Wednesday 5 pm Update: Tropical Storm Chantal has weakened into merely a tropical wave, according to the National Hurricane Center’s 5pm advisory. The system was still producing wind gusts to 45 mph and very heavy rain in its northeast quadrant, a trend that will likely continue for several days.
Hurricane Hunter aircraft from NOAA had a difficult time justifying the presence of a tropical storm last night in the northern Caribbean. A closed circulation center was not ascertainable and maximum winds with Chantal were reduced to 45 mph. A second flight this morning concluded that tropical storm force winds were still occurring east of the center, so the 11 am advisory kept the intensity at 45 mph. The most-recent flight this afternoon confirmed that Chantal is no longer a tropical storm, but rather just an open wave of low pressure.
Remnants of Chantal are moving very quickly to the west at 29 mph and still encountering high wind shear (sort of like a strong head wind) on its west side. As a result, the system may become difficult to track over the coming days and it could dissipate entirely. However, the moisture pool left over from Chantal – her ghost so to speak – will be pulled north and west, likely moving into the Florida Straits or the Gulf of Mexico by Friday. This area of deeper moisture will feed into a stalled front and upper-level area of low pressure over the Southeast US and likely bring above normal rainfall to much of the state during the period Friday through Monday.
Update from earlier Wednesday: Forecast confidence on the track and strength of Chantal’s remnants over the coming days is unusually low. This is due in part to the 1) potential interactions with mountainous terrain over Haiti and Cuba, and 2) the faster winds aloft that will be interfering with the cyclone on its entire journey back into the Atlantic or Gulf of Mexico. It is entirely possible at this point that Chantal, or the remnants thereof, would have more of a direct impact on the peninsula of Florida or even move up the west side of the state this weekend. The verdict on this may not be apparent, however, until the storm crosses the hurdles of both Haiti and Cuba later today and Thursday. At the very least, Floridians can expect an increase in rain coverage and the potential for heavy rain at times as we approach the weekend. Even if Chantal is no longer a tropical cyclone by Friday, its remnant moisture pool will likely work in concert with an upper-level area of low pressure to the west to soak much of the state off and on for days.