Flooding, isolated severe threat to emerge for central US

After a rather tumultuous February for many residents across the central United States, a much more tranquil weather pattern has settled into place for the beginning of March.

AccuWeather meteorologists say this pattern of generally dry and warm weather is expected to last through the early week before the next feature of concern develops midweek across the Plains and Midwest. This feature is forecast to bring rounds of heavy rainfall, flooding concerns and even isolated bouts of severe weather to the center of the country through the end of the week.

A turn toward unsettled weather will begin later Tuesday evening as a storm begins to take shape and ejects eastward out of the southern Rockies. The center of this storm will quickly push northeastward throughout the day Wednesday and bring a variety of precipitation types to portions of the Plains and Midwest.

While a swath of snow spreads from Wyoming to southwestern Ontario, Canada, rain and showers will overspread areas from the central Plains to the Great Lakes. A wet and dreary day is in store on Wednesday for cities like Minneapolis, Madison, Wisconsin and Chicago.

By later Wednesday afternoon, colder air will filter into the northern tier of the U.S. and will begin to press southward and encounter very warm air in place across southern and central Plains as well as the Ohio Valley. By Thursday, the battle between these two air masses will ignite rain and thunderstorms with the ability to unleash heavy downpours and even isolated severe weather.

CLICK HERE FOR THE FREE ACCUWEATHER APP

"Although the setup at midweek does not look like one that will typically produce a widespread severe thunderstorm outbreak, there is still enough concern that some strong to locally severe thunderstorms can erupt each afternoon from Wednesday through Friday," AccuWeather Senior Meteorologist Dan Pydynowski said.

AccuWeather meteorologists say that although the risk for widespread severe weather appears to be lower than originally thought several days ago, there still remains a significant degree of uncertainty with the overall atmospheric setup at midweek.

"If any strong to locally severe thunderstorms are to develop, the most likely area for this to happen would be for portions of the south-central Plains," Pydynowski explained.

Associated risks with any stronger storms would largely be in the form of strong, possibly damaging wind gusts.

One aspect of the midweek setup that AccuWeather meteorologists have pinpointed with growing confidence, is a prolonged and widespread heavy rain threat for portions of the Plains and Midwest.

The front expected to set up along the boundary between colder air from the northern tier of the U.S. and very warm air from the southern U.S. is set to become nearly stationary by the end of the week. Rain and thunderstorms are likely to fire up along this boundary each day through Saturday and continually increase the risk for flooding.

A swath of the country from Kansas and Oklahoma to Indiana and portions of Ohio and Kentucky will be at risk for repetitive, downpours late this week.

A general 3 to 6 inches of rain can fall across large swaths of Missouri, Illinois and Indiana later this week and into this weekend as a slow-moving storm and frontal boundary works its way through the region. An AccuWeather Local StormMax™ of 11 inches is anticipated.

The risk for flash flooding across the affected areas will increase each day downpours continue to develop. Travelers across the region, especially those moving through low-lying or poor drainage areas, should remain on alert for ponding or outright flooding of roadways. Travel across portions of interstates 35, 44 and 70 can be slow-going at times through Saturday as rain continues to fall.

In addition to flash flooding concerns, the risk for river flooding will also increase through the end of the week.

"Many rivers across the region are already under flood warnings and this rain would only exacerbate ongoing flooding issues," Pydynowski cautioned.

Flood warnings were in effect on Sunday afternoon along portions of the Ohio River as well as other parts of Indiana, Kentucky and Tennessee. (AccuWeather)

"In addition, the spring planting season is right around the corner in many of these areas and the additional rain could make getting equipment into soggy fields very difficult for pre-planting preparations such as plowing or tilling," Pydynowski said.

March is notorious for being a time of volatile weather conditions, as the month usually marks an uptick in severe weather across central and southern regions of the nation. AccuWeather meteorologists will continue to monitor the possibility of a more widespread threat for strong to severe thunderstorms to end the week in portions of Texas and Oklahoma.

The year is off to a slow start in terms of severe weather compared to the last decade and beyond. Only 24 tornadoes have been confirmed by the National Weather Service's Storm Prediction Center (SPC) from Jan. 1 to March 1, 2021. That figure - although still a preliminary tornado count - is the lowest number of tornadoes compared to the past 16 years, according to the SPC.

Transitioning from the winter season to the severe weather season can be an adjustment in any year, but especially so for this upcoming spring due to the cold, snow and ice that wreaked havoc across the South Central states during the middle of February. AccuWeather estimates that damage and economic losses related to winter weather across the United States in February will approach $155 billion.

The severe weather season, which extends into August, typically begins to ramp up in March. On average, May produces the greatest number of tornadoes across the nation, according to the National Climatic Data Center (NCDC).

Texas typically experiences the greatest number of tornadoes of any state during March, as well as annually, based on data from NCDC. This is not only due to the state's large size compared to others in the Lower 48 states, but the Lone Star State is in a portion of the nation where ingredients often come together for severe weather.

Warm, moist air from the Gulf of Mexico often collides with dry air from the Southwest deserts across Texas, and that is a recipe for dangerous weather conditions to erupt.

Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, Fubo, and Verizon Fios.