Extended Forecast Discussion NWS Weather Prediction Center College Park MD 302 PM EDT Mon Oct 26 2020 Valid 12Z Thu Oct 29 2020 - 12Z Mon Nov 02 2020 ...Heavy rain threat for the Mid-Atlantic later this week from Zeta... ...Possible wintry weather in New England Friday... ...Guidance Evaluation/Preferences... The beginning of the extend period has a closed low tracking through the Mississippi and Tennessee Valleys and eventually lifting through the Mid-Atlantic as an open wave in tandem as a hurricane makes landfall over the central Gulf Coast and curves northeast toward the Mid-Atlantic. The GFS continues to be the faster solution moving Zeta inland and along its path through toward the East Coast. The ECWMF, CMC and the UKMET have been fairly consistent will the pattern evolution, strength, axis orientation and intensity of both the winter storm over the Plains, the heavy rain over the Mississippi/Tennessee Valleys and the heavy swath of tropical-induced rainfall over the Gulf states and Appalachians. Therefore, to maintain a sense of continuity the blend for this forecast consisted of the 00Z ECWMF/CMC/UKMET and the ensemble means. ...Weather/Hazard Highlights... Temperatures across the Southern Plains will moderate by the weekend as the closed low and associated surface fronts progresses eastward, however any northward moving precipitation will more than likely fall as snow Friday. In contrast, above-normal temperatures are forecast for parts of the Pacific Northwest, California and into the Great Basin region. Daily values will be around 5 to 15 degrees warmer. Moderate, possibly locally heavy rain will align from southern portions of the Appalachians and northward to the Ohio Valley to the Mid-Atlantic/southern new England region as Zeta tracks north/east toward the East Coast. Zeta is forecast to progress quickly as it transitions from tropical to extratropical. This should limit some of the excessive rainfall potential. For the Northwest, onshore flow will lend to light rain shower with possibly now in the higher elevations. Campbell 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