September’s reputation as the busiest Tropical month is taking shape as we watch four areas of interest and the potential of a developing tropical system.
Let’s start with Invest - AL99: Showers and thunderstorms have become better organized in association with a non-tropical area of low pressure located a few hundred miles east of North Carolina, and recent satellite data indicates the system is producing winds to near gale-force. This system could acquire some tropical or subtropical characteristics over the next day or two while it moves generally north-northeastward, remaining offshore of the northeastern United States. Once the low moves over cooler waters by early Saturday, further development is not expected.
Formation chance through 48 hours and 7 days is 30%.
In the Northwest Gulf of Mexico, another area of showers and thunderstorms continues in association with a broad area of low pressure interacting with a weak frontal boundary located over the northwestern Gulf of Mexico. Upper-level winds are expected to become less conducive for development by late Friday and Saturday as another frontal boundary approaches the system. Although development is unlikely, heavy rainfall is expected across portions of the northern Gulf Coast during the next day or so.
Formation chance through 48 hours and 7 days is 10%.
In the Southwestern Gulf of Mexico Shower and thunderstorm activity remains disorganized in association with a westward-moving tropical wave located over the western Caribbean Sea. Development is not expected before the system reaches Belize and the Yucatan Peninsula by early Friday. Some gradual development is possible late in the weekend into early next week after the system emerges over the southwestern Gulf of Mexico.
Formation chance through 48 hours is 0 percent. Formation chance through 7 days is 20%.
Closer to the Caribbean, another tropical wave located a few hundred miles east of the Leeward Islands is producing limited shower and thunderstorm activity. Strong upper-level winds are expected to inhibit the development of this system during the next few days while it moves west-northwestward at 10 to 15 mph. By early next week, environmental conditions could become more conducive for some slow development while the system moves over the southwestern Atlantic Ocean.
Formation chance through 48 hours is 0 percent. Formation chance through 7 days is 0%.
Deep in the Atlantic: An elongated trough of low pressure over the eastern tropical Atlantic is producing limited shower activity. Development is not expected through this weekend while the system moves little. Some slow development appears possible early next week when the disturbance begins moving slowly northwestward.
Formation chance through 48 hours is 0 percent. Formation chance through 7 days is 20%.