US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
401 PM EST Tue Nov 16 2021
 
Valid Friday November 19 2021 - Tuesday November 23 2021
 
Hazards:
- Heavy precipitation across portions of the Northeast, Mon-Tue, Nov 22-Nov 23.
- Heavy rain across portions of the Northeast, Mon-Tue, Nov 22-Nov 23.
- Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Fri, Nov 19.
- Flooding occurring or imminent across portions of the Pacific Northwest and the Northern Great 
Basin.
- Flooding likely across portions of the Northern Great Basin.
- Much below normal temperatures across portions of the Southeast, the Lower Mississippi Valley, 
the Southern Appalachians, and the Tennessee Valley, Tue, Nov 23.
- Heavy precipitation across portions of the Alaska Panhandle, Sun-Mon, Nov 21-Nov 22.
- Much below normal temperatures across portions of mainland Alaska, Fri-Mon, Nov 19-Nov 22.
- Much below normal temperatures across portions of mainland Alaska, Fri, Nov 19.
 
Detailed Summary:

A weak front crossing the Northwest moving to the Great Lakes by Sunday will produce areas of heavy 
snow across parts of the Northern Intermountain Region and the Northern Rockies on Friday. 

A stronger front moving out of South-Western Canada will move into the Great Lakes on Sunday into 
Monday. The associated surface low goes through rapid deepening during that time period, developing 
a Norâ€easter along the Northeast Coast by Tuesday.  The deep area of low pressure will pull cold 
air southward out of Canada that will aid in the rapid deepening as well as bringing temperatures 
in the upper 20s to lower 30s over parts of the interior Northeast on Tuesday.  Likewise, the storm 
will pull moisture off the Atlantic into the Northeast on Tuesday. The moisture will produce heavy 
rain over parts of the New England Coast and heavy precipitation, in the form of rain and snow over 
the interior parts of the Northeast on Monday into Tuesday.  However, there are some differences in 
the models, with the GFS being faster with the system and hence lower precipitation totals over the 
Northeast.  On the other hand, the ECMWF has much more precipitation over the Northeast as the 
model moves the system slower across the region.  With Thanksgiving being later on Thursday, and 
this being a heavily traveled time period, WPC though it would be in the best interest to show the 
complexed mix precipitation, with this also being the first snowfall for this parts of the country 
this year.   The WPC will continue to monitor the situation and make changes as the dates get close 
in time.  

Additionally, the deep area of low pressure will pull cold air southward over the Southeast with 
low temperatures reaching the low 30s to upper 20s on Tuesday morning, which may be the first frost 
to the region. Therefore, an area of much below normal temperatures is depicted on the Hazards 
Chart over northern Mississippi, Alabama, and Georgia for Tuesday.  

For Alaska, an area of cold high pressure will move over the mainland with a deep upper-level low 
moving over the Aleutians and Southwest and South-Central Coast from Friday into Monday.  The 
temperatures will be in the single digits to below zero, therefore an area of much below normal is 
depicted on the Hazards Chart over the South-Central mainland on Friday.  Much below normal is also 
depicted over parts of the Southwest, including parts of the Alaska Peninsula, Kuskokwim Mountains, 
and the western part of the Alaska Range and the Aleutian Range on Friday into Monday. 

An area of low pressure will move into the Gulf of Alaska by Saturday that will move eastward to 
the Alaskan Panhandle by Monday.   The storm will produce heavy precipitation from the Inside 
Passage southward including Juneau from Sunday to Monday.  The system will produce heavy rain along 
the coast and lowest elevations and snow at the higher elevations and inland.  

Ziegenfelder