US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
319 PM EDT Thu Apr 25 2019
 
Valid Sunday April 28 2019 - Thursday May 02 2019
 
Hazards:
- Heavy rain across portions of the Central/Southern Plains, the Middle/Lower Mississippi Valley, 
the Great Lakes, and the Ohio Valley, Sun-Thu, Apr 28-May 2.
- Heavy snow across portions of the Northern Rockies, Sun, Apr 28.
- Heavy snow across portions of the Northern/Central Rockies Mon-Wed, Apr 29-May 1.
- Heavy snow across portions of the Northern Plains (Bighorn Mountains), Tue-Wed, Apr 30-May 1.
- Severe weather across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, 
and the Southern Plains, Tue, Apr 30.
- Flooding possible across portions of the Great Lakes and the Southern Plains.
- Flooding occurring or imminent across portions of the Mississippi Valley, the Northern and 
Southern Plains, the Tennessee Valley, the Great Lakes, the Northern Rockies, the Northern Great 
Basin, the Ohio Valley, and the Northeast.
- Flooding likely across portions of the Northern Great Basin.
- High winds across portions of the Aleutians, Sun-Mon, Apr 28-Apr 29.
 
Detailed Summary:

Persistent moisture is expected to flow into the Plains and Mississippi Valley through the medium 
range period ahead of general upper-level troughing in the western U.S., with bouts of shortwave 
energy traversing the region, as well as surface fronts. Thus, periods of heavy rain are expected 
in this region for much of next week. Multi-day rainfall totals of 4 to 6 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 Upper Great Lakes region as well. Ahead of one of the shortwaves as lift increases, 
severe weather is also expected for the Southern Plains on Tuesday.  

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 Rockies, Wind River Mountains/Tetons, 
and Bighorn Mountains all expecting heavy snow at some point. 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 Sunday and 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, hazardous temperatures are not expected for the medium range period. 

Tate