The blob

A massive blob of rain has slowly worked its way north from near San Antonio to Dallas and now in the Tyler area, and has dumped as much as NINE inches of rain on some locations. It certainly looks impressive on radar:

What’s even more impressive is how little forcing it is taking to generate this low. The National Weather Service described this system as an “effective rainfall producer”. It is warm core, which just means that it is tropical in nature, not unlike a very weak, very rainy hurricane. Of course, hurricanes usually show up on surface analyses, because there is lower pressure at their core. This isn’t even a blip on the surface pressure plots. It sort of shows up in the mid-levels and even then, it’s very week. It doesn’t look like much.
Until you look at the output at the surface. The crazy thing is, all models have pegged this blobby mass of rain up to this point. They have even suggested the torrential rain that has been caused by the system so far. Ignoring the fact that this is the only thing the models have handled well lately, I have no reason, then, to believe that this mid level low and it’s associated wall of water won’t track through Arkansas into southeastern Missouri by tomorrow, then slowly march its way up the Ohio to Cincinnati overnight into Saturday, as the GFS posits. The good news is, the system is actually, you know, moving now, so there is a better chance that the overall rain totals won’t be up to a foot in Cincinnati, instead around the more manageable 3 or 4 inches. So that’s good.
What a weird system.