US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
427 PM EST Mon Jan 25 2021
 
Valid Thursday January 28 2021 - Monday February 01 2021
 
Hazards:
- Heavy rain across portions of California and the Pacific Northwest, Sat-Mon, Jan 30-Feb 1.
- Heavy rain across portions of California, Thu-Fri, Jan 28-Jan 29.
- Heavy snow across portions of the Pacific Northwest, the Northern Rockies, and the Northern Great 
Basin, Sat-Sun, Jan 30-Jan 31.
- Heavy snow across portions of the Central Great Basin, California, and the Southwest, Thu-Mon, 
Jan 28-Feb 1.
- Heavy snow across portions of the Central Rockies, the Great Basin, and the Northern Rockies, 
Thu-Fri, Jan 28-Jan 29.
- Heavy snow across portions of the Central Great Basin and the Southwest, Fri, Jan 29.
- Heavy snow across portions of the Middle Mississippi Valley, the Great Lakes, the Ohio Valley, 
and the Upper Mississippi Valley, Sat, Jan 30.
- Heavy snow across portions of the Great Lakes, the Mid-Atlantic, the Northeast, the Central 
Appalachians, and the Ohio Valley, Sun, Jan 31.
 
Detailed Summary:

On Thursday, a front approaching the West Coast will move inland over Central/Southern California 
on Friday, racing to the Plains by Saturday.  The system will have a plume of moisture associated 
with it streams moisture into Central/Southern California through Friday evening.  The system will 
produce heavy rain over parts of Central/Southern California and snow over the Siskiyou Mountains, 
Mount Shasta, and the Sierra-Nevada Mountains through Friday and beyond.  Furthermore, the storm 
will produce heavy snow over parts of the Salmon and Sawtooth Mountains into the Monte Cristo Range 
and the Uinta Mountains on Thursday and Friday.  The heavy snow will also develop over parts of the 
Mogollon Rim on Friday. On Saturday, another front approaches the West Coast that will linger along 
the West Coast through Monday.  An associated plume of moisture will stream into the Pacific 
Northwest/Northern California through Monday, then the plume of moisture moves southward, streaming 
into Central/Southern California.  The system will produce heavy rain along the Pacific Northwest 
Coast and the Northern California Coast through Monday.  The system will also produce heavy snow 
over the Cascades through Sunday.  Additionally, the system will produce heavy snow over the 
Siskiyou Mountains, Mount Shasta, and the Sierra-Nevada Mountains through Monday. 

Meanwhile, the storm over the Plains moves into the Great Lakes/Ohio Valley on Saturday and off the 
Mid-Atlantic Coast by Sunday.  The storm will produce heavy snow over parts of the Midwest on 
Saturday and heavy snow over parts of the Central Appalachians, the Northern Mid-Atlantic, Lower 
Great Lakes, and parts of the Northeast on Sunday.

Over Alaska, low pressure over the Gulf of Alaska on Thursday will move southeastward into the 
Lower 48 States on Saturday and Sunday.   The system will have some moisture with it, but it will 
not be heavy enough to produce an area of heavy precipitation along the Gulf of Alaska Coast on 
Thursday and Friday.  High pressure will build southward over the Far North into the Interior and 
the South-Central Regions of the mainland on Saturday into Monday.

Ziegenfelder