STATUS: IOP Watch

The VORTEX-SE researchers are watching the pattern change that has been forecast by the ensembles of global models for the past week or so.  This will be a change from the deep trough in the NE US (and the associated wintery weather there) and strong ridge in the western US.  The new pattern is likely to be one of a trough in the west, with waves moving through the flow and possibly affecting the VORTEX-SE domain.  There should be a big uptick in the strength of the upper flow as well, so supercells will become a greater concern as time goes on.

The first opportunity for observations may be on Tue 21 Mar.  This is another very difficult forecast problem, because the teams would like to make a decision on this event tomorrow (Fri 17 Mar).  If they could make that decision, they could take care of travel arrangements during the afternoon, and get to Alabama on Sunday or Monday.  If the decision isn’t clear until Saturday, then travel arrangements become much more difficult.  Right now, it looks like there may be CAPE (buoyant thermal energy to drive the updrafts) but it’s very unlikely that the atmospheric flow structure would support supercells.  So now we have to ask ourselves whether we think the flow, and the vertical shear of that flow, will be strong enough near the ground to support tornadoes from non-supercell storms.

So far in VORTEX-SE, we rarely have had an obvious “go” decision.  This is partly because during the 2016 campaign, and so far in 2017, there haven’t been any of the strong systems that are normally associated with tornadic weather.  It’s also because of the uncertainty that is always present 3-5 days before an event.

Tue 21 Mar is “Media Day” in Huntsville, when the media will have a chance to look at a lot of our instruments and interview us about the science issues surrounding the tornado problems of the Southeast US.