US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 411 PM EST Fri Dec 03 2021 Valid Monday December 06 2021 - Friday December 10 2021 Hazards: - Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, Mon, Dec 6 and Wed-Thu, Dec 8-Dec 9. - Heavy precipitation across portions of the Northeast, the Pacific Northwest, and the Northern Great Basin, Wed, Dec 8. - Heavy precipitation across portions of the Central Great Basin, California, and the Southwest, Thu, Dec 9. - Heavy precipitation across portions of the Northern/Central Rockies, and the Great Basin, Mon, Dec 6 and Wed, Dec 8. - Heavy precipitation across portions of the Central Rockies and the Central Great Basin, Mon, Dec 6 and Thu, Dec 9. - Heavy rain across portions of the Mid-Atlantic, the Northeast, the Tennessee Valley, the Lower Mississippi Valley, the Southern Appalachians, the Southeast, and the Southern Plains, Wed-Thu, Dec 8-Dec 9. - High winds across portions of the Northeast, the Middle Mississippi Valley, the Mid-Atlantic, the Upper Mississippi Valley, the Great Lakes, and the Ohio Valley, Mon, Dec 6. - Heavy precipitation across portions of mainland Alaska, Mon, Dec 6. - Heavy precipitation across portions of the Alaska Panhandle, Tue, Dec 7. - High winds across portions of mainland Alaska, Mon, Dec 6. Detailed Summary: On Monday, a deep area of low pressure over the Great Lakes moves quickly into Southeastern Canada by Tuesday. Also, on Monday, the system will produce an area of High Winds from parts of the Upper/Middle Mississippi Valley into the Great Lakes/Ohio Valley. Additionally, the winds across the Lakes will be higher on Monday than over the land. Furthermore, the same system will also produce another High Winds area across the Northeast Coast to Cape Hatteras on Monday. On Monday, a front over the North Pacific comes onshore over the Northwest, moving to the Ohio Valley to the Southern Plains by Wednesday. Also, on Monday, the storm will produce heavy precipitation over parts of the Pacific Northwest and parts of the Northern/Central Rockies. By Thursday, the front continues to move eastward off the Northeast/Mid-Atlantic Coast. The system will produce an area of Heavy Rain over parts of the Lower Mississippi Valley to the Southern Appalachians on Wednesday and continue over parts of the Southeast Mid-Atlantic into parts of the New England Coast on Thursday. There will be heavy precipitation over parts of New England on Wednesday, too, a little farther inland. Furthermore, on Wednesday, another front will come onshore over the Pacific Northwest and move eastward to the Great Lakes by Friday. Weak onshore flow will stream some moisture into the Northwest and the Northern Rockies. Multiple areas of Heavy Precipitation will develop over parts of the Cascades and Northern Rockies on Wednesday into Thursday. As the front moves south over California and the Great Basin on Thursday, Heavy precipitation will develop over the Sierra Nevada Mountains and the Wasatch Range. There is uncertainty whether or not the Heavy Precipitation will continue over the Sierra Nevada Mountains for Friday, or there could be heavy rain over parts of the Southeast. At this point in time, the spread is too great to make a call one way or the other. Over Alaska, the deep area of low pressure over the Southwest Coast of the Mainland will produce Blizzard conditions overnight Sunday into Monday morning. On Monday, the high winds will come down over the state's western portion, while High Winds will be over the middle of the Brooks Range and the Alaska Range, east of Denali. Furthermore, on Monday, Heavy Precipitation will develop over the Kenai Peninsula eastward to Yakutat and extend across the Cook Inlet to parts of the Alaska Range. On Tuesday, as the low moves across the Gulf of Alaska, moisture will stream into the Alaskan Panhandle producing Heavy Precipitation across the Panhandle. Wednesday, the low and associated front moved into Western Canada as another low move off Asia into the Bering Sea. The low will sit over the Bering Sea on Thursday and creep inland over the west coast of the Mainland on Friday. Ziegenfelder