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.
A late-April snowstorm dumped over a foot of heavy, wet snow across parts of Colorado on Thursday into Friday, boosting snowpack for an extended ski season at local resorts.
Expanding rainfall will bring good news for unusually dry portions of the northeastern United States into the start of May.
Residents of the southeastern United States may feel like the calendar has flipped ahead to Memorial Day weekend with warm and muggy weather in place for the start of May.
Those traveling during the end of the bank holiday weekend across the United Kingdom will face bouts of rain and increasingly gusty winds.
The seven-story building, which housed more than 125 single units, collapsed around 9:15 p.m. local time (2:15 p.m. Friday), officials said.
One of the largest severe weather outbreak so far this year occurred this week as powerful winds, large hail and heavy rains pummeled the Plains and parts of the Ohio Valley over the course of several days.
United States (1982)
May produced 365 tornadoes in the U.S., the highest number for any month since reliable records have been available, according to NOAA. The May figure topped by 90 the May 1965 high of 275.
Guangxi, China (1986)
Hailstones weighing up to 11 pounds killed 16 people and injured 125.
Quanah, TX (1993)
Golf ball-sized hail piled up 4" deep.