As a storm moves out of the Rockies, the risk of violent thunderstorms, some capable of producing large hail and a few tornadoes, will progress slowly eastward across the Plains Tuesday night.
The storms will threaten lives and property and bring the risk of power outages and travel delays.
The first storms erupted Sunday in portions of Kansas and Missouri, but they were merely a small preview of what is expected to unfold this week over the middle of the nation.
The storms have the potential to cross through some or all of these major metropolitan areas over the Plains and Mississippi Valley during the middle of the week, including Austin, Dallas, Houston, Kansas City, Little Rock, Memphis, Oklahoma City, Omaha, San Antonio, Shreveport, Springfield, Mo., Springfield, Ill., St. Louis, Topeka, Tulsa and Wichita.
The storms will bring the full spectrum of severe weather ranging from large hail and damaging wind gusts to flash flooding and frequent lightning strikes. There is also the potential for a few of the storms to produce tornadoes Tuesday night.
The potential for the storms to continue to fire after dark will raise danger factor.
During Wednesday, the storms will swing farther east at increasing forward speed reaching the Mississippi River.
By the time the storms reach the Mississippi River, they are likely to organize into a squall line. However, while the risk of strong tornadoes may be significantly lower in this phase, there is still the potential for damaging wind gusts, hail and flash flooding.
People within or near the red highlighted areas should be on the lookout for rapidly changing and potentially dangerous weather conditions.
Severe thunderstorm or tornado watch areas will follow in all or part of these regions generally when storms can affect an area within six to eight hours.
When a severe thunderstorm or tornado warning is issued, it is a time for action as life-threatening conditions are possible within minutes.
Thumbnail images of a tornado by Steve Tegtmeier of the National Severe Storm Laboratory.
Autumn officially starts at 10:29 p.m. EDT on Monday, but it will not feel like autumn in some parts of the U.S.
After storms clipped Chicagoland early Sunday, drier air will filter into the area for the rest of the week.
A brief warmup is in store for residents of the Northeast this weekend before more fall-like conditions return.
The weekend will conclude with a couple of showers throughout the area on Sunday, but more favorable conditions will mark the start of the workweek in Detroit.
In keeping with tradition, temperatures will continue their up-and-down cycle during the second half of September around New York City.
Drier and more tranquil weather will move into the Atlanta area for the upcoming week.
Roosevelt Roads Naval Station Puerto Rico (1998)
107 mph wind gust from Hurricane Georges.
Skidaway Island Georgia (2007)
4 inches of rain in just one hour
New England (1938)
New England hurricane smashed across Long Island, then bisected New England. Enormous shore damage, extensive forest losses, devastating floods, $306 million damage, 600 plus dead. The storm was the fastest moving of any recorded hurricane - 58 mph. Providence, R.I. under 14 feet of water. Connecticut Rive rose to 35.4 feet at at Hartford, CT -- second highest stage ever.