417 FXUS05 KWBC 161231 PMD90D Prognostic Discussion for Long-Lead Seasonal Outlooks NWS Climate Prediction Center College Park MD 830 AM EDT Thu Jul 16 2026 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS El Nino has strengthened over the past month and is forecast to intensify through 2026 and continue through early 2027. There is an 81% chance that this event will be very strong during October-December (OND) 2026. The August-September-October (ASO) 2026 Temperature Outlook favors above-normal temperatures for much of the Contiguous United States (CONUS) and Alaska. A broad area of above-normal temperatures covers the West, South, and East, with the highest probabilities of above-normal temperatures over the Northwest, southwestern Texas, and parts of the Southeast. Over Alaska, above-normal temperatures are favored over much of the state, except for the west and north coasts, which are depicted as having equal-chances of above-, near-, and below-normal (EC) temperatures. An area of EC is also indicated over the north-central US extending to the Central Plains. The ASO Precipitation Outlook indicates above-normal precipitation for the Southwest to southern parts of the Northern Rockies and Northern Plains, and into parts of the Central Plains. Above-normal precipitation is also indicated for parts of the Middle Mississippi, western Ohio, and Tennessee Valleys and western Alaska. Precipitation probabilities are generally low and do not exceed 33 to 40% chances, except over parts of Southern California, Nevada, Utah, and western Arizona which reach 40 to 50% chances of above-normal precipitation. Below-normal precipitation is indicated for parts of the Pacific Northwest, parts of the Southern Plains and Lower Mississippi Valley, and parts of the Upper Mississippi Valley and Upper Great Lakes. 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 El Nino Southern Oscillation (ENSO) Alert System Status is an El Nino Advisory, meaning El Nino is present, equatorial SSTs are above-average across the central and eastern Pacific Ocean, and atmospheric circulation anomalies over the equatorial Pacific Ocean are consistent with El Nino. Above-average SST anomalies emerged in the far eastern equatorial Pacific in early February 2026, and have increased across the east-central and eastern Pacific Ocean since mid-April 2026. The latest weekly SST departures in the Nino 1+2 region reached +2.6 deg C above-average. Nino3 SSTs reached +1.7 deg C and Nino 3.4 +1.3 deg C above-average. The atmosphere is responding as typical for El Nino, with suppressed convection over Indonesia and enhanced convection over the central and east-central Pacific. Above-average SST anomalies have persisted near the coast of Southern California, but have weakened in more recent observations. These above-average SSTs contrast with weak below-average SSTs off the coast of Northern California, Oregon, and Washington. During early to mid-June below-average or only weakly above-average SSTs were found in the Gulf and along parts of the East Coast, but above-average SST anomalies began to dominate in early July and have strengthened off the Southeast Coast and around Florida, and along parts of the East Coast. Persistent below-average SSTs surround much of Alaska, with anomalous sea-ice coverage off the northern part of the state. Persistent coastal SST anomalies as well as sea ice, where applicable, may influence seasonal temperatures of adjacent areas. PROGNOSTIC DISCUSSION OF SST FORECASTS The North American Multi-Model Ensemble (NMME) favors intensification of El Nino through the end of 2026, and there is high confidence that El Nino will continue into early 2027. Most models favor a peak in relative SST anomalies in the Nino3.4 region this fall. The Copernicus Climate Change Service (C3S) MME is similar in its prediction of the Nino3.4 anomaly, adding confidence to this forecast. The SST Consolidation forecast for the relative Nino3.4 region increases until fall and winter, with the consolidation reaching just under +2.5 deg C above-average. The chances of a very strong event are 81% in October-November-December (OND) 2026, and drop to 75% in November-December-January (NDJ) 2026-2027, and decrease thereafter. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS Dynamical model forecasts from the NMME, the Climate Forecast System version 2 (CFSv2), and the C3S multi-model ensemble system are used extensively for the first six leads when they are available. The objective, historical skill weighted consolidation and Calibration, Bridging, and Merging (CBaM) guidance, that combines both dynamical and statistical forecast information is also used. A consolidation of dynamical models and statistical tools, including the ENSO-OCN tool, is used for the first six leads. This tool represents the combined influence of ENSO (when active) and decadal timescale trends in temperature and precipitation utilizing the Optimum Climate Normal (OCN). When appropriate, canonical impacts of El Nino based on composite and regression analysis from historical El Nino events are considered, including stratification into strong or very strong events. Local SST anomalies, sea ice, and soil moisture are also considered for early leads when appropriate. Following lead 6, the ENSO-OCN forecast tool is used more extensively. 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. PROGNOSTIC DISCUSSION OF OUTLOOKS - ASO 2026 TO ASO 2027 TEMPERATURE The ASO 2026 Temperature Outlook favors above-normal temperatures for much of Alaska, and the western, southern, and eastern CONUS. A gradient of above-normal probabilities covers much of Mainland Alaska, transitioning from 33 to 40% chances to 50 to 60% chances over the Southeastern Mainland and Southeast. EC is indicated over the Aleutians, and the west and north coasts. The above-normal probabilities are supported by dynamical models including the NMME and C3S, above-average temperature trends, and the potential impacts of El Nino (though we expect these impacts to be weak over Alaska during this season). The area of EC is due to the potential temperature influence from persistent below-average local SSTs and anomalously high sea ice coverage to the north. Over the CONUS, strong model agreement supports above-normal temperatures over the West. The highest confidence in models, and thus probabilities (reaching 50 to 60% chances), is over the Northwest. Probabilities diminish, but remain above-normal, over the Southwest where above-normal precipitation may moderate temperatures slightly. Above-average decadal trends are also high over the West, further supporting the tilt toward above-normal temperatures. Anomalously low soil moisture partially adds to the tilt toward above-average temperatures. A second maxima of above-normal probabilities is depicted over southwestern Texas, owing to consistency amongst dynamical models including NMME, C3S, CBaM, and probability anomaly correlation (PAC) calibrated versions of these models. Similar reasoning, along with above-average local SSTs in the Gulf and around Florida, supports the increased probabilities for above-normal temperatures over parts of the Southeast. Although the NMME and C3S both show stronger probabilities over the Carolinas, statistical tools indicate lower probabilities over that area due to weaker trends and weaker impacts from El Nino. Consequently, probabilities over the Carolinas up to New England are depicted as 40 to 50% chances of above-normal temperatures. The area of EC that covers the Northern Plains, Upper Mississippi Valley, Upper Great Lakes, Central Plains, and Middle Mississippi Valley is due to potential for moderation of temperatures from El Nino and weaker probabilities in this region in NMME and C3S. This temperature pattern continues through September-October-November (SON) 2026 before transitioning to a pattern that is more dominated by above-normal probabilities over the west, north, and east rather than the southern tier, by winter 2026. Temperatures are above-normal over Alaska throughout this period, though with lower probabilities to the North given the cold SSTs and anomalously high sea ice. Overall, these above-normal temperatures are supported by dynamical models and trends, as well indicating the transition of the temperatures to a more El Nino-like teleconnection pattern. Beginning in OND 2026, an area of EC is depicted over parts of the Southwest and Southern Plains, which increases to the southern half of the CONUS (excepting the west) by NDJ 2026-2027. This shift in the pattern is reflective of the El Nino, which is characterized by a warmer northern tier and milder temperatures to the south. 33 to 40% chances of near-normal temperatures are indicated over parts of the Southwest in NDJ 2026-2027 and December-January-February (DJF) 2026-2027, and over parts of the Southeast and Lower Mississippi Valley in DJF 2026-2027. While El Nino can lead to periods of below-normal temperatures over the southern tier, this is often offset by above-average temperature trends, particularly over the Southeast. Therefore, near-normal is favored rather than an area of below-normal temperatures. Above-normal temperatures are indicated over the western and eastern CONUS and Alaska in February-March-April (FMA), with an area of EC across the central CONUS. El Nino impacts can typically be seen through at least FMA, and this outlook mainly incorporates the potential influence of El Nino, which can moderate temperatures over the central CONUS, and above-average temperature trends over the West and East. Spring generally marks the beginning of a less predictable time of year, and trends become the primary driver of these outlooks during late spring, summer, and early fall 2027. Above-normal temperatures gradually increase in spatial coverage over the CONUS from spring to early fall 2027. Meanwhile, EC is favored over northern and western Alaska, with above-normal temperatures favored elsewhere, before shifting back to full coverage of above-normal temperatures by ASO 2027. PRECIPITATION The ASO 2026 Precipitation Outlook favors above-normal precipitation over the western half of mainland Alaska and parts of the Aleutians, and transitions to below-normal precipitation over Southeast Alaska. Over the CONUS, below-normal precipitation is favored over parts of the Pacific Northwest, parts of the Upper Mississippi Valley and Upper Great Lakes, and parts of the Southern Plains and Lower Mississippi Valley. Above-normal precipitation is indicated over the Southwest stretching to the Northern Rockies and Northern and Central Plains, as well as over the Middle Mississippi, western Ohio, and Tennessee Valleys. This pattern is generally consistent with El Nino (though teleconnections are weaker than in winter months), decadal trends in precipitation, and dynamical models. The NMME and C3S forecast generally above-normal precipitation over much of the CONUS. However, given below-average decadal trends, we have moderated these probabilities to EC over parts of the Central Plains and Middle Mississippi Valley. Probabilities are tilted toward below-normal over the Southern Plains and Lower Mississippi Valley, reflecting strong below-average decadal trends and a supporting below-normal signal from El Nino. El Nino teleconnections ramp up through the fall 2026 and winter 2026-2027, and the precipitation pattern over the CONUS becomes more El Nino-like as the Outlooks progress. Over the CONUS, below-normal precipitation stretches from the Northwest into Central Plains by NDJ 2026-2027, before shifting to two centers of probabilities over the Northwest/north central CONUS and Great Lakes through about March-April-May (MAM) 2026-2027. Below-normal precipitation over these regions is juxtaposed with above-normal precipitation over the southern tier, with highest probabilities over parts of the Southeast in winter 2026-2027 when teleconnections are strongest. Typically, we may see below-average precipitation dipping further toward the Gulf States during an El Nino, however, this is more uncertain in the dynamical model guidance. In addition, decadal trends tilt above-average for this region, and thus EC is favored. Through fall into spring, above-normal precipitation over Alaska shifts from the west to the east, and a weak probability of below-normal precipitation is depicted over the central parts of the west during the winter seasons, consistent with El Nino impacts. For seasons past MAM 2026, the influence from decadal trends is increasingly relied upon to create these Outlooks. FORECASTER: Johnna Infanti 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 Case 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 Aug 20 2026 1991-2020 base period means were implemented effective with the May 20, 2021 forecast release. $$