FXUS06 KWBC 181902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Mon May 18 2026 6-10 DAY OUTLOOK FOR MAY 24 - 28 2026 Positive 500-hPa height anomalies are forecast across much of eastern North America during the 6-10 day period. Corresponding strong mid-level ridging is favored over the eastern contiguous U.S. (CONUS) during the period. Over Alaska, mid-level troughing and negative 500-hPa height anomalies are favored with positive 500-hPa height anomalies forecast to the south. This may set up enhanced onshore flow at the mid-levels into parts of western North America. Unfortunately, there are significant differences among the tools regarding the development of a mid-level trough (ECENS) or expanded positive 500-hPa height anomalies (GEFS and CMCE) along the West Coast. The evolution of the mid-level pattern in this region will influence the forecast. At this time, the manual blend favors a weak trough over this region but is more of a compromise between these to diverging solutions. As a result of the differences between the mid-level height forecasts, there is more uncertainty across the West Coast for the period average temperatures. As a result, near normal temperatures are favored along the West Coast. A separate area of near normal temperatures is favored over parts of the Southwest and Texas. This is a region that is strongly favored to see above normal precipitation which is most likely to bring near normal temperatures. Across the rest of the CONUS, above normal temperatures are favored with mid-level ridging and positive 500-hPa height anomalies forecast. Below normal temperatures are favored in Alaska, with mid-level troughing over the state. Chances for below normal increase towards southern Alaska. In Hawaii, above normal temperatures are favored for the eastern islands, while near normal temperatures are favored for Oahu and Kauai. Above normal precipitation is generally favored from near and along the Rockies through the East Coast during the period. There is strong model agreement for above normal precipitation over the Four Corners region, Southern Plains, and Lower Mississippi Valley. Corresponding to the strongest and most consistent chances in the tools is a 60% chance of above normal for the Rio Grande Valley. Guidance suggests that elevated precipitation chances could potentially extend from the Plains through the East Coast during the period. While the ECENS solutions are most aggressive with this pattern, support from the GEFS remains somewhat limited. Nevertheless, as analog tools remain generally supportive of this evolution, a 40-50% probability of above normal precipitation is favored for this region. There are reduced chances for above normal precipitation over the Northern Plains, Great Lakes, and Northeast, relative to regions further south. In the West, uncertainty regarding the mid-level pattern and differences among the precipitation guidance support near normal precipitation. In Alaska, with mid-level troughing over the state, above normal precipitation is forecast. In Hawaii, above normal precipitation continues to be favored consistent with model guidance. The official 6-10 day 500-hPa height blend consists of 25% of Today's 6z GFS Ensemble Mean centered on Day 8, 50% 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: Average, 3 out of 5, average tool agreement is offset by differences in the evolution of the pattern over the western U.S. 8-14 DAY OUTLOOK FOR MAY 26 - JUN 01, 2026 Positive 500-hPa height anomalies and mid-level ridging are favored over most of eastern North America during week-2. There continues tobe some differences among the tools over the western CONUS regarding the evolution of the mid-level heights but there is generally better agreement for a weak trough. In Alaska, mid-level troughing is weakening from the 6-10 day period and yesterday's forecast, such that by the end of week-2, negative anomalies have been mostly eroded. Over Hawaii, near normal 500-hPa heights remain favored. Above normal temperatures are favored over most of the CONUS during week-2. The strongest chances are over the Northern Plains, Upper Mississippi Valley, and Great Lakes. Near normal temperatures are favored over parts of New Mexico and Texas where enhanced precipitation may limit temperatures. Meanwhile, along the immediate coast of northern California, Oregon, and Washington, near normal is favored with some uncertainty regarding the mid-level height pattern over the region. In Alaska, below normal temperatures remain favored, with the strongest chances increasing towards southern Alaska. Much of this is likely front loaded with temperature anomalies decreasing over time. In Hawaii, above normal temperatures are favored over the state. Above normal precipitation remains favored from the Four Corners region eastward to the southern Mid-Atlantic and Southeast. Forecast guidance continues to support elevated chances for above normal precipitation in this region. The best model support is over the eastern Four Corners and Southern Plains with lower chances further towards the Southeast and Mid-Atlantic. There could be a relatively quick flip in probabilities in this region as precipitation times off in the next few days. Below normal precipitation is forecast for the Great Lakes and Northeast consistent with the positive 500-hPa height anomalies over eastern U.S. Below normal precipitation is also forecast over the Pacific Northwest consistent with the statistical guidance. Finally, a small area of above normal precipitation is favored over parts of the Northern Plains consistent with dynamical precipitation guidance. In Alaska, above normal is favored for southern and eastern Mainland and Southeast Alaska. In Hawaii, above normal precipitation is favored across the islands. The official 8-14 day 500-hPa height blend consists of: 30% of Today's 6z 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: Average, 3 out of 5, good consistency among the tools is offset by differences in how the pattern will evolve across the western U.S. FORECASTER: Ryan Bolt 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 May21. 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: 20240531 - 20060506 - 20250501 - 20110505 - 20170501 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: 20240531 - 20250501 - 20070427 - 20180507 - 20060506 6-10 DAY OUTLOOK TABLE Outlook for May 24 - 28 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N N OREGON N N NRN CALIF N N SRN CALIF A N IDAHO A N NEVADA A N W MONTANA A N E MONTANA A N WYOMING A A UTAH A A ARIZONA A A COLORADO A A NEW MEXICO N A N DAKOTA A N S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS N A S TEXAS N A W TEXAS N A MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN A N ILLINOIS A A MISSISSIPPI A A MICHIGAN A N 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 B A AK S INT B A AK SO COAST B A AK PNHDL B A 8-14 DAY OUTLOOK TABLE Outlook for May 26 - Jun 01, 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A N SRN CALIF A N IDAHO A N NEVADA A N W MONTANA A N E MONTANA A N WYOMING A A UTAH A A ARIZONA A N COLORADO A A NEW MEXICO N A N DAKOTA A A S DAKOTA A N NEBRASKA A N KANSAS A A OKLAHOMA A A N TEXAS N A S TEXAS N A W TEXAS N A MINNESOTA A N IOWA A N MISSOURI A N ARKANSAS A A LOUISIANA A A WISCONSIN A N ILLINOIS A N MISSISSIPPI A A MICHIGAN A B INDIANA A N OHIO A B KENTUCKY A N TENNESSEE A A ALABAMA A A NEW YORK A B VERMONT A B NEW HAMP A B MAINE A B MASS A B CONN A B RHODE IS A B PENN A B NEW JERSEY A B W VIRGINIA A N MARYLAND A N DELAWARE A N VIRGINIA A N N CAROLINA A A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE B N AK ALEUTIAN B A AK WESTERN B N AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL B 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. NORMALVALUES - 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. $$