US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
407 PM EDT Thu Aug 20 2020
 
Valid Sunday August 23 2020 - Thursday August 27 2020
 
Hazards:
- Heavy rain across portions of the Southeast, the Lower Mississippi Valley, and the Southern 
Plains, Mon-Wed, Aug 24-Aug 26.
- Heavy rain across portions of the Southeast and the Lower Mississippi Valley, Sun-Thu, Aug 23-Aug 
27.
- Heavy rain across portions of the Southeast, the Southern Appalachians, and the Tennessee Valley, 
Thu, Aug 27.
- Excessive heat across portions of California, the Northern/Central Great Basin, and the Northern 
Rockies, Sun-Mon, Aug 23-Aug 24.
- Excessive heat across portions of California and the Southwest, Mon-Thu, Aug 24-Aug 27.
- Excessive heat across portions of the Central Great Basin, California, and the Southwest, 
Sun-Thu, Aug 23-Aug 27.
- Much above normal temperatures across portions of the Central Great Basin, the Northern/Central 
Rockies, the Northern/Central Plains, the Upper/Middle Mississippi Valley, and the Great Lakes, 
Sun-Wed, Aug 23-Aug 26.

Detailed Summary:

Over the medium range period (Sunday, August 23 - Thursday, August 27), tropical weather is a 
threat from what are (as of Thursday afternoon) Tropical Depressions Thirteen and Fourteen. The 
current National Hurricane Center track takes Fourteen toward the western Gulf Coast on Tuesday, 
and Thirteen near the Florida peninsula and into the Gulf of Mexico on Monday into Tuesday, but 
this is subject to change and forecasts should continue to be monitored. No high winds hazards were 
placed on the hazards graphic for now due to uncertainty in strength and placement of the tropical 
cyclones making landfall. Despite the exact track of the storms, heavy rainfall is likely with the 
influx of tropical moisture into the Gulf Coast, Florida, and then the Southeast by Thursday.

Persistent upper-level high pressure over the Four Corners region will lead to continued above 
normal temperatures for the western half of the U.S. Some above normal temperatures are likely to 
spread eastward even into the Northern/Central Plains and Midwest by Tuesday/Wednesday of next week 
under the influence of the ridge. Meanwhile, upper-level troughing coming into the Northwest may 
limit the excessive heat concerns for California and the Great Basin to early next week, but it 
depends on how far southward the trough can encroach upon the ridge. Meanwhile, the Desert 
Southwest will see continued heat. Only isolated to scattered showers and thunderstorms are 
currently forecast for the West, in what would normally be monsoon season.

Over Alaska, a cooldown is expected over most areas as a cold front sweeps across early next week. 
This could also bring rain and even snow to higher elevations of the Alaska Range. Then a 
potentially pretty potent low pressure system is forecast to develop over the Bering Sea. This 
could lead to moderate to locally heavy rain from Tuesday to Thursday, spreading from the 
south-central coast into southeastern Alaska and the Panhandle. The depth and timing of the low as 
well as precipitation amounts remain uncertain though, precluding a heavy rain area being drawn.

Tate