US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
345 PM EST Mon Nov 09 2020
 
Valid Thursday November 12 2020 - Monday November 16 2020
 
Hazards:
- Heavy precipitation across portions of the Northern/Central Plains, the Great Basin, the 
Northern/Central Rockies, California, and the Pacific Northwest, Thu-Mon, Nov 12-Nov 16.
- Heavy rain across portions of the Southeast and the Mid-Atlantic, Thu, Nov 12.
- Heavy rain across portions of the Central/Southern Appalachians, the Tennessee Valley, the 
Mid-Atlantic, the Southeast, the Great Lakes, and the Ohio Valley, Sat, Nov 14.
- Heavy rain across portions of the Great Lakes, the Mid-Atlantic, the Northeast, and the Central 
Appalachians, Sun, Nov 15.
- Flooding possible across portions of the Southeast, the Great Lakes, the Mid-Atlantic, the 
Southern Appalachians, and the Upper Mississippi Valley.
- Much below normal temperatures across portions of the Great Basin, the Northern Rockies, and the 
Northern Plains, Thu, Nov 12.
 
Detailed Summary:

Tropical Cyclone ETA is forecast to move slowly southwestward away from the Florida Keys then, on 
Tuesday morning, move northeastward to near Perry, Florida by Saturday.  ETA will interact with a 
near by front to become a wave of low pressure on the boundary.  There is a lot of uncertainty with 
this forecast so see the latest advisory from NHC for the latest on track and intensity of ETA.

Meanwhile, multiple systems will move into the Pacific Northwest through Monday.  The three systems 
will each bring moisture into the Northwest Coast and inland allowing for higher elevation snow and 
lower elevation rain over the Pacific Northwest inland to the Northern/Central Rockies through 
Monday.  The changing precipitation type meets our criteria for depicting and area of heavy 
precipitation over the region.  In addition, an upper-level troughing associated with the first 
system will aid in allowing morning low temperatures to be 12 degrees or greater below normal 
temperatures with some areas experiencing single digits and low teens on Thursday morning. 

Out East, a front extending from New England Coast southwestward to the Central Gulf Coast will 
have moisture pooling along the boundary aiding in producing an area of heavy rain along the 
Southeast Coast into the Mid-Atlantic mainly on Thursday.  An area of low pressure over the Central 
Plains, on Saturday, will move northward to Central Canada by Sunday.  The system will have a 
strong contention to moisture from the Western Gulf of Mexico that will aid in producing and area 
of heavy rain over parts of the Tennessee/Ohio Valleys and Central/Southern Appalachians on 
Saturday.  Additionally, low pressure over the Mid-Atlantic Coast, on Sunday, will move northward 
and merge with the system moving eastward from Central Canada by Monday.  The low will have a 
strong connection to moisture that will produce heavy rain over parts of the Mid-Atlantic and 
Northeast on Sunday.  As the strong low over Central Canada moves eastward rain will develop over 
parts of Maine but at this time there is uncertainty about if the system will produce enough rain 
to put an area of heavy rain on the Hazards chart on Monday. 

Over Alaska, low pressure along the Gulf of Alaska Coast will slowly move eastward and weaken as 
high pressure builds over most of the state by Monday.  The low will be lacking moisture to produce 
any areas of heavy precipitation over the area from Thursday to Monday.

Ziegenfelder