Extended Forecast Discussion NWS Weather Prediction Center College Park MD 322 PM EDT Sun Oct 19 2025 Valid 12Z Wed Oct 22 2025 - 12Z Sun Oct 26 2025 ...General Overview... A closed low positioned north of the Great Lakes will sustain an occluded surface low with a cold front that will exit the coast on Wednesday, with a return to cooler conditions as Canadian high pressure settles into the region. Further west, a closed upper low initially off the coast of California will advance 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 latest suite of guidance have a good handle on the large scale patterns and their evolution. It was noted that the CMC was persistently on the leading edge of with the cluster with the feature crossing the Plains and deeper/slower with the low/trough north of the Great lakes/Northeast. Whereas, the Ecmwf/EC mean migrated to the back edge/slowing from the rest of the solutions. A multi- deterministic model blend was used as a starting point and gradually increased the ensemble means to 40% by next weekend. ...Weather/Hazards Highlights... The West Coast will be heading into a more active, wet pattern as an amplifying trough and strong cold front advects copious Pacific moisture towards the coast. Western Washington and Oregon will have an increase in precipitation Thursday night (Day 5/Thursday Marginal Risk area) before spreading to northern California into Friday, with a few inches of rainfall possible for the coastal mountain ranges with a potential atmospheric river affecting the region. Convection will develop and increase in coverage across the south- central U.S. later int he week as a surface low develops. There continues to be a signal for some locally heavy rainfall across the Southern Plains to the Lower Mississippi Valley. The Day 5 Marginal Risk area was maintained for 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. Campbell/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