FXUS06 KWBC 312002 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EST Wed December 31 2025 6-10 DAY OUTLOOK FOR JAN 06 - 10 2026 The 0Z ECMWF, GEFS, and Canadian ensemble mean forecasts generally agree on the average large-scale circulation pattern over North America for the 6-10 day period, with uncertainty related to a variable pattern. A near equal weighted manual blend of these three ensemble mean forecasts indicates a large positive 500-hPa height anomaly over the North Pacific and southwestern Alaska. Negative 500-hPa height anomalies are predicted over most of Mainland Alaska in the manual blend. However, the GEFS predicts positive 500-hPa height anomalies across the entire state in the 6-10 day average, while the ECMWF predicts large negative 500-hPa height anomalies over Mainland Alaska for the 6-10 day period. The ECMWF and Canadian ensemble means predict a trough centered over the Southwest around day 6 to quickly deamplify before redeveloping, while the GEFS ensemble mean solution persists a more amplified trough through the period over the western contiguous U.S. (CONUS). Positive 500-hPa height anomalies are predicted over the eastern half of the CONUS for the 6-10 day period by all ensemble mean solutions. Below normal temperatures are favored over northwestern Mainland Alaska and the North Slope, under negative 500-hPa height anomalies early in the period and consistent with calibrated ECMWF temperature forecasts. With uncertainty due to increasing mid-level heights, near-normal temperatures are favored for the remainder of Mainland Alaska and the Alaska Panhandle. Above normal temperatures are favored for the Aleutians under positive 500-hPa height anomalies. Near normal temperatures are favored for most of the west coast of the CONUS and along the Canadian border into the Northern Plains, with decreasing temperatures related to a variable trough during the period. Above normal temperatures are favored for the remainder of the CONUS related to southerly mid-level flow in the West and positive 500-hPa height anomalies in the East. Above normal temperatures are favored for most of Hawaii, consistent with the consolidation of calibrated temperature forecasts. Enhanced mid-level onshore flow into Alaska favors above normal precipitation across the state. Under and ahead of a predicted trough, above normal precipitation is favored from the Pacific coast eastward across much of the CONUS excluding the Gulf and Southeast Atlantic Coasts, with probabilities exceeding 60 percent in some climatologically drier regions of the Southwest. Probabilities for above normal precipitation are enhanced for parts of the Central Plains and the Central Mississippi Valley, as a low pressure system is predicted to develop during the period. Above normal precipitation is favored across Hawaii, supported by the precipitation consolidation of calibrated GEFS and ECMWF forecasts. The official 6-10 day 500-hPa height blend consists of 35% of Today's 0z GFS Ensemble Mean centered on Day 8, 35% of Today's 0z European Ensemble Mean centered on Day 8, and 30% of Today's 0z Canadian Ensemble Mean centered on Day 8 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above average, 4 out of 5, due to overall agreement among ensemble means on the average 500-hPa height pattern, offset by a variable circulation pattern and some differences among temperature and precipitation tools. 8-14 DAY OUTLOOK FOR JAN 08 - 14 2026 Ensemble means predict a transition in the mid-level circulation pattern over and near Alaska during the week-2 period, with increasing mid-level heights over the state. A ridge and associated positive 500-hPa height anomaly are predicted over the Gulf of Alaska and Mainland Alaska in the 8-14 day period manual blend, with greater positive anomalies predicted by the GEFS ensemble mean than the ECMWF. Ensemble mean 500-hPa height forecasts are much more consistent over the CONUS in today's week-2 forecasts relative to yesterday's forecasts. The manual blend predicts a trough and negative 500-hPa height anomalies over most of the western CONUS, excluding the Northwest coast, and a ridge and positive 500-hPa height anomalies over the eastern CONUS. Above normal temperatures are favored for the Aleutians under predominantly positive 500-hPa height anomalies. Above normal temperatures are increasingly favored for most of Mainland Alaska, excluding northern regions, and northern areas of Southeast Alaska, under positive 500-hPa height anomalies. Near normal temperatures are favored for much of the western and northern central CONUS, under a variable and uncertain trough in dynamical model forecasts. Above normal temperatures are slightly favored for Utah, Colorado, and the Four Corners region consistent with the temperature consolidation. Above normal temperatures are favored for the southern central and eastern CONUS in the 8-14 day period, under a predicted ridge and positive 500-hPa height anomalies during most of the period. Above normal temperatures are favored across Hawaii in the 8-14 day period, consistent with the temperature consolidation. Above normal precipitation is favored for the Aleutians and Mainland Alaska, under increasingly southwesterly flow in the week-2 period. Below normal precipitation is slightly favored for parts of the Pacific Northwest under rising mid-level heights. Above normal precipitation is favored from Southern California, the Great Basin, and the Northern Rockies eastward to the Atlantic Coast, excluding only the Florida Peninsula, consistent with most dynamical model forecasts and ahead of the predicted trough. Probabilities exceed 50 percent for the Four Corners region, the Central Mississippi Valley, and the Ohio Valley, consistent with the consolidation. Above normal precipitation is likely for Hawaii, consistent with the consolidation. The official 8-14 day 500-hPa height blend consists of: 35% of Today's 0z GFS Ensemble Mean centered on Day 11, 35% of Today's 0z European Ensemble Mean centered on Day 11, and 30% of Today's 0z Canadian Ensemble Mean centered on Day 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About average, 3 out of 5, due to model agreement on the overall circulation pattern forecast, offset by a changing pattern, as well as differences among the model temperature and precipitation tools. FORECASTER: Notes: The notation for the categorical forecast indicated on the maps is the same as that in the tables: A-above N-near normal B-below The temperature map shows regions with > 33% chance of being warmer (orange, "A"), colder (blue, "B"), or close to (gray, "N") normal. Labels on the shaded lines give the probability (> 33%) of the more likely category (B or A). Probability of N is always < 40%. The precipitation map shows regions with > 33% chance of being wetter (green, "A"), drier (tan, "B"), or close to (gray, "N") normal. Labels on the shaded lines give the probability (> 33%) of the more likely category (B or A). Probability of N is always < 40%. In the southwest and other climatologically dry regions - there will be a greater than 33.3% chance of no precipitation and occasionally even a normal (i.e. Median) value of zero - especially during the dry seasons. In such cases a forecast of near normal is effectively a forecast of little or no precipitation. The climate prediction center uses 1991-2020 base period means as reference in the climate outlooks. The next set of long-lead monthly and seasonal outlooks will be released on 2025-12-31. Analogs to the 5 day mean observed pattern centered 3 days ago (D-3) for the region from 20N to 70N latitude and 175E to 60W longitude include the 5 day periods centered on the following dates: 20081230 - 20221215 - 20101216 - 20000114 - 20211226 Analogs to the 7 day mean observed pattern centered 4 days ago (D-4) for the region from 20N to 70N latitude and 175E to 60W longitude include the 7 day periods centered on the following dates: 20211222 - 20041227 - 20000113 - 20211217 - 20221211 6-10 DAY OUTLOOK TABLE Outlook for Jan 06 - 10 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON N A NRN CALIF N A SRN CALIF N A IDAHO A A NEVADA A A W MONTANA N A E MONTANA A A WYOMING A A UTAH A A ARIZONA A A COLORADO A A NEW MEXICO A A N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN A A ILLINOIS A A MISSISSIPPI A A MICHIGAN A A INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK A A VERMONT A A NEW HAMP A A MAINE A A MASS A A CONN A A RHODE IS A A PENN A A NEW JERSEY A A W VIRGINIA A A MARYLAND A A DELAWARE A A VIRGINIA A A N CAROLINA A N S CAROLINA A N GEORGIA A N FL PNHDL A N FL PENIN A B AK N SLOPE B A AK ALEUTIAN A A AK WESTERN N A AK INT BSN N A AK S INT N A AK SO COAST N A AK PNHDL N A 8-14 DAY OUTLOOK TABLE Outlook for Jan 08 - 14 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N B OREGON N N NRN CALIF N N SRN CALIF N N IDAHO N N NEVADA N N W MONTANA N A E MONTANA N A WYOMING N A UTAH A A ARIZONA N A COLORADO A A NEW MEXICO A A N DAKOTA N A S DAKOTA N A NEBRASKA N A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA N A IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN N A ILLINOIS A A MISSISSIPPI A A MICHIGAN A A INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK A A VERMONT A A NEW HAMP A A MAINE A A MASS A A CONN A A RHODE IS A A PENN A A NEW JERSEY A A W VIRGINIA A A MARYLAND A A DELAWARE A A VIRGINIA A A N CAROLINA A A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A N AK N SLOPE N A AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A AK S INT A A AK SO COAST A A AK PNHDL N N LEGEND TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN A - ABOVE N - NEAR NORMAL A - ABOVE N - NEAR MEDIAN B - BELOW B - BELOW THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE. FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS PMDMRD. $$