US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
443 PM EDT Thu Aug 27 2020
 
Valid Sunday August 30 2020 - Thursday September 03 2020
 
Hazards:
- Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee 
Valley, the Middle Mississippi Valley, the Southern Plains, and the Ohio Valley, Sun-Tue, Aug 
30-Sep 1.
- Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee 
Valley, the Middle Mississippi Valley, the Southern Plains, and the Ohio Valley, Tue-Wed, Sep 1-Sep 
2.
- Heavy rain across portions of the Southern Appalachians, the Mid-Atlantic, the Central 
Appalachians, the Upper Mississippi Valley, and the Tennessee Valley, Sun-Mon, Aug 30-Aug 31.
- Heavy rain across portions of the Northeast, the Central Appalachians, the Mid-Atlantic, the 
Southern Appalachians, the Great Lakes, and the Ohio Valley, Mon-Wed, Aug 31-Sep 2.
- Flooding possible across portions of the Lower Mississippi Valley, the Central Appalachians, the 
Middle Mississippi Valley, the Mid-Atlantic, the Southern Appalachians, and the Southern Plains.
- Flooding likely across portions of the Lower Mississippi Valley and the Southern Plains.
- Excessive heat across portions of the Southern Plains, Sun-Wed, Aug 30-Sep 2.
- Much below normal temperatures across portions of the Northern Plains and the Northern Rockies, 
Sun-Mon, Aug 30-Aug 31.
- Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Aug 30-Aug 31.
- Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Mon-Wed, Aug 31-Sep 2.
- High winds across portions of mainland Alaska and the Aleutians, Sun-Mon, Aug 30-Aug 31.
 
Detailed Summary:

Laura made landfall as a high-end category 4 hurricane early this morning (Aug 27th) in southwest 
Louisiana and is forecast to eventually curve to the northeast on Friday. Flooding will persist in 
Laura's wake through at least Monday along the Lower/Middle Mississippi Valley while heavy rain 
spreads along its track across parts of the Tennessee Valley and Mid-Atlantic regions Sunday and 
Monday. If Laura is able to maintain a well-defined circulation while traversing the interior Deep 
South toward the Mid-Atlantic, a period of gusty winds and heavy rainfall could impact parts of the 
Mid-Atlantic on Saturday. In addition to Laura, a low pressure system is expected to develop along 
a nearly stationary front draped across the northern states. This may provide a focus for heavy 
rainfall, especially for parts of the Upper Mississippi Valley. For more information about Tropical 
Cyclone Laura visit the National Hurricane Center's website: www.nhc.noaa.gov.

Cool, Canadian air will settle into the Northern Rockies and adjacent High Plains as an upper-level 
trough tracks across the Rockies this weekend. Much below normal temperatures can be expected 
Sunday into Monday, before moderating back to near normal. South Texas will have persistent heat 
and humidity- heat indices could exceed 110 degrees through the medium-range period.

High winds and heavy rain will impact portions of the Aleutians, southwest, south-central and 
southeast Alaska as a potent low pressure system draws in moisture from Tropical Storm Bavi in the 
Western Pacific. This system will produce gale to possibly storm-force winds across the eastern 
Aleutians and southwestern mainland Alaska on Sunday and Monday. Although the exact track of the 
center low is not certain, it will likely favor a southern track across the region. This would 
spread heavy rainfall along the southern mainland coast around Anchorage on Saturday and Sunday and 
then to the panhandle Monday and Tuesday with lingering rain into Wednesday. 

Campbell