By The Numbers: How Maria strengthened
The numbers speak for themselves: Tropical Depression Maria formed 2pm Saturday afternoon. By Sunday 5pm, it was a hurricane. Then by Monday at 7:45pm, it was a Category 5 beast.
What's the science behind this 'explosion' in the wind speeds?
Maria underwent something called rapid intensification, which is defined as a tropical cyclone's maximum winds increasing at least 35mph in a 24 hour period or more. 35mph? Let's more than double that -- and you have Hurricane Maria. Sunday at 8pm, the hurricane had max winds of 80mph. Monday at 8pm, the hurricane had 160mph.
How does a period of rapid intensification happen?
Hurricanes and tropical cyclones need a "Goldilocks And The Three Bears" situation -- with perfect environmental conditions to be favorable for that significant of an increase in just 1 day. In the case of Hurricane Maria, it did.
The ingredients that were "Just Right" included:
- Warm Ocean Waters - Hurricanes are like steam engines and get their energy from warm ocean waters. Warmer ocean water fuels more energetic storms. Hurricanes need temperatures around 80-degrees to maintain enough energy to thrive. East of Dominica, ocean waters were much warmer than that, providing energy for rapid intensification.
- Weak Wind Shear - Wind shear is the changing of wind speed and/or direction with vertical height in the atmosphere, which disrupts the natural flow of a hurricane. In the case of Maria, there was very little wind shear to interrupt the natural flow of the storm. Because of this, the hurricane remained symmetrical and was able to continue it's path to major hurricane status without being "torn apart" by shear in the atmosphere.
Little Interaction With Land - Land adds friction to the equation, and mountainous terrain adds even more friction. Land also cuts a hurricane off from it's life source: warm ocean waters. Before Hurricane Maria made landfall in Dominica, it had not interacted with any land masses or island groups, which would have inhibited the extent of the strengthening possible.