317 FXUS06 KWBC 151901 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Fri May 15 2026 6-10 DAY OUTLOOK FOR MAY 21 - 25 2026 Ensemble solutions for 500-hPa height anomalies from the ECENS, GEFS, and CMCE are in reasonably good agreement today regarding the synoptic setup over North America throughout the 6-10 day forecast period, with anomalous ridges over the North Pacific and the eastern Contiguous U.S. (CONUS). Mid-level troughs and associated negative height anomalies are depicted across the higher latitudes, with one over the Bering Sea/western Alaska and another south of Greenland. A weak extension of the Bering Sea/western Alaska trough is forecasted along the entire western coast of North America, though the 0z ECENS and 0z CMCE favor weak positive height anomalies overspreading the trough over southwestern portions of Canada and much of the West Coast of the CONUS. These two ensemble means also predict a mean shortwave trough ejecting through the south-central CONUS, with only the weakest hint of this feature depicted by the 0z GEFS. Near-normal 500-hPa heights are favored over Hawaii, with an anomalous ridge centered to its north, and a sheared-out trough to its east-northeast. Above-normal temperatures are favored over most of the western, north-central, and southeastern CONUS, with a weak bridging of the latter two areas of favored above-normal temperatures over much of the Mississippi and Ohio Valleys. The widespread anomalous warmth over much of the Lower 48 states is consistent with broad coverage of mid-level positive height anomalies and widespread southerly flow. The highest chances (>60%) are centered over the Florida peninsula, where mid-level ridging is further supported by southerly flow at the surface on the western edge of the Bermuda high. Near to below-normal temperatures are favored over the south-central states and parts of the Lower Four Corners, as indicated by the reforecast temperature tools and aligned fairly well with expected cloud cover and precipitation. Troughing over the Bering Sea and western parts of Alaska tilts the odds towards below-normal temperatures for Alaska, especially south of the Brooks Range. Anomalously warm sea-surface temperatures in the Central Pacific favor above-normal temperatures for Hawaii. A shortwave trough forecast to move across the vicinity of the Southern Plains and Lower Mississippi Valley, along with a meandering baroclinic zone focused over the Southeast quarter of the CONUS favors increased chances of wetter-than-normal conditions from near the spine of the central and southern Rockies eastward to the Atlantic coast, as far north as Massachusetts. Return flow around the Bermuda High supports elevated dew points over this same general area of the country. Odds are highest (>60%) over much of the lower and middle Rio Grande Valley, likely where the above-described interaction will be best-focused. A weak frontal system is forecast to move across south-central Canada, slightly elevating the chances of above-normal precipitation from North Dakota eastward to western Upper Michigan. Most of the western and northern CONUS are favored to experience near-normal precipitation, with the exception of the Olympic Peninsula of Washington state, where above-normal precipitation is slightly favored. The mid-level trough over the Bering Sea favors above-normal precipitation for most of Alaska, while near-normal precipitation is indicated for the North Slope. Enhanced subtropical convection in the Central Pacific tilts the odds towards above-normal precipitation for 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: 4 on a scale of 1-5, due to reasonably good agreement among the various height and temperature guidance, offset somewhat by differences in precipitation tools. 8-14 DAY OUTLOOK FOR MAY 23 - 29 2026 The week-2 500-hPa height blend features the continuation of an anomalous ridge over the central North Pacific, and the westward and northward expansion and amplification of the eastern CONUS ridge. During week-2, the latter ridge is predicted to extend over most of the central and interior western CONUS, and much of Canada, becoming the most significant mid-level feature over North America. A trough remains along the western coast of North America, with its strongest portion located over southwestern Alaska and the adjacent Bering Sea. The trough predicted south of Greenland during the earlier 6-10 day period has mostly filled, with height anomalies close to zero in week-2. The predicted westward and northward expansion and strengthening of the eastern CONUS ridge supports elevated chances of above-normal temperatures over most of the CONUS, with the exception of near-normal temperatures for the West coast states, southern portions of the Lower Four Corners region, and much of Texas. Chances favoring above-normal temperatures exceed 60% over the Northern Plains near the anomalous ridge center. Along the Northeast and Mid-Atlantic coasts, a slight tilt towards warmer-than-normal temperatures is indicated, though some of the tools support near-normal temperatures as the ridge center advances farther west. Subsequent temperature outlooks may support backdoor cold fronts over the Northeast and near-to-below normal temperatures, depending on how far west the ridge center gets. The mid-level trough over the Bering Sea/western Alaska continues to favor below-normal temperatures for most of Alaska, as far north as the Brooks Range, with near-normal favored for the North Slope. Warmer-than-normal temperatures remain likely for most of the islands, based on the ERF-CON and automated temperature tools. The week-2 precipitation outlook is very similar to the earlier 6-10 day precipitation outlook, favoring above-normal precipitation from near the spine of the central and southern Rockies eastward across the southern half of the CONUS to the Atlantic coast from Delaware southward. This is supported by the reforecast precipitation tools, and by a synoptic pattern predicted to be similar to that of the 6-10 day period. Near-normal precipitation is favored for the northern half of the CONUS, consistent with most guidance. Near-normal precipitation is also favored for nearly all areas west of the Continental Divide, in advance of the weak West Coast trough. A small area of anomalous wetness is favored over the Olympic Peninsula of Washington state. Above-normal precipitation is also favored for Alaska and Hawaii, due to similar reasoning for the 6-10 day period. 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: 3 on a scale of 1-5, based on decent agreement among the various height, temperature, and precipitation tools. FORECASTER: Anthony A 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: 20070427 - 20200427 - 20130514 - 20010427 - 20180507 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: 19940511 - 20130514 - 20200426 - 20070427 - 20200501 6-10 DAY OUTLOOK TABLE Outlook for May 21 - 25 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N 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 N ARIZONA A N COLORADO A A NEW MEXICO N A N DAKOTA A N S DAKOTA A N NEBRASKA A A KANSAS A A OKLAHOMA N A N TEXAS N A S TEXAS N A W TEXAS N A MINNESOTA A N IOWA A N MISSOURI A A ARKANSAS N A LOUISIANA A A WISCONSIN N N ILLINOIS A A MISSISSIPPI A A MICHIGAN N N INDIANA A A OHIO N A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK N N VERMONT N N NEW HAMP N N MAINE N N MASS N N 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 A AK N SLOPE B N 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 23 - 29 2026 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N N OREGON N N NRN CALIF N N SRN CALIF N N IDAHO A N NEVADA A N W MONTANA A N E MONTANA A N WYOMING A N UTAH A N ARIZONA N N COLORADO A A NEW MEXICO A A N DAKOTA A N S DAKOTA A N NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS N A W TEXAS N A MINNESOTA A N IOWA A N MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN A N ILLINOIS A N MISSISSIPPI A A MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A A TENNESSEE A A ALABAMA A 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 A MARYLAND A N 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 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 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. $$