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Prognostic Discussion for Long-Lead Seasonal Outlooks NWS Climate Prediction Center College Park MD 830 AM EDT Thu Jun 19 2025 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS El Niño Southern Oscillation (ENSO)-neutral conditions continue with sea surface temperatures (SSTs) near average over most of the equatorial Pacific Ocean. ENSO-neutral is likely to persist through September (near 70% chance). By the late fall and early winter (November-December-January, NDJ 2025-26), ENSO-neutral is favored but confidence is lower with a 48% chance of ENSO-Neutral and a 41% chance of La Niña. The July-August-September (JAS) Temperature Outlook favors above-normal temperatures throughout the lower 48 states with the highest forecast confidence across the Great Basin and New England. The JAS outlook only slightly leans towards above-normal temperatures for much of the Great Plains and Mississippi Valley. Above-normal temperatures are also favored for eastern and southern Alaska. The JAS Precipitation Outlook depicts elevated above-normal precipitation probabilities for the Mid-Atlantic, Southeast, and Upper Ohio Valley. Below-normal precipitation is more likely across the Northern to Central Great Plains, Northern Rockies, and Pacific Northwest. Above-normal precipitation is favored for central and western Alaska. Areas depicted in white and labeled “Equal-Chances” or “EC” are regions where climate signals are weak, and so there are equal chances for either above-, near- or below-normal seasonal mean temperatures or total precipitation amounts. 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 Weekly observed SSTs in the Niño 3.4 region are average with small positive SST anomalies closer to the South American coast. Since late April, subsurface temperature anomalies (averaged from 180-100W and 0-300 meters) are slightly above-average. From May 20, 2025 to June 14, 2025, negative outgoing longwave radiation (OLR) anomalies (enhanced convection and precipitation) continued over Indonesia and northern Australia. Near average OLR anomalies were present throughout the rest of the equatorial Pacific. Both the low-level (850-hPa) and upper-level (200-hPa) wind anomalies were near average across the central equatorial Pacific. These atmospheric and oceanic conditions reflect ENSO-neutral conditions. The Madden-Julian Oscillation (MJO) has generally remained weak and incoherent during the late spring as other modes of tropical variability (fast-moving Kelvin waves and equatorial Rossby waves) dominate. The GEFS and ECMWF models favor a continued weak MJO heading into July with fast-moving Kelvin waves the primary influence on anomalous tropical rainfall and tropical cyclone development. PROGNOSTIC DISCUSSION OF SST FORECASTS The CPC SST consolidation forecast for Niño 3.4 depicts ENSO-neutral conditions persisting through August-September-October (ASO) as SST anomalies remain between 0 and -0.5 degrees C. Later in the fall and heading into the early winter, dynamical models and statistical tools diverge on the ENSO state. In addition, ensemble spread among the NMME members becomes large at the same time. Most of the International Multimodel Ensemble (C3S) members favor ENSO-neutral conditions persisting through the fall. The CPC ENSO outlook indicates that ENSO-neutral is likely during JAS (near 70 percent chance) but those probabilities decline closer to 50 percent by the fall season. During the 2025-2026 winter (DJF), either ENSO-neutral or La Niña is the most likely outcome. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS The Temperature and Precipitation Outlooks for JAS 2025 were based on dynamical models such as the North American Multi-Model Ensemble (NMME) and the Copernicus (C3S) multi-model ensemble system. A Calibration, Bridging, and Merging (CBaM) version of the NMME was also used in the outlooks. An objective, historical skill-weighted consolidation that includes the NMME along with statistical tools such as the SST-based Constructed Analog and the ENSO-OCN was used through November-December-January (NDJ) 2025-2026. Beyond that time, the consolidation only includes statistical tools. Long-term climate trends were considered for all leads, but were relied upon most during the 2026 spring and summer. PROGNOSTIC DISCUSSION OF OUTLOOKS - JAS 2025 TO JAS 2026 TEMPERATURE The highest forecast confidence for above-normal temperatures (probabilities more than 60 percent) during JAS 2025 is across the Great Basin and New England where there is excellent agreement and consistency among the dynamical models . Although above-normal temperatures are favored throughout the lower 48 states, probabilities are limited (less than a 40 percent chance) across most of the central contiguous U.S. (CONUS). The smaller above-normal temperature probabilities for the Lower Mississippi Valley and Tennessee Valley are consistent with high soil moisture and favored wetness during this three-month period. Above-normal temperatures are most likely across eastern and southern Alaska, while the NMME and nearby negative SST anomalies result in equal chances of below, near, or above-normal temperatures for northwestern Alaska. Compared to the previous month, the NMME depicts lower above-normal temperature probabilities for the northwestern and north-central CONUS from the late summer through the fall. Beginning in August-September-October, EC of below, near, or above-normal temperatures are forecast for parts of the north-central CONUS and the coverage of EC expands in spatial coverage through the fall. Since ENSO-neutral or La Niña is favored during the late fall and 2025-2026 winter, the temperature outlook generally followed those temperature composites along with the consolidation. Elevated below-normal temperature probabilities are forecast for the northwestern CONUS beginning in December-January-February 2025-2026 through February-March-April 2026. Following this, long-term trends became the major factor in the temperature outlook during the 2026 spring and summer. PRECIPITATION During JAS 2025, below-normal precipitation remains the most likely outcome for the Pacific Northwest, Northern Rockies, Northern to Central Great Plains, and parts of the Upper Mississippi Valley. The NMME has maintained this dry signal dating back to February. In addition to the good model consistency, the C3S, CBaM, and consolidation support an increased chance of below-normal precipitation for those areas. One notable change in the NMME from one month ago is the lack of a dry signal across the Southern Great Plains. The JAS outlook now calls for EC of below, near, or above-normal precipitation from southern Kansas southward through Oklahoma and much of Texas. Although above-normal precipitation was favored across the Southwest during JAS in previous outlooks, EC of below, near, or above-normal precipitation are now forecast for this region since the July outlook has EC and there is no dynamical model support for leaning towards the wet side. Based on the NMME, C3S, and consolidation, above-normal precipitation is most likely across the Mid-Atlantic and Southeast. Compared to the JAS outlook released in May, the elevated above-normal precipitation probabilities were expanded west to include the Upper Ohio Valley and Tennessee Valley due to changes in the dynamical model output. The NMME and C3S support an increased chance of above-normal precipitation across the western two-thirds of Alaska for JAS. Similar to JAS, the dry signal among the dynamical models diminished in coverage throughout the central CONUS for August-September-October (ASO) and only a slight lean towards below-normal precipitation (33 to 40 percent chance) is forecast across the Northern to Central Great Plains and Upper Mississippi Valley. A slight lean towards above-normal precipitation was maintained for parts of the Mid-Atlantic and Southeast during ASO and September-October-November (SON) which is consistent with an increased chance of an above-normal Atlantic hurricane season. Also, there is a wet signal in the NMME and C3S during ASO. Since the SST-based Constructed Analog loses the wet signal across the Southwest during ASO and there is no dynamical model support for favoring above-normal precipitation, EC of below, near, or above-normal precipitation are forecast for the Southwest. During November-December-January (NDJ) and December-January-February (DJF) 2025-2026, below-normal precipitation probabilities were slightly increased across the Southeast since the chances for El Niño developing by next winter are only at near 10 percent. EC is forecast for a majority of the forecast domain during the 2026 spring and summer except for an increased chance of below-normal precipitation for parts of the northwestern and north-central CONUS. FORECASTER: Brad Pugh 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 Jul 17 2025 1991-2020 base period means were implemented effective with the May 20, 2021 forecast release. $$
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