735 FXUS07 KWBC 161231 PMD30D Prognostic Discussion for Monthly Outlook NWS Climate Prediction Center College Park MD 830 AM EDT Thu Oct 16 2025 30-DAY OUTLOOK DISCUSSION FOR NOVEMBER 2025 The November 2025 outlooks are issued against the backdrop of a La Nia Advisory and the potential emergence of an enhanced Madden Julian Oscillation (MJO) signal. La Nia conditions are present and favored to persist through the month of November and beyond. Natural analog composites derived from a nearest neighbor analysis of the past 12 months of equatorial Pacific Sea Surface Temperature (SST) and Upper Ocean Heat anomalies are supportive of anomalous mid-level troughing along the Eastern Seaboard with above normal heights more likely for much of the central and western Contiguous United States (CONUS) and northern Alaska. Meanwhile, the magnitude of the Real-time Multivariate based Madden Julian Oscillation (MJO) index has been weak since early September but is showing signs of emerging in the Indian Ocean. Both the Global Ensemble Forecast System (GEFS) and the European Centre for Medium Range Weather Forecasts (ECMWF) predict this emerging MJO event to strengthen and approach the Western Pacific by the start of November. Composite analysis of Western Pacific MJO events is suggestive of anomalous ridging over much of the western and central CONUS early followed by potential troughing across the Northern Plains later in the month (if the MJO signal continues its eastward propagation). Recent analysis of extratropical indices show that the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO) have been mostly positive in early October while the Pacific North America (PNA) index has largely been negative. All three of these extratropical indices are currently in the process of switching phases to the opposite sign from that observed earlier in the month. Composites derived from analysis of the recent evolution of these extratropical indices favor above normal mid-level heights across the higher latitudes of the Western Hemisphere in November, consistent with the negative phase of both the AO and NAO and ridging over the southeast, suggestive of a return to a negative PNA. Combined natural analog composites derived from the recent evolution of tropical and extratropical indices depict a 500-hPa flow pattern dominated by above normal heights across much of the higher latitudes of the Western Hemisphere and below normal heights farther to the south across the northeastern CONUS during the month of November. Weakly above normal heights are illustrated across the Lower Mississippi Valley and much of the western CONUS. Meanwhile, trends during the last 15 years favor above normal heights across most of Alaska as well as most of the central and eastern CONUS, with the exception of the Northern Tier. SSTs are currently above normal adjacent to the Western and Central Gulf Coast, Southern Florida, the Northeast, California, and much of the south and west coasts of Mainland Alaska. Arctic Sea Ice extent is currently below normal but not at record low levels. Natural analog composites, trends, and dynamical guidance from the Copernicus Climate Change Service (C3S), North American Multi-Model Ensemble (NMME), the Couple Forecast System Version 2 (CFSv2), and the Forecast Consolidation Tool (CON) (which includes both dynamical model input and statistical guidance) form the basis of the November outlooks. The latest CPC Weeks 3-4 Outlooks and associated ensemble guidance from the European Centre for Medium Range Weather Forecasts (ECMWF), Global Ensemble Forecast System (GEFS), and the CFS also contributed. Antecedent conditions such as extratropical SSTs, sea ice extent, and snow cover anomalies were also considered where appropriate. Above normal temperatures are favored for most of the western and central CONUS, with the exception of the Northern Tier. This tilt toward above normal temperatures is consistent with La Nia composites, dynamical model guidance from the NMME, C3S, and CFSv2, as well as the official CPC Weeks 3-4 temperature outlooks. Probabilities of above normal temperatures exceed 50 percent for much of the Southern Plains and Southwest, where dynamical model guidance and CPCs Weeks 3-4 outlooks show the most support. Confidence is much lower across the Northern Tier as the NMME and CFSv2 show little or no above normal temperature signals for the Pacific Northwest and Northern Rockies. Additionally, composites from the predicted enhanced MJO signal in the Western Pacific are suggestive of a potential cold air outbreak across the Northern Plains during the month of November. Combined natural analog composites from the current evolution of tropical and extratropical indices are suggestive of a mean negative AO pattern in November. Composites from a combined negative AO and La Nia state favor colder than normal conditions across the Northern Plains, which are at odds with dynamical model guidance such as the C3S. For these reasons Equal Chances (EC) of above, near, or below normal temperatures are posted for the Northern Tier from the Pacific Northwest, Northern Rockies, Northern Plains, and Upper Mississippi Valley. Uncertainty is also high across the eastern third of the CONUS as La Nia composites depict a weak or even cold signal across parts of the East. Moreover, combined natural analogs from the current evolution of tropical and extratropical drivers are supportive of anomalous troughing, particularly over the Northeast. This reduced confidence is supported by the NMME, which has a weak temperature signal across much of the Eastern Seaboard and from CPCs Weeks 3-4 outlooks, which has EC across much of the Southeast. For these reasons, EC is forecast for most of the Eastern Seaboard, Appalachians, Great Lakes, and parts of the Ohio Valley. A slight tilt toward above normal temperatures are indicated for parts of southern Florida owing largely to observed above normal SSTs in adjacent waters. Despite the anomalous troughing suggested by natural analog composites across the Northeast, a slight tilt toward above normal temperatures is indicated for areas of Northern New England. This modest tilt toward above normal temperatures was posted due to support from recent trends, above normal observed SSTs in the adjacent Atlantic, and the CPC Weeks 3-4 outlooks. Confidence is low across Alaska as forecast guidance is mixed at best. Dynamical model guidance is inconsistent with the NMME offering a weak signal across almost the entire state with a tilt toward cold forecast for inland areas of the northwestern Mainland while the C3S and CFSv2 are more supportive of warmth across most of the state. As a result, the final consolidation of dynamical and statistical guidance does not present much in the way of a coherent pattern across much of the state. A slight tilt toward above normal temperatures is posted for southwestern and northwestern parts of the state, consistent with above normal SSTs in adjacent waters and observed below normal sea ice extent. One of the more confident aspects in the precipitation outlook for the month of November is the prospect of a drier than normal pattern across the Southeast and adjacent areas. The NMME, C3S, and CFSv2, and La Nia composites are all supportive of dryness across the Southeast and much of the Mid Atlantic. As a result, below normal precipitation is favored across much of the East, with the greatest confidence across much of the Southeast. A second area where below normal precipitation is favored is across much of the Southwest and Southern High Plains due to good agreement among dynamical guidance. Below normal precipitation probabilities were kept more modest across the Southwest/Southern High Plains than the Southeast as support from statistical guidance is not as robust. Conversely, above normal precipitation is favored for the Northern Plains and adjacent areas of the Central Plains and Upper Mississippi Valley. These areas have among the strongest above normal precipitation signals in the combined natural analog composites. Additionally the final consolidation shows a wet signal from the Northern High Plains to the Central Plains. The most confident above normal precipitation area (greater than 40 percent chance) corresponds to this signal in the final consolation combined with natural analog composites. The area of favored above normal precipitation extends westward from here to include the Pacific Northwest and Northern California due largely to La Nia Composites. Most of this area of favored above normal precipitation is also consistent with the CPC Weeks 3-4 Outlooks. As was the case with temperature, the precipitation forecast for Alaska is low confidence as the NMME has virtually no signal at all for the entire state. Despite this uncertainty, an area of modestly enhanced probabilities of above normal precipitation was posted for the northwestern Mainland, consistent with the final consolidation. FORECASTER: Scott Handel 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 Nov will be issued on Fri October 31 2025 These outlooks are based on departures from the 1991-2020 base period. $$