US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
307 PM EST Wed Feb 13 2019
 
Valid Saturday February 16 2019 - Wednesday February 20 2019
 
Hazards:
Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, 
the Southern Appalachians, the Southeast, and the Ohio Valley, Mon-Wed, Feb 18-Feb 20.
Heavy snow across portions of the Central Plains, the Central Great Basin, the Northern Plains, the 
Great Lakes, the Northern Great Basin, the Middle Mississippi Valley, California, the Upper 
Mississippi Valley, the Pacific Northwest, and the Ohio Valley, Sat-Sun, Feb 16-Feb 17.
Heavy snow across portions of the Central Plains, the Central Rockies, the Central Great Basin, the 
Southern Rockies, the Southern Plains, and the Southwest, Mon-Tue, Feb 18-Feb 19.
Heavy snow across portions of the Central Plains, the Mid-Atlantic, the Lower Mississippi Valley, 
the Central Appalachians, the Tennessee Valley, the Middle Mississippi Valley, the Northeast, the 
Southern Appalachians, the Upper Mississippi Valley, the Great Lakes, and the Ohio Valley, Sun-Mon, 
Feb 17-Feb 18.
and Tue-Wed, Feb 19-Feb 20.
Flooding possible across portions of the Middle Mississippi Valley, the Great Lakes, and the Ohio 
Valley.
Flooding occurring or imminent across portions of the Middle Mississippi Valley, the Lower 
Mississippi Valley, the Great Lakes, the Ohio Valley, and the Tennessee Valley.
Flooding likely across portions of the Ohio Valley.
Much below normal temperatures across portions of the Central Plains, the Central Great Basin, the 
Northern Plains, the Southern Plains, the Northern Rockies, the Central Rockies, the Middle 
Mississippi Valley, California, the Northern Great Basin, the Pacific Northwest, and the Southwest, 
Mon-Wed, Feb 18-Feb 20.
Much below normal temperatures across portions of the Central Plains, the Upper Mississippi Valley, 
the Middle Mississippi Valley, the Northern Plains, and the Northern Rockies, Sat-Wed, Feb 16-Feb 
20.
High significant wave heights for coastal portions of California and the Pacific Northwest, Sat, 
Feb 16.
Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Feb 
17-Feb 18.
High winds across portions of mainland Alaska and the Aleutians, Sat-Wed, Feb 16-Feb 20.
High significant wave heights for coastal portions of mainland Alaska and the Aleutians, Mon-Tue, 
Feb 18-Feb 19.
 
Detailed Summary:

Persistent high pressure at the surface and upper-level troughing will lead to much below 
temperatures throughout the day 3-7 period. The cold air will be centered in the Northern Plains, 
and instances of below average temperatures will extend into the Central Plains and Upper/Middle 
Mississippi Valley at times. Better chances for below normal low temperatures are expected to the 
west and south into the Rockies by Wednesday.

Though much of the heavy precipitation in the West is now in the short range period, another 
shortwave trough is currently forecast to come into the West on Friday. This could lead to 
significant waves and gusty winds (though might not exceed high wind criteria) along the Pacific 
Northwest and Northern California coast on Friday. The Sierra Nevada mountains could have 
additional heavy snow, and along the Northern California and southern Oregon coast can expect some 
additional heavy lower elevation rain and mountain snow.

A wave of low pressure along a boundary will move eastward off the East Coast followed by another 
wave of low pressure follow by a third wave of low pressure by Wednesday.  By Monday to Wednesday, 
copious amounts of Gulf moisture will return to the Southeastern U.S. ahead of upper-level energy, 
leading to the possibility of heavy rain from the Lower Mississippi Valley eastward into the South 
Mid-Atlantic.  Heavy snow is possible from parts of the Northern/Central Plains into parts of the 
Western Ohio Valley on Saturday into Sunday.  As the system moves eastward, heavy snow will develop 
over the Western Ohio Valley eastward to parts of the Northeast from Sunday into Wednesday.  

For Alaska, a strong low pressure system is forecast to make its way across the Aleutians on Sunday 
and into the western Alaska mainland by Monday night to Tuesday. This low will help cause strong 
winds and significant waves for the Aleutians, and heavy precipitation for southern Alaska on 
Sunday into Monday.  

Ziegenfelder