Watching the Atlantic for Possible Tropical Development Near the Bahamas

Quincy Vagell
Published: November 8,2015

The Atlantic hurricane season is not over yet, and an area of low pressure dubbed Invest 94-L continues to be monitored for possible tropical cyclone development in the coming days. 

(MORE: What is an Invest?)

Since Hurricane Joaquin dissipated just about a month ago, the tropics have been quiet in the North Atlantic. A persistent pattern characterized by record levels of wind shear has been a driving force in inhibiting tropical development this season.

Nonetheless, a window of opportunity is opening for Invest 94-L to grow into a tropical depression or tropical storm during the next couple of days.

An Air Force Reserve hurricane hunter aircraft is scheduled to investigate this system Monday morning.

Watching Area Near the Bahamas This Week

With a plume of rich, tropical moisture feeding north from the Caribbean and wind shear relaxing near the Bahamas, an area of low pressure moving near those islands has become better organized as of early Sunday afternoon.

Invest 94-L Satellite

The National Hurricane Center said Sunday night that Invest 94-L was centered near the southeastern Bahamas and had a high chance of developing into a tropical depression or tropical storm.

As the system moves northwest, heavy rain, flash flooding and gusty winds may be concerns in the Turks and Caicos and most of the Bahamas through early week.

The tropical system has already doused parts of the Lesser Antilles with excessive rainfall. Martinique had already picked up 192.4 millimeters (7.57 inches) of rain since Thursday, as of 8 p.m. AST Saturday. Most of that fell Friday, causing serious flooding on parts of the island.

Due to atmospheric steering currents on the western periphery of high pressure over the open Atlantic, the system will continue to be pulled north, then northeast early in the week ahead, remaining off the Southeast coast. No direct threat to Florida is anticipated, but some increased surf would be possible along Atlantic-facing shores of the Sunshine State if the system can develop appreciably.

Forecast Model Tracks

Farther north, shower and thunderstorm activity with locally heavy rain will impact the coastal Carolinas early this week from a separate weather system. However, the area of low pressure that will move near the Bahamas may help to add more moisture to the already soaking setup there.

All things considered, there is a window of opportunity for the low pressure system to become better organized near the Bahamas and Gulf Stream. In this area, sea-surface temperatures do remain above average for this time of the year, providing just enough heat content to support a tropical cyclone.

As the system moves further north, increasing wind shear will create a less favorable environment and the system would then curl northeastward out to sea, perhaps brushing Bermuda by mid-week.

November Climatology in the Tropics

The typical areas of tropical cyclone development across the North Atlantic, including the common tracks of such systems.

The Atlantic hurricane season officially comes to an end on Nov. 30. With the ocean cooling from north to south, particularly at the mid-latitudes, the formation zone for tropical systems shrinks.

The number of tropical storm and hurricane impacts by state in the month of November.

Although the Gulf of Mexico stays relatively warm through much of the month, historically, as the jet stream shifts south, the environment tends to become increasingly hostile due to stronger wind shear.

In the period of record from 1851 to 2014, no tropical storm or hurricane has impacted the western Gulf Coast from Texas to Mississippi.

To the southeast, systems that do develop across the Caribbean can gain some organization, as the area has supported such late-season hurricanes as Kate in 1985 and Michelle in 2001. The former became the latest landfalling hurricane in Florida’s history on Nov. 21.

(MORE: No Hurricanes Have Struck Florida in 10 Years)

Otherwise, due to increasing upper level flow, any system that does develop tends to quickly turn north and northeast into the open Atlantic and away from the United States.

Since 1851, Florida has been impacted by eight tropical storms and hurricanes in November. The only other states with more than one impact were also in the Southeast: Alabama, Georgia and North Carolina.

MORE: Hurricane Strikes by County, Parish