US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
327 PM EST Tue Feb 12 2019
 
Valid Friday February 15 2019 - Tuesday February 19 2019
 
Hazards:
Heavy precipitation across portions of California and the Pacific Northwest, Fri-Sat, Feb 15-Feb 16.
Heavy rain across portions of the southeastern U.S., Mon-Tue, Feb 18-Feb 19.
Heavy precipitation across portions of the Tennessee Valley to Southern Appalachians just north of 
the heavy rain, Mon-Tue, Feb 18-Feb 19.
Heavy snow across portions of the Central Great Basin and California, Fri-Sat, Feb 15-Feb 16.
Heavy snow across portions of the Northeast, Fri, Feb 15.
Flooding possible across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, 
the Great Lakes, the Ohio Valley, and the Tennessee 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 Northern/Central Plains to Upper/Middle 
Mississippi Valley, Fri-Tue, Feb 15-Feb 19.
Much below normal temperatures across portions of the Northern/Central Great Basin, 
Northern/Central Rockies, and Central Plains, Mon-Tue, Feb 18-Feb 19.
High significant wave heights for coastal portions of California and the Pacific Northwest, Fri, 
Feb 15.
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, Sun-Mon, Feb 17-Feb 18.
High winds across portions of mainland Alaska, Mon-Tue, Feb 18-Feb 19.
High significant wave heights for coastal portions of mainland Alaska and the Aleutians, Sun-Mon, 
Feb 17-Feb 18.
 
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 the beginning of next week. 

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.  

By Monday to Wednesday of next week, copious amounts of Gulf moisture will return to the 
southeastern U.S. ahead of upper-level energy, leading to the possibility of heavy rain and heavy 
precipitation. Heavy rain is most likely in the Southeast, and at this point, there is still plenty 
of uncertainty as to the precipitation type on the northern edge of the precipitation. Snow appears 
possible to the north of the drawn heavy precipitation area, in the Ohio Valley to the northern 
Mid-Atlantic and Northeast. In between the rain and snow in the transition zone, mixed 
precipitation and freezing rain appear possible, but forecast uncertainty precluded us from drawing 
a heavy snow or freezing rain area at this time. 

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, high winds for western Alaska, and heavy 
precipitation for southern Alaska. 

Tate