STATUS: IOP WATCH (new)

In the midday conference call today, the VORTEX-SE researchers decided to not conduct observations on Tue 21 Mar, but are now watching a likely IOP opportunity toward next weekend.  (If you haven’t been following these messages, “IOP” stands for “Intensive Observing Period”… that’s when the researchers hit the field with all their observing equipment.)

The Tuesday forecast illustrates one of the many challenges the researchers face.  Most of the VORTEX-SE researchers travel to Alabama to conduct observations because staying there for two months or more would consume resources better spent on the science.  The funds support about four IOPs.  And so they have to weigh the likelihood that an event will provide enough data to generate some new knowledge, and whether there will be better opportunities as March and April go on.

So on Tuesday, there will be enough CAPE around to support thunderstorms, if they were initiated.  (CAPE is “Convective Available Potential Energy” which measures how much updraft air will be accelerated because of the difference between the updraft temperature and the temperature outside the updraft.)  But, because of an upper ridge, the winds will be fairly weak through the whole depth of the atmosphere.  One can never rule out tornadoes completely, but given our current understanding of tornadic storms and the environmental conditions that support them, this looks like an extremely-low probability day.  If we had unlimited resources and could observe 24/7 for a number of months, we could probably catch one or two surprising events… and there’s probably a lot to be learned from them when they happen.  But we have to spend the research funds in a way that can give us the most new knowledge for the buck.

Looking ahead, we see another challenge.  The forecast models are pretty adamant that a strong wave and associated cold front will move through the Southeast toward this weekend.  Right now, the major models are in very poor agreement about the timing of this, and individual models are in poor agreement with themselves from one model run to the next.  It looks like an IOP is quite likely for this system, and it will be up to the researchers and their forecast team at the University of Alabama-Huntsville and NWS-Huntsville to try to get a good enough picture of the timing so that the researchers can assemble in Huntsville and plan the details of their deployment.  Stay tuned…