Severe Weather: March 22

A strong trough, which may be closed, will move out of the inter-mountain west tonight and onto the plains states tomorrow. This trough with the combined dynamics of a mid-level jet, vorticity maxima, and other details will allow for a potentially significant severe weather event across the plains states tomorrow. This has prompted the SPC to issue a moderate risk across portions of the plains, and a slight risk for much of the state of Iowa.

An initial round of thunderstorms should develop along the strong southerly flow both at low and mid-levels tonight, these thunderstorms are likely to be elevated in nature with a marginal large hail threat through the nighttime and morning hours on Monday. These thunderstorms should initiate near the Missouri River around Midnight tonight, and move eastward with time through the night into central Iowa by sunrise. These thunderstorms may linger into eastern Iowa during the afternoon hours, however, with little in the way of severe weather.

As the mid-level jet and an increase in moisture/temperatures ahead of the cold front move into the central plains, a stronger threat of severe weather is likely to develop during the afternoon hours on Monday. Thunderstorms over SD/NE will continue to move eastward during the day, entering eastern SD/NE by afternoon. With the potential for instability and strong shear, both large hail and damaging winds, along with a few tornadoes may be possible if storms can remain discrete. As the cold front begins to sweep eastward during the evening and overnight hours, these storms should become more linear and move into Iowa. As they move quickly into the state during the evening/overnight hours on Monday into Tuesday they may pose both a wind and hail threat for the state. Additional updates are possible tomorrow for the severe weather threat for Iowa...