US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
246 PM EDT Wed Mar 18 2020
 
Valid Saturday March 21 2020 - Wednesday March 25 2020
 
Hazards:
- Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the 
Mid-Atlantic, the Southern Appalachians, the Southeast, and the Southern Plains, Sun-Mon, Mar 
22-Mar 23.
- Heavy rain across portions of the Mid-Atlantic, Mon-Tue, Mar 23-Mar 24.
- Heavy snow across portions of the Central Great Basin, California, and the Southwest, Sun-Tue, 
Mar 22-Mar 24.
- Flooding possible across portions of the Central Plains, the Middle Mississippi Valley, and the 
Southern Plains.
- Flooding occurring or imminent across portions of the Southeast, the Lower Mississippi Valley, 
and the Northern Plains.
- Flooding likely across portions of the Middle Mississippi Valley.
- Much below normal temperatures across portions of the Central Plains, the Northern Plains, the 
Southern Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Great Lakes, 
Sat, Mar 21.
- Heavy snow across portions of mainland Alaska, Sat, Mar 21 and Mon-Tue, Mar 23-Mar 24.
- Much above normal temperatures across portions of mainland Alaska, Sat-Tue, Mar 21-Mar 24.
 
Detailed Summary:

The medium-range period (Saturday 3/21 to Wednesday 3/25) will begin with a strong cold front 
departing the eastern Untied States. One last day of well below average temperatures will be found 
across the Great Plains and Upper Midwest. Temperatures are forecast to dip into the single digits 
and below zero across certain portions of the Northern Plains. This cold front is forecast to stall 
once it reaches the Gulf of Mexico Friday night. A wave of low pressure is forecast to form along 
this front and move across the Deep South/Southeast on Sunday and Monday, before exiting near the 
Mid-Atlantic coast sometime on Monday. This will produce areas of heavy rain across portions of the 
Deep South and Southeast. Total rainfall amounts could add up to near 3 inches in certain areas, 
leading to isolated flooding concerns. Heavy rain is also possible across the eastern Mid-Atlantic 
on Monday and Tuesday as the coastal low strengthens. Snow will be possible across interior 
sections and higher elevations of the Mid-Atlantic and Northeast, but uncertainty currently remains 
high regarding specific amounts.

Across the western U.S., a persistent upper-level trough and multiple impulses of upper-level 
energy will lead to cooler than average temperatures and chances for precipitation. The most 
impactful weather will be found across the Sierra Nevada, where another round of heavy snow 
(measured in feet) is increasingly likely between Sunday and Tuesday. The probability for heavy 
snow also increases across the northern and central Rockies by Wednesday, but these areas were too 
small in size to add on the national hazards graphic. 

Active weather will be found across northern Alaska during the medium range period. Multiple waves 
of low pressure are forecast to lead to heavy snow (greater than 12 inches) across eastern portions 
of the Brooks Range and southern sections of the Lisburne Peninsula. Snowfall will also be common 
across central Alaska, but with lighter amounts most likely. Temperatures are forecast to run 20 to 
40 degrees above average across northern Alaska through Tuesday, which could mean the first time at 
or above freezing since Autumn for some portions of the state.

Snell