Tropical Storm Fiona continues to organize and strengthen as it enters the Caribbean Sea. First, here are the links to NHC’s Key Messages regarding Tropical Storm Fiona (en Español: Mensajes Claves). That should be your “go to” for the quick overview for any storm. Here is the impact swath from my TAOS/TC model:
The storm dumped a months worth of rain on the island of Guadeloupe in less than 24 hours (Le Monde, in French), and it is still causing flash flooding and some gusty winds. Fiona will be flirting with hurricane status as it passes south of Puerto Rico and the Virgin Islands. Expect heavy rain and strong tropical storm force winds. Flash flooding and mudslides are inevitable in the vulnerable places. It’s (profanity deleted) embarrassing to have to still be discussing Puerto Rico’s electrical grid problems five years after Maria, here we are. No doubt there will be widespread, possibly long outages. I’ll somehow avoid a rant here, although one is needed. After swiping Puerto Rico, Fiona is expected to make a direct hit on the Dominican Republic as a minimal hurricane. Again, the main risk is flash flooding from heavy rains, although there will be wind, wave, and storm surge damage along the coast as well. After that, Fiona will continue to strengthen, but move away from land. The only impact expected to the mainland US at this time are rip currents as it moves parallel to the shoreline. Here is the official forecast, along with the major objective (computer) models and estimated dispersion (where we expect the storm to end up, given history and the spread of the models on this storm so far):
Originally Fiona wasn’t expected to become a hurricane until after it passed Hispaniola, but now may do so passing Puerto Rico. What happened? Let’s compare the Tropical Analysis and Forecast Branch (TAFB) analysis from yesterday and today:
If you look at the Fiona symbol, it was on the edge of the moist (gray/green/blue/red) clouds and there was lots of dry air; by today, the center was embedded within the moist cloud center. That means the storm could draw on that warm moist air to strengthen and organize.
Elsewhere in the Atlantic there are two disturbances being watched by NHC in their five day outlook, but neither are given much chance of development. Tropical Storm Larry (seen in the TAFB outlook above if you swipe all the way to the left) is expected to bring rain and flash flooding to the coast of Mexico over the next day.
There is potentially big hurricane news in the Pacific in the form of Supertyphoon Nanmadol. Nanmadol is expected to make a direct hit on the major southern Japanese of Kyushu, and could cause upwards of $18 Billion in damage if the JTWC track and intensity holds up. Over 85% of Japan’s population – 107 million out of 125 million people – might experience tropical storm force winds! It will cause disruptions across most of Japan over the next three days, but unlike some countries Japan has a fairly well developed emergency response system and resilient infrastructure. Here is the expected damage swath: