US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
436 PM EST Thu Jan 14 2021
 
Valid Sunday January 17 2021 - Thursday January 21 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, Jan 19-Jan 21.
- Heavy snow across portions of the Pacific Northwest, the Northern Rockies, and the Northern Great 
Basin, Sun, Jan 17.
- Heavy snow across portions of the Southern Rockies, the Central Rockies, the Central Great Basin, 
and the Southwest, Tue, Jan 19.
- Heavy snow across portions of the Plains, the Central Rockies, the Northern Rockies, and the 
Southern Rockies, Mon, Jan 18.
- Flooding occurring or imminent across portions of the Southeast and the Pacific Northwest.
- High winds across portions of the Central Great Basin, California, and the Southwest, Mon-Tue, 
Jan 18-Jan 19.
- High winds across portions of the Central Rockies, and the Northern/Central Plains, Wed, Jan 20.
- Enhanced wildfire risk across portions of California, Mon, Jan 18.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Jan 
17-Jan 18.
- High winds across portions of the Alaska Panhandle and mainland Alaska, Mon, Jan 18.
 
Detailed Summary:

A Front and associated upper-level energy will move into the Northwest on Sunday and move southward 
to the Southwest to Southern High Plains on Monday and into Northern Mexico by Tuesday.   The 
system will help produce snow over parts of the Northern Cascades and parts of the Northern 
Rockies, including the Bitterroot Mountain Range on Sunday with Heavy Snow depicted on the Hazards 
Chart.  As the system moves southward, snow will develop over parts of the Absaroka Mountain Range, 
the Black Hills, and the Central Rockies on Monday. As the storm settles south of the border, snow 
will also develop over the Mogollon Rim into the Southern Rockies and the San Juan Mountains in 
Colorado on Tuesday.  These areas will be marked as Heavy Snow on the Hazards Chart.  The pressure 
gradient, associated with the system, over parts of the Southwest and Southern California will be 
strong.  The wind will be very gusty over this region, with wind gust of 45 mph or greater.  The 
strong wind will also contribute to dangerous fire weather conditions on Monday.  An area of High 
Winds is depicted on the Hazards Chart on Monday and Tuesday.  The system will be quasi-stationary 
across the Western/Central Gulf Coast through Thursday.  Moisture from the Western Gulf of Mexico 
will stream northward over the Southern Plains/Lower Mississippi Valley into the Tennessee Valley 
that will overrun the boundary producing Heavy Rain on Tuesday into Thursday.
 
Meanwhile, a storm over the Gulf of Alaska will move eastward into Western Canada, moving to 
Central Canada by Wednesday.  The system will be relatively deep, producing a strong pressure 
gradient over the Northern Rockies/Northern High Plains on Wednesday.  The pressure gradient will 
produce a wind speed of 45 mph or greater.  An area of High Winds is displayed on the Hazards Map, 
valid for Wednesday.  Additionally, non-hazardous above normal temperature anomalies for both 
maximum and minimum temperatures will be present all around the CONUS throughout the period.
 
Over Alaska, a deep area of low pressure over the Alaska Peninsula will slowly move eastward into 
Canada by Tuesday.  The system will have a plume of moisture that will stream into the Gulf of 
Alaska Coast, producing rain and snow over the region into Tuesday.  An area of Heavy Precipitation 
is portrayed on the Hazards Chart on Sunday into Monday.  High Winds is depicted on the map along 
the coast from near Valdez to near Yakutat on Monday.

Ziegenfelder