US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
341 PM EDT Wed Sep 29 2021
 
Valid Saturday October 02 2021 - Wednesday October 06 2021
 
Hazards:
- Flooding occurring or imminent across portions of the Great Lakes.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat, Oct 2.
- High winds across portions of the Alaska Panhandle and mainland Alaska, Sat, Oct 2.
- High winds across portions of mainland Alaska and the Aleutians, Mon-Tue, Oct 4-Oct 5.
 
Detailed Summary:

The main threats during the medium range period, (Saturday, October 2nd - Wednesday, October 6th) 
will be over the Mississippi/Ohio Valleys and along the Alaskan coast. A potent low pressure system 
will spread an axis of rainfall and thunderstorms to much of the Lower to Middle Mississippi Valley 
on Saturday, where locally heavy rainfall is possible. Scattered thunderstorms are also expected 
out ahead of this system from the Southern Plains and into the Lower/Middle Mississippi Valley and 
Midwest this weekend, with the severe potential remaining too low. The 12z deterministic runs tend 
to suggest more of a localized and split heavy rain threat on Saturday, with one area being over 
the Central Plains and Middle Mississippi Valley and the second being an axis extending from the 
Southern Plains through the Lower Mississippi Valley. Meanwhile, the ensembles agree on areal 
coverage of precipitation, but do not exceed our heavy rain threshold. Rainfall will spread into 
the eastern half of the country heading into next week along the amplifying upper-level trough. 
Temperatures will be above normal across the Upper Great Lakes this weekend before the cold front 
sweeps through on Sunday. A cooler air mass will settle in over the Rockies this weekend in the 
wake of the cold front and the arrival of high pressure.

In Alaska, a pair of potent low pressure systems will bring heavy precipitation and high winds to 
much of the Aleutians and Panhandle through the medium range. The first system will move from the 
eastern Kenai into the Panhandle on Saturday, bringing heavy high elevation snow and low elevation 
rain to the region. The NBM signaled high wind potential with this system during this period, but 
the threat should be relegated to the Panhandle. High winds are expected across much of the Kenai 
peninsula early next week out ahead of the next deep low pressure system.

Kebede