We have an unusually High #Tornado Threat from #Hurricane Isaias This movie uses real data, to help educate on why this storm poses an enhanced risk. Notice the yellow vs blue arrows. Yellow are the winds just below the clouds, it’s the low level wind flow (jet) around and feeding into the storm. Blue are the mid-level winds associated with the jet stream. You’ll notice that as Isaias approaches the Gulf Coast the blue arrows increase and the low-level vs mid-levels winds vigorously cross (X) each other. That’s the jet stream (blue arrows) being infused into the tropical system. That will create more cross winds/ shear, weaken #Isaias, but embolden spin in the outer bands. This injection of energy will power strong #tornadoes on the storm’s east side at landfall in the #Florida Panhandle and beyond into the Southeast. Not all storms have this, but it’s more common in fall as the mid-latitude jet stream increases. And it gives the transitioning tropical storm system a different character. It causes the wind field at the core to expand, making the storm larger, empowering the outer bands with more wind, at the expense of the core winds which weaken. (Although all set ups are different, Milton and Sandy come to mind) *This animation does use real wind data, but the tornadoes are added to illustrate where the greatest risk is. They are not meant to forecast exactly where the tornadoes will be.