US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 221 PM EST Mon Jan 06 2020 Valid Thursday January 09 2020 - Monday January 13 2020 Hazards: - Heavy precipitation across portions of California, the Pacific Northwest, and the Northern Great Basin, Fri-Mon, Jan 10-Jan 13. - Heavy precipitation across portions of the Northeast, the Central Appalachians, the Middle Mississippi Valley, the Mid-Atlantic, the Great Lakes, and the Ohio Valley, Sat-Mon, Jan 11-Jan 13. - Heavy rain across portions of the Mid-Atlantic, the Lower Mississippi Valley, the Central Appalachians, the Tennessee Valley, the Great Lakes, the Middle Mississippi Valley, the Northeast, the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Thu-Sun, Jan 9-Jan 12. - Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, and the Ohio Valley, Mon, Jan 13. - Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Sat-Mon, Jan 11-Jan 13. - Severe weather across portions of the Lower Mississippi Valley and the Southern Plains, Fri, Jan 10. - Severe weather across portions of the Southeast, the Lower Mississippi Valley, the Southern Appalachians, and the Tennessee Valley, Sat, Jan 11. - Flooding occurring or imminent across portions of the Lower Mississippi Valley, the Northern Plains, and the Tennessee Valley. - Flooding likely across portions of the Pacific Northwest. - Much below normal temperatures across portions of the Northern Plains, the Northern Rockies, and the Northern Great Basin, Sun-Mon, Jan 12-Jan 13. - Much below normal temperatures across portions of the Alaska Panhandle and mainland Alaska, Thu-Mon, Jan 9-Jan 13. Detailed Summary: A very active medium range period (Thursday Jan. 9 to Tuesday Jan. 14) means a busy hazards graphic. A highly amplified trough in the western U.S. and ridge in the East will be the culprit for the hazardous weather. A long-duration heavy rain event is forecast to begin on Thursday across portions of the Lower and Middle Mississippi Valley. Heavy rain will be possible across this same area on Friday and Saturday while also shifting into the Tennessee Valley as well, with a general 3 to 5 inches of total rainfall and locally higher amounts possible. Severe weather will be a concern on Friday and Saturday across the Arklatex and Deep South regions. The Storm Prediction Center has placed highlighted areas here due to the increased threat of severe thunderstorms capable of producing large hail, damaging winds, and tornadoes. Heavy rain is also a high possibility across the Ohio Valley, Lower Great Lakes and Northeast between Friday and Sunday. Slightly lesser amounts of rain are forecast here, but 1 to 3 inches of rainfall could still lead to localized flooding. Portions of the Ohio and Tennessee valleys have seen 150-200% of normal precipitation over the last month, possibly making this event even more impactful. Meanwhile, on the northern and western periphery of the precipitation shield, a wintry mix is possible from the Southern Plains to New England. The greatest threat for impactful winter weather exists from the Midwest and Lower Great Lakes to New England. Snow, sleet, freezing rain will all be possible here thanks to a high pressure system moving just north of the region and ushering in surface temperatures below freezing. Due to changing precipitation types and uncertainty in where exactly the rain/snow line will set up, a "heavy precipitation" label was used instead of "heavy snow". As we approach the beginning of next week another wave of low pressure is forecast to develop across the Lower Mississippi Valley and is likely to bring even more heavy rain across this region and eastward towards the Tennessee Valley and Southeast. The Northwest will have an active weather pattern during this period as well. Multiple rounds of heavy snow, as well as coastal rain and gusty winds will be possible. Colder temperatures are also expected to move in by Sunday and Monday, which means valleys and lower elevations that don't normally see snow could see flakes fly. The core of the colder than average temperatures on Sunday and Monday will be across northern and central Montana. High temperatures here are currently forecast to remain in the single digits or lower, with lows in the minus teens. Meanwhile, temperatures will feel more like Spring across the eastern U.S. as highs soar 20 to 30 degrees above average. Low temperatures will also remain extremely warm for this time of year, with widespread daily record high minimum temperatures expected to be broken. Across Alaska, cold temperatures are forecast to continue across eastern Portions of the state. These much below average temperatures will spill into the Panhandle by Thursday and Friday. A couple potent lows will swing close to the Aleutians, but fail to reach the hazardous wind threshold currently. Snell