I have been a bit too busy to blog for a while. Basically, it’s been status quo for VORTEX-SE the last few weeks, with huge forecast difficulties costing us an event last weekend. We had decided to hold an IOP, but then we cancelled it when the numerical models suggested a very slim chance of tornadoes. But they were wrong, and there were two interesting supercells in the domain.
Some of our difficulties relate to the fact that we have a domain about eight counties in size. I don’t think we would ever confine ourselves to eight counties in the Plains, and hope to learn about tornado formation in a domain of that size. And the best eight counties we’ve found in the Southeast U.S. (northern Alabama) are not very well suited to traditional tornado research.
But we are back at it again. Tonight, a line of convection will move into AL from the west. Most of the models are suggesting that this line will weaken as it moves into AL, and pose only a very small tornado threat. However, the operational HRRR model shows the line breaking up, and then more discrete cells developing within the overall area of convection in northern Alabama. Some of these are forecast to have rotating updrafts.
The teams are here through Sunday. So there is no huge cost to operating tonight. We may also operate on Friday… this should be a high-CAPE day with weaker shear, and little chance of storm initiation. So if we operate, we will be looking at land use and land cover influences, including lake breezes west of Huntsville. We will cross our fingers that initiation does occur close to where we are operating.
And Sunday continues to look like a fairly big event, but we have learned that there are a lot of ways for these big waves to fail to be associated with tornadoes. Sunday will be the last operations day for VORTEX-SE in 2017.
I will likely blog again later this evening as the line of activity moves into our research area.