Inside Edge on What Helped Hurricane Michael to Rapidly Intensify Leading up to Landfall. (Imagery credit: Meteorologist Stu Ostro)
DISCUSSION: There is no question that Hurricane Michael shocked the state of Florida and the rest of the world for that matter on the morning of October 10th, 2018. It goes without saying that Hurricane Michael will undoubtedly go down in history as one of the top five most intense hurricanes to make a direct hit on the contiguous United States as far back as records go. Having said that, it is even more interesting to learn more about and why Hurricane Michael managed to intensify so quickly and so close to the official point of landfall in northeast Florida as this system did. This is complicated and yet, at the same time represents a perfect example of a classic tropical cyclone intensification scenario.
To get into the factors which went into how and why Hurricane Michael intensified as quickly and abruptly just before its landfall near Mexico Beach, Florida, there are some atmospheric and environmental fundamentals which must exist. It is imperative to establish the fact that for a hurricane to intensify and/or rapidly intensify at any point in time, there must always be sufficiently warm sea-surface temperatures in place both under and out ahead of an approaching tropical cyclone. In the case of Hurricane Michael, there was more than sufficiently warm sea-surface temperatures spread across the northeastern Gulf of Mexico out ahead of the forward approach of Hurricane Michael. Hence, the first major piece was most certainly in place for this tropical cyclone.
The second major environmental factor which is key and essential for tropical cyclone intensification is the presence of little to no vertical wind shear both surrounding the immediate location of the intensifying tropical cyclone and out ahead of the given tropical cyclone. In the case of Hurricane Michael, the main concern regarding the presence of vertical wind shear was when this system was developing both near and just to the north of the Yucatan Peninsula in eastern Mexico. However, as this storm continued to move northward with time, the issues pertaining to the presence of vertical wind shear subsided rather quickly as the storm’s inner and outer core organized rather quickly with time which limited the vertical wind shear threat and concerns thereof. Thus, the second piece of the puzzle was most certainly in place for then intensification of Hurricane Michael.
The third major piece which is important and is critical both ahead and during a period of intensification and/or rapid intensification of a tropical cyclone is to have an effective and consistent outflow channel both surrounding and out ahead of a strengthening tropical cyclone. This consistent outflow surrounding an intensifying tropical cyclone is important since this allows a tropical cyclone to vent all the excess “cloud debris” and excess heat energy which is always being released both above and surrounding the convective inner and outer portions of a developing and/or mature tropical cyclone. As shown in the animated graphic attached above, there was most certainly an effective outflow channel in place with Hurricane Michael which allowed for this outflow channel to be maintained incredibly well with Michael right up to the point of landfall.
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© 2018 Meteorologist Jordan Rabinowitz