We are beginning day two of what will end up being a multi-day severe weather outbreak across the United States. After analyzing the latest forecast model runs and today’s soundings, environmental conditions will become favorable for the development of strong, violent, and long-track tornadoes. We have a strong upper-level system that is moving across the United States, and it is in no hurry to get out of here as it slowly moves east. As early-day convection continues to move out of the lower Mississippi River Valley, surface temperatures will continue to increase, and given the strength of the system that will be moving overhead, wind shear will be plenty sufficient to sustain and allow for rapid tornado development.
After looking at today’s soundings, I noticed a very evident dry layer just above the surface in the mid-levels of the atmosphere. This is referred to as an elevated mixed layer (EML), and it is often present prior and during a major severe weather event. This is quite common in the Plains, but once these systems move east, this dry layer is typically not as evident. This dry layer will prevent the very moist air at the surface from mixing with the mid-levels, and as a result, instability will build up throughout the day, which will eventually lead to rapid storm development. This will also keep the storms more discrete, which will give these storms more available energy to work with, and once they develop, deep-layer wind shear will immediately start rotating these storms.
For those of you that follow my forecasts on a consistent basis know that I always choose my wording carefully when I release my forecasts to the Firsthand Weather readers. Please hear me when I say that today is going to be very dangerous and could be deadly. After looking over everything, I see an environment that will be very capable of producing strong and long-lived tornadoes.
Let me detail where the highest threat will be for tornadoes today going into tonight. Areas from northeastern Louisiana, central and northern Mississippi, northwestern and northern Alabama, and into Tennessee will see the highest threat of strong tornadoes. Please note that the tornado threat is not limited to just those areas. As I have been writing this article, the Storm Prediction Center has put out a particularly dangerous situation (PDS) tornado watch until 9 pm CDT for the areas that I just mentioned. The SPC only issues PDS watches for the most severe of events. The tornado threat will continue into the evening and overnight hours.
Again, please have a plan in place now! This will be an event that will produce strong tornadoes and does not need to be taken lightly. Please share this with your friends and family that live in the area and tell them to get prepared now. Please follow me on the Firsthand Weather Facebook page as I will continue to post updates throughout the day.
Matthew Holliday (Curriculum Vitae - Resume) is a graduate of the University of Oklahoma, where he completed a B.S. in Meteorology and a B.S. in Geographic Information Science. He completed his master's degree in meteorology and climatology at Mississippi State University and is currently pursing a Ph.D. in Earth and Atmospheric Sciences.