I haven’t had much time to forecast tonight. I worked late, took Duck for a run in the park and then worked out, so I’m just now getting a chance to look at data. I skipped over tomorrow’s setup because I’m not going to New Mexico for a lower end tornado threat and went straight into Wednesday’s forecast, which I might chase. I’m going to get straight to the heart of it and talk tornado potential. I don’t have the time to run through the surface pattern and all the basic details tonight or get a map made. I will try to get a map up tomorrow night though.
My thinking with Wednesday’s potential hasn’t changed a whole lot since my last post. Morning precipitation and how the surface pattern will setup through the day has been jumping around a bit from model to model, so it’s still tough to pin down the exact location of the greatest tornado threat on Wednesday. Current thinking is that the best tornado potential is going to be along an outflow boundary leftover from morning storms tracking through the Texas panhandle. Where this OFB may end up being has changed a fair amount over the last few days, so details are still a bit sketchy. However the models have been consistent with storms tracking through that area in the morning with an OFB intersecting the dryline somewhere over the western plains. With the 00Z NAM it looks like the OFB/dryline intersection will set up Wednesday afternoon. With ambient low level shear ahead of the dryline being fairly weak, if there is an OFB that would be an obvious choice for better tornado potential (where low level shear may be more supportive of tornadic supercells). This is supported by 1km SRH solutions from the NAM, with low level shear being strongest in the vicinity of the OFB triple point around 00Z. With storm motions somewhat normal to the boundary, you’d expect storms to be at least semi discrete coming off the dryline. It’s a little iffier with any triple point storm. I’m never quite sure what to expect with convective evolution in that type of situation. It may be one discrete supercell or you may get a couple cells with it getting a little sloppy as the day unfolds. For this reason and also because hodographs are forecast to enlarge significantly in the 00-03Z timeframe, I’m a little worried about timing with any OFB storms. I think it would be good if they held off until later in the afternoon. Overall parameters are pretty good for supercells with moderate instability and deep layer shear around 60kts in the Texas panhandle. With fairly weak low level shear until perhaps right before dark when it ramps up, I think the tornado potential is towards the lower end of the spectrum, but the potential seems a little higher with an OFB potentially helping and the fact that it’s now May and these types of setups tend to start coming together this time of year. I’m having a hard time talking myself out of chasing this one. It’s been slow this season and I’d be super pissed if I missed out on a good tornadic storm, so I’m definitely leaning towards chasing. I was hoping the better tornado potential would be in SW Kansas, but it’s not looking like that will be the case right now. At this point I’m hunting elephants, so I’ll absolutely pass on lower end tornado potential closer to home for where I think the best tornado potential will be. I thin the east central Texas panhandle looks best right now, so at least for the moment, that’s where I’m planning on going.
I’ll try to update tomorrow night with a map. I’m curious whether or not SPC will go with an enhanced risk on the day 2. If they don’t do it on the first day 2, I’d be willing to be that’s what they’ll take it to with the second day 2 outlook. That’s all for tonight, but check back tomorrow for an update if you’re interested.