US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
412 PM EDT Tue Oct 12 2021
 
Valid Friday October 15 2021 - Tuesday October 19 2021
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, Sat, 
Oct 16.
- Heavy rain across portions of the Pacific Northwest, Sat, Oct 16.
- Heavy rain across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, the 
Ohio Valley, and the Tennessee Valley, Fri, Oct 15.
- Flooding possible across portions of the Southern Plains.
- Flooding occurring or imminent across portions of the Southeast.
- Much below normal temperatures across portions of the Northern/Central Plains, the Great Basin, 
the Northern/Central Rockies, and the Southwest, Fri, Oct 15.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Tue, Oct 
18-Oct 19.
- High winds across portions of mainland Alaska and the Aleutians, Sat-Sun, Oct 16-Oct 17.
 
Detailed Summary:

On Friday, a front extending from the Lower Great Lakes to the Southern Plains will move off the 
East Coast by Sunday.  Moisture pooling along the front on Friday will produce an area of heavy 
rain from parts of the Middle/Lower Mississippi Valley to the Ohio Valley. 

A second front moving onshore over the Pacific Northwest on Friday and Saturday will advance 
eastward to the Upper Great Lakes to the Southern High Plain/Southern Rockies by Tuesday. The 
system will produce heavy rain over the Olympic Peninsula and heavy precipitation to the Northern 
Cascades on Saturday. Yet, as the boundary moves east, the front will be mainly dry until running 
into some moisture over Texas on Tuesday. The pressure gradient looks somewhat strong over the 
Upper Midwest on Monday and Tuesday, producing strong wind over the region.

Furthermore, high pressure over parts of the Rockies will allow temperatures to cool off at night 
over the region as an area of much below normal temperatures is depicted on the hazards chart on 
Friday.  Low temperatures will be in the mid-teens to the low 20s. 

Over Alaska, a deep area of low pressure will come off the Asian continent, moving across the North 
Pacific on Friday, moving into the Bering Sea on Saturday, and crossing the Aleutians on Sunday.  
The very strong pressure gradient associated with the surface low will produce high winds across 
the Aleutians on Saturday and Sunday.  Also, on Sunday, the system will produce precipitation 
across Kodiak Island and the Kenai Peninsula. Nevertheless, there is uncertainty whether or not the 
storm will produce heavy precipitation across the region.  Some models have heavy precipitation and 
some do not. However, as the low moves into the Gulf of Alaska, heavy precipitation will develop 
over parts of the Panhandle to the west of Yakutat on Monday and Tuesday.

Ziegenfelder