US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
321 PM EST Wed Jan 09 2019
 
Valid Saturday January 12 2019 - Wednesday January 16 2019
 
Hazards:
Heavy precipitation across portions of California, Tue-Wed, Jan 15-Jan 16.
Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, 
the Southern Appalachians, the Southeast, and the Ohio Valley, Sat, Jan 12.
Heavy snow across portions of the Central Great Basin, California, and the Southwest, Tue-Wed, Jan 
15-Jan 16.
Heavy snow across portions of the Southeast, the Southern Appalachians, the Mid-Atlantic, the 
Central Appalachians, and the Ohio Valley, Sat-Sun, Jan 12-Jan 13.
Flooding occurring or imminent across portions of the Lower Mississippi Valley, the Middle 
Mississippi Valley, the Mid-Atlantic, the Southeast, the Southern Plains, and the Ohio Valley.
High winds across portions of California, Sun, Jan 13.
Heavy precipitation across portions of mainland Alaska, Sun-Mon, Jan 13-Jan 14.
High significant wave heights for coastal portions of the Aleutians, Sat, Jan 12.
 
Detailed Summary: 

A frontal system is expected to develop in the southern Plains on Saturday, January 12 and move 
eastward off the Carolina coastline on January 13. This system will bring heavy rainfall to 
portions of the Southeast and western Tennessee Valley. Snow will also become a hazard for parts of 
the Ohio Valley and Mid-Atlantic. Models continue to disagree on how far north the heavy snow will 
spread--but for now areas from the southern and central Appalachians to southern and central 
Virginia will receive most of the heavy snowfall. However, as the event gets closer, this snow line 
could stretch northward into the Delmarva region. Additionally, the rain/snow line could also shift 
in North Carolina. As this system exits the East Coast, there could also be high winds impacting 
the Delmarva/North Carolina coast. 

Multiple systems are expected to impact California between January 13 - 16. Initially, on January 
13, the heavy rain/higher elevation snow will mostly impact northern California along with high 
winds. There will be a break in heavy precipitation on January 14, although lighter precipitation 
could still occur. On the 15th and 16th, another trough will dig off the California coast. This 
will bring heavy rain across northern California southward into central California along with heavy 
snow for the Sierra Nevada mountains. 

Alaska will finish it's period of below normal temperatures by the 12th. A strong upper low and 
occlusion will push across the Aleutians and bring significant waves to the western Aleutian 
islands on the 12th. Furthermore, an active pattern in the Gulf of Alaska will bring heavy 
precipitation to south-central Alaska.


Reinhart