929 FXUS06 KWBC 201912 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Mon April 20 2026 6-10 DAY OUTLOOK FOR APR 26 - 30 2026 The 0Z ECMWF, GEFS and Canadian ensemble mean forecasts agree on the overall average large-scale circulation pattern over North America for the 6-10 day period, as well as underlying variations through the period. The manual height blend of 500-hPa height forecasts is based on 0Z ensemble means, weighting the ECMWF model greater due to recent model skill. All ensemble means predict an amplified trough over the Aleutians at the start of the 6-10 day period, that deamplifies over time. A ridge and associated positive 500-hPa height anomalies are predicted over the northeastern Pacific Ocean extending into Southeast Alaska and eastern Mainland Alaska. The ECMWF ensemble mean predicts slightly larger positive 500-hPa height anomalies over the northwestern contiguous United States (CONUS) relative to the GEFS ensemble mean. A trough and associated negative 500-hPa height anomalies extend from the southwestern to the northern central CONUS at the start of the period in all ensemble means. During the period, the trough deamplifies somewhat over Southern California and the Southwest, while the northern extension progresses eastward into the northeastern CONUS. A ridge and positive 500-hPa height anomalies are predicted along the Gulf Coast in the ECMWF ensemble mean forecast, and over the western Gulf Coast in the manual blend. Below normal temperatures are favored for the western Aleutians, under anomalous northerly flow behind a predicted trough. Above normal temperatures are favored for most Mainland Alaska, excluding the south coast under southerly mid-level flow, and for Southeast Alaska, under positive 500-hPa height anomalies. Above normal temperatures are favored for most of the Pacific Northwest, under a predicted ridge. Below normal temperatures are favored for parts of the Southwest across the Central Rockies, and are likely for much of the northern central CONUS, under a predicted trough early in the period. Above normal temperatures are likely from most of Texas across the Southeast, the southern Ohio Valley, and parts of the Mid-Atlantic, under weak ridging and consistent with the consolidation of calibrated ECMWF and GEFS temperature forecasts. Above normal temperatures are favored for far northern areas of the Northeast, under positive 500-hPa height anomalies early in the period. Above normal temperatures are likely for Hawaii, with positive sea surface temperature anomalies in the vicinity. Above normal precipitation is favored for the Aleutian Islands and Mainland Alaska, under and ahead of a predicted trough. Below normal precipitation is favored for southern areas of Southeast Alaska, consistent with most precipitation tools. Below normal precipitation is slightly favored for parts of northwestern Oregon and western Washington, under a predicted ridge. Above normal precipitation is favored from California eastward across most of the CONUS ahead of predicted troughs over Southern California and the northern central CONUS, excluding much of the northern tier from the Pacific Northwest to the western Great Lakes. Probabilities for above normal precipitation exceed 50 percent from central California into parts of the Four Corners, although predicted precipitation anomalies are relatively small. Probabilities favoring above normal precipitation exceed 50 percent for the Lower Mississippi Valley, consistent with the precipitation consolidation. Above normal precipitation is favored for Hawaii, consistent with the precipitation consolidation. 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 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 APR 28 - MAY 04, 2026 Ensemble mean forecasts for the 8-14 day period from the 0Z ECMWF, GEFS, and Canadian models predict some persistent large-scale features from the 6-10 day period forecasts, along with weakening of anomalies and some changes in the pattern over the CONUS. A trough and negative 500-hPa height anomalies persist but deamplify somewhat over the Aleuitians. A ridge persists into the week-2 period over eastern Mainland Alaska, Southeast Alaska, and parts of the Pacific Northwest, while positive 500-hPa height anomalies weaken. With increasing uncertainty and differences among model ensemble means, weak troughing is present over California and parts of the Southwest in the manual blend for week 2. A trough and negative 500-hPa height anomalies are predicted from the Upper Mississippi Valley across the Northeast and Mid-Atlantic, in dynamical model forecasts. Above normal temperatures are favored for central and northern Mainland Alaska, as well as most of Southeast Alaska, under a predicted ridge and consistent with the temperature consolidation. Above normal temperatures are favored for the Pacific Northwest, Northern Rockies, and the California coast, under rising mid-level heights and consistent with calibrated ECMWF temperature forecasts. Below normal temperatures are favored for the Central and Northern Plains eastward across the Midwest to the Mid-Atlantic and most of the Northeast, excluding northern Maine, under a predicted trough. Above normal temperatures are favored for southern Texas and the Gulf Coast, consistent with the temperature consolidation. Above normal temperatures are likely for Hawaii, surrounded by positive sea surface temperature anomalies. Above normal precipitation is favored for the Aleutians and Mainland Alaska in the 8-14 day period, under and ahead of the predicted trough. Below normal precipitation is favored for southern areas of Southeast Alaska, consistent with calibrated ECMWF model precipitation forecasts. Ahead of predicted troughing, above normal precipitation continues to be favored into the week-2 period across most of the western CONUS, excluding parts of the Pacific Northwest. Enhanced probabilities for above normal precipitation extend across most of the Central and Southern Plains into the Southeast, and northward through the Mid-Atlantic coast into the Northeast, consistent with the precipitation consolidation. Above normal precipitation is favored for 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: Below average, 2 out of 5, with model agreement on the 500-hPa height pattern forecast, offset by weaker anomalies in the manual blend of mid-level height forecasts and 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 May 21. 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: 20180502 - 20210331 - 20040417 - 20020416 - 20090425 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: 20210330 - 20180502 - 20020417 - 20040417 - 20030401 6-10 DAY OUTLOOK TABLE Outlook for Apr 26 - 30 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON N N NRN CALIF N A SRN CALIF B A IDAHO N A NEVADA B A W MONTANA B N E MONTANA B N WYOMING B A UTAH B A ARIZONA B A COLORADO B A NEW MEXICO N A N DAKOTA B N S DAKOTA B N NEBRASKA B A KANSAS B A OKLAHOMA N A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA B N IOWA B A MISSOURI N A ARKANSAS A A LOUISIANA A A WISCONSIN B N ILLINOIS N A MISSISSIPPI A A MICHIGAN N A INDIANA N A OHIO N A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK N A VERMONT N A NEW HAMP N A MAINE A A MASS N A CONN N A RHODE IS N A PENN N A NEW JERSEY N A W VIRGINIA A A MARYLAND N A DELAWARE N 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 A A AK ALEUTIAN N A AK WESTERN A A AK INT BSN A A AK S INT N A AK SO COAST N A AK PNHDL A B 8-14 DAY OUTLOOK TABLE Outlook for Apr 28 - May 04, 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON A N NRN CALIF A A SRN CALIF N A IDAHO A A NEVADA N A W MONTANA A A E MONTANA B N WYOMING N A UTAH N A ARIZONA N A COLORADO N A NEW MEXICO N A N DAKOTA B N S DAKOTA B N NEBRASKA B A KANSAS B A OKLAHOMA B A N TEXAS N A S TEXAS A A W TEXAS N A MINNESOTA B N IOWA B N MISSOURI B N ARKANSAS N A LOUISIANA A A WISCONSIN B N ILLINOIS B N MISSISSIPPI N A MICHIGAN B N INDIANA B N OHIO B N KENTUCKY B N TENNESSEE N A ALABAMA A A NEW YORK B A VERMONT B A NEW HAMP B A MAINE N A MASS B A CONN B A RHODE IS B A PENN B N NEW JERSEY B A W VIRGINIA B N MARYLAND B A DELAWARE B A VIRGINIA B A N CAROLINA N A S CAROLINA N A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE A A AK ALEUTIAN N A AK WESTERN A A AK INT BSN A A AK S INT N A AK SO COAST N A AK PNHDL A 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. $$