US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
329 PM EDT Mon Apr 01 2019
 
Valid Thursday April 04 2019 - Monday April 08 2019
 
Hazards:
- Heavy precipitation across portions of California, the Central Great Basin, the Pacific 
Northwest, and the Northern Great Basin, Thu-Sun, Apr 4-Apr 7.
- Heavy rain across portions of California and the Pacific Northwest, Thu-Sun, Apr 4-Apr 7.
- Heavy rain across portions of the Lower Mississippi Valley and the Southern Plains, Sat-Sun, Apr 
6-Apr 7.
- Heavy rain across portions of the Southeast, the Lower Mississippi Valley, and the Tennessee 
Valley, Thu-Fri, Apr 4-Apr 5.
- Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Sat-Sun, Apr 
6-Apr 7.
- Heavy snow across portions of the Northeast, Fri-Sat, Apr 5-Apr 6.
- Severe weather across portions of the Southeast, the Lower Mississippi Valley, the Southern 
Plains, and the Tennessee Valley, Thu, Apr 4.
- Flooding possible across portions of the Middle Mississippi Valley.
- Flooding occurring or imminent across portions of the Central Plains, the Lower Mississippi 
Valley, the Northern Plains, the Tennessee Valley, the Middle Mississippi Valley, the Upper 
Mississippi Valley, the Great Lakes, and the Ohio Valley.
- Flooding likely across portions of the Middle Mississippi Valley and the Northern Plains.
- High significant wave heights for coastal portions of California and the Pacific Northwest, 
Sat-Sun, Apr 6-Apr 7.
 
Detailed Summary:

Two rounds of heavy rain will be possible across the Deep South in the medium range. The first 
round is forecast to be focused across the Lower Mississippi Valley and central Gulf Coast Thursday 
and Friday (Apr 4-5). Moisture will flow northward from the Gulf of Mexico ahead of a low pressure 
system approaching from the central/southern Plains. Thunderstorms will also be likely and could 
turn severe according to the Storm Prediction Center's Severe Weather Outlook. The potential for a 
second round of heavy rain will be possible on Saturday and Sunday (Apr 6-7), slightly west of the 
previous event across the Southern Plains and Lower Mississippi Valley. The weekend heavy rainfall 
will be focused along a stalled frontal boundary and ahead of another system entering the Southern 
Plains.

Across northern New England there is potential for heavy snow on Friday and Saturday (Apr 5-6). 
High pressure will usher in cold temperatures ahead of an approaching area of precipitation from 
the Ohio Valley. There is still uncertainty related to the amount of precipitation available, but 
nonetheless the potential for a late season heavy snow event is there. If snowfall amounts greater 
than 4 inches were to occur, the greatest chance will be across the Adirondack Mountains of New 
York State, as well as the Green and White Mountains across New Hampshire, Vermont, and western 
Maine.

The Western U.S. will see an active period from Thursday to Sunday (Apr 4-7). A strong Pacific 
front will enter the Northwest on Saturday and bring the possibility of significant waves from 
northern California northward to coastal Washington. Heavy rain is possible along the coast of the 
Pacific Northwest, as well as northern California. Meanwhile, a mix of heavy rain and snow will be 
possible across the higher elevations, including the Sierra Nevada and Cascades. Inland, heavy snow 
will be possible across the Northern Rockies and Northern Great Basin, particularly across the 
Sawtooth Mountains of Idaho.

Alaska will again remain fairly quiet during the medium range period. Any precipitation will be 
light and not enough to meet hazardous criteria. Rain and snow will be confined to the southern 
parts of the state, as well as the Aleutians. A strong low pressure system could approach the 
western Aleutians by Monday and bring gusty winds, but confidence is low at this point. 

Snell