Extended Forecast Discussion NWS Weather Prediction Center College Park MD 348 AM EDT Sun Oct 19 2025 Valid 12Z Wed Oct 22 2025 - 12Z Sun Oct 26 2025 ...General Overview... A well developed closed low north of the Great Lakes on Wednesday will sustain an occluded surface low with a cold front that will exit the coast on Wednesday, with a return to cooler conditions to close out the week as Canadian high pressure settles into the region. Meanwhile, a closed upper low initially off the coast of California moves inland across the southern Rockies and evolves into an upper trough in the southern stream to support a surface low over the central Plains with increasing showers and thunderstorms. A stronger storm system is likely to approach the Pacific Northwest Thursday into Friday with a potential atmospheric river ahead of a strong cold front, bringing widespread rain and mountain snow to close out the work week. ...Guidance/Predictability Assessment... The 00Z model guidance suite features good overall synoptic scale agreement across the Continental U.S. through the end of the week. However, at the time of fronts/pressures preparation, the 12Z Canadian model was an outlier solution with respect to a much stronger low over the eastern Pacific, whereas the other guidance supported a weaker solution, so the 12Z CMC was not used beyond Friday. The latest 00Z CMC run did trend favorably with the other guidance and ensemble means, but still has a slightly stronger low next weekend west of the Washington and Oregon coasts. A multi- deterministic model blend was used as a starting point for Wednesday into Thursday, and gradually increased the ensemble means to about half by next Sunday. ...Weather/Hazards Highlights... The weather pattern gets more active across the West Coast region going into the Thursday-Friday time period, as an amplifying trough and strong cold front advects copious Pacific moisture towards the coast. This will initially affect the western portions of Washington and Oregon Thursday night, where a new Day 5/Thursday Marginal Risk area is being introduced, and then northern California going into Friday, with a few inches of rainfall possible for the coastal mountain ranges with a potential atmospheric river affecting the region. Showers and storms also increase in coverage across the south-central U.S. by late week as well in association with the surface low that develops. Guidance has continued to show a signal that some locally heavy rainfall may be possible from the southern Plains to the Lower Mississippi Valley, and therefore a Marginal Risk of excessive rainfall is now warranted in the new Day 5/Thursday outlook from central Kansas to northwestern Arkansas. Some strong to severe thunderstorms will also be possible in this same general area as instability increases. High temperatures across the south-central U.S. are forecast to remain above average for mid to late week, especially for Texas where highs into the 90s may tie/break a few daily high temperature records. There may be some periods of below average temperatures for the Midwest/Northeast following cold frontal passages, though highs in general look to remain near average through much of next week. The northern-tier from the Rockies east to the Plains/Upper Midwest will see increasingly above average highs late next week and into the weekend as an upper-ridge builds overhead. The Pacific system will bring cooler, well below average temperatures to portions of the West Coast by early next weekend. Hamrick Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw