Prognostic Discussion for Long-Lead Seasonal Outlooks 
NWS Climate Prediction Center College Park MD 
830 AM EDT Thu Apr 17 2025 
 
SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS 
 
At present, the El Niño Southern Oscillation (ENSO) is neutral, after La Niña 
conditions diminished through last month. ENSO-neutral conditions are highly 
likely for the first lead of the CPC Seasonal Outlook, with the CPC consensus 
ENSO outlook indicating greater than an 80 percent probability. ENSO-neutral 
conditions are expected to persist into summer with probabilities exceeding 50 
percent. 
 
The May-June-July (MJJ) 2025 temperature outlook favors above-normal 
temperatures for southern and eastern regions of Alaska. Above-normal 
temperatures are likely for the western Contiguous U.S. (CONUS), across the 
Southern Plains into the Gulf Coast region, and for the Northeast. Above-normal 
temperatures are favored with weaker probabilities for much of the Central 
Plains, the Central Mississippi Valley, the central Great Lakes region, and the 
Ohio and Tennessee Valleys, with probabilities for above-normal temperatures 
below 50 percent. Equal Chances (EC) of below, near, and above-normal seasonal 
mean temperatures are indicated for parts of the northern central CONUS. 
 
The MJJ 2025 precipitation outlook slightly favors above-normal precipitation 
across most of Alaska, excluding the Aleutians, parts of the southwestern 
Mainland, and Southeast Alaska. The outlook favors below-normal precipitation 
across most of the West from the Pacific Coast to most of the Great Plains. 
Above-normal precipitation is slightly favored for a small area of Arizona and 
New Mexico near the Mexico border, while EC is indicated for most of the region 
from Southern California to western New Mexico and Texas. Above-normal 
precipitation is favored for the central and eastern Gulf Coast northward up 
the central Atlantic coast into the northeastern CONUS. For the remaining areas 
of the central CONUS, where possible seasonal total precipitation amounts are 
predicted to be similar to climatological probabilities, EC is forecast. 
 
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 
 
The most recent seasonal mean Niño 3.4 index value for January through March is 
-0.4 degrees Celsius (C), and the most recent weekly mean sea surface 
temperature (SST) anomaly for the Niño 3.4 region is -0.1 C, as the equatorial 
Pacific is warming in recent weeks. A small reservoir of colder than average 
ocean temperatures below the surface remains near the Date Line at a depth of 
50 to 200 meters. However, subsurface negative temperature anomalies present 
several weeks ago in the Eastern Pacific have mostly disappeared. Positive SST 
anomalies persist near the equator in the Western Pacific with anomalies 
exceeding +2.0 degrees C at depths of 100 to 200 meters. Outgoing longwave 
radiation (OLR) anomalies are negative, indicating suppressed convection, near 
the Date Line. Low-level (850-hPa) wind anomalies remain easterly over the 
west-central tropical Pacific Ocean. Upper-level (200-hPa) wind anomalies are 
westerly over the central equatorial Pacific. Most recent, short term, 
atmospheric and oceanic anomalies are indicative of ENSO-neutral conditions. 
Negative soil moisture anomalies are observed across much of the Southwest, as 
well as the Central and Northern Plains. A constructed analog (CA) statistical 
forecast for the MJJ season from the present soil moisture anomaly pattern 
predicts associated positive temperature anomalies in the West and weaker 
negative temperature anomalies over the Central Mississippi Valley. Enhanced 
precipitation relative to climatology is predicted for parts of the Southwest 
Monsoon region in Arizona and New Mexico, while persistent negative 
precipitation anomalies are predicted over the northwestern and north-central 
CONUS. Enhanced precipitation over much of the eastern CONUS is associated with 
the CA of soil moisture. 
 
Negative SST anomalies, likely related to residual sea ice, are observed near 
the west coast of Mainland Alaska, while positive SST anomalies are present 
around the Alaska Peninsula and along the south and southeast coasts. Positive 
SST anomalies are observed near the Pacific coast of the CONUS. Negative SST 
anomalies are presently near the coast of the Mid-Atlantic. Positive SST 
anomalies are observed near the Gulf Coast. Persistent coastal SST anomalies 
may influence seasonal temperatures of adjacent areas. 
 
PROGNOSTIC DISCUSSION OF SST FORECASTS 
 
SST forecasts from most North American Multi-Model Ensemble (NMME) dynamical 
models and from most statistical models, including the CPC Constructed Analog 
(CA) and Canonical Correlation Analysis (CCA) predict near average SST 
anomalies for the Niño 3.4 region in the the MJJ season. A consolidation of 
dynamical and statistical forecasts for the Niño 3.4 region predicts 
continuation of ENSO-neutral SST anomalies between negative and positive 0.5 
degrees C through the boreal summer seasons. The CA and CCA predict 
increasingly negative Niño 3.4 SST anomalies for next autumn and winter, 
associated with a possible La Niña. However, the uncertainty in Niño 3.4 SST 
forecasts at longer leads is fairly large for these seasons. The emergence of 
El Niño conditions this year is considered less likely than La Niña or 
ENSO-neutral conditions. 
 
PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS 
 
The seasonal temperature and precipitation outlooks are based primarily on 
forecast tools derived from the NMME, including calibrated versions, such as 
the Probability Anomaly Correlation (PAC) and the Calibration, Bridging and 
Merging (CBaM), which calibrates the dynamical model forecast using Bayesian 
Joint Probability (BJP) models, as well as generating statistical or “bridging” 
BJP models of temperature and precipitation from dynamical model Niño 3.4 
anomaly forecast predictors. An ENSO-OCN forecast tool is used to represent the 
combined influence of the El Niño Southern Oscillation (ENSO) and decadal 
timescale trends  in temperature and precipitation, using the Optimum Climate 
Normal (OCN). The presence and forecast of ongoing ENSO-neutral conditions 
means that longer timescale decadal variability in temperature and 
precipitation are generally the largest predictable signal for the seasonal 
forecasts. Decadal variability and trends  are determined from the OCN, 
representing the difference between the most recent 15-year period average 
seasonal temperature or precipitation and the average for the climatology 
period, from 1991-2020. Outlooks for the cold seasons, from 
October-November-December (OND) through March-April-May (MAM), are in part 
influenced by the greater likelihood of a La Niña relative to the likelihood of 
an El Niño. A consolidation of multiple statistical and dynamical forecast 
tools that utilizes PAC calibration is used throughout the outlooks from MJJ 
2025 to MJJ 2026. 
 
PROGNOSTIC DISCUSSION OF OUTLOOKS - MJJ 2025 TO MJJ 2026 
 
TEMPERATURE 
 
The MJJ 2025 seasonal temperature outlook favors above-normal temperatures for 
much of Alaska, excluding the west coast of Mainland Alaska where EC is 
indicated, due in part to adjacent negative SST anomalies. Above-normal 
temperatures continue to be favored through the August-September-October (ASO) 
season for Mainland and Southeast Alaska, supported primarily by NMME 
forecasts. Areas where EC is indicated expand in later leads where signals  are 
weaker in forecast tools, such as the ENSO-OCN. Decadal variability leads to a 
signal for above-normal temperatures for parts of the west and north coasts 
through the coming year. 
 
Above-normal temperatures are favored across nearly all of the CONUS through 
the first five seasonal leads, with higher probabilities for the West, the 
southern CONUS, and the Northeastern CONUS, supported by dynamical model 
forecasts and the temperature consolidation. An area of EC is indicated for the 
north-central CONUS in the MJJ 2025 season, where statistical tools and 
calibrated dynamical models  indicate lower chances of above-normal 
temperatures. Weaker probabilities favoring above-normal temperatures are also 
forecast for the Central Mississippi and Ohio Valleys, related to statistical 
guidance such as the soil moisture CA tool. Decadal variability and forecast 
guidance from the ENSO-OCN tool leads to favored above-normal temperatures 
across the CONUS for June-July-August (JJA) 2025 through ASO 2025. An area of 
EC emerges and expands across much of the north-central and northwestern CONUS 
in the next several leads into the start of winter, related to the relative 
greater chances of ENSO-neutral and La Niña conditions compared to El Niño 
conditions. During the upcoming winter, December-January-February (DJF) through 
early spring of 2026, February-March-April (FMA), slightly enhanced 
probabilities for below-normal temperatures appear in parts of the Northwest. 
The longest lead seasonal outlooks through MJJ 2026 are based primarily on 
signals due to decadal variability as shown by the OCN tool. 
 
PRECIPITATION 
 
The MJJ though ASO 2025 precipitation outlooks favor above-normal precipitation 
for most of Mainland Alaska, supported primarily by dynamical model forecasts 
from the NMME and by decadal trends  for most areas. Signals  for above-normal 
precipitation are more confined to western and northern regions of Alaska for 
the seasons that follow, relying on the ENSO-OCN tool and primarily resulting 
from decadal trends . Although greater precipitation is historically associated 
with cooler temperatures in many areas, decadal trends  tend to favor both 
above-normal temperatures and above-normal precipitation, driven in part by 
anomalous decreasing sea ice and warmer ocean water temperatures. 
 
Below-normal precipitation is favored across most of the western and central 
CONUS, excluding the southwestern CONUS, in the MJJ and JJA 2025 seasons, 
supported by both dynamical and statistical model forecasts and the 
consolidation. The area of favored below-normal precipitation is more confined 
to the northern central CONUS in longer leads through 
September-October-November (SON) 2025, as the signal decreases in forecast 
tools. A small area of enhanced probabilities for above-normal precipitation 
emerges in the Southwest in the outlook for MJJ 2025 and expands and persists 
through the ASO 2025 season. The likelihood of an enhanced Southwest Monsoon is 
increased due to current negative soil moisture anomalies and predicted 
above-normal temperatures. Above-normal precipitation is favored for parts of 
the Gulf and Atlantic Coasts for MJJ through SON 2025, supported primarily by 
the consolidation of dynamical and statistical models. Enhanced seasonal 
precipitation is in part associated with above average tropical Atlantic SSTs 
and predicted ENSO-neutral conditions. 
 
In the late autumn of 2025 through early spring of 2026, precipitation signals  
are associated with decadal trends , decreased chances of El Niño conditions, 
and favored ENSO-neutral or La Niña conditions. This leads to enhanced 
probabilities for below-normal precipitation for parts of the eastern Gulf and 
Atlantic Coasts from NDJ 2025 through FMA 2026 and for parts of the Southwest 
near the Mexico border from DJF through MAM 2026. Probabilities for 
above-normal precipitation are enhanced for parts of the Northern Rockies and 
northwestern CONUS from NDJ 2025 though FMA 2026 and for parts of the Midwest 
from DJF through FMA 2026. At the two longest leads, the seasonal outlooks 
favor below normal precipitation for parts of the northwestern CONUS, entirely 
due to reliable signals  from decadal trends . EC is indicated for remaining 
areas of the CONUS and Alaska, where signals  are weak. 
 
FORECASTER: Dan Collins 
 
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 May 15 2025 
 
 
1991-2020 base period means were implemented effective with the May 20, 2021 
forecast release. 
$$