725 FXUS06 KWBC 241902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Mon August 24 2026 6-10 DAY OUTLOOK FOR AUG 30 - SEP 03, 2026 The 0z GEFS, ECMWF, and Canadian ensembles are in good agreement regarding the evolution of the 500-hPa height pattern across North America during the 6-10 day period. Initially, anomalous mid-level troughing is favored across the northeastern Pacific into the West Coast of the CONUS. This feature is forecast to weaken with time, with mid-level ridging shifting eastward from the Aleutians to the Gulf of Alaska. Toward the end of the period, troughing is forecast to dig southward from the Chukchi Sea and northwestern Alaska into southwestern Mainland Alaska and the Aleutians. Despite the transitioning pattern forecast across the north Pacific, the 6-10 day manual height blend depicts below-normal heights over much of Mainland and Southeast Alaska and the northwestern CONUS, with above-normal heights indicated across the Aleutians, generally matching the early- to mid-period pattern. To the east of the Rockies, the large-scale pattern continues to be influenced by broad ridging, with a +180 meter positive height anomaly center situated just to the north of Hudson Bay and +30 meter anomalies extending throughout much of the east-central CONUS. Downstream, weak troughing remains predicted across portions of the northeastern CONUS into the Canadian Maritimes. Near- to above-normal heights are forecast for Hawaii. Probabilities for above-normal temperatures are increased across much of the Southwest, Interior West, central, east-central, and southeastern CONUS, with the highest probabilities (greater than 80 percent) over the Southern Plains. While the ECMWF ensemble and its corresponding reforecast tool support higher probabilities of above-normal temperatures extending through the Northeast, the GEFS and Canadian are on the cooler side, and this is consistent with more troughing, and also aligns with teleconnection analysis on the positive height anomaly center near Hudson Bay. Therefore, near-normal temperatures are favored for much of the Northeast. Troughing initially near the West Coast favors increased chances of below-normal temperatures across the Pacific Northwest into the Central Great Basin and northern and central California with strong support from the reforecast and uncalibrated tools, as well as the analogs. Odds for above-normal temperatures are increased across the Aleutians, with below-normal temperature chances elevated across much of Mainland Alaska, and near-normal temperatures favored for Southeast Alaska due to a slow progression of ridging to the east and height falls across western Alaska later in the period along with more cloud cover and precipitation. Above-normal temperatures are favored for Hawaii consistent with the reforecast consolidation. Troughing across the West Coast favors enhanced onshore flow and subsequent increased chances for above-normal precipitation throughout much of the western half of the CONUS, with odds exceeding 50 percent across the Pacific Northwest. Precipitation signals are weak underneath ridging over the east-central CONUS, with near- to slightly below-normal precipitation favored across portions of the Southern Plains, Middle and Lower Mississippi and Tennessee Valleys, and Southeast. Farther to the north, transient shortwaves or frontal systems propagating overtop the ridge and along the trough axis over the Northeast lead to slightly enhanced chances for above-normal precipitation across the Northern Tier of the CONUS, including the Great Lakes, Ohio Valley, Northeast, and northern Mid-Atlantic. Forecast tools are in good agreement regarding elevated probabilities for above-normal precipitation across much of Alaska tied to increasing troughing and onshore flow. A continued active pattern remains forecast across the eastern and central Pacific tied to El Nino, with chances for above-normal precipitation increased over Hawaii. The official 6-10 day 500-hPa height blend consists of 30% of Today's 0z GFS Ensemble Mean centered on Day 8, 40% 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: Average, 3 out of 5, due to good model agreement regarding the mid-level circulation pattern, offset by weak precipitation signals across the CONUS and uncertainty regarding the extension of above-normal temperatures into the Northeast. 8-14 DAY OUTLOOK FOR SEP 01 - 07 2026 During week-2, positive 500-hPa height anomalies remain forecast across portions of Southeast Alaska and throughout much of Canada, with a +120 meter positive height anomaly center to the north of Hudson Bay in the manual height blend. To the south, a weakening of positive height anomalies is depicted across the CONUS as the mid-level pattern becomes more zonal, with near-normal heights indicated over most of the CONUS in the manual blend. However, ensemble spread is likely contributing to the less amplified outlook, with a large variation in heights across the north Pacific, which leads to higher uncertainty downstream across the CONUS. Weak negative height anomalies are indicated in the week-2 manual blend across much of Mainland Alaska and the Aleutians given greater confidence earlier in the period, with near-normal heights forecast across Hawaii. Probabilities for above-normal temperatures remain elevated across much of the CONUS, with the highest chances (above 70 percent) across the Southern Plains. As in the 6-10 day outlook, there continues to be more uncertainty across the Northeast with the GEFS and Canadian ensembles favoring a cooler outcome than the ECMWF ensemble, resulting in a near-normal temperature forecast. While below-normal temperatures are slightly favored across portions of the Pacific Northwest and Great Basin for the period as a whole, a gradual warming trend is likely as troughing weakens and positive height anomalies expand across Southeast Alaska leading to height rises along the West Coast. Tied with this ridging, along with increased onshore flow, weak probabilities for above-normal temperatures are indicated across Southeast Alaska, with increased probabilities for below-normal temperatures across the remainder of Alaska due to greater influence from troughing. Above-normal temperatures are forecast across Hawaii given continued strong support from the reforecast consolidation tool. The more zonal flow pattern across the CONUS later in week-2 leads to a low confidence precipitation forecast with weak signals for coherent precipitation in the models. Enhanced troughing near the West Coast early in the period favors enhanced chances of above-normal precipitation across much of the Northwest extending into parts of the Plains and Mississippi Valley. There is more uncertainty in the East where the analogs indicate a very dry signal, although the dynamical tools continue to tilt toward enhanced odds of near- to above-normal precipitation. Therefore a large region of near-normal precipitation is depicted across the eastern and south-central CONUS. Reforecast and uncalibrated tools support increased odds of above-normal precipitation across Alaska tied to troughing over the western half of the state and enhanced onshore flow. An active pattern over the eastern and central Pacific tied to El Nino supports enhanced chances for above-normal precipitation across Hawaii. The official 8-14 day 500-hPa height blend consists of: 30% of Today's 0z GFS Ensemble Mean centered on Day 11, 40% 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: Below average, 2 out of 5, despite some agreement on the 500-hPa height pattern early in the period, an emerging zonal flow pattern across the CONUS and weak signals for precipitation lowers confidence. FORECASTER: Thomas Collow 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 September 17. 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: 20240907 - 20250822 - 20220811 - 20170804 - 20240901 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: 20240904 - 20250906 - 20220810 - 20240830 - 20240803 6-10 DAY OUTLOOK TABLE Outlook for Aug 30 - Sep 03, 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B A SRN CALIF A N IDAHO B A NEVADA B N 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 N N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA A A IOWA A A MISSOURI A N ARKANSAS A N LOUISIANA A N WISCONSIN A A ILLINOIS A N MISSISSIPPI A N MICHIGAN A A INDIANA A N OHIO A A KENTUCKY A N TENNESSEE A N ALABAMA A N NEW YORK N A VERMONT N A NEW HAMP N A MAINE N A MASS N A CONN N A RHODE IS N A PENN N A NEW JERSEY N 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 N AK N SLOPE B A AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL N A 8-14 DAY OUTLOOK TABLE Outlook for Sep 01 - 07 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON B A NRN CALIF N N SRN CALIF A N IDAHO N A NEVADA N N W MONTANA N A E MONTANA A A WYOMING A A UTAH A N ARIZONA A N COLORADO A A NEW MEXICO A N N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A N LOUISIANA A N WISCONSIN A A ILLINOIS A N MISSISSIPPI A N MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A N ALABAMA A N NEW YORK N N VERMONT N A NEW HAMP N A MAINE N A MASS N A CONN N A RHODE IS N A PENN A N NEW JERSEY N N W VIRGINIA A N MARYLAND A N DELAWARE A N VIRGINIA A N N CAROLINA A N S CAROLINA A N GEORGIA A N FL PNHDL A N FL PENIN A N AK N SLOPE B A AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A AK S INT B A AK SO COAST B 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. $$