905 FXUS02 KWBC 152012 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 412 PM EDT Thu Oct 15 2026 Valid 12Z Sun Oct 18 2026 - 12Z Thu Oct 22 2026 ...Frost/freeze threats across parts of the Mid-Atlantic and Northeast Sunday and Monday... ...A possible East Coast low early to mid next week could bring coastal impacts... ...Overview... A chilly surface high over the eastern U.S. will bring frost and freeze concerns to parts of the Mid-Atlantic and Northeast early in the period. A cold front sinking through Florida may bring a threat for locally heavy rainfall on Sunday into Monday. There is also increasing potential for a low pressure system to develop off the East Coast along this front, which may bring coastal impacts depending on how close to the coast the low gets. Out West, an upper low will drop down the West Coast with deep troughing likely over the West by next Thursday. This brings the potential for widespread rain and high elevation snows especially Tuesday and Wednesday next week, with some showers increasing across the Central U.S. as well late period. ...Guidance/Predictability Assessment... The latest model trends continue to favor the development of a low pressure system somewhere off the Mid-Atlantic/Southeast coast in the western Atlantic either later this weekend or early next week. Despite these trends, uncertainty remains high as the location and timing of development, degree of amplification, strength, and track all remain in question. As a result, the WPC forecast utilized a blend that tried to take a middle ground approach, while leaning towards a more developed and relatively closer to the coast solution. This ended up being primarily a non-NCEP consensus with increasing weight on the EC ensemble mean beyond Day 5. Given the potential for coastal impacts with a possibly stronger and closer coastal low next week, model trends will need to be monitored in the coming days as future forecast adjustments could be dramatic. Out West, the latest guidance shows better agreement with the evolution of an upper trough that drops southward along the coast and eventually closes off into a closed low over the Southwest late this weekend into next week. The slower and more amplified solutions are looking more likely to verify, which will result in a slower progression of inland penetration of precipitation and a generally warmer system evolution featuring mostly rain and only high elevation snow above 9000-10000 feet. ...Weather/Hazards Highlights... A cold front moving slowly southward through Florida will allow for increased onshore flow and locally heavy rainfall, especially along the East Coast. WPC has this region in a marginal risk for Sunday. Coastal low pressure development off the Mid-Atlantic coast may allow for more showers and locally heavy rainfall for the eastern Carolinas and southeast Virginia, with possible gusty winds; however, concerns for coastal impacts are all highly dependent on how close to the coast this low forms, which is still high uncertain. A closer low would mean much greater impacts (high winds, rough surf, coastal flooding, etc), especially if the low lingers for any period of time. Out West, precipitation chances increase by Monday and especially Tuesday into Wednesday with rain and high elevation snow. Some rainfall may begin to develop across the south-central U.S. by mid next week as well. Canadian high pressure will be in place across much of the East on Sunday, with frost/freeze concerns for parts of the Mid-Atlantic and the Northeast. Elsewhere, above normal temperatures will expand across the Central U.S. as conditions trend cooler across the West underneath deep troughing next week. Miller/Santorelli 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, excessive rainfall outlook, winter weather outlook probabilities, heat indices and Key Messages are at: 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 $$