436 FXUS06 KWBC 271902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Wed May 27 2026 6-10 DAY OUTLOOK FOR JUN 02 - 06 2026 The 0Z ECMWF, GEFS, and Canadian ensemble mean forecasts generally agree on the overall average large-scale circulation pattern over North America for the 6-10 day period, with some differences between models on the evolution of the pattern during the period and in the phase and amplitude of 500-hPa height anomalies. The manual height blend is based on 0Z ECMWF, GEFS, and Canadian model 500-hPa height forecasts, weighting the ECMWF ensemble mean greater due to recent model skill. All models predict positive 500-hPa height anomalies across the Bering Sea, Alaska, and western Canada at the start of the 6-10 day period. A ridge and positive 500-hPa height anomaly center is predicted over eastern Canada and Hudson Bay at the start of the period. A trough and associated negative 500-hPa height anomalies are predicted by all models to progress eastward over the North Pacific into western Canada and the western contiguous United States (CONUS) during the 6-10 day period. Positive 500-hPa height anomalies that extend across much of the western and northern CONUS in model forecasts for day 6 are predicted to persist over the north-central CONUS, while weakening over the western CONUS. A trough and associated negative 500-hPa anomalies predicted over the East on day 6 in all models, quickly deamplify as heights rise. The 0Z ECMWF, GEFS, and Canadian ensemble mean forecasts generally agree on the overall average large-scale circulation pattern over North America for the 6-10 day period, with some differences between models on the evolution of the pattern during the period and in the phase and amplitude of 500-hPa height anomalies. The manual height blend is based on 0Z ECMWF, GEFS, and Canadian model 500-hPa height forecasts, weighting the ECMWF ensemble mean greater due to recent model skill. All models predict positive 500-hPa height anomalies across the Bering Sea, Alaska, and western Canada at the start of the 6-10 day period. A ridge and positive 500-hPa height anomaly center is predicted over eastern Canada and Hudson Bay at the start of the period. A trough and associated negative 500-hPa height anomalies are predicted by all models to progress eastward over the North Pacific into western Canada and the western contiguous United States (CONUS) during the 6-10 day period. Positive 500-hPa height anomalies that extend across much of the western and northern CONUS in model forecasts for day 6 are predicted to persist over the north-central CONUS, while weakening over the western CONUS. A trough and associated negative 500-hPa anomalies predicted over the East on day 6 in all models, quickly deamplify as heights rise. Above normal temperatures are favored across Southeast Alaska and most of Mainland Alaska excluding the North Slope, under positive 500-hPa height anomalies. Above normal temperatures are likely across the western CONUS, the northern and central CONUS, and northern New England and New York, under average positive 500-hPa height anomalies during the 6-10 day period. Below normal temperatures are favored from the Southern Plains across the lower Mississippi Valley and Ohio Valley into much of the Mid-Atlantic and Southeast, excluding the Florida Peninsula, consistent with most dynamical model temperature tools. Above normal temperatures are favored for Hawaii and South Florida, consistent with most temperature tools. With the passage of a predicted surface low, above normal precipitation is favored for the Aleutians, consistent with reforecast calibrated model precipitation forecasts. Below normal precipitation is favored for much of western Mainland Alaska, under predicted positive 500-hPa height anomalies. Above normal precipitation is slightly favored in far northeastern Mainland Alaska and southern Southeast Alaska, consistent with a consensus of model precipitation forecasts. Above normal precipitation is slightly favored for parts of western Washington, ahead of an approaching trough over the North Pacific. Below normal precipitation is favored for parts of Northern California and Nevada, and southern Oregon and Idaho, under a predicted ridge and consistent with a consensus of dynamical model precipitation tools. Below normal precipitation is favored for the Midwest and interior areas of the Northeast, under the predicted ridge. Above normal precipitation is likely for eastern areas of the Southwest, and parts of the Southern and Central Plains, with enhanced southerly moisture flow from the Gulf. Above normal precipitation is also likely for the Gulf Coast region and the Southeast Atlantic Coast, consistent with dynamical model precipitation tools. Above normal precipitation is favored across the Hawaiian Islands, consistent with most dynamical 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, 45% of Today's 0z European Ensemble Mean centered on Day 8, and 25% 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 general agreement among ensemble means on the predicted 500-hPa height pattern, offset by a changing circulation pattern and some differences among model temperature and precipitation tools. 8-14 DAY OUTLOOK FOR JUN 04 - 10 2026 Ensemble mean forecasts for the 8-14 day period from the 0Z ECMWF, GEFS, and Canadian models all predict a similar pattern evolution from the 6-10 day period forecasts, with some differences in the phase and amplitude of anomalies. Negative 500-hPa height anomalies push southward across Alaska in the week-2 period as a trough amplifies over the region. A weak trough progresses eastward into the northwestern CONUS early in the period, followed by a ridge and associated positive 500-hPa height anomalies later in week 2. Weak troughing persists throughout week 2 near the California coast in all model forecasts, while a ridge and positive 500-hPa height anomalies amplify over the central CONUS in the GEFS ensemble mean and over the central and eastern CONUS in the ECMWF and Canadian ensemble means. With a changing mid-level height pattern across the Alaska region, probabilities are weak in the temperature forecast. Below normal temperatures are favored for the eastern Aleutians and western Alaska Peninsula, consistent with most model temperature tools. Below normal temperatures are slightly favored for the North Slope of Alaska, under negative 500-hPa height anomalies in the manual blend. Above normal temperatures are slightly favored for interior Mainland Alaska and Southeast Alaska, consistent with a consensus of dynamical model temperature tools. Under persistent ridging and positive 500-hPa height anomalies, above normal temperatures are likely for most of the CONUS, excluding parts of the Southern Plains and Southeast. Above normal temperatures are favored for southern Florida and below normal temperatures continue to be favored for parts of southern Texas, as in the 6-10 day period, consistent with most dynamical model temperature tools. Near normal temperatures are favored for much of the remainder of Texas and the Southeast, where temperature tools are less consistent. Above normal temperatures are favored for Hawaii, consistent with most dynamical model forecasts. Above normal precipitation is favored across the Aleutians in the 8-14 day period, consistent with most dynamical model precipitation tools. Above normal precipitation is slightly favored for eastern and northern Mainland Alaska, as well as Southeast Alaska, ahead of a predicted amplifying trough during the period. Above normal precipitation is favored for much of the Southwest and Southern Plains in week 2, with potential shortwaves ahead of a predicted trough. Above normal precipitation is favored across much of the Southeast, with probabilities exceeding 50 percent in some areas, with enhanced southerly moisture flow into the region. Above normal precipitation is favored across Hawaii, 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, 45% of Today's 0z European Ensemble Mean centered on Day 11, and 25% 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, with general model agreement on the 500-hPa height pattern forecast, offset by and changing pattern and increasing uncertainty among the temperature and precipitation tools. 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 June 18. 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: 20240507 - 19980508 - 19910530 - 20230529 - 20240601 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: 20240507 - 20060506 - 19910530 - 19980508 - 20250515 6-10 DAY OUTLOOK TABLE Outlook for Jun 02 - 06 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 B NEVADA A B W MONTANA A N E MONTANA A N WYOMING A N UTAH A N ARIZONA A N COLORADO A A NEW MEXICO N A N DAKOTA A N S DAKOTA A N NEBRASKA A A KANSAS N A OKLAHOMA N A N TEXAS B A S TEXAS B A W TEXAS B A MINNESOTA A N IOWA A N MISSOURI N N ARKANSAS B N LOUISIANA B A WISCONSIN A B ILLINOIS N B MISSISSIPPI B A MICHIGAN A B INDIANA N B OHIO N B KENTUCKY B N TENNESSEE B N ALABAMA B A NEW YORK N B VERMONT A B NEW HAMP A N MAINE A N MASS N N CONN N N RHODE IS N N PENN N B NEW JERSEY B N W VIRGINIA B B MARYLAND B N DELAWARE B N VIRGINIA B N N CAROLINA B N S CAROLINA B A GEORGIA B A FL PNHDL B A FL PENIN N A AK N SLOPE N N AK ALEUTIAN N N AK WESTERN A B AK INT BSN A N AK S INT A N AK SO COAST A N AK PNHDL A N 8-14 DAY OUTLOOK TABLE Outlook for Jun 04 - 10 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A A OREGON A N NRN CALIF A N SRN CALIF A N IDAHO A N NEVADA A N W MONTANA A N E MONTANA A N WYOMING A N UTAH A A ARIZONA A A COLORADO A A NEW MEXICO A A N DAKOTA A N S DAKOTA A N NEBRASKA A N KANSAS A N OKLAHOMA A N N TEXAS N A S TEXAS N A W TEXAS N A MINNESOTA A N IOWA A N MISSOURI A N ARKANSAS A N LOUISIANA N A WISCONSIN A N ILLINOIS A N MISSISSIPPI N A MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A A ALABAMA N A NEW YORK A N VERMONT A N NEW HAMP A N MAINE A N MASS A N CONN A N RHODE IS A N PENN A N NEW JERSEY A N W VIRGINIA A N MARYLAND A N DELAWARE A N VIRGINIA A A N CAROLINA N A S CAROLINA N A GEORGIA N A FL PNHDL N A FL PENIN A A AK N SLOPE B A AK ALEUTIAN B A AK WESTERN N N AK INT BSN A A AK S INT A A AK SO COAST N 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. $$