US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 355 PM EDT Thu Sep 26 2019 Valid Sunday September 29 2019 - Thursday October 03 2019 Hazards: - Heavy precipitation across portions of the Upper Mississippi Valley, the Northern Plains, and the Northern Rockies, Sun, Sep 29. - Heavy rain across portions of the Central Plains, the Southern Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, the Great Lakes, and the Ohio Valley, Mon-Thu, Sep 30-Oct 3. - Flooding possible across portions of the Middle Mississippi Valley, the Great Lakes, and the Upper Mississippi Valley. - Flooding occurring or imminent across portions of the Central Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Northern Plains. - High winds across portions of the Central Rockies, Sun, Sep 29. - Much above normal temperatures across portions of the Lower Mississippi Valley, the Central Appalachians, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, and the Ohio Valley, Sun-Thu, Sep 29-Oct 3. - Much below normal temperatures across portions of the Central Plains, the Central Great Basin, the Northern Plains, the Northern Rockies, the Central Rockies, California, the Northern Great Basin, the Pacific Northwest, and the Southwest, Sun-Thu, Sep 29-Oct 3. - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Sun-Tue, Sep 29-Oct 1. Detailed Summary: Medium range period (Sunday to Thursday) continues to be highly amplified with a deep trough over the West and an upper ridge over the East. Temperatures under the trough will be well below normal by 10 to 25 degrees (locally 25 to 35 degrees below normal across parts of Montana). Morning lows are also expected to be below normal, though not to the extreme as the daytime highs. Temperatures rising only into the 30s and 40s will very likely set many record cold maxes as well as record low minimums with readings into the 10s and 20s. The cold temperatures will start to relent by the end of the period Thursday. Meanwhile in the East, daytime highs could be 10 to 25 degrees above normal generally east of the Mississippi River (though perhaps not necessarily hazardous farther north). However, temperatures in the Deep South to the lower Ohio Valley and southern Mid-Atlantic may see highs in the mid to upper 90s which will likely come close to or exceed daily high temperature records. For this reason, a much above normal temperatures hazard area was included for this region that has seen well below normal precipitation this month (many areas are in the top 5 driest Septembers to date). In between the western trough and eastern ridge, plenty of moisture will be funneled northward and northeastward across the Plains region as a couple areas of low pressure lift through the region. This will aide in producing areas of heavy rain from the southern Rockies northeastward to the western Great Lakes and an area of heavy rain (and mountain snow) from the northern Rockies eastward to North Dakota/northern Minnesota. Though the heaviest snow will generally be in higher elevations, appreciable snow may also spill over into the lower elevations as well. The attendant cold front may slow or stall across the Central Plains to the Upper Midwest/Great Lakes Monday-Wednesday which would provide an additional focus for heavy rainfall. By next Thursday, the front may sink southward into the lower Mississippi Valley/Tennessee Valley in tandem with the heavy rain threat. Several inches of rain are possible within this one sizable area, focused from north to south through the week. In Alaska, a system moving into the Gulf of Alaska early next week should bring a threat for heavy rainfall across the southern Coast (western side of Cook Intel, eastern Kenai across Southcentral coast to the Panhandle). Much of this should be rain, though some snow (probably below hazard criteria) is possible in the highest terrain. Wind and waves will be modest but perhaps below criteria levels. Fracasso