Hurricane Jimena rapidly intensified doubling its wind speed in 12 hours and nearly doubling again. Then it underwent eyewall replacement cycles and the intensity fluctuated and the wind field expanded. I have not read up on annular hurricanes, but there was much discussion with Hurricane Bill about this. That there were forces at play that kept the inner eyewall seperate from the harmful effects of dry air on the perimeter until enough shear caused this structure to deteriorate and allow the dry air to get inside the core.
TS Erika had a long pre-tropical storm period, fluctuating in tropical wave strength for many days. finally sunday evening a central dense overcast developed over or around the wave trough. The convection later became distorted and weakened presumably with the diurnal cycle. Then it erupted again today, somewhat displaced from its previous position closer to the center of the surface circulation. However, it was remarkable how the upper level transverse cirrus "fingers" depicted the outflow in all quadrants. There is debate on whether there was some shear present, and the surface circulation was broad, and I presume from the transects at 400 meters, more like a wave than a tropical cyclone.
Another CDO tonight, with good outflow in all quadrants. I wonder, given the scale of the outflow horizontally and its shallowness vertically, if an NWP model would benefit from its inclusion rather than simply the low level vortex insertion.
I see little in the way any "MCS" activity as I have with previous tropical cyclones. Same holds true for Jimena. Thus the asymmetry in the convective clouds appears low. Someone needs to work on that asymmetric appearance and what it means, represents, or signifies about the low level vortex interacting with its environment.
