Hazardous weather conditions are set to impact millions of people across more than a dozen states as a developing storm brings the potential for tornadoes, extreme flash flooding, heavy snow, and high winds. The initial threat begins with severe thunderstorms forming late Tuesday across the Plains, advancing eastward overnight into Wednesday.
On Wednesday, these storms will draw from a tropical moisture plume originating from the Caribbean Sea, which may contribute to the formation of strong tornadoes and life-threatening flash flooding, particularly in a corridor stretching from Arkansas to western Kentucky. Rainfall in this region is expected to persist until Sunday as a front stalls, allowing waves of moisture to continuously travel along it. In some areas, rainfall totals could exceed a foot, significantly increasing the risk of flooding.
The National Oceanic and Atmospheric Administration’s Weather Prediction Center has issued warnings of an “extreme flooding scenario,” indicating that communities could experience repeated flooding events over the next four days. More than 8 million people reside in a corridor designated with a moderate risk (Level 3 out of 4) for excessive rainfall this week.
A significant highway of moisture is anticipated to fuel intense rain, strong tornadoes, and heavy snow along a 1,200-mile zone from the southern Plains to the Upper Midwest through the week. Here are the key weather hazards to be aware of:
A line of heavy rain and thunderstorms is forecast to become slow-moving, potentially stalling over an area from eastern Arkansas to southwestern Ohio on Wednesday evening and overnight. According to NOAA's Weather Prediction Center, this setup could lead to life-threatening flash flooding across regions including eastern Arkansas, southeastern Missouri, southern Illinois, and others.
Between Thursday and early Sunday, two or three additional surges of moisture may affect the highest risk corridor, which might expand to include northeastern Texas, eastern Oklahoma, and the remainder of Arkansas. Some areas could see rainfall totals equivalent to three months’ worth of precipitation by the end of the weekend, creating particularly dangerous conditions for roadways, creeks, and rivers.
The storm system poses a significant threat for tornadoes, including strong twisters, across approximately 15 states on Tuesday and Wednesday. Severe thunderstorms are expected to develop Tuesday afternoon and evening in eastern Nebraska and central Kansas, moving into Iowa and western Missouri overnight. Additionally, more storms are likely to form across Oklahoma and northern Texas.
Cities that fall within the tornado risk area from late Tuesday into early Wednesday include Oklahoma City, Kansas City, and Tulsa. From Wednesday afternoon through that night, a broader region will face severe thunderstorm risks, including very large hail, damaging winds, and strong tornadoes, extending from eastern Texas to southern Michigan. Major cities like Chicago, Indianapolis, and Memphis will be particularly vulnerable, affecting a population of over 43 million.
Winter storm warnings are currently in effect across parts of North Dakota, South Dakota, Minnesota, and Wisconsin. The combination of heavy, wet snow and strong winds from Tuesday night through Wednesday night is expected to create whiteout conditions, with a risk of downed trees and power outages. In some areas, snowfall could exceed a foot.
On Wednesday, significant icing is anticipated across Ontario and Quebec in Canada, with regions north of Toronto still recovering from a previous ice storm. Northern New England may also experience considerable freezing rain from late Wednesday into Thursday, leading to hazardous travel conditions in northern New York, Vermont, New Hampshire, and Maine.
This week’s storm system is driven by three primary factors: a slow-moving upper atmospheric spin, a strong area of blocking high pressure, and access to rich tropical moisture. The area of spin is expected to remain stagnant over the western United States, obstructed by a heat dome over the Southeast. This atmospheric “traffic jam” will enable tropical moisture from the Caribbean, influenced by a marine heat wave, to be transported northward.
Due to the warmer-than-average waters in the Caribbean and western Gulf of Mexico, this storm system is equipped with a high-octane fuel source. As storms develop in the central states in the coming days, they will draw upon this moisture, resulting in dangerous weather conditions for millions of residents across impacted states.
