US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
358 PM EDT Fri Apr 26 2019
 
Valid Monday April 29 2019 - Friday May 03 2019
 
Hazards:
- Heavy precipitation across portions of the Central Rockies, the Central Plains, and the Central 
Great Basin, Mon-Wed, Apr 29-May 1.
- Heavy rain across portions of the Central Plains, the Mid-Atlantic, the Lower Mississippi Valley, 
the Central Appalachians, the Tennessee Valley, the Great Lakes, the Middle Mississippi Valley, the 
Northeast, the Upper Mississippi Valley, the Southern Plains, and the Ohio Valley, Mon-Fri, Apr 
29-May 3.
- Heavy snow across portions of the Central Rockies, the Central Plains, the Northern Plains, and 
the Northern Rockies, Mon-Wed, Apr 29-May 1.
- Heavy snow across portions of the Northern Plains, Tue-Wed, Apr 30-May 1.
- Severe weather across portions of the Lower Mississippi Valley and the Southern Plains, Tue, Apr 
30.
- Flooding possible across portions of the Northeast, the Great Lakes, the Upper Mississippi 
Valley, and the Northern Plains.
- Flooding occurring or imminent across portions of the Lower Mississippi Valley, the Northern 
Plains, the Great Lakes, the Northern Rockies, the Middle Mississippi Valley, the Northeast, the 
Northern Great Basin, the Upper Mississippi Valley, the Southern Plains, and the Ohio Valley.
- Flooding likely across portions of the Northern Great Basin.
- High winds across portions of the Aleutians, Mon, Apr 29.
 
Detailed Summary:

The most noteworthy hazard in the medium range period will be a wide area of prolonged heavy rain 
from the Southern Plains into the Interior Northeast. Several rounds of heavy rain spanning 
multiple days could cause flooding concerns. The ingredients consist of persistent moisture flow 
into the Plains and Mississippi Valley, general upper-level troughing in the western U.S., bouts of 
shortwave energy traversing the region, as well as quasi-stationary surface fronts. Multi-day 
rainfall totals of 3 to 7 inches are currently forecast for portions of the Southern Plains and 
Middle Mississippi Valley. Particularly in the Mississippi Valley, flooding has been a concern for 
several weeks, and this event will exacerbate flooding concerns. At times, most likely on 
Wednesday, heavy rainfall could encroach upon the Ohio Valley and the Lower Great Lakes region as 
well. By Thursday the heavy rain threat could move into portions of the Interior Northeast and by 
Friday the axis of heaviest rain should be situated across central and eastern Texas. Ahead of one 
of the shortwaves on Tuesday, severe weather is expected for parts the Southern Plains.

With the upper troughing, the northwestern U.S. will see cool temperatures and the potential for 
heavy snow in higher elevations. The Hazards chart followed the higher probabilities of heavy snow 
on the WPC Winter Weather Forecast charts, with the Northern and Central Rockies, Wind River 
Mountains/Tetons, and Bighorn Mountains all expecting heavy snow at some point. Parts of Central 
Rockies are highlighted in a heavy precipitation region due to heavy rain mixing into the lower 
elevations. Some late-season snow is also possible farther east in the Northern/Central High Plains.

Upper ridging is expected over mainland Alaska generally throughout the forecast period. Over the 
Aleutians, a surface low moving through on Monday could lead to high winds particularly in the 
western Aleutians.

Below average temperatures are forecast for the northwestern to north central parts of the 
contiguous U.S. with the aforementioned upper-level troughing. On the other hand, a subtropical 
ridge building across the Southeast should lead to above average temperatures for Monday onward in 
the Tennessee Valley and Southeast, with some periods of warmth in the Ohio Valley and Mid-Atlantic 
region possible. However, these temperatures are not expected to be considered hazardous for the 
medium range period.

Snell