Hurricane Matthew becomes powerful Category 5 in the Caribbean on 9/30/16

You can also use our interactive tropical cyclone map to view more data about Hurricane Matthew.

At 11 pm EDT, Friday September 30, Hurricane Matthew was upgraded to category 5 status by the National Hurricane Center.  The latest Air Force reconnaissance mission measured a peak Stepped Frequency Microwave Radiometer (SFMR) wind of 143 kt (165 mph), followed by 138 kt (159 mph) during penetrations of the eye wall.  Satellite data confirmed that Matthew had become very well organized and increasingly symmetric around a well-defined eye surrounded by very deep convection. 

Based on these data, Matthew met all of the criteria of a category 5 hurricane and was officially upgraded with NHC’s 11 pm EDT update.  Located in the Caribbean, nearly due south of Jamaica, Matthew now had maximum sustained winds of 140 kt (160 mph) and a minimum central pressure of 941 millibars. Matthew is the first hurricane to achieve Category-5 status in the Atlantic Basin in over nine years; the last category 5 was Hurricane Felix in early September 2007 (Felix was at category 5 intensity on Sept. 3-4, 2007).  Like Hurricane Matthew, Felix also moved through the Caribbean. 

Tidbit: Category-5 storms are extremely rare in the Atlantic basin. 

Satellite Animation of Hurricane Matthew Becoming a Category 5

hurricane-matthew-becoming-category-5-animated
Hurricane Matthew undergoing rapid intensification on the evening of September 30, 2016. Credit: Brian McNoldy, Senior Research Associate at the University of Miami and Tropical Weather Expert with the Capital Weather Gang

The Rapid Intensification of Hurricane Matthew

Matthew has just completed a period of rapid intensification (link: research by Chris Robbins and Stacy Stewart at the National Hurricane Center).  The rapid intensification of tropical cyclones is the result of very complex dynamics and ocean-atmosphere feedback loops that create very deep convection (thunderstorms) organized with near perfect symmetry around the eye.  As all of this happens, the central pressure falls dramatically followed by a rapid and equally dramatic response by the wind field throughout the hurricane.  RI is typically defined as an increase in the maximum sustained winds of at least 35 mph during a 24-hour period.   On September 29th, Matthew was strong tropical storm with 70 mph winds; within 24 hours, Matthew’s maximum sustained wind had more than doubled* to 160 mph.

*Note: Although the wind speed increased by a factor of 2, the resulting increase in the pressure/force exerted by the wind is non-linear. In fact, the wind force increases exponentially with increasing wind speeds.  Therefore, it would be incorrect to conclude that the damage caused by a storm with 160 mph wind will be “twice as bad” than the damage caused by an 80 mph wind.  We will leave the longer explanation for a future post.

One of the last major hurricanes in the Atlantic Basin to undergo significant rapid intensification was Hurricane Wilma of 2005. Wilma strengthened from a Category-1 to a Category-5 hurricane within 24-hours, with maximum sustained winds of 185mph and the lowest pressure ever recorded in the Atlantic Basin at 882 millibars (mb).

Animated GIF of Major Hurricane Matthew up until 12:45am EDT. GIF courtesy of the National Hurricane Center

Remarkable Intra-Model Consistency

The Global Forecast System (GFS) model has shown remarkable consistency.  Other models have trended toward the GFS solution.
The Global Forecast System (GFS) model has shown remarkable consistency. Other models have trended toward the GFS solution.