Tuesday and Wednesday are shaping up to be highly volatile, with over 100 million people in the path of severe storms — which are expected to deliver destructive hail, strong tornadoes and damaging straight-line wind gusts.
Forty-five million people are at risk for severe storms Tuesday along a 1,000-mile stretch from southern Minnesota to the Gulf Coast. Cities at risk Tuesday include Minneapolis; Des Moines, Iowa; Omaha, Nebraska; Kansas City, Missouri; Wichita, Kansas; Oklahoma City; Tulsa, Oklahoma; Little Rock, Arkansas; Dallas; Austin, Texas; Houston; Shreveport, Louisiana; and Baton Rouge, Louisiana.
Storms are expected during the afternoon hours and will last into the night. Fast storm motions (at times moving faster than 50 mph) and storms, expected to continue after dark, will enhance Tuesday's dangerous setup.
Nighttime tornadoes are more than twice as likely to be fatal compared to their daytime counterparts.
While tornadoes, high winds and very large hail will be possible across the entire area, there are two specific areas that are of special concern.
The first area includes much of Iowa, eastern Nebraska and eastern Kansas, as well as southern Minnesota. This is where the highest risk exists for strong, long-track tornadoes (EF2 or higher) Tuesday afternoon and evening.
The second area with a higher severe potential Tuesday is across central and northern Texas, which has the greatest risk of destructive hail, baseball-sized or larger.
In between these two areas there is high uncertainty in storm coverage. A strong cap in place (a warm layer of air aloft that can inhibit storms from forming) may prevent many storms from firing until late in the evening, if any do at all.
On Wednesday the risk expands north and east to include 60 million people from the Great Lakes to the Gulf Coast. Cities to watch include Chicago; St. Louis; Nashville, Tennessee; Memphis, Tennessee; Little Rock, Arkansas; Jackson, Mississippi; Birmingham, Alabama; and New Orleans.
Severe storms will likely be ongoing during the morning hours and will persist throughout the day. Damaging winds in excess of 75 mph will be the greatest risk, followed by strong tornadoes and very large hail.
Widespread flooding is not likely, but 1 to 2 inches of rain, if it falls in a short period of time, could cause some isolated instances of flash flooding, especially in urban areas.
At the same time, a historic April blizzard will pound the northern Rockies and northern Plains on Tuesday through Thursday.
Blizzard warnings were up Tuesday for the combination of heavy snow and wind gusts up to 50 mph, which will make travel impossible and life-threatening at times. Widespread power outages are also possible, and the storm could have damaging impacts on crops and livestock.
A large swath of area will see 6 to 12 inches of snow, but eastern Montana into North Dakota could see up to 2 to 3 feet.
Due to the expected long-duration nature of this storm, snowfall totals this high could be record-setting.
Bismarck, North Dakota's largest April snowstorm on record was 17.8 inches in 2013. The current forecast has it possibly beating that record, with 12 to 24 inches of snow possible.
Perhaps more impressive, a statewide snowfall record could be in jeopardy. The North Dakota state record for the greatest 24-hour snowfall is 27 inches set April 27, 1984, in Minot. Some localized areas could pick up 30 to 40 inches of snow, which would shatter that record.
On the opposite side of the spectrum, high temperatures in the 90s combined with low humidity and wind gusts beyond 55 mph could lead to a wildfire outbreak across the western high Plains.
Fourteen million people are under red flag warnings and 27 million people are under wind alerts Tuesday encompassing the desert Southwest to Four Corners to western high Plains.
An extremely critical fire risk is in place Tuesday across western portions of Kansas, Oklahoma and the Texas Panhandle. Amarillo and Lubbock in Texas are the largest cities in the fire risk area.
Compounding the wildfire threat, a fast-moving cold front is expected to slice across the critically outlooked area near sunset. Strong winds along the front combined with a dramatic wind shift to the north and northwest may impact fire direction and spread rates.