My 45-years as an Operational User of the Dvorak Tropical Cyclone Intensification Technique, a Perspective

In the spirit of this conference’s 50^th anniversary celebration of the Dvorak Technique, this presentation gives a perspective of my firsthand experiences using the Dvorak Tropical Cyclone Intensification Technique (Dvorak Technique). Although first hearing about the technique from Vern Dvorak, himself, as a graduate student in the mid-70s, it was not until a couple of years later that I learned first-hand about the visual technique, while using single frame polar-orbiting images. I remember hearing my trainers tell me after almost daily visits for help, to think of the technique as a way of explaining the degree of energy and organization that the tropical cyclone represented. They told me not to worry about the method I chose from the complex set of tables; but if done properly, it did not matter and that everyone should be within a half T# of each other. Unfortunately, this was easier said than done. Later when I went to the Joint Typhoon Warning Center (JTWC) on Guam in the 80s and 90s, the process became a little easier to perform using the new IR technique and with animation for positioning. However, the final T numbers still often remained confusing. Different users often had T# greater than the ½ T# apart, especially for the initial and developing systems. Even dedicated computer systems like the McIDAS and MIDDAS required a subjective human interphase that was not always consistent. From my perspective, there are two basic needs for a more consistent and sustaining Dvorak technique: the first to be able to handle the systems that Dvorak never saw in the Atlantic basin such as midgets and developing monsoon circulations; and the second, the use of other remote sensing systems to position the surface center more accurately and to be able to integrate knowledge gained from these other sensors into the Dvorak technique tables.