452 FXUS06 KWBC 291902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Thu September 29 2022 6-10 DAY OUTLOOK FOR OCT 05 - 09 2022 Today's model solutions are in good agreement on the predicted 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 GFS, ECMWF, and Canadian model ensembles due to recent model skill. The resultant manual blend features a high amplitude 500-hPa ridge and above normal 500-hPa heights over the Aleutians. A 500-hPa trough is forecast over the northeastern Pacific. Anomalous 500-hPa ridging and above normal 500-hPa heights are predicted over western North America, while troughing is forecast across the eastern Contiguous United States (CONUS). The height pattern strongly supports elevated probabilities for above normal temperatures throughout the western third of the CONUS with the largest probabilities (more than 80 percent) across Washington. Most dynamical temperature forecast tools also favor above normal temperature over parts of the Southern Plains and the Lower Mississippi Valley. Due to the troughing aloft, near to below normal temperatures are most likely over the eastern CONUS and Great Lake region. Above normal 500-hPa heights favor above normal temperatures for nearly all of Alaska, supported by most of the dynamical temperature forecast tools. Tropical Storm ORLENE is developing across the East Pacific later this week with model guidance showing a track northward to the Gulf of California and western Mexico by early next week. Based on this predicted track and an increasing chance that a surge of low to mid-level moisture spreads northward into the Southwest, probabilities for above normal precipitation are enhanced for this region. Near to below normal precipitation is forecast over the remainder of the CONUS. In Alaska, enhanced onshore flow also increases probabilities for near to above normal precipitation for the state, except for the Alaska Panhandle where below normal precipitation is favored. The official 6-10 day 500-hPa height blend consists of 30% of Today's GFS Superensemble 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: Above average, 4 out of 5, due to good agreement and consistency between the GEFS and ECMWF ensemble means. 8-14 DAY OUTLOOK FOR OCT 07 - 13 2022 Dynamical model forecasts agree on general persistence of the 500-hPa circulation pattern over the CONUS and feature a highly amplified 500-hPa ridge over the North Pacific and Aleutians during the 8-14 days period. Downstream of this Aleutian ridge, a 500-hPa trough is forecast to develop over the northeastern Pacific early in week-2. Mid-level ridging is forecast to persist over the middle to high latitudes of west-central North America. A weak 500-hPa trough is predicted over the eastern CONUS. Temperature tools are in good agreement with enhanced probabilities for above normal temperatures throughout most of the CONUS, except for the northeastern CONUS where enhanced probabilities of near to below normal temperatures are indicated. This temperature forecast is consistent with a weak 500-hPa trough over eastern North America. In Alaska, persistent onshore flow favors above normal temperatures for much of Mainland Alaska and the Panhandle. Probabilities for above normal precipitation are enhanced over southwestern CONUS, consistent with the GERF and ECMWF precipitation calibrated reforecast tools. Mean upper-level ridging over the west-central CONUS along with broad surface high pressure favors near to below normal precipitation over the remainder of the CONUS. In Alaska, the surface flow pattern along with cyclonic flow aloft supports elevated probabilities for above normal precipitation across most of the state. The official 8-14 day 500-hPa height blend consists of: 30% of Today's GFS Superensemble 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 and consistency between the GEFS and ECMWF ensemble means. 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 October 20. 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: 19660921 - 19620921 - 19881006 - 19511007 - 19870921 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: 19660920 - 19870922 - 19511007 - 19881005 - 20081002 6-10 DAY OUTLOOK TABLE Outlook for Oct 05 - 09 2022 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A N SRN CALIF A A IDAHO A B NEVADA A B W MONTANA A B E MONTANA A B WYOMING A N UTAH A A ARIZONA A A COLORADO N A NEW MEXICO N A N DAKOTA N B S DAKOTA N N NEBRASKA N N KANSAS N N OKLAHOMA A N N TEXAS A B S TEXAS A B W TEXAS A A MINNESOTA B B IOWA N N MISSOURI N N ARKANSAS A B LOUISIANA A B WISCONSIN B N ILLINOIS N N MISSISSIPPI A B MICHIGAN B N INDIANA B N OHIO B N KENTUCKY B N TENNESSEE N B ALABAMA N B NEW YORK B N VERMONT B N NEW HAMP B N MAINE B N MASS B N CONN B N RHODE IS B N PENN B N NEW JERSEY B N W VIRGINIA B N MARYLAND B N DELAWARE B N VIRGINIA B N N CAROLINA B N S CAROLINA B N GEORGIA N B FL PNHDL N B FL PENIN B N AK N SLOPE A A AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A AK S INT A A AK SO COAST A A AK PNHDL A B 8-14 DAY OUTLOOK TABLE Outlook for Oct 07 - 13 2022 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 A W MONTANA A B E MONTANA A B WYOMING A N UTAH A A ARIZONA A A COLORADO A N NEW MEXICO A A N DAKOTA A B S DAKOTA A B NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA N B IOWA A B MISSOURI A B ARKANSAS A B LOUISIANA A N WISCONSIN N B ILLINOIS A B MISSISSIPPI A B MICHIGAN N B INDIANA N B OHIO N B KENTUCKY A B TENNESSEE A B ALABAMA A N NEW YORK B N VERMONT B N NEW HAMP B N MAINE B N MASS B N CONN B N RHODE IS B N PENN N N NEW JERSEY N N W VIRGINIA N N MARYLAND N N DELAWARE N N VIRGINIA N N N CAROLINA N N S CAROLINA A N GEORGIA A N FL PNHDL A N FL PENIN A N AK N SLOPE A A AK ALEUTIAN N N AK WESTERN A A AK INT BSN A A AK S INT A A AK SO COAST A 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. $$