Extended Forecast Discussion NWS Weather Prediction Center College Park MD 253 AM EDT Wed Oct 09 2019 Valid 12Z Sat Oct 12 2019 - 12Z Wed Oct 16 2019 ...Pattern Overview and Guidance/Uncertainty Assessment... An anomalously deep upper low over norther Minnesota Saturday will slowly weaken and drift northeastward toward Hudson Bay through the period. Pacific flow will bring one shortwave to the Pacific Northwest by the start of the weekend and then the central U.S. early next week, followed by another shortwave that could approach the Northwest Tue/Wed. The potential subtropical system just off the East Coast on Saturday is forecast to move away from New England Sunday. The National Hurricane Center is monitoring this area for development. Please reference their outlooks for more information. Overall a model/ensemble blend sufficed through the forecast period with a majority weight to the 12Z ECMWF and its ensemble mean next Tue/Wed. GFS runs appeared a bit too quick relative to the multi-center ensemble spread though recent trends have been a bit quicker. ...Weather Highlights/Threats... Wrap-around precipitation will wind down across the Upper Midwest/Great Lakes this weekend but the tail end of the front will linger across the Southeast. This will likely spur an increase in rainfall as the western system organizes in the Plains by Tuesday. This will be the focus for the potentially heaviest rainfall through the medium range. Over the eastern Pacific, a potential tropical system may spread some moisture across northern Mexico into west Texas but this remains uncertain given the spread in its track. Record cold temperatures on Saturday will slowly moderate but remain much colder than average over the Dakotas and western/central Great Lakes. Above average temperatures will precede the cold front in the east on Saturday with modestly above normal readings persisting over the Southeast through early next week. Fracasso Additional 3-7 Day Hazards information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation, winter weather outlook probabilities and heat indices 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/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml