US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
505 PM EST Thu Dec 02 2021
 
Valid Sunday December 05 2021 - Thursday December 09 2021
 
Hazards:
- Heavy precipitation across portions of the Central Rockies, the Central Great Basin, the Pacific 
Northwest, the Northern Rockies, and the Northern Great Basin, Mon, Dec 6.
- Heavy precipitation across portions of the Great Lakes, the Mid-Atlantic, the Northeast, the 
Pacific Northwest, and the Northern Great Basin, Wed, Dec 8.
- Heavy rain across portions of the Southeast, the Mid-Atlantic, the Lower Mississippi Valley, the 
Southern Appalachians, and the Tennessee Valley, Thu, Dec 9.
- High winds across portions of the Central Plains, the Great Lakes, the Upper Mississippi Valley, 
the Northern Plains, and the Ohio Valley, Sun-Mon, Dec 5-Dec 6.
- Heavy precipitation across portions of mainland Alaska, Mon, Dec 6.
- Heavy snow across portions of mainland Alaska, Sun, Dec 5.
- High winds across portions of mainland Alaska, Sun-Mon, Dec 5-Dec 6.
- Much below normal temperatures across portions of mainland Alaska, Tue-Thu, Dec 7-Dec 9.
 
Detailed Summary:



On Sunday, a deep area of low pressure over the Upper Midwest moves eastward across the Great Lakes 
into Southeastern Canada by Tuesday.  The system will produce an area of High Winds from the 
Northern Plains to the Great Lakes on Sunday and Monday.  Additionally, the winds across the Lakes 
will be higher on Monday than over the land. The wind will be strong along the Northeast to 
Mid-Atlantic Coast on Monday, too.

On Monday, a front over the North Pacific comes onshore over the Northwest, moving to the Great 
Lakes 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 precipitation over the Northeast on Wednesday.

Furthermore, on Thursday, moisture will pool along the front producing an area of heavy rain from 
parts of the Lower Mississippi /Tennessee Valleys into the Southern Appalachians.  There is some 
uncertainty about how much rain and the areal coverage, so the area may change as the event gets 
closer in time.

Meanwhile, another front comes onshore over the Pacific Northwest on Wednesday, moving inland to 
the Northern Plains southwestward to Northern California by Thursday.  The system will produce an 
area of Heavy Precipitation over parts of the Northwest on Wednesday, but it will be farther north 
than the area of Heavy Precipitation from Monday.  The storm will also produce areas of Heavy 
Precipitation over parts of the Northern Rockies, likewise, on Wednesday.

Over Alaska, a deep area of low pressure over the Bering Sea on Sunday will move eastward over the 
Mainland and weaken by Tuesday.  The system will bring many hazards to Alaska. First, the storm 
will produce Heavy Snow over parts of the Seward Peninsula and parts of the Ahklun Mountains on the 
Southwest Mainland on Sunday.  Second, the strong pressure gradient associated with the low will 
produce an area of High Winds from parts of the Seward Peninsula to the northern portion of the 
Alaska Peninsula on Sunday and Monday.   The third hazard will be Heavy Precipitation over parts of 
the Kenai Peninsula and parts of the Prince William Sound inland to the Chugach Mountains on 
Monday.  The fourth and final hazard will be an area of Much Below Normal Temperatures from the 
Seward Peninsula to the northern portion of the Alaska Peninsula and the adjacent regions of the 
Southwest Mainland from Tuesday to Thursday.

Ziegenfelder