 
TEMPERATURE 
 
The seasonal temperature outlooks for this fall and winter rely heavily on the 
high likelihood of a very strong El Niño. In most cas es, the presence of a 
very strong El Niño would overwhelm contributions from climatic modes of mid 
to high-latitude variability, such as the Arctic Oscillation (AO) or North 
Atlantic Oscillation (NAO). There are two factors that make the current 
situation unique. The first factor is the presence of a fairly strong, 
negatively phased Pacific Decadal Oscillation (PDO), with the August PDO index 
value of -1.11 . The "€œBig Three"€ historical El Niño's since 1950 include the 
warm events of 1982-83, 1997-98, and 2015-16, all of which occurred when the 
PDO phase was positive, leading to constructive interference. This time, 
however, the PDO phase is negative and may dampen the typical impacts of a 
strong El Niño in certain areas. The second factor involves the large region 
of warmer-than-normal SSTs that is typically present in the Gulf of Alaska 
during strong El Niños. The current situation shows a significant westward 
shift in these warmer SSTs, which may allow for slightly cooler water to 
influence portions of the U.S. West coast. In addition, even with the 
possibility of one or more cold air outbreaks across the northwestern quarter 
of the Lower 48 states, it is unlikely that this will have much of an impact on 
the average temperature for a 90-day season. 
 
With the above considerations in mind, the October-November-December (OND) 2026 
temperature outlook favors above normal mean temperatures over most of the 
western, northern, and eastern Contiguous U.S. (CONUS). This is based on much 
of the dynamical and statistical temperature guidance, including the hybrid 
CBaM output. Adjustments rendered to the OND outlook made last month include an 
expansion of modest probabilities of above normal temperatures across most of 
the Southeast, which is reasonable given the typical El Niño cool signal 
doesn't usually show up in this region until December. Over the Northern CONUS, 
the 40-50 percent probabilities favoring relative warmth were extended eastward 
across the Great Lakes and Northeast, with October and November warmth also 
supported by longer-term trends . Over the Pacific Northwest coastal region, 
probabilities favoring warmer-than-normal temperatures were tempered a bit in 
response to potential influences from a negative PDO. In Alaska, most of the 
models and tools support above normal temperatures over much of the central and 
eastern Mainland, the North Slope, and Southeast Alaska, with the highest 
probabilities (50-60 percent) favored over Southeast Alaska. A broad area of 
Equal Chances (EC) of above, near, and below normal temperatures is depicted 
from the southern Rockies eastward across the southern Plains and into the 
Lower Mississippi Valley, based on weak and/or conflicting signals . 
 
From late fall to early spring (November-December-January (NDJ 2026-27) to 
February-March-April (FMA 2027), the outlooks showcase a classic El Niño 
signature featuring increased chances of above normal temperatures over many 
areas west of the Rockies, and over northern and central portions of the 
country east of the Rockies. The highest chances (50-60 percent) for above 
normal temperatures are indicated over interior portions of the Northwest and 
along much of the northern tier of states. Over the Southwest, the modest tilt 
towards relative warmth gradually gives way to EC. For much of the Southeast, a 
region of near normal temperatures is introduced during NDJ and continues 
through the FMA season. This reflects competing influences between the cooler 
El Niño signal during winter and milder historical trends . 
 
By March-April-May (MAM 2027), the current El Niño is forecast to weaken 
significantly, possibly becoming ENSO-neutral later in the spring. Anomalous 
warmth is expected to return to the Southeast by this time, with much of the 
East favoring above normal temperatures with the highest chances of 50-60 
percent depicted from the Lower Great Lakes eastward to the Northeast coast. 
Relative warmth is also favored to extend westward across the Dakotas, Northern 
Rockies, and Pacific Northwest. From April-May-June (AMJ 2027) through the 
remaining leads, the temperature outlooks are based primarily on long-term 
historical trends  and feature widespread above normal temperatures. 
 
For Alaska temperatures, widespread above normal temperatures are favored over 
the central and eastern Mainland, Southeast Alaska, and the North Slope for the 
first three leads, OND 2026 through DJF 2026-27. This is supported by most of 
the dynamical and statistical guidance, the hybrid CBaM output, and trends . The 
greatest probabilities are indicated over Southeast Alaska, and range from 
50-60 percent. Relatively warm mean temperatures are favored over the state for 
the remaining leads, with the exception of EC over western portions of Alaska 
during MJJ, JJA, and JAS 2027, in part due to the effects of sea ice and cooler 
SSTs. 
 
PRECIPITATION 
 
El Niño composites highlight a robust wet signal across the southern and 
central CONUS in OND, primarily from the Four Corners region eastward across 
the southern Plains to the Southeast coast. Modest extensions of this wet 
signal extend westward across the southern half of California, northward over 
the Great Plains into portions of South Dakota, and northward along the Eastern 
Seaboard to include the Upper Mid-Atlantic region. Maximum probabilities for 
above normal precipitation range from 60-70 percent over parts of the 
Southeast, which is well supported by a large number of models and tools, and 
is reasonable given the current and predicted strength of El Niño. Two 
relatively modest signals  for below normal precipitation are depicted over the 
interior northwestern CONUS and the Great Lakes region, consistent with 
historical El Niño events and many of the objective tools. 
 
From NDJ 2026-27 through FMA 2027, the precipitation outlooks are heavily based 
on ENSO composites, with adjustments rendered according to dynamical and 
statistical model guidance. The wet signal across the southern and central 
CONUS, and extending northward along the Atlantic coast into New England, is 
the dominant precipitation signal this fall and winter, and is associated in 
large part with the mean position of the subtropical jet stream and the mean 
storm track. Probabilities favoring wetter-than-normal conditions increase 
across California, reaching a maximum of 50-60 percent near the coast during 
DJF, JFM, and FMA. These probabilities may be increased further in the next set 
of seasonal outlooks, to be released in mid-late October, pending reassessment 
of the latest model forecasts. The favored area of above normal precipitation 
is expected to reach as far north as central Oregon, and possibly farther north 
given the intensity of this current El Niño event. Over the southern Plains, 
probabilities for above normal precipitation reach a maximum of 40-50 percent, 
increasing across much of the Gulf and Southeast coasts to a maximum of 70-80 
percent over southern Georgia and northern Florida. The two areas of modestly 
favored below normal precipitation over the interior Northwest and Great Lakes 
region are expected to persist but remain rather weak through FMA 2027. 
 
During March-April-May (MAM) 2027, the El Nino signal is expected to weaken 
considerably with the dominant and contiguous wet signal over the southern and 
central CONUS forecast to split into three separate, and less widespread, 
regions: one over California and the Southwest, another over the Upper 
Midwest/eastern Dakotas, and the third encompassing much of the Gulf and 
Atlantic coasts. The token dry signal favored over the Great Lakes during the 
fall and winter disappears, and the below normal precipitation region over the 
interior Northwest begins to expand in spatial extent from MAM to JJA 2027, 
heavily influenced by decadal trends . In addition, the precipitation anomalies 
typically associated with El Niño are forecast to gradually wane during the 
spring. For the summer and early fall of 2027, long-term precipitation trends  
play a large role in the outlooks. 
 
In Alaska, newer ENSO composites were used for the fall and winter, followed by 
dynamical model output; for subsequent seasons decadal precipitation trends  
formed the basis of the outlooks. In OND 2026, small areas of slightly favored 
below normal precipitation are depicted over portions of the Central Interior 
and the Aleutians, while above normal precipitation is slightly favored from 
the southeastern Alaska Mainland to the northern Panhandle region.  In NDJ, the 
two dry signals  consolidate into one larger one that extends from the 
southwestern Mainland to the Central Interior, and above normal precipitation 
continues over Southeast Alaska, the latter being a common occurrence during 
warm events. By DJF, composites show a widespread dry signal over most of the 
Mainland, which continues through FMA but weakens significantly by MAM 2027. 
The Southeast Alaska wet signal remains throughout these seasons, though waxes 
and wanes in coverage. The precipitation outlooks from AMJ 2027 onward are 
based on longer-term precipitation trends , with the primary and most durable 
signal being above normal precipitation favored over much of the southern coast 
of Alaska. 
 
FORECASTER: Anthony Artusa 
 
The Climatic normals are based on conditions between 1991 and 2020, following 
the World Meterological Organization convention of using the most recent 3 
complete decades as the climatic reference period.  The probability anomalies 
for temperature and precipitation based on these new normals better represent 
shorter term climatic anomalies than the forecasts based on older normals. 
 
For a description of of the standard forecast tools - their skill- and the 
forecast format please see our web page at 
http://www.cpc.ncep.noaa.gov/products/predictions/long_range/tools.html 
(Use Lower Cas e Letters) 
Information on the formation of skill of the CAS forecasts may be found at: 
http://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/US/Outlook/outlook.shtm 
l 
(use lowercase letters) 
Notes - These climate outlooks are intended for use prior to the start of their 
valid period.  Within any given valid period observations and short and medium 
range forecasts should be consulted. 
 
This set of outlooks will be superseded by the issuance of the new set next 
month on Oct 15 2026 
 
 
1991-2020 base period means were implemented effective with the May 20, 2021 
forecast release. 
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