####018011910#### FXUS06 KWBC 091902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Tue April 09 2024 6-10 DAY OUTLOOK FOR APR 15 - 19 2024 Today's model solutions are in good agreement on the predicted amplified 500-hPa circulation pattern across North America and surrounding regions during the 6-10 day period. The manual 500-hPa height blend is based primarily on the ensemble means from the GEFS, ECENS, and Canadian models due to recent model skill. The resultant manual blend features positive 500-hPa height anomalies over Alaska down into the eastern Pacific off the West Coast. An anomalous mid-level trough and associated negative 500-hPa height anomalies are forecast over the western CONUS, while ridging and positive anomalies are predicted over the eastern CONUS. Weak troughing with negative 500-hPa height anomalies are favored for Hawaii. Mid-level ridging forecast across the East brings elevated chances for above-normal temperatures across much of the central and eastern CONUS. The strongest chances are forecast parts of the Southeast with probabilities exceeding 80% in this region. Below-normal temperatures are forecast over much of the western CONUS under below-normal 500-hPa height, consistent with the GEFS and ECMWF temperature reforecast consolidation tools. In Alaska, near- to below-normal temperatures are favored, supported by most of the dynamical temperature forecast tools. In Hawaii, slightly below-normal temperatures are forecast over Kauai, while above-normal temperatures are likely over Oahu, Maui and the Big Island, consistent with the consolidation tool. Below-normal precipitation is favored over parts of the southeastern CONUS beneath strongly positive 500-hPa height anomalies and mid-level ridging. While behind the trough axis across the West, below-normal precipitation is favored across western one third of the CONUS. Near- to above-normal precipitation is favored across the remainder of the CONUS due to a mid-level trough predicted over the western CONUS and a surface low predicted over the central CONUS, consistent with the GEFS and ECMWF precipitation reforecast consolidation tools. In Alaska, above-normal precipitation is favored across much of the Mainland with below-normal precipitation favored in the Alaska Peninsula and near-normal precipitation favored in Southeast Alaska. In Hawaii, above-normal precipitation is favored for much of the state with strong chances forecast by the consolidation tools. The official 6-10 day 500-hPa height blend consists of 40% of Today's 6z GFS Ensemble Mean centered on Day 8, 30% 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: Above average, 4 out of 5, due to good agreement among model solutions and forecast temperature and precipitation tools. 8-14 DAY OUTLOOK FOR APR 17 - 23 2024 Ensemble mean solutions for the 8-14 day period predict a fairly consistent 500-hPa circulation pattern relative to the 6-10 day period across North America and the surrounding regions. During week-2 a strong positive 500-hPa height anomaly is forecast over the Bering Sea with positive anomalies across most of Alaska and into the eastern Pacific off the West Coast. Weakly negative anomalies are forecast across the northern Interior West with near-normal heights over the southern Four Corners region. While across the eastern CONUS, ridging with positive 500-hPa height anomalies remain forecast as in the 6-10 day period. A weak trough with slightly below-normal 500-hPa heights are still predicted over Hawaii. Above-normal temperatures are forecast over south-central and eastern CONUS due the forecast ridging and above-normal 500-hPa heights over the region. Above-normal temperature chances exceeding 50% are favored over the southeastern CONUS. Elevated probabilities of above-normal temperatures are also favored over parts of the Pacific Northwest, California, and western Nevada, while below-normal temperatures are likely over the Northern Rockies and Northern Plains region, and supported by most dynamic temperature forecast tools. In Alaska, below-normal remains favored across most of the State, consistent with the GEFS calibrated reforecast tool. In Hawaii, near- to above-normal temperatures are favored, and supported by the consolidation temperature forecast tool. The week-2 precipitation forecast is similar to the 6-10 day forecast with a large area of slightly enhanced chances for above-normal precipitation across the center of the CONUS in conjunction with the troughing across the Interior West and southerly return flow associated with mean surface high pressure over the western Atlantic. Behind the trough along the West Coast, below-normal precipitation is favored with positive 500-hPa heights beginning to progress into the region by the end of the period. In the East, near- to below-normal is favored along the Eastern Seaboard with positive 500-hPa height anomalies remaining forecast in the region. In Alaska, above-normal precipitation remains favored across much of the state. In Hawaii, a slight tilt towards above-normal precipitation is favored for much of the state, excluding the southern Big Island. 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: Above average, 4 out of 5, due to good agreement among model solutions and forecast temperature and precipitation tools. FORECASTER: Luke H Notes: Automated forecasts are issued on Saturday and Sunday. Occasionally manual intervention is necessary to address quality control and consistency issues. In these cases, forecasts are manually drawn but a full discussion is not issued. 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 (unshaded, "N"). Historical average values for the calendar period of the forecast (dashes, "f"). 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 (unshaded, "n"). Historical median values for the calendar period of the forecast (dashes, "inches"). 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 April 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: 20060418 - 20050410 - 19950323 - 20060320 - 19990404 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: 20060418 - 20090323 - 19950323 - 19770416 - 19990411 6-10 DAY OUTLOOK TABLE Outlook for Apr 15 - 19 2024 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B B OREGON B B NRN CALIF N B SRN CALIF B B IDAHO B N NEVADA B B W MONTANA B A E MONTANA B A WYOMING B A UTAH B A ARIZONA B N COLORADO A A NEW MEXICO A A N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN A A ILLINOIS A A MISSISSIPPI A A MICHIGAN A A INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A N 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 N N CAROLINA A N S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN A B AK N SLOPE B A AK ALEUTIAN B B AK WESTERN B A AK INT BSN B A AK S INT B A AK SO COAST B N AK PNHDL N N 8-14 DAY OUTLOOK TABLE Outlook for Apr 17 - 23 2024 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A B SRN CALIF N B IDAHO B B NEVADA A B W MONTANA B B E MONTANA B A WYOMING B A UTAH N N ARIZONA A N COLORADO N A NEW MEXICO A A N DAKOTA B A S DAKOTA B A NEBRASKA N A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA N A IOWA N A MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN N A ILLINOIS A A MISSISSIPPI A A MICHIGAN A A INDIANA A A OHIO A A 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 A NEW JERSEY A N W VIRGINIA A A 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 N AK WESTERN B A AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL N 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. $$