


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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969 FXUS06 KWBC 092105 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Thu October 09 2025 6-10 DAY OUTLOOK FOR OCT 15 - 19 2025 Dynamical models remain in good agreement regarding the predicted 500-hPa height pattern during the 6-10 day period. A negative North Atlantic Oscillation (-NAO) is forecast to develop in conjunction with strong ridging near Greenland, and troughing over the northwest Atlantic, associated with a departing coastal storm that is anticipated to impact the East Coast prior to the start of the period. Upstream, ridging is forecast across the central CONUS. At the outset of the period, anomalous ridging and troughing is predicted across Southeast Alaska and the West Coast of the CONUS respectively, with a gradual weakening of these features later in the period. Additional troughing is forecast to progress from eastern Russia into the Bering Sea and western Alaska by day-10. Todays manual 6-10 day 500-hPa height blend depicts above-normal heights across eastern Alaska extending across the northwestern CONUS along the Canadian border, and into much of the central CONUS. Conversely, below-normal heights are indicated across much of western Alaska, including the Aleutians, parts of the southwestern CONUS and Great Basin, and the Mid-Atlantic and Northeast. Near-normal heights are forecast across Hawaii, with a weakness progressing across the northern islands around or just before the start of the period. Increased chances for below-normal temperatures are favored across the CONUS west of the Rockies due to the influence of troughing, especially early in the period. Increasing Pacific flow later in the period may help moderate temperatures across the Northwest where probabilities for below-normal temperatures are lower compared to farther south. Conversely, above-normal temperatures are strongly favored across the Central CONUS tied to ridging, with the highest probabilities (greater than 80 percent) across north-central Texas. Daily temperature anomalies exceeding +10 deg F are possible over parts of the Central and Southern Plains into adjacent areas of the Mississippi Valley based on the uncalibrated 0z ECENS and GEFS. While the reforecast tools lean warmer compared to the uncalibrated tools across the Mid-Atlantic and Northeast, analogs and teleconnections as well as the evolving -NAO favor enhanced chances of below-normal temperatures. Strong southerly flow at the surface and aloft due to troughing over the Bering Sea and ridging over Southeast Alaska support high probabilities for above-normal temperatures across Alaska. Above-normal temperatures are also forecast across Hawaii supported by the consolidation reforecast tool. Troughing in the west along with increased moisture advection from the tropical East Pacific favor elevated chances for above-normal precipitation extending from the Southwest to the Northern Plains with models indicating some potential for lee cyclogenesis early in the period. Probabilities for below-normal precipitation are increased across portions of the far northwestern CONUS closer to the positive height anomaly center over Southeast Alaska. There is a strong signal for below-normal precipitation in nearly all of the forecast tools across the Southern Plains into much of the southeastern CONUS extending north into the Ohio Valley tied to surface high pressure. 6-10 precipitation totals from the 0z ECENS, GEFS, and CMCE are generally less than a quarter-inch across much of the south-central and southeastern CONUS. This supports increased chances of below-normal precipitation in the forecast, with the highest chances (greater than 60 percent) extending from eastern Texas through the northern Gulf Coast states. Some residual moisture from a departing coastal low is possible across eastern New England slightly tilting the odds to above-normal precipitation. Troughing across the Bering Sea and potential surface low pressure favors enhanced probabilities for above-normal precipitation over much of Alaska, increasing to the west. Elevated chances for below-normal precipitation remain across parts of Southeast Alaska tied to predicted ridging across the region. Above-normal precipitation is forecast across Hawaii, with higher probabilities across the northern islands. The official 6-10 day 500-hPa height blend consists of 30% of Today`s 6z 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: Above average, 4 out of 5, due to good model agreement in depicting an amplified 500-hPa pattern across much of the forecast domain. 8-14 DAY OUTLOOK FOR OCT 17 - 23 2025 During week-2, the 500-hPa height pattern across the CONUS is predicted to de-amplify, with some weakening of the -NAO. The 0z ECENS, GEFS, and CMCE are in good agreement regarding troughing spreading from western Alaska southeastward through the Gulf of Alaska and Northeast Pacific later in the period resulting in height falls and increasing onshore flow across Southeast Alaska and the Pacific Northwest. Todays week-2 manual height blend is generally tied to stronger anomalies earlier in the period, and is also similar to that of the 6-10 day period, except weaker in magnitude as a faster, more progressive mid-level flow pattern develops over the CONUS. Above-normal heights are depicted across eastern Alaska and over the central CONUS. Areas of near-to below-normal heights are indicated across western Alaska, the western CONUS, and over the Mid-Atlantic and Northeast. Near-normal heights are forecast across Hawaii. The week-2 temperatures outlook is similar to the 6-10 day outlook, with the largest change being a trend toward warmer temperatures across the West, particularly the Northwest, as Pacific flow increases ahead of troughing moving into the Northeast Pacific. This slightly tilts the odds toward above-normal temperatures across the Pacific Northwest, with elevated chances for below-normal temperatures remaining over parts of the Southwest. Increased chances of above-normal temperatures are forecast for much of the central and southeastern CONUS supported by the GEFS and ECENS reforecast tools and tied to enhanced ridging early in the period. As discussed in the 6-10 outlook, the -NAO along with uncalibrated guidance support higher chances for below-normal temperatures across portions of the Mid-Atlantic and Northeast. High probabilities for above-normal temperatures remain forecast across Alaska underneath enhanced southerly flow. Above-normal temperatures are also forecast for Hawaii, supported by the consolidation reforecast tool. The de-amplifying mid-level pattern across the CONUS results in decreasing signals for precipitation during week-2. However, increased Pacific flow and potential shortwave impulses support a broad area of enhanced above-normal precipitation across much of the western half of the CONUS, extending into the Great Plains and Upper Mississippi Valley. Troughing shifting toward the Northeast Pacific may further elevate precipitation chances across the Pacific Northwest by the end of the period. Below-normal precipitation chances remain elevated across parts of the south-central and southeastern CONUS, although probabilities are reduced compared to the 6-10 day period as the ridging weakens. Near-normal precipitation is favored across the Northeast where there is some potential for additional surface low pressure development. Increased chances for above-normal precipitation are forecast for much of Alaska, with the highest probabilities (40 percent) shifting into the southern Mainland. Above-normal precipitation is forecast across Hawaii. 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, due to good model agreement on the 500-hPa pattern evolution, offset by uncertainty regarding a de-amplifying flow pattern. FORECASTER: Thomas Collow The next set of long-lead monthly and seasonal outlooks will be released on October 16. 6-10 DAY OUTLOOK TABLE Outlook for Oct 15 - 19 2025 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B B OREGON B A NRN CALIF B A SRN CALIF B A IDAHO B A NEVADA B A W MONTANA B A E MONTANA B A WYOMING A A UTAH B A ARIZONA B A COLORADO A A NEW MEXICO A A N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A B N TEXAS A B S TEXAS A B W TEXAS A B MINNESOTA A A IOWA A A MISSOURI A B ARKANSAS A B LOUISIANA A B WISCONSIN A A ILLINOIS A N MISSISSIPPI A B MICHIGAN A N INDIANA A B OHIO N B KENTUCKY A B TENNESSEE A B ALABAMA A B NEW YORK B N VERMONT N N NEW HAMP N A MAINE A A MASS B A CONN B N RHODE IS B A PENN B N NEW JERSEY B N W VIRGINIA N B MARYLAND B N DELAWARE B N VIRGINIA B B N CAROLINA B B S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN A B 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 A 8-14 DAY OUTLOOK TABLE Outlook for Oct 17 - 23 2025 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON N A NRN CALIF B A SRN CALIF B A IDAHO N A NEVADA B A W MONTANA N A E MONTANA N A WYOMING A A UTAH N A ARIZONA A A COLORADO A A NEW MEXICO A A N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A N N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA A A IOWA A A MISSOURI A N ARKANSAS A N LOUISIANA A B WISCONSIN A A ILLINOIS A N MISSISSIPPI A B MICHIGAN N N INDIANA A N OHIO N N KENTUCKY A N TENNESSEE A B ALABAMA A B NEW YORK B N VERMONT B N NEW HAMP B N MAINE A N MASS B N CONN B N RHODE IS B N PENN B N NEW JERSEY B N W VIRGINIA B B MARYLAND B N DELAWARE B N VIRGINIA B B N CAROLINA B B S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN A B 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 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. $$