825 FXUS07 KWBC 211231 PMD30D Prognostic Discussion for Monthly Outlook NWS Climate Prediction Center College Park MD 830 AM EDT Thu May 21 2026 30-DAY OUTLOOK DISCUSSION FOR JUN 2026 The June 2026 Monthly Outlook was made with El Nino conditions expected to develop by this summer. The most recent weekly Nino 3.4 sea surface temperature (SST) anomaly is about +0.5 degrees Celsius, corresponding to the threshold between ENSO-neutral and El Nino. Positive SST anomalies in the central and eastern equatorial Pacific Ocean are greater than in the Nino 3.4 region. Outgoing longwave radiation (OLR) anomalies were positive over the far western Pacific Ocean, associated with suppressed convection and precipitation over parts of the Maritime Continent. Negative OLR anomalies, indicating enhanced convection and precipitation, were present near the International Date Line to the north of the equator, consistent with developing El Nino conditions. Low-level (850-hPa) easterly trade winds were near average across the equatorial Pacific. Upper-level (200-hPa) wind anomalies were westerly over the central and eastern equatorial Pacific Ocean in recent weeks. Positive subsurface ocean temperature anomalies increased in magnitude near the surface in the central and eastern equatorial Pacific Ocean, increasing the likelihood and potential strength of an El Nino. Dynamical model forecasts and the CPC El Nino Southern Oscillation (ENSO) Outlook predict El Nino conditions are likely to be weak for the May-June-July season with a probability slightly greater than 70 percent. El Nino conditions are most likely to strengthen in the summer and autumn seasons. Although potential El Nino conditions are likely to be weak and not impact the predictability of the June climate outlook, subseasonal forcing and tropical-extratropical teleconnections may impact the outlook. The Madden Julian Oscillation (MJO) has begun to propagate with enhanced convection currently over the eastern Indian Ocean. Dynamical models, including the ECMWF, predict the propagation of the MJO signal eastward into and across the Western Pacific in early June. The MJO in this phase enhances the chances of cooler conditions over the east-central contiguous United States (CONUS) in early June extending into the Northeast with time. The combined influence of the MJO, the current state of ENSO, and decadal trends were considered in the June climate outlook, using a multivariate linear regression (MLR) statistical model. The June temperature and precipitation outlooks were based primarily on dynamical model and statistical model forecasts. Dynamical model forecasts for the month of June are from the North America Multimodel Ensemble (NMME) and the International Multimodel Ensemble (IMME). In addition to the NMME, a consolidation of model forecasts was utilized, which includes the following statistical tools: the Canonical Correlation Analysis (CCA), the Constructed Analog (CA), and an ENSO OCN tool, that combines the impact of ENSO, based on the CPC SST consolidation predicted median Nino 3.4 SST anomaly, with the Optimum Climate Normal (OCN) to represent decadal trends. Daily initialized forecasts from the Climate Forecast System (CFSv2) dynamical model for the month of June and the most recent ECMWF dynamical model forecasts for the week 3-4 period that is valid for June 2-15 were also considered. Recent boundary conditions, including coastal SSTs and soil moisture anomalies, were additional factors considered in the outlook. The June outlook favors below normal temperatures for the Alaska Peninsula, coastal southwestern Mainland Alaska, and islands in the southeastern Bering Sea, due to negative SST anomalies in the adjacent waters and consistent with dynamical model forecasts from the IMME and CFSv2. Above normal temperatures are favored for most of the remainder of Mainland Alaska and for Southeast Alaska, consistent with dynamical model forecasts from the NMME, IMME and CFSv2, as well as the combined impacts of developing El Nino conditions and the predicted propagation of the MJO into the Western Pacific. Above normal temperatures are favored across the western CONUS from the Pacific coast to the Rocky Mountains and High Plains, across the Central Plains and much of the Southern Plains, into the Central and Lower Mississippi Valley, the Ohio Valley, Mid-Atlantic, and Southeast. Probabilities exceed 60 percent over much of the northwestern CONUS, consistent with recent temperature forecasts from the CFSv2, the consolidation, and decadal trends. Probabilities for above normal temperatures for this region are also enhanced by the correlation between predicted below normal precipitation and above normal temperatures. Probabilities favoring above normal temperatures exceed 50 percent over the Southeast Atlantic coast, consistent with most dynamical model forecasts for June and ECMWF and MLR forecasts for the first half of the month. Equal chances of below, near, and above normal temperatures are forecast for the north-central and northeastern CONUS, due to uncertainty in temperature forecast tools for the first half of June and low predictability as indicated by the calibrated NMME forecasts. The June outlook favors above normal precipitation for northwestern Mainland Alaska, consistent with NMME and IMME anomaly forecasts, the consolidation of dynamical and statistical model precipitation forecasts, and decadal trends. Below normal precipitation is favored for Southeast Alaska, consistent with dynamical model forecasts for June and the MLR and ECMWF forecasts for early June. Below normal precipitation is favored over much of the northwestern CONUS from the Pacific Northwest to the northern Rockies, consistent with the CFSv2 forecast for June, the ECMWF forecast for the first half of the month, and decadal trends. Above normal precipitation is favored for much of the Southwest, central Rockies, and southern High Plains, as well as for much of the Southeast, consistent with NMME, IMME, and CFSv2 dynamical model forecasts for June, as well as ECMWF forecasts for the first half of June. Equal chances of below, near, and above normal precipitation is indicated for the remainder of the CONUS, where there is greater variability among precipitation forecast tools. FORECASTER: Dan Collins The climatic normals are based on conditions between 1991 and 2020, following the World Meteorological Organization convention of using the most recent 3 complete decades as the climate 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. An updated monthly outlook... for Jun will be issued on Sun May 31 2026 These outlooks are based on departures from the 1991-2020 base period. $$