US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
201 PM EST Tue Dec 31 2019
 
Valid Friday January 03 2020 - Tuesday January 07 2020
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, 
Fri-Sun, Jan 3-Jan 5.
- Heavy rain across portions of the Southeast, the Mid-Atlantic, and the Southern Appalachians, 
Fri-Sat, Jan 3-Jan 4.
- Flooding possible across portions of the Middle Mississippi Valley, the Great Lakes, the Ohio 
Valley, and the Upper Mississippi Valley.
- Flooding occurring or imminent across portions of the Northern Plains.
- High winds across portions of the Southern Appalachians, the Mid-Atlantic, the Central 
Appalachians, and the Ohio Valley, Sun, Jan 5.
- Much below normal temperatures across portions of mainland Alaska, Fri-Tue, Jan 3-Jan 7.
 
Detailed Summary:

Across the Eastern U.S. at the beginning of the medium range period (Friday), a vigorous 
upper-level vortex emerging from northern Mexico will draw moisture northward from the Gulf of 
Mexico. Heavy rain will be likely across the southern Appalachians and Southeast on Friday, with 24 
hour rainfall totals between 1 to 2 inches. Snow will be possible on the northwestern edge of the 
precipitation shield across the Midwest and Great Lakes on Friday and Saturday, but amounts at the 
moment appear light and uncertainty was enough to exclude a highlighted area from the hazards chart 
today. Snow is also possible across New England on Saturday and Sunday, but total snowfall amounts 
also appear less than 5 inches. As this system strengthens and races off the northeast coast on 
Sunday, high winds are possible across the Mid-Atlantic, central and southern Appalachians. Wind 
gusts could approach 50 mph in some areas, bringing the risk of tree damage.

Active weather will continue across the Northwest through the first weekend of the new year. Heavy 
rain and mountain snow will be the main hazards, with 3 to 6 inches of total precipitation possible 
by Sunday. Once we approach Monday and Tuesday, there is a large spread of possibilities across the 
central and eastern United States as upper-level energy enters from the Northwest. A few of these 
possibilities include impactful winter weather. Due to the high uncertainty no hazards were 
included in today's graphic, but it is something to watch over the next few days. 

Alaska is forecast to endure a less active pattern during this time frame, but temperatures 20 to 
40 degrees below average across the southwest mainland warranted a highlighted area on the hazards 
chart. These temperature anomalies equate to lows around minus 30 degrees. 

Happy New Year!

Snell