US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
320 PM EST Fri Dec 27 2019
 
Valid Monday December 30 2019 - Friday January 03 2020
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest, the Northern Rockies, and the 
Northern Great Basin, Wed-Fri, Jan 1-Jan 3.
- Heavy precipitation across portions of the Great Lakes and the Upper Mississippi Valley, Mon-Tue, 
Dec 30-Dec 31.
- Heavy precipitation across portions of the Northeast, Mon-Wed, Dec 30-Jan 1.
- Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Southern 
Mid-Atlantic, the Southern Appalachians, the Southeast, and the Southern Plains/Western Gulf Coast, 
Wed-Fri, Jan 1-Jan 3.
- Heavy rain across portions of the Northeast, Mon-Tue, Dec 30-Dec 31.
- 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 Northern Plains.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Wed, Dec 
30-Jan 1.
- High winds across portions of mainland Alaska, Mon-Tue, Dec 30-Dec 31.
- High winds across portions of mainland Alaska, Mon-Wed, Dec 30-Jan 1.
- High significant wave heights for coastal portions of the Alaska Panhandle and mainland Alaska, 
Tue-Wed, Dec 31-Jan 1.
 
Detailed Summary:

A storm over the Great Lakes will move northward into Canada, by Tuesday, as the parent low weakens 
significantly while the secondary low moves into the Canadian Maritimes by New Year's Day, 
Wednesday.  The system will produce rain that will change over to snow over parts of the Upper 
Midwest and the Northeast and was depicted on the hazards map as heavy precipitation.  A small area 
of heavy rain will occur over Southern New England also on Wednesday.  

The next system to impact the country with hazards is a combination of return flow off the Western 
Gulf of Mexico and an approaching system out of Mexico that will produce a region of heavy rain 
over parts of Western Gulf coast into parts of the Lower Mississippi Valley and Tennessee Valley on 
New Year's Day, Wednesday.  On Thursday and Friday a front will help to focus the precipitation 
along the Western Gulf Coast into Central Gulf Coast while rain develops ahead of the boundary over 
parts of the Southeast and into parts of the Southern Appalachians/Southern Mid-Atlantic as an area 
of heavy rain is depicted as the weather hazard.  

Another system will move onshore over the Pacific Northwest on Tuesday afternoon that will quickly 
move to the Upper Mississippi Valley to the Southern High Plains by Thursday and to the Great Lakes 
to the Lower Mississippi Valley by Friday.  This system will be quickly followed by another system 
moving onshore over the Pacific Northwest Thursday afternoon into Friday.  The hazard will be areas 
of heavy precipitation over parts of the Cascades into parts of the Northern Rockies with higher 
elevation snow and lower elevation rain on Wednesday into Friday.  As these systems pass by there 
will be several areas of high wind but the areas are to small to depict on the hazards chart.   

Across Alaska, deep low pressure will move into the southern mainland and parts of the Alaska 
Peninsula on Monday and Tuesday.  The system will slowly weaken on Thursday into Friday.  The 
pressure gradient associated with the deep area of low pressure will produce areas of high wind 
over the adjacent coastal regions along the Chukchi Sea, Bering Strait, into the Bering Sea on 
Monday into Wednesday, New Year's Day.  Likewise, the pressure gradient will produce high wind over 
parts of the Alaska Peninsula, Kodiak Island, and parts of Kenal Peninsula on Monday into Tuesday.  
Furthermore, significant waves will develop along the coast of the Alaska Panhandle and the 
Southeast corner of the mainland coast on Tuesday into Wednesday, New Year's Day.  A plume of 
moisture associated with the storm will aid in producing an area of heavy precipitation from parts 
of the Kenal Peninsula eastward to the Alaska Panhandle on Monday into New Year's Day, Wednesday. 

Ziegenfelder