US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
342 PM EDT Wed Sep 11 2019
 
Valid Saturday September 14 2019 - Wednesday September 18 2019
 
Hazards:
- Heavy rain across portions of the Southeast, the Lower Mississippi Valley, and the Tennessee 
Valley, Sat-Tue, Sep 14-Sep 17.
- Flooding possible across portions of the Great Lakes, the Upper Mississippi Valley, and the 
Northern Plains.
- Flooding likely across portions of the Upper Mississippi Valley and the Northern Plains.
- Much above normal temperatures across portions of the Central Plains, the Great Lakes, the Upper 
Mississippi Valley, and the Northern Plains, Mon-Wed, Sep 16-Sep 18.
- Enhanced wildfire risk across portions of the the Central Great Basin and the Northern Great 
Basin, Sun, Sep 15.
- Heavy rain across portions of mainland Alaska, Sun-Mon, Sep 15-Sep 16.
 
Detailed Summary:

The medium range (Saturday-Wednesday) will feature zonal upper-level flow to start the period, with 
upper-level troughing  in the western U.S. and ridging across the East after Day 5 (Monday). The 
biggest threat for heavy rain across the Continental United States will be along the central and 
eastern Gulf Coast, Florida, and Southeast beginning on Saturday. An area of showers and 
thunderstorms currently over the Bahamas, and being watched by the National Hurricane Center for 
possible development, is expected to track across the Florida Peninsula this weekend and eventually 
approach the central and eastern Gulf Coast by Monday. Regardless of development, heavy rain will 
be possible from northern Florida to central Alabama between Saturday and Tuesday. The potential 
exists for greater than two inches of rain within 24 hours across these areas. Heavy rain could 
extend further inland across the Southeast and Tennessee Valley on Wednesday, but confidence is low 
at the moment. For more information, visit the National Hurricane Center (www.nhc.noaa.gov).

Anomalous upper-level ridging is forecast to build across the Great Lakes early next week. As a 
result, maximum temperatures anomalies are expected to reach 10 to 20 degrees above normal from the 
Central Plains to the Upper Great Lakes between Monday and Wednesday. Minimum temperatures could be 
as much as 25 degrees above normal Tuesday morning, prompting the much above normal temperatures 
area on the hazards map. Actual high temperatures are forecast to range from the upper 80s across 
the Central Plains to low 80s across the Upper Great Lakes, with low temperatures ranging from the 
low 60s to low 70s. Meanwhile, a cold front is forecast to cross the Great Basin on Monday and will 
be responsible for an increase in winds and wildfire risk ahead of the front on Sunday. 
Temperatures will drop behind the front and could result in scattered frost/freeze impacts in the 
lower valleys of Nevada and northern California. Opted to leave out a much below average 
temperatures area on the hazards map here due to low confidence and a relatively small area of 
impact.

In Alaska, an active and wet pattern is expected during the forecast period. A modest low pressure 
system is forecast to impact the western mainland on Sunday and Monday. Rainfall amounts greater 
than 1 inch will be possible, hence the heavy rain area on the hazards map. Heavy rain will also be 
possible across the south coast and Alaskan Panhandle as well, but rainfall will occur over a 
longer time frame. 

Snell