US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
215 PM EST Mon Mar 01 2021
 
Valid Thursday March 04 2021 - Monday March 08 2021
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest, Thu-Fri, Mar 4-Mar 5.
- Heavy precipitation across portions of California and the Pacific Northwest, Fri-Sat, Mar 5-Mar 6.
- Flooding possible across portions of the Mid-Atlantic, the Northeast, the Central Appalachians, 
the Tennessee Valley, the Lower Mississippi Valley, the Southern Appalachians, and the Ohio Valley.
- Flooding occurring or imminent across portions of the Southeast and the Ohio Valley.
- Flooding likely across portions of the Southeast, the Central Appalachians, and the Ohio Valley.
- High winds across portions of mainland Alaska and the Aleutians, Fri, Mar 5.
- High winds across portions of mainland Alaska, Sun, Mar 7.
 
Detailed Summary:

The medium range forecast period extending from Thursday, March 4th to Monday, March 8th will 
feature a relatively quiet weather pattern. Only isolated instances of heavy precipitation will be 
possible across CONUS as upper-level ridging locks in place over the central United States. A 
fast-moving upper-level low will exit the southern/central Rockies on Thursday and produce an area 
on moderate rain on Friday across portions of Kansas and Oklahoma. Current guidance hints at the 
potential for maximum rainfall amounts of 1-2 inches; however, these amounts will likely fall in 
localized areas and shouldn't produce any widespread flooding concerns. Light to moderate snow will 
be found across the central Rockies on Thursday and Friday as well. As the system swings toward the 
Southeast, showers and thunderstorms will likely break out across Florida on Saturday. Meanwhile, 
heavier coastal rain and mountain snow will be found across the Pacific Northwest. Heavy 
precipitation is forecast to move into the Olympic Peninsula on Thursday evening and last through 
Friday. Further south, a plume of moisture could bring locally heavy rain along coastal regions 
near the Oregon/California border on Friday and Saturday. Snow is likely to mix with rain across 
the Klamath Mountains.

For the entire forecast period, maximum temperatures are expected to run around 10 to 20 degrees 
above average for the northern Plains. This equates to highs in the 50s, with 60s found as far 
north as South Dakota and eastern Montana. Nighttime temperatures may also struggle to reach below 
the freezing mark on Sunday and Monday. This region has experienced very little snow as of late, 
therefore rapid snow melt is not a concern. Farther east, the current snow depth will greatly 
diminish across the Upper Midwest. This melting should occur gradually and not lead to widespread 
river flooding. One potential hazard due to the early warmth are ice jams. Any rivers that 
currently remain mostly ice covered could experience a rapid thaw and flooding could result if ice 
chunks block rivers from flowing down its natural channel. Across the Northeast and East Coast, 
slightly below average temperatures are expected to hang around through the beginning of next week.

In Alaska, below average temperatures will be found on Thursday across much of the Interior and 
western sections of the state, but a warming trend will commence and last through Monday. An active 
parade of storm systems are expected to traverse the Bering Sea and bring gusty winds to the 
Aleutian Islands. The best chance for wind gusts greater than 50 mph will be on Friday as energy 
transfers to the Gulf of Alaska. High winds could also lead to coastal hazards along the west coast 
as a potent low pressure system passes by the northwest on Sunday. As a result, strong southerly 
winds could lead to sea ice/shore fast ice interacting with coastal regions.

Snell