An area of low pressure will move out of Texas on Wednesday (May 15th) causing widespread showers and thunderstorms to develop across our area. This low pressure is actually removed from the polar branch of the jet stream so there isn’t much upper level wind energy to work with for severe storms; but widespread rain will be possible.
In the spring, the changing wind speed and direction with height is known as wind shear and the buoyancy (or tendency of the air to rise) is known as instability. We don’t have much wind shear at all this week and we only have low to modest levels of instability. Lows that are disconnected from the jet stream don’t move in much cold air aloft to make the warm air want to rise faster; the result is a fairly stable airmass.
We will, however, see some lift from the low pressure which will cause scattered showers and thunderstorms on Wednesday evening and Thursday. Rainfall totals appear to be on the order of .50″ to 1″ on average. Much like last week, there will be isolated higher amounts. If we see additional heavy rains in Benton County it could cause additional flooding problems but right now it appears the best and highest rainfall totals will be closer to the area of low pressure and the Gulf of Mexico in SE Oklahoma and SE Arkansas.
The rainfall map shown is from the Weather Prediction Center and details the estimated rain for Wednesday thru Friday.