046 FXUS07 KWBC 311900 PMD30D Prognostic Discussion for Monthly Outlook NWS Climate Prediction Center College Park MD 300 PM EDT Sun May 31 2026 30-DAY OUTLOOK DISCUSSION FOR JUN 2026 The updated June 2026 Monthly Outlook is based on the latest dynamical model guidance, including CFSv2 forecasts for the month of June, as well as the Weather Prediction Center (WPC) temperature and precipitation forecasts for the first week of the month, the Climate Prediction Center (CPC) 6-10 day and 8-14 day temperature and precipitation outlooks, and the latest CPC Week 3-4 Outlook (valid June 13-26). Dynamical model forecasts from the ECMWF were also consulted for weeks 2 through 4. Transition to an El Nino background state appears under way over the equatorial Pacific and could possibly impact the climate of North America in June. The latest weekly Nino 3.4 index is +0.5 degrees Celsius. Weak El Nino conditions are likely to be present for the three month season centered on June, with a probability exceeding 80 percent. The Madden Julian Oscillation (MJO) convective phase propagated across the Maritime Continent and amplified over the Western Pacific, as it interacted with the emerging El Nino signal. Dynamical model forecasts, including the ECMWF, predict a deamplification of the MJO signal as it propagates eastward out of the Western Pacific. Impacts of tropical variability were primarily considered in the updated June Monthly Outlook through canonical seasonal impacts of the likely El Nino state, in addition to the dynamical model forecasts of tropical impacts on the climate of North America. The updated June temperature outlook favors below normal temperatures for the Alaska Peninsula, the southwestern and western southern coasts of Mainland Alaska, and islands in the southeastern Bering Sea and western Gulf of Alaska, due to negative sea surface temperature (SST) anomalies in adjacent waters and consistent with recent ECMWF dynamical model forecasts for weeks 1 through 4. Above normal temperatures continue to be favored for central and eastern interior Mainland Alaska and Southeast Alaska, consistent with recent CFSv2 forecasts for June, as well as ECMWF model forecasts for the first half of June and week 4. Above normal temperatures continue to be likely across the western contiguous United States (CONUS) from the Pacific coast to the Rocky Mountains, consistent with dynamical model guidance and CPC and WPC outlooks for all timescales. Elevated probabilities of above normal temperatures exceeding 60 percent across much of the northwestern interior are also supported by negative correlations between precipitation and temperature. Above normal temperatures are favored across the northern central and northeastern CONUS in the updated June Monthly Outlook, consistent with WPC temperature forecasts for the first week of June, the CPC forecast for week 2, and the CFSv2 temperature forecast for the month. Equal chances of below, near and above normal temperatures are forecast for most of the southern central and southeastern CONUS, where temperatures are forecast to be near or below normal early in the month and below normal in the latest CPC Week 3-4 Outlook for the southern central CONUS. Above normal temperatures are likely for the southern Florida Peninsula in June, consistent with the CFSv2 forecast and ECMWF model forecasts for weeks 1 through 4. The updated June precipitation outlook favors above normal precipitation for eastern Mainland Alaska, consistent with the CPC Week 2 Outlook and ECMWF forecasts for weeks 3 and 4. Below normal precipitation is favored for far southern Southeast Alaska and most of the northwestern CONUS, consistent with the CFSv2 forecast, model forecasts for early June, and the CPC Week 3-4 Outlook. Above normal precipitation is favored from eastern areas of the Southwest northeastward into parts of the Central Plains, consistent with the CPC Week 2 and Week 3-4 Outlooks, and the WPC precipitation forecast for the first seven days of June. Probabilities are enhanced to exceed 50 percent for parts of New Mexico and West Texas, where predicted precipitation amounts for the first week of the month are near the climatological threshold for above normal precipitation for the entire month. The updated June precipitation outlook favors below normal precipitation for most of the Great Lakes region and northern New York and New England, consistent with model precipitation forecasts for the first week of June and recent CFSv2 precipitation forecasts for the month. Above normal precipitation is favored for most of the Gulf Coast states and the Southeast Atlantic coast, consistent with the CFSv2 precipitation forecast for June and ECMWF forecasts for the first half of the month. ****************************************************************************** ***** Previous mid-month discussion below ***** ****************************************************************************** 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. The next monthly outlook...for Jul ... will be issued on Thu Jun 18 2026 These outlooks are based on departures from the 1991-2020 base period. $$