Dry air around Invest 91L is creating an environment that is not conducive for tropical development over the next two days.
MIAMI – The odds that a disturbance on a long trek across the Atlantic Ocean will become a more organized tropical system have been lowered.
The FOX Forecast Center has been keeping a close eye on Invest 91L, located in the central Atlantic. An “invest” is a term used by the National Hurricane Center to indicate a system being watched for possible tropical development.
Models had showed favorable conditions for 91L for much of the week, but those trends have started to dwindle in recent runs.
The NHC which had given the invest high chances of development began dropping the odds early Friday afternoon. The disturbance now has a medium chance of developing within the next two days, but a high chance of development within the next week.
WHAT IS AN INVEST?
(FOX Weather)
The NHC said in its early Friday afternoon update that 91L is now in an area where environmental conditions will likely cap its development over the next 48 hours. However, they noted that 91L could still develop into a tropical depression early next week as the system moves westward at around 10 mph.
“A tropical depression is a low bar. It just means that the system has developed an organized circulation,” says FOX Weather Hurricane Specialist Bryan Norcross. “As it moves slowly west, it will be plowing through patches of dusty air, which will likely keep it from intensifying quickly, and the dry air could do it in.”
WHAT’S THE DIFFERENCE BETWEEN A TROPICAL DEPRESSION VS. TROPICAL STORM VS. HURRICANE?
The FOX Forecast Center said that the steering currents are weak across the tropical belt, so it may take about a week until the system is in the vicinity of the Caribbean islands.
While confidence is still high that a tropical system will eventually form over the next week, its track and strength remains an open question.
“The upper winds are forecast to be conducive to development, but the persistent dry, dusty air and the disturbance’s slow forward movement are deterrents to strengthening. How those factors balance accounts for the uncertainty,” Norcross said.
In the long range, the FOX Forecast Center said that computer forecast models remain split.
HOW TO WATCH FOX WEATHER
This graphic shows the potential setup for a tropical disturbance in the Atlantic.
(FOX Weather)
Be sure to download the free FOX Weather app to keep up with developments of this tropical disturbance.
