A Tropical Depression or Tropical Storm May Form in the Caribbean Sea This Week

November 13,2016
The Atlantic hurricane season lasts through the end of November, and there are indications this week that the 2016 season may deliver at least one more tropical depression or storm.
(MORE: How the 2016 Hurricane Season Stacks Up, So Far | Hurricane Central)
Long-range guidance, for the past several days, has suggested an area of disturbed weather may fester in the typical hotbed for November activity, the western Caribbean Sea generally south of Jamaica, later this week.
In fact, thunderstorms have been flaring up in the western Caribbean the past couple of days along the "monsoon trough," from near the coasts of Venezuela and Colombia westward to Nicaragua. There is no sign of a surface low-pressure system developing in conjunction with that activity at the moment, however.

Current Satellite Image: Caribbean Sea

Sea-surface temperatures in the southwest Caribbean Sea are running about 0.5 to 1.5 degrees Celsius above average for this time of year, according to a NOAA/ESRL analysis.
Also, wind shear – the change in wind speed and/or direction with height that typically rips apart tropical disturbances trying to become depressions – seems to be fairly low, as of Sunday.
Both of those factors are favorable for the possible development of a tropical depression or storm in the days ahead.

Current Satellite, Wind Shear

The National Hurricane Center has given this area of the southwest Caribbean Sea a medium chance of development into a tropical cyclone within the next five days.
As with any weather forecast several days out, it's highly uncertain whether a tropical cyclone, or even just a surface low, will form in the western Caribbean Sea.
(MORE: 4 Reasons Why It's Not Time to Put Your Hurricane Kit into Storage)

Area of low pressure may develop in the western Caribbean late this week.

If a tropical depression or storm does form this week, it's not clear yet if it would simply sit and stall in the southwest Caribbean Sea, or get pulled north-northeastward toward Jamaica, Hispañiola, Cuba or the Bahamas ahead of a cold front.
If another tropical storm forms this calendar year, it's name would be "Otto." Otherwise, we'll have to wait for "Arlene" next spring or summer.

One Potential Threat, Regardless

Regardless of whether this future system develops, the area of disturbed weather could cause heavy rain to fall from Central America to parts of Hispañiola, Jamaica and Cuba.
This may particularly be the case as moisture interacts with a sluggish frontal boundary from the western Atlantic Ocean southward into the Caribbean Sea late in the week.
All eyes will be on Haiti for this heavy rain potential, still struggling after Hurricane Matthew, and after a renewed round of flooding this past week.

November Named Storms Aren't Unusual in the Atlantic Basin

As waters cool farther north and east, and upper-level winds strengthen, the area where tropical cyclones can form shrinks.
In November, tropical cyclones typically form where the waters are warmest. This typically is in the western Caribbean Sea, where you see two clusters of storm origins below.

Tropical cyclone origin points for November.

Although the Gulf of Mexico and Bay of Campeche stay relatively warm, the jet stream shifts south, bringing with it cold fronts. The environment tends to become increasingly hostile due to stronger wind shear, dry air intrusions and cooler air.
Occasionally, tropical systems can spin off of one of these decaying fronts in the western Atlantic or Caribbean.

November tropical storm and hurricane impacts in the United States

According to NOAA's best track database, there have been 36 Atlantic tropical cyclones of at least tropical storm strength in November from 1950 through 2015. Twenty of those became hurricanes.
Just eight years ago, Hurricane Paloma reached Category-4 intensity, the second-strongest November hurricane of record, damaging or destroying nearly every building on Cayman Brac, according to the National Hurricane Center's final report. "Paloma" was retired from the Atlantic hurricane name list following this event.
(MORE: Retired Atlantic Hurricane Names)
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 Sea 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.
Since 1851, Florida has been impacted by eight tropical storms and hurricanes in November. The only other states with more than one November impact were also in the Southeast: Alabama, Georgia and North Carolina.
Typically, November tropical systems follow upper-level flow and cold fronts northeastward into the Atlantic Ocean.

Typical Tropical Tracks for November.

In 2015, Hurricane Kate was an early-November oddity, forming from a tropical wave that first soaked the Lesser Antilles, then becoming the farthest north hurricane so late in the season on record north of Bermuda.
By the way, Atlantic Basin tropical storms even form in December, and January, on rare occasions.
Check back with us at weather.com for the latest on this potential late-season tropical system.

MORE: Late Season Hurricanes