An Inside Edge to Tropical Cyclone Eye-Wall Dynamics

(credit: Meteorologist Jordan Rabinowitz)

DISCUSSION: Over the past couple of days, there is no doubt that the Tropical Western Pacific Ocean basin has continued to impress the world in the context of tropical cyclone development (i.e., which are regionally referred to as typhoons). More specifically, over the past few days, the world observed in unison as Tropical Storm Maria developed into Typhoon Maria before quickly blossoming into Super Typhoon Maria shortly thereafter within the past 24 to 36 hours.  Having said that, it is worth noting that the transition from Maria being a weaker-level typhoon to a robust and massive super typhoon occurred within approximately a 24 to 30-hour period. Hence, this was a massive typhoon which likely caught a lot of people living and/or vacationing across various parts of the Western Pacific Ocean by surprise in many cases.

As captured above in the high-resolution satellite imagery (courtesy of Himawari-8’s rapid scan imagery capability), there was also very complex convective activity evolving in and around the heart of Maria’s eye wall as of earlier today (local time). Though, it is important to acknowledge that this is quite common within the core convection near and around the center of a tropical cyclone’s inner vortex due to natural eye and eye wall dynamics which evolve with time. Upon closer inspection, you would be more than likely to first notice how towards the top of the deep convective thunderstorm towers wrapping around the center of Maria, there appear to be ripples emanating outward from the center of this intense tropical cyclone. These ripples being sent outward from the center are scientifically known as gravity waves which is the atmosphere’s immediate responses to more abrupt changes in both convective intensity as well as the corresponding atmospheric sea-level pressure changes between the inner and outer portions of the tropical cyclone. Gravity wave propagation as described here is also incredibly common to observed in powerful tropical cyclones during the majority of rapid intensification periods which occur as well as while the particular tropical cyclone is maintaining its peak intensity for whatever period of time.

In addition, you may also notice how within the eye itself, there appear to be very small-scale cloud vortices “dancing around” the outer edges of the eye region. These are quite common since when tropical cyclones ramp up in intensity rather quickly, there is often very strong corresponding low-level inflow to facilitate the powerful and efficient development of more intense convection and maximum wind speeds near the center. Thus, within the eye, there can often be low-level moisture which “squeezes” into the eye of the storm very close to the surface.  Moreover, due to the rapidly rotating convection just beyond the eye (and the net cyclonic rotation of the storm itself in the Northern Hemisphere), there can sometimes be tightly-wrapped meso-vortices or miso-vortices spinning around the periphery of the eye of the tropical cyclone. Therefore, the core message here is that even with a predictable tropical cyclone, there are still many aspects of tropical cyclones which can often mesmerize even the most experienced atmospheric scientists anywhere in the world.

To learn more about other interesting tropical cyclone-related stories from around the world, be sure to click here!

© 2018 Meteorologist Jordan Rabinowitz