US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 207 PM EST Thu Nov 05 2020 Valid Sunday November 08 2020 - Thursday November 12 2020 Hazards: - Heavy precipitation across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, the Upper Mississippi Valley, and the Northern Plains, Tue-Wed, Nov 10-Nov 11. - Heavy rain across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, the Ohio Valley, and the Upper Mississippi Valley, Tue-Wed, Nov 10-Nov 11. - Heavy rain across portions of the Southeast, Sun-Tue, Nov 8-Nov 10. - Heavy rain across portions of the Central Appalachians, the Tennessee Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, and the Ohio Valley, Wed-Thu, Nov 11-Nov 12. - Heavy snow across portions of the Central Rockies and the Central Great Basin, Sun-Mon, Nov 8-Nov 9. - Heavy snow across portions of the Northern Plains and the Northern Rockies, Sun, Nov 8. - High winds across portions of the Central Plains, the Northern Plains, and the Northern Rockies, Sun, Nov 8. - High winds across portions of the Southeast, Sun-Mon, Nov 8-Nov 9. - 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, Mon-Thu, Nov 9-Nov 12. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Nov 8-Nov 9. - High winds across portions of mainland Alaska, Tue-Wed, Nov 10-Nov 11. Detailed Summary: The medium range period (Sunday, November 8th - Thursday, November 12th) will start with a deep upper-level trough moving slowly through the western U.S. toward the north-central U.S. by Tuesday, bringing anomalously cold air and precipitation potential. Heavy snow is likely across portions of Montana and far northwestern North Dakota on Sunday and Sunday night. Total snowfall amounts greater than 6 inches and locally higher than a foot are possible across north central Montana. High winds will also be possible throughout this region, as well as throughout the northern and central Plains as a low pressure system rapidly strengthens. These winds could lead to blizzard conditions across Montana, and the combination of high winds and low relative humidity could enhance fire weather in the Plains. Meanwhile, widespread and much-needed light to moderate precipitation can be expected across much of the Southwest, Intermountain West, and Rockies on Sunday and Monday. Particularly high snowfall totals are possible in higher elevations of the San Juan Mountains in Colorado, with snowfall also likely from the Sierra Mountains of California eastward to the southern Rockies. The cold air associated with this system will be quite cold and last through late next week. High temperatures of 15 to 30 degrees below normal are expected in the West starting on Sunday, while low temperatures will become especially cold by Monday and Tuesday from parts of the West into the Northern High Plains. Single digit lows are forecast in lower elevations of Montana, and in higher elevations of the Intermountain West. By Tuesday, the frontal system is forecast to track slowly through the Plains and Mississippi Valley, providing a focus for heavy precipitation both on Tuesday and Wednesday. On the warm side of the front, heavy rain is likely, but rain could change over to snow in on the western edge from about eastern Nebraska to the Upper Great Lakes. Models have trended towards less wintry precipitation, but the likelihood of impactful snow is still high enough to include a highlighted area. The heavy rain threat will shift eastward to the southern/central Appalachians and Mid-Atlantic by Wednesday and Thursday. The combination of an incoming upper-level jet streak and moisture entering the region from the eastern Gulf of Mexico could create an area of heavy rain from the southern Appalachians to eastern North Carolina. Meanwhile, ahead of the upper trough and frontal system, high pressure is generally expected, causing warmer than normal conditions to shift away from the Plains/Midwest on Sunday and further develop in the Great Lakes/Northeast through midweek. High temperature anomalies in the Great Lakes and Ohio Valley toward the Northeast will be 10 to 20 degrees above normal, which equates to comfortable temperatures in the 60s and 70s. Widespread record warm minimum and maximum temperatures could be set through parts of the central and eastern CONUS between Sunday and Wednesday. The active weather pattern also continues to include tropical trouble associated with Tropical Depression Eta. There is still plenty of uncertainty regarding what happens with Eta as it currently meanders in Central America. It still appears that Eta will reemerge over the northwestern Caribbean and could track northward toward Cuba and Florida early next week. See the National Hurricane Center for updated forecasts on this system. Regardless, rain and gusty winds are forecast to persist across southern and eastern Florida over the weekend and early next week thanks to easterly flow with tropical moisture. If Eta does end up approaching closer the state next week, additional heavy rainfall is likely. Across Alaska, the most certain potential hazard during the period is heavy precipitation spreading from west to east across the Gulf of Alaska Coast/Southcentral region into the Panhandle Sunday into Monday as a strong surface low pressure system tracks along the coast. Localized areas of high winds are also possible given the depth of the low, leading to the potential for some isolated areas of blizzard conditions in Southcentral Alaska. By Tuesday and Wednesday a separate system is forecast to enter the Bering sea, bringing gusty winds, along with rain and snow across western portions of the state. Snell