US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
447 PM EDT Wed Sep 23 2020
 
Valid Saturday September 26 2020 - Wednesday September 30 2020
 
Hazards:
- Heavy rain across portions of the Pacific Northwest and the Northern Great Basin, Sat-Sun, Sep 
26-Sep 27.
- Heavy rain across portions of the Northeast and the Great Lakes, Sun-Mon, Sep 27-Sep 28.
- Flooding possible across portions of the Lower Mississippi Valley.
- Flooding occurring or imminent across portions of the Southeast.
- Much above normal temperatures across portions of California, the Northern/Central Great Basin, 
and the Pacific Northwest, Mon-Wed, Sep 28-Sep 30.
- Much above normal temperatures across portions of the Great Plains, the Central Rockies, and the 
Middle/Upper Mississippi Valley, Sat, Sep 26.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Wed, Sep 
28-Sep 30.
 
Detailed Summary:

An otherwise quiet medium range period (Saturday, September 26 - Wednesday, September 30) will 
feature above average temperatures and heavy precipitation for parts of the U.S.. A ridge 
protruding into the Southern Plains from the Pacific will produce areas of much above normal high 
temperatures across the central U.S. on Saturday. That same day, a low pressure system will 
approach the Pacific Northwest. This system will produce heavy rainfall for that area on Saturday 
and Sunday. An upper level disturbance will traverse the Great Lakes this weekend, and may generate 
a small area of heavy rainfall downwind of Lake Ontario on Sunday and Monday. A secondary shortwave 
trough will amplify behind the aforementioned one and may produce heavy rainfall over the Upper 
Midwest/Great Lakes on Tuesday. There isn't a particularly strong signal for the heavy rainfall in 
model guidance at this time, therefore a hazard area has not been drawn.

The Pacific ridge will build and settle over the western U.S. through the medium range. This will 
lead to rising temperatures over much of northern/central California and Oregon, where severe 
drought is already occurring. Much above normal temperatures are expected for this area between 
Monday and Wednesday as a result.

Meanwhile in Alaska, a pair of occluded low pressure system will impact the southeast coast and 
panhandle through the medium range period. The second system is likely to produce heavy 
precipitation for the area from Monday through Wednesday. These systems are also likely to produce 
strong winds off the southeast Alaskan coast. 

Kebede