US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 445 PM EDT Thu Oct 08 2020 Valid Sunday October 11 2020 - Thursday October 15 2020 Hazards: - Heavy rain across portions of the northwestern Washington, Sun-Wed, Oct 11-Oct 14. - Heavy rain across portions of the Ohio Valley to the central Appalachians, the Mid-Atlantic, and into southern New England, Sun-Mon, Oct 11-Oct 12. - Heavy precipitation across portions of northern Idaho, Sun, Oct 11. - Heavy precipitation across portions of northwestern Wyoming, Sun, Oct 11. - Severe weather possible across portions of the northern to central Plains into the upper Midwest, Sun, Oct 11. - Flooding possible across portions of western Louisiana into the lower to middle Mississippi Valley. - Flooding occurring or imminent across portions of northeastern Florida. - Flooding likely over southwestern Louisiana. - Much above normal temperatures across a large portion of the Great Plains, Sun, Oct 11. - Enhanced wildfire risk across portions of the southern High Plains, Sun, Oct 11. - Heavy precipitation across much of the Alaska Panhandle, Tue, Oct 13 and Thu, Oct 15. Detailed Summary: The medium range period will begin with moisture associated with the remnants of Hurricane Delta moving across the Ohio Valley into the central and southern Appalachians Sunday morning when the storm center is forecast to move across Tennessee. Heavy rainfall can be expected in these areas on Sunday, before shifting into portions of the Mid-Atlantic states followed by southern New England on Monday. Global models indicate that the circulation center of Delta should dissipate on Monday but the associated remnant moisture should continue to spread into the rest of New England on Tuesday ahead of an approaching cold front. This cold front, which signals a major change in the synoptic pattern across the U.S., appears to accompany with rather vigorous dynamics. While a region-wide heavy rain event is not expected at this point in time, it appears that some heavy downpours and gusty winds associated with strong thunderstorms are possible in New England on Tuesday ahead of the front. Over the western U.S. a large dome of cold air associated with a deep upper trough will be ushered into the northern and central Plains on Sunday and Monday behind the strong cold front. The Storm Prediction Center is highlighting portions of northern to central Plains as well as nearby upper Midwest as the area to watch for the possibility of severe weather on Monday. Moisture being lifted in the cold air mass over the rugged terrain could bring a period of mixed precipitation to the higher elevations of northwestern Wyoming and northern Idaho on Monday before tapering off on Tuesday. Some meaningful snowfall accumulations can be expected at the coldest locations from northern Idaho to northwestern Wyoming, and possibly the higher elevations of northern Colorado as well. Ahead of the strong cold front however, another day of much above normal temperatures is forecast for much of the Plains, especially for the southern Plains, where record high temperatures reaching into the upper 90s to near 100 are possible Sunday afternoon. In addition, an enhanced wildfire risk is forecast for the southern High Plains on Sunday. Meanwhile, an active weather pattern over the northeastern Pacific will likely bring persistent rain into the Pacific Northwest, particularly the higher elevations of northwestern Washington, into the middle of next week. Finally, a relatively quiet start to the medium range period for Alaska will become more active toward the middle of next week when global models indicate the possibility of a couple of strong occluded cyclones edging close to the Alaska Panhandle. It appears that the most likely dates of seeing heavy precipitation impacting the Alaska Panhandle will be next Tuesday and Thursday. Nevertheless, the timing of the heavy precipitation is subject to change as global models are indicating a great deal of uncertainty forecasting this active synoptic pattern. Kong