Severe Weather Outbreak, Including Tornadoes, Possible Next Week in Midwest, Plains, South

Jon Erdman
Published: April 4,2015



 
True to April's dangerous reputation, a widespread, multi-day severe weather outbreak, including tornadoes, is possible next week in parts of the South and Midwest.

The meteorological ingredients that may be in play for the potential mid-week severe weather outbreak.

Meteorologists use pattern recognition, or the general forecast orientation of upper-air and surface weather features, to help identify the potential for high-impact weather events  – severe weather outbreaks, winter storms, cold air outbreaks and heat waves –  several days out.
The pattern potentially setting up next week has some similarities to a classic heartland spring severe weather outbreak.
First, a bullish southward plunge of the jet stream, or trough, will carve into the western U.S. early in the week.
In the atmosphere's lowest levels, progressively warmer and more humid air will flow northward from the Gulf of Mexico into parts of the Plains and Mississippi Valley.
With that vigorous jet stream overlapping warm, humid air and surface features – such as a drylines that divide High Plains dry air from more humid air to the east – and a warm front helping to lift the unstable air, the stage may be set for severe thunderstorms with large hail, damaging winds and tornadoes.
Early in the week, there may be pulses of thunderstorms each day through Tuesday, particularly along a quasi-stationary front oriented roughly west-to-east from the Plains into the Ohio Valley.
(NOW: Track Current Severe Weather | Live Blog)

Potential Severe Threat Timing

The larger concern for a possible severe weather outbreak is when the western U.S. trough pushes east into the Plains, bringing the core of colder air aloft and the strongest jet stream winds over the warm, humid near-surface air.
This far out, there is uncertainty how quickly this western U.S. jet stream trough pushes east into the Plains, which could add a day or so to the end, or delay the onset of what may be a multi-day severe weather outbreak.
(MAPS: 10-day Forecast)

Model Rainfall Forecast Through Friday

For now, here is an outlook based on our latest forecast thinking, subject to change.

• Wednesday: Isolated/scattered severe storms possible in the central and southern Plains along the dryline and near the surface low/stationary front. Some supercells with tornadoes possible.
• Thursday: More widespread severe thunderstorms possible in the central/southern Plains, possibly in the mid-Mississippi and lower Missouri Valleys. 

Additional severe thunderstorms are possible next Friday, perhaps even next Saturday, if the western U.S. jet stream trough moves more slowly east.
(MORE: Dr. Greg Forbes' TOR:CON Tornado Threat Forecasts)
Also, with this slow-moving western trough and the east-west frontal boundary in play, heavy rain and flash flooding could become serious threats, particularly in parts of the mid-Mississippi and Ohio Valleys saturated from heavy rain this past Thursday night and Friday.
(MORE: Louisville Water Rescues, Homes Evacuated | Photos | Vehicle a Flood Danger)
Critical details will come into greater focus in the days ahead, so check back with us at The Weather Channel and weather.com for the latest on this potential severe weather outbreak.
Do you know where to go in your home, apartment, condo, or place of business if a tornado warning is issued?
(MORE: 7 Things You Should Never Forget When Tornadoes Threaten | Watches and Warnings Explained)
Now is a good time to refresh your tornado safety plan, before a warning is issued.

MORE: Tornadoes Strike Oklahoma (March 25, 2015)