


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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067 FXUS06 KWBC 171902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Fri October 17 2025 6-10 DAY OUTLOOK FOR OCT 23 - 27 2025 An amplified mid-level height pattern is forecast for the 6-10 day period with a deep trough across the northeastern Pacific progressing into the northwestern contiguous U.S.(CONUS) A mid-level ridge is forecast ahead of this trough with above-normal 500-hPa heights increasing across the Plains. A mid-level trough and negative 500-hPa height anomalies are forecast along and just offshore the Eastern Seaboard. Near-normal heights are favored across the southern tier of the CONUS. Negative 500-hPa height anomalies are forecast for Alaska with a negatively tilted trough centered over the Gulf of Alaska. Heights are favored to rise across the Bering Sea during the period, limiting the potential for additional strong low pressure systems to develop during the 6-10 day period. In Hawaii, positive 500-hPa height anomalies are forecast to be centered north of the state. Above normal temperatures are forecast across much of the CONUS today with the strongest chances in the Plains with decreasing confidence towards both coasts. This is the result of relatively strong ridging across the central CONUS during the forecast period. As this ridge shifts east with time, chances for above-normal temperatures will increase over the eastern CONUS. A slight tilt towards below-normal temperatures are favored for the Mid-Atlantic where tools are in good agreement for a brief period of cooler conditions. Along the West Coast, near-normal temperatures are forecast with strong onshore flow into the region. This onshore flow will likely limit diurnal temperature swings and near- to below-normal temperatures are favored in most of the tools. In Alaska, below-normal temperatures are favored across the western third of Mainland Alaska, the Aleutians, and Southeast Alaska closer to the mid-level negative 500-hPa height anomalies. Above-normal temperatures are favored for the northeast Mainland. Above-normal temperatures remain strongly favored across Hawaii. The main story during the 6-10 day period are the very strong chances of above-normal precipitation across the western CONUS. Chances for 70% or higher are forecast for much of the West Coast north of the Bay Area. The highest chances exceed 80% straddling the California-Oregon border. Above-precipitation chances are elevated through the Central and Northern Rockies. Relative to yesterday, there is increased confidence for above-normal precipitation in the Plains and into the Mississippi Valley. This is a fairly substantial change relative to yesterday. However, a shortwave trough ejecting out of the Rockies is the favored solution amongst most of the forecast guidance at this time. Below-normal precipitation remains favored across much of the eastern CONUS with surface high pressure forecast across the region. In Alaska, near to below-normal precipitation is favored for southwest Mainland Alaska with above-normal favored for the northern and eastern Mainland and into Southeast Alaska. In Hawaii, a slight tilt towards above-normal is favored for the eastern islands while near-normal is favored further west. The official 6-10 day 500-hPa height blend consists of 10% of Today`s 0z GFS Ensemble Mean centered on Day 8, 35% of Today`s 6z GFS Ensemble Mean centered on Day 8, 40% of Today`s 0z European Ensemble Mean centered on Day 8, and 15% 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. Very good agreement among the temperature and precipitation dynamical and statistical tools is offset by diverging model solutions late in the period. 8-14 DAY OUTLOOK FOR OCT 25 - 31 2025 At the start of week-2 a deep 500-hPa trough is forecast to be just offshore of the Pacific Northwest. Conversely, a strong 500-hPa height ridge is forecast over the Plains and Mississippi Valley. A weak 500-hPa height trough is forecast along the East Coast. The strong trough and ridge dipole over the western two-thirds of North America will drive strong southerly flow into much of the West during the first half of week-2. Heights then slowly rise across the southwestern CONUS shifting the strongest onshore flow further north by the second half of the week. A shortwave trough pinched off from the 500-hPa height trough over the eastern Pacific will progress across parts of the northern tier by the middle of the week. Ahead of this trough the mid-level ridge will progress into the Great Lakes and Northeast before stronger mid-level troughing develops over the eastern CONUS at the end of the period. Overall, the pattern across the CONUS is amplified and progressive during week-2. In Alaska, mid-level heights remain below-normal with strong troughing over the northeastern Pacific. By the end of the period, tools suggest falling heights across the Bering Sea. For Hawaii, positive 500-hPa heights remain forecast north of the state with associated surface high pressure. Increased probabilities for above-normal temperatures are forecast across the interior CONUS underneath transient ridging early in the period and good support from the ECENS and GEFS reforecast and uncalibrated tools. The highest probabilities (greater than 70 percent) are highlighted across the Northern Plains and Upper Mississippi Valley. Reduced chances for above-normal temperatures are forecast across the Mid-Atlantic tied to troughing and a weak -NAO persisting. Below-normal temperatures slightly favored over the West due to enhanced cloud cover and precipitation. The temperature forecast for Alaska and Hawaii is very similar to that of the 6-10 day period. Near- to below-normal temperature probabilities are increased for much of Alaska underneath troughing, with higher odds for above-normal temperatures remaining across the northeastern Mainland. Above-normal temperatures continue to be strongly favored across Hawaii. The ongoing atmospheric river event across the West Coast continues to favor high probabilities for above-normal precipitation across much of the West. The highest chances (greater than 70 percent) are focused across portions of western Oregon and northwestern California where several inches of rain may fall during the week-2 period based on the 0z ECENS and GEFS. Additional shortwave troughing as depicted in the 0z ECENS and CMCE favors an increase in the odds for above-normal precipitation across portions of the Great Plains into the Mississippi Valley and Southeast. Slightly below-normal precipitation chances remain preferred for parts of Northeast further displaced from this feature. A drying trend remains forecast across Alaska, with near-normal precipitation favored across most of the state, with the exception of portions of the Aleutians and Southeast Alaska where weak probabilities for above-normal precipitation are favored. A slight tilt toward enhanced probabilities for above-normal precipitation is forecast for western Hawaii with near-normal favored further east. The official 8-14 day 500-hPa height blend consists of: 10% of Today`s 0z GFS Ensemble Mean centered on Day 11, 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 20% of Today`s 0z Canadian Ensemble Mean centered on Day 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About average, 3 out of 5. Good agreement among the temperature and precipitation dynamical and statistical tools is offset by diverging model solutions as the period progresses. FORECASTER: Ryan Bolt The next set of long-lead monthly and seasonal outlooks will be released on November 20. 6-10 DAY OUTLOOK TABLE Outlook for Oct 23 - 27 2025 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON N A NRN CALIF N A SRN CALIF N A IDAHO A A NEVADA N A W MONTANA A A E MONTANA A N WYOMING A A UTAH A A ARIZONA A A 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 A N W TEXAS A A MINNESOTA A N IOWA A N MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN A N ILLINOIS A N MISSISSIPPI A N MICHIGAN A B INDIANA A N OHIO N B KENTUCKY N B TENNESSEE A N ALABAMA A B NEW YORK N B VERMONT N N NEW HAMP N N MAINE A N MASS N N CONN N N RHODE IS N N PENN N B NEW JERSEY B B W VIRGINIA B B MARYLAND B B DELAWARE B B VIRGINIA B B N CAROLINA B B S CAROLINA N B GEORGIA N B FL PNHDL A B FL PENIN A N AK N SLOPE N A AK ALEUTIAN B N AK WESTERN B N AK INT BSN N A AK S INT N N AK SO COAST B A AK PNHDL B A 8-14 DAY OUTLOOK TABLE Outlook for Oct 25 - 31 2025 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B A SRN CALIF N A IDAHO N A NEVADA B A W MONTANA A A E MONTANA A A WYOMING A A UTAH N A ARIZONA A N COLORADO A A NEW MEXICO A B N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A N W TEXAS A N 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 N INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A A ALABAMA A A NEW YORK A N VERMONT A N NEW HAMP A N MAINE A B 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 A GEORGIA A A FL PNHDL A N FL PENIN A A AK N SLOPE N N AK ALEUTIAN B A AK WESTERN B N AK INT BSN N N AK S INT N N AK SO COAST B N AK PNHDL B 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. $$