US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 422 PM EDT Thu Oct 24 2019 Valid Sunday October 27 2019 - Thursday October 31 2019 Hazards: - Heavy rain across portions of the Southeast, the Southern Mid-Atlantic, the Southern Appalachians, and the Tennessee Valley, Wed-Thu, Oct 30-Oct 31. - Heavy rain across portions of the Northern Mid-Atlantic, the Northeast, and the Central Appalachians, Thu, Oct 31. - Heavy rain across portions of the Northern Mid-Atlantic and the Northeast, Sun-Mon, Oct 27-Oct 28. - Heavy snow across portions of the Central Rockies and the Central Plains, Sun-Mon, Oct 27-Oct 28. - Heavy snow across portions of the Great Lakes and the Upper Mississippi Valley, Tue-Wed, Oct 29-Oct 30. - Flooding possible across portions of the Lower Mississippi Valley, the Southern Plains, and the Northern Plains. - Flooding occurring or imminent across portions of the Upper/Middle Mississippi Valley, and the Northern Plains. - Flooding likely across portions of the Northern Plains. - Much below normal temperatures across portions of the Plains, the Northern/Central Great Basin, the Northern/Central Rockies, and the Upper/Middle Mississippi Valley, Sun-Thu, Oct 27-Oct 31. - Much below normal temperatures across portions of the Plains, the Mississippi Valley, the Tennessee Valley, the Great Lakes, the Central Rockies, and the Ohio Valley, Wed-Thu, Oct 30-Oct 31. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Wed, Oct 27-Oct 30. - Heavy rain across portions of mainland Alaska, Sun-Mon, Oct 27-Oct 28. - Much above normal temperatures across portions of mainland Alaska, Sun-Thu, Oct 27-Oct 31. Detailed Summary: Deep low pressure over the Aleutians, on Sunday, will move northward into Chukchi Sea by Wednesday. A plume of moisture coming from northwest of Hawaii will stream moisture into the Alaska Peninsula and the Southwest Alaska mainland that will aid in producing an area of heavy rain over the Alaska Peninsula and the Southwest Alaska mainland on Sunday into Monday. The same plume of moisture will move northeastward along the the Alaska Peninsula Coast to the Kenal Peninsula by Monday as the plume continues to move northeastward into the Alaska Panhandle by Tuesday. The moisture will aid in producing an area of heavy precipitation over the Kenal Peninsula into Aleutian Range eastward to the Chugach Mountains from Sunday into Wednesday with heavy snow and rain. Additionally, a strong upper-level ridge will extend from parts of the Eastern Pacific northward to the Arctic Coastal Plain and along with the moisture moving northward from the Central Pacific, will aid in produce much above normal temperatures from Point Lay to Kakrtovil/Beaufort Sea from Sunday into Thursday. Over the lower forty-eight states, an area of cold high pressure over Western Canada and a deep upper-level trough will bring much below normal temperatures the Northern/Central Rockies and the Northern/Central Plains from Sunday into Thursday. As the area of cold high pressure moves southeastward to the Southern High Plains, the region of much below normal temperatures will expand eastward and southward to most of the Mississippi Valley and to the Southern High Plains into parts of the Lower Mississippi Valley on Wednesday into Thursday. Also from Sunday into Wednesday a strong pressure gradient associated with the high pressure, will develop along the leading edge of the high pressure from Northern California to the Central High Plains producing a possible area of high winds over the region moving into parts of Southern California to the Southern Plains. The model guidance does not show winds high enough to meet the criteria to draw an area of high winds but the pressure gradient looks strong enough to meet the criteria. A wave of low pressure on a front over the Great Basin/Southwest will aid in producing an area of heavy snow over parts of the Central Rockies/Central High Plains on Sunday into Monday. In addition, low pressure over the Upper Mississippi Valley, on Tuesday, will move eastward into the Upper Great Lakes on Wednesday that will aid in producing an area of heavy snow over parts of the Upper Mississippi Valley/Upper Great Lakes, near Lake Superior on Tuesday into Wednesday. Over the Northeast, low pressure over the Great Lakes will move off the Northeast Coast by Monday. The storm will produce an area of heavy rain over Southern New England Coast on Sunday into Monday. Furthermore, the aforementioned area of low pressure over the Upper Great Lakes, on Wednesday, and the associated fronts will aid in producing an area of heavy rain over parts of the Southern Appalachians/Tennessee Valley on Wednesday into Thursday. A second area of heavy rain will also develop over parts of the Northern Mid-Atlantic/Northeast also on Wednesday into Thursday. Ziegenfelder