Eighth Named Storm of 2017 Battling Northerly Shear Is Downgraded

On Thursday, Tropical Storm Harvey emerged in the Atlantic just east of the Windward Islands. Traveling a more southerly track, the storm headed toward the island of Barbados, where it brought significant flooding on Friday.

Rain began on the island of Barbados as early as Thursday night according to an article from The Loop, which reports local news in the Caribbean. The flooding was the worst on the island since 1984. The tropical moisture that produced the heavy rain was the only significant effect from the storm so far.

Presently, Harvey is located 140 miles to the North-Northwest of Curaçao, or approximately 885 miles to the East of Cabo Gracias a Dios on the border between Nicaragua and Honduras according to the 5:00 PM Advisory from the Natonal Hurricane Center. Tropical Depression Harvey has been moving very rapidly to the West at 22 miles per hour.

Winds have only been between 35 and 40 miles per hour through its short lifetime. Barometric pressure has been between 29.68 and 29.77 inches of Hg. Currently, the minimum central pressure in the low is at 29.74 inches. Here is one thing to consider though. Over the past 24 to 36 hours, Harvey has been moving through the Central Caribbean including the ABC islands of Aruba, Bonaire, and Curaçao.

The Central Caribbean and the ABC islands are usually not an area for fertile tropical cyclone development and formation. Historically, there have been very few tropical systems that have moved through and flourished. So, I wouldn’t write this storm off yet since Harvey is going to be moving into the very warm waters of the Western Caribbean. The problem that Harvey has been encountering is northerly shear.

This northerly shear, which has ranged between 15 to 20 miles per hour, has literally beat the storm up. Harvey’s rapid movement could also be a factor since its circulation could be outrunning its convection. The structure of this tropical cyclone has eroded to the point where there is not really any solid convection, and the look of the depression has more of an open wave like feel to it according to the most recent forecast discussion from the National Hurricane Center (5:00 PM EDT on Saturday).

The shear is expected to slacken over the next day or so, which should allow for some intensification, especially considering that Harvey will be moving into the Western Caribbean where sea surface temperatures are very warm. Sea surface temperatures in this portion of the Atlantic Basin could be almost as high as in the Gulf of Mexico. The concern is that it might be too late since the shear has torn apart the storm so well that it may not be able to recover.

The National Hurricane Center’s intensity forecast still hangs on to the belief that Harvey will recover, and likely become a tropical storm again on either Sunday or Sunday night. The intensity forecast is calling for Harvey to strengthen to a moderately strong storm with 50 mile per hour winds within 48 to 72 hours before making landfall somewhere in Belize on Tuesday afternoon.

Whatever form Harvey takes, it will be making landfall somewhere across Belize on Tuesday afternoon, then cross the southern portion of the Yucatan Peninsula while weakening to a depression before re-emerging in the Bay of Campeche on Wednesday afternoon. The system could become a storm for the third time by mid-afternoon on Thursday.

Keep in mind though, that the NHC also suggests in its discussion that there is a possible scenario that continues to fall apart, become an open wave, and not regenerate for 72 hours. Looking at the current state of the system, it is very plausible that Harvey may be a mess and could get into the Bay of Campeche in such a state that it doesn’t even become a depression or a storm.

Interests in the Western Caribbean, Northern Nicaragua, Northern Honduras, Belize, and the Yucatan Peninsula in Mexico should pay close attention to the developments with Harvey over the next few days. A Tropical Storm Watch may be issued for the coasts of Northeastern Nicaragua and Northern Honduras later tonight.