303 FXUS06 KWBC 041902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Sun October 04 2026 6-10 DAY OUTLOOK FOR OCT 10 - 14 2026 The 0Z ECMWF, GEFS, and Canadian ensemble model forecasts predict a variable 500-hPa height pattern over the North America region during the 6-10 day period, consistent with a slight evolution of yesterday's manual blend forecast. Today's manual height blend is based on the 0Z ECMWF, GEFS, and Canadian model 500-hPa height forecasts, weighting the ECMWF ensemble mean greater due to recent model skill. Dynamical model forecasts are in greater agreement with each other, relative to yesterday's model runs. An amplified trough is forecast across the Bering Sea related to a recurving tropical cyclone from the Western Pacific. Negative 500-hPa height anomalies extend across the Aleutians and western Mainland Alaska. A ridge and positive 500-hPa height anomalies are now predicted by all ensemble means over the North Pacific to the northeast of the Hawaiian Islands. Models predict a trough and negative 500-hPa height anomalies over the western contiguous United States (CONUS) at the start of the 6-10 day period. This trough is predicted to lift out and progress eastward during the period. Negative 500-hPa height anomalies are predicted over much of the northwestern CONUS in the manual blend. All ensemble mean forecasts predict positive 500-hPa height anomalies and ridging over the eastern half of the CONUS in the 6-10 day period. Overall 500-hPa height anomalies deamplify over the CONUS later in the period. Below normal temperatures are favored for the far western Aleutians, under northerly flow behind the predicted trough. Above normal temperatures are favored for southern and central Mainland Alaska and northern areas of Southeast Alaska, under anomalous southerly flow ahead of the trough. Under transient ridging and positive 500-hPa height anomalies and consistent with reforecast calibrated GEFS and ECMWF temperatures, enhanced probabilities for above normal temperatures are predicted across much of the CONUS, excluding a large area of the northwestern CONUS. Near normal temperatures are favored for the northwestern CONUS, under a transient trough early in the period. Above normal temperatures are favored across most of the Hawaiian Islands, excluding far northwestern islands, consistent with an automated blend of temperature tools. Above normal precipitation is favored for the central and eastern Aleutian Islands, consistent with most dynamical model precipitation tools. Ahead of the amplified trough over the Bering Sea, above normal precipitation is favored across Mainland and Southeast Alaska. Near to below normal precipitation is favored for much of the West Coast, west of the predicted trough axis and consistent with the precipitation consolidation. Most tools favor above normal precipitation for Southern California and the interior West, under a predicted trough and with enhanced moisture flow from the tropical Pacific. Near normal precipitation is favored for parts of the Central and Southern Plains, consistent with calibrated ECMWF and GEFS forecasts and the consolidation. Above normal precipitation is favored across the eastern CONUS, with probabilities exceeding 60 percent for parts of the Southeast, consistent with precipitation anomaly forecasts from the consolidation. Above normal precipitation is favored across Hawaii, consistent with all model precipitation tools. The official 6-10 day 500-hPa height blend consists of 30% of Today's 0z GFS Ensemble Mean centered on Day 8, 50% of Today's 0z European Ensemble Mean centered on Day 8, and 20% of Today's 0z Canadian Ensemble Mean centered on Day 8 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: About average, 3 out of 5, due to good agreement between model forecasts of the large-scale mid-level height pattern, offset by a variable pattern during the period and differences among temperature and precipitation tools in some areas. 8-14 DAY OUTLOOK FOR OCT 12 - 18 2026 During the week-2 period, transient positive 500-hPa height anomalies are predicted over most of the CONUS. A trough and negative 500-hPa height anomalies persist across most of Alaska for the 8-14 day period in most models and the ECMWF ensemble mean in particular. Ridging and positive 500-hPa height anomalies are predicted over the eastern CONUS at the start of week 2, before deamplifying. Positive 500-hPa height anomalies and a ridge progress eastward into the western CONUS from the Pacific during week 2. In the middle of the period, positive 500-hPa height anomalies briefly extend into the southeastern CONUS in GEFS and ECMWF ensemble mean forecasts. The week-2 manual blend of 500-hPa height forecasts shows weak anomalies across most of the CONUS, with slightly larger positive 500-hPa height anomalies over the Pacific Northwest. Below normal temperatures are favored across the Aleutian Islands and the west coast and northwestern Mainland Alaska, under the predicted trough and consistent with most model tools. Above normal temperatures are favored for southeastern Mainland Alaska and Southeast Alaska, under anomalous southwesterly flow and consistent with the consolidation. Above normal temperatures are favored across most of the CONUS under transient positive 500-hPa height anomalies during the period. Probabilities for above normal temperatures are enhanced and exceed 50 percent for parts of the southwestern CONUS, where dynamical model forecasts are consistent. Probabilities favoring above normal temperatures weaken further north over the western CONUS, as a ridge builds over the region only later in the forecast period. Near normal temperatures are favored for much of the northern central CONUS and above normal temperatures are favored for the southern central and eastern CONUS, under positive 500-hPa height anomalies through much of the forecast period and consistent with the consolidation temperature forecast probabilities. Above normal temperatures are favored for most of Hawaii, excluding the far northwestern islands, consistent with the temperature consolidation. Above normal precipitation is favored across the Aleutian Islands in the week-2 period, supported by all dynamical model precipitation tools. With a persistent amplified trough over the region, above normal precipitation continues to be favored across the Mainland and Southeast Alaska. Under rising mid-level heights, as a ridge pushes eastward from the Pacific, below normal precipitation is favored over a substantial area of the West, including northern California, southwestern Oregon, and western Nevada. Above normal precipitation continues to be favored for the Southwest extending into the central and southern Rockies, with the potential for an enhanced moisture flux from an active Eastern Pacific. Above normal precipitation is favored for most of Texas and the eastern half of the CONUS with probabilities exceeding 50 percent for parts of the Southeast, consistent with precipitation anomaly forecasts from the consolidation. Above normal precipitation continues to be favored across Hawaii in week 2, consistent with the precipitation consolidation. The official 8-14 day 500-hPa height blend consists of: 30% of Today's 0z GFS Ensemble Mean centered on Day 11, 50% of Today's 0z European Ensemble Mean centered on Day 11, and 20% of Today's 0z Canadian Ensemble Mean centered on Day 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Below average, 2 out of 5, due increasing disagreement between model forecasts of the large-scale mid-level height pattern during the period, and weak or inconsistent signals in the tools for temperature and precipitation. FORECASTER: D Collins 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 October 15. 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: 20171016 - 20081016 - 20241004 - 20210916 - 20040926 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: 20210920 - 20241003 - 20081017 - 20040925 - 20171017 6-10 DAY OUTLOOK TABLE Outlook for Oct 10 - 14 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N N OREGON N N NRN CALIF A N SRN CALIF A N IDAHO N A NEVADA A N W MONTANA N A E MONTANA N 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 N OKLAHOMA A N N TEXAS A A S TEXAS A A W TEXAS A N 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 N 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 A 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 A 8-14 DAY OUTLOOK TABLE Outlook for Oct 12 - 18 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON A B NRN CALIF A B SRN CALIF A N IDAHO A N NEVADA A N W MONTANA A N E MONTANA N N WYOMING A N UTAH A A ARIZONA A A COLORADO A N NEW MEXICO A A N DAKOTA N N S DAKOTA N N NEBRASKA N N KANSAS A N OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA N A IOWA N 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 A AK N SLOPE B A AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A AK S INT N A AK SO COAST A A AK PNHDL A A 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. $$