US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
344 PM EDT Fri Apr 09 2021
 
Valid Monday April 12 2021 - Friday April 16 2021
 
Hazards:
- Heavy rain across portions of the Southeast, the Southern Appalachians, the Lower Mississippi 
Valley, the Southern Plains, and the Tennessee Valley, Tue-Thu, Apr 13-Apr 15.
- Heavy snow across portions of the Central Rockies, the Central Plains, and the Central Great 
Basin, Tue-Thu, Apr 13-Apr 15.
- Flooding occurring or imminent across portions of the Middle Mississippi Valley and the Lower 
Mississippi Valley.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Wed, Apr 
12-Apr 14.
 
Detailed Summary:

In the medium-range forecast period, the hazards chart has an area of heavy rain near the Gulf of 
Mexico Coast, heavy snow over parts of the Central Rockies, and heavy precipitation over parts of 
the Gulf of Alaska/Alaska panhandle.   A front extending from the Upper Great Lakes roughly 
southwestward to the Southern Plains on Monday will move eastward to the East Coast and Southward 
to The Gulf Coast by Wednesday.  The front will move off the East Coast on Thursday but will linger 
across the Gulf Coast on Thursday and Friday.  Moisture from the Western Gulf of Mexico will stream 
northward, pooling along the boundary. Heavy rain will develop over the Central Gulf Coast States 
starting on Tuesday, with the heaviest rain on Wednesday, and then the rain will taper off on 
Thursday. 

A wave of low pressure on the western end of the front will develop over parts of the Great Basin 
and move southward into parts of the Southwest by Thursday.  Associated upper-level energy over the 
Northwest on Monday will move southeastward to the Great Basin by Thursday.  The low and 
upper-level energy will help produce heavy snow over parts of the Central Rockies and the Uinta 
Mountains on Tuesday into Thursday. 

For Alaska, a deep low over the Bering Sea will slowly weaken over the sea, while a wave of low 
pressure develops along the associated front over the North Pacific and move northward into the 
Gulf of Alaska by Wednesday.    A plume of moisture associated with the system will stream moisture 
into the Gulf of Alaska Coast and the Alaskan Panhandle on Monday into Thursday.  The moisture will 
help produce heavy precipitation along the Gulf Coast into the Alaskan Panhandle from Monday into 
Wednesday.

Ziegenfelder