Severe weather warning from Nebraska to Oklahoma

 Forecasters say the Midwest could be in for another round of strong storms and heavy rain.

The National Weather Service Storm Prediction Center says that severe thunderstorms may develop in parts of Kansas, Oklahoma, Nebraska and Texas on Saturday.

The center says there is a risk of large hail, strong winds and several tornadoes with the system.

The greatest chance of severe weather stretches from southern Nebraska to central and western Kansas and Oklahoma.

The Weather Channel reports:

Saturday

• Where: A more widespread threat of severe thunderstorms in the Plains from central Texas to the eastern Dakotas and Minnesota. Overnight clusters of t-storms with locally flooding rain appear likely, particularly in the southern Plains.  
• Threats: Tornadoes, large hail, damaging straight-line winds, flash flooding.

Sunday

• Where: Scattered severe storms should flare up from the Upper Mississippi Valley to the Ozarks and perhaps southward into northeastern Texas. 
• Threats: Damaging straight-line winds, large hail, some tornadoes, flash flooding especially in Oklahoma and northern Texas.

Last weekend's weather caused several tornadoes, flooding and at least four deaths.

As The Christian Science Monitor reports, the US Storm Prediction Center last year modified its language to better communicate the level of risk. The terminology includes using "enhanced" risk of severe thunderstorms, rather than "slight."

At first glance, the changes may seem like an exercise in semantics. And to some extent they are. For several years, the National Weather Service has been working with social scientists to find better ways of communicating the contents of its forecasts in ways meaningful to emergency managers, radio and TV weathercasters, and the general public, not just experienced forecasters, notes John Ferree, the SPC's severe-storms services leader.

But the "slight" category for severe storms and for tornadoes actually spans a threefold increase in risk, from a 5 percent chance of severe weather to a 15 percent chance, he notes. At 15 percent, the risk for severe weather is considered moderate.

Such numbers may sound low, but even a twofold increase "is a big difference," especially if they relate to tornadoes, he says; it means those in an area covered by the larger number are twice as likely to see tornadoes as people covered by the lower probability.

Indeed, once the risk level rises to 15 percent, forecasters are anticipating "a pretty darn big event," Mr. Ferree says.