It has been quiet out in the Plains, severe weather wise, for much of this week. However, that looks to change this weekend. While there is a severe weather risk Saturday just east of the Rocky Mountains, this blog post will focus more on the severe weather risk for Sunday. That area stretches from Southwest Texas north into central Nebraska. For this blog posting, we will be using the data from this afternoon’s 18z GFS model run.
As with most severe weather setups in the Spring on the Plains, this setup features what is called a dryline. The areas in brown indicate dewpoints generally below 30° to 40°F. The dark green colors indicate where dewpoint temperatures range above 60°F. Areas in the green color are more at risk for seeing potential severe thunderstorm development.
While the surface based instability Sunday evening is more than sufficient for thunderstorm development, the amount of surface based inhibition is there that could initially hinder storm development. However, that particular amount is not enough that it will totally hinder it either.
The amount of 1 km and 6 km shear, shown here, are more that sufficient for supercell thunderstorm developing Sunday evening. Just to point out, the 6 km shear is really up there, as noted in the darker yellows and oranges.
There is also plentiful amounts of helicity in the lowest one and three kilometers for Sunday Evening. When we see these values, that usually signals the distinct possibility of robust updrafts within any severe thunderstorm that does develop.
Plenty of wind is noted as well at the surface, 850 mb (5,000 feet above ground level), and 500 mb (18,000 feet above ground level). Also to note, notice on each level there how the wind direction changes with height. That will allow any thunderstorm that develops to potentially sustain rotation during its life cycle. With the strong south to southeast winds at the surface, transporting of low level moisture looks to be a non-issue as well.
With all those storm ingredients noted above, we now come to the final piece of the puzzle. The Vorticity Generation Parameter. Values above 0.2 indicate an environment where tornado producing thunderstorms are a possibility. The darker yellows there in central and eastern Oklahoma indicate an even higher potential for tornado activity Sunday evening.
BOTTOM LINE : The forecast models continue to come into general agreement of severe thunderstorm activity on Sunday evening across the Plains. All severe weather hazards look to be in play (Damaging Straight-Line Wind, Large Hail, Tornadoes). We will keep you updated with the latest. Stay tuned.