Not a day goes by where somebody in Florida or the Islands of the Caribbean remembers the day Hurricane Irma paid a visit in September of 2017. In that year, all the signs of an extreme hurricane season where there. SST temperatures were at their highest, the wind shear in the Atlantic and Caribbean was low and the Bermuda high was in the perfect position for a US landfall. All the ingredients were in place.
Irma formed on August 30, 2017 from a tropical wave that moved off the coast of Africa. It was almost immediately known that this system was going to mean trouble. Irma became the first Cat 5 hurricane to strike the Leeward Islands in history. As the storm intensified, an anti-cyclone formed right over the storm. This paved the way for catastrophic strengthening that caused the system to cap out at an amazing 180 MPH.
AS Irma raced West, the models changed dramatically. At first, it looked like she might go well east of the US and go out to sea.
Things started to change rapidly there after. Little did we know that Irma would be one of worst forecasting nightmares on record. As she progressed towards the islands with fierce Cat 5 winds, the models were locked on a either a Florida landfall or a ride just east of Florida up the coast. At the time, this looked quite likely and the possibility of a Carolina landfall was in the cards.
As she passed through the islands ushering in catastrophic death and destruction from the intense winds was left behind.
To make matters worse, Irma was heading into an area of almost no wind shear. you can see on the above image all the green areas which indicates low wind shear.
The models around September 7 were locking in on an East Coast Florida or a track up the spine of the state. On this course, a cat 5 storm could cause catastrophic damage throughout the state. The scenario was not a good one.
As the monster storm churned through the Atlantic, the models kept switching back and forth. All we knew is that a catastrophic event was going to soon take place. We just did not know exactly where the worst would hit. To make matters worse, Irma was going through eyewall replacement cycles that was expanding the wind field. The storm was spreading out its winds farther from the center. this meant that wherever Irma hit, most of Florida was going to feel it. There was no escape. By this time it was September 8 and people that went west to get away from the East Coast would soon be reversing and coming back to the East Coast as Irma locked onto the West Coast of Florida on her final approach.
Millions of other folks gave up trying to follow the models and either stayed where they were or went north out of Florida for safety.
The reason this system was so hard to forecast was because The system was approaching an area with very weak steering currents and the system was forecast to make a hard right turn into Florida. Trying to predict a turn such as this is very difficult and the NHC had a very hard time trying to pinpoint a track.
Once the system began its approach, the track deviated towards the East and moved closer to the center of the state then first thought. Along the Treasure Coast, most of the winds were actually within the tropical storm force range. A 100 MPH gust was reported at the Nuclear Power Plant on Hutchinson island. Millions of people were without power as damage assessments were made throughout the state. The Keys and the SW coast of the state were hit the hardest as they were the locations were landfalls were made.
The 2018 season looks to be no match to the 2017 season. SST temperatures are below average, wind shear is high and the air is dry. This is a complete 360 from last year. With a little luck 2018 will be a well deserved hurricane vacation.