US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
316 PM EDT Wed Sep 04 2019
 
Valid Saturday September 07 2019 - Wednesday September 11 2019
 
Hazards:
- Heavy rain across portions of the Upper Mississippi Valley, the Great Lakes, the Northern Plains, 
and the Northern Rockies, Mon-Tue, Sep 9-Sep 10.
- Heavy rain across portions of the Northeast, the Upper Mississippi Valley, and the Northern 
Plains, Sat-Sun, Sep 7-Sep 8.
- Heavy rain across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, 
and the Upper Mississippi Valley, Sun-Mon, Sep 8-Sep 9.
- Heavy rain across portions of the Northeast, Sat, Sep 7.
- Flooding possible across portions of the Southeast and the Mid-Atlantic.
- Flooding occurring or imminent across portions of the Northern Plains.
- Flooding likely across portions of the Southeast.
- Excessive heat across portions of the Southeast, the Lower Mississippi Valley, and the Southern 
Plains, Sat-Mon, Sep 7-Sep 9.
- High winds across portions of the Northeast, Sat, Sep 7.
- High winds across portions of the Northeast, Sat-Sun, Sep 7-Sep 8.
- High significant wave heights for coastal portions of the Northeast, Sat, Sep 7.
 
Detailed Summary:

Hurricane Dorian will be making its final mark on the United States on Saturday as the tropical 
cyclone passes well to the east of New England. High winds (greater than 34 mph sustained) and 
significant waves (greater than 20 feet) will be the main hazard from Cape Cod to eastern Maine. 
Heavy rain (greater than 1 inch) will also be possible for these areas, particularly if the storm 
trends closer to the coast. Rain could linger into Sunday morning across eastern Maine. Please 
refer to the National Hurricane Center for the latest information regarding Dorian.

A western trough and several pieces of upper-level energy entering the north-central U.S. will 
bring the possibility of heavy rain to portions of the Midwest, Northern Plains, and Northern 
Rockies this weekend and early next week. Beginning on Saturday, there is increasing confidence in 
a band of heavy rain stretching from northeast Montana into northeast South Dakota. This same 
system is then forecast to impact the Midwest Sunday into Monday, bringing the risk of heavy rain. 
A more amplified trough will enter the western U.S. by Sunday and lead to a broad area of rain 
across the Northern Tier of the United States Monday and Tuesday. The greatest chances for heavy 
rain will be across western Montana, as easterly winds produce upslope flow along the Northern 
Rockies, and the Upper Midwest where greater instability is found. 

In addition, upper-level ridging will continue across the Western and Central Gulf Coast States 
resulting in above normal and potentially record-breaking temperatures across much of the Deep 
South. The highest maximum temperature anomalies (around 10 to 15 degrees above normal), will be 
centered from roughly far eastern Texas to southern Alabama/western Florida. High temperatures 
across these areas will reach the upper 90s and low 100s, which could break several daily high 
temperature records. Humidity will bring heat indices up to around 105-110F, which is enough to 
warrant an excessive heat area.

In Alaska, a low pressure system is forecast to enter southwest portions of the state by Wednesday, 
Sep. 11 but confidence at this point is too low to include any hazard areas.

Snell