US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
422 PM EDT Tue May 05 2020
 
Valid Friday May 08 2020 - Tuesday May 12 2020
 
Hazards:
- Heavy rain across portions of the Southern Plains, Fri-Sat, May 8-May 9.
- Heavy rain across portions of the Southeast, the Lower Mississippi Valley, and the Tennessee 
Valley, Fri, May 8.
- Heavy rain across portions of the Southeast, Sun-Mon, May 10-May 11.
- Flooding occurring or imminent across portions of the Southeast, the Middle/Lower Mississippi 
Valley, the Great Lakes, and the Northern Plains.
- Much above normal temperatures across portions of California, the Central/Northern Great Basin, 
the Pacific Northwest, and the Southwest, Fri-Sun, May 8-May 10.
- Much above normal temperatures across portions of the Central/Northern Great Basin, the Pacific 
Northwest, the Northern Rockies, and the Southwest, Sat-Mon, May 9-May 11.
- Much below normal temperatures across portions of the Plains, the Mississippi Valley, the 
Tennessee Valley, the Ohio Valley, the Southern/Central Appalachians, the Great Lakes, the 
Southeast, the Mid-Atlantic, and the Northeast, Fri-Tue, May 8-May 12.
- Heavy precipitation across portions of mainland Alaska, Fri, May 8.
- High winds across portions of mainland Alaska, Fri, May 8.
- Much above normal temperatures across portions of mainland Alaska, Fri-Tue, May 8-May 12.
 
Detailed Summary:

The medium range period (Friday 5/8 to Tuesday 5/12) will be characterized by an upper-level trough 
across the eastern half of the contiguous U.S., with shortwave troughs progressing through the 
general troughing pattern. Much below temperatures are forecast due to the below normal heights, 
with multiple rounds of cold air in many areas underneath the shortwaves. Temperatures will be 
closer to March values than May, below freezing temperatures are forecast for parts of the Midwest 
to Ohio Valley and Northeast, and dozens of record low minimum and maximum temperatures could be 
set over the weekend. There is even the possibility for a few inches of snow in the Central 
Appalachians to interior Northeast behind a low pressure system forecast to be near the coast of 
Maine on Saturday morning.

Meanwhile over the West, an upper-level ridge should shift from the West Coast for the end of this 
week eastward into the Great Basin for the beginning of next week. Above normal temperatures are 
expected underneath the ridge, and a handful of record highs and high minimum temperatures could be 
set. Heat could be close to excessive across the Southwest once again through the weekend. Then an 
upper-level low is forecast to approach the West on Monday and Tuesday, cooling down temperatures 
and leading to precipitation in the Pacific Northwest and northern California. Heavy rain is 
possible, but appears pretty localized for now. 

In terms of rainfall, the Lower Mississippi Valley could see a quick round of heavy rain on Friday 
as moisture feeds into the vicinity of a front. Given the strong trough in the East, this front 
will be pushed far south (with some gusty winds behind it) into southern Texas, across the Gulf, 
and into Florida, leading to heavy rain in those areas. Southern Texas can expect locally heavy 
rain for the end of the week, and the front stalling over the Florida peninsula on Sunday and 
Monday will create heavy rain potential there, likely lingering over the Keys on Tuesday. 

Over Alaska, above normal temperatures can be expected over the mainland with a persistent 
upper-level ridge overhead. High winds and heavy precipitation could continue over portions of 
Kenai Peninsula and Cook Inlet on Friday. A strong low pressure system in the Bering Sea should 
bring rain and gusty winds to the Aleutians, and then the possibility of some high winds across the 
southwestern coast of the mainland and toward the St. Lawrence Island, depending on the exact low 
track. Meanwhile, ice jam and snowmelt flooding remain threats across some areas of the mainland 
where rivers have not yet opened up.

Tate