Tropical Storm Erin is on a trajectory to become the first hurricane of the season, with forecasts indicating that it could reach Category 3 hurricane strength by this weekend. The storm, which was officially named early Monday, is currently churning in the open Atlantic. While the likelihood of a direct strike on the United States remains low, meteorologists caution that its path is not yet fully determined.
As of Tuesday morning, the center of Erin was located approximately 750 miles west of the Cabo Verde Islands. The storm is exhibiting maximum winds of around 45 mph, moving westward at a speed of 22 mph. On Monday night, thunderstorm activity associated with Erin appeared somewhat disorganized due to interference from dry air originating from the Sahara, which is limiting its potential for immediate strengthening. Nevertheless, Erin appears more organized than it did earlier in the week.
At the beginning of the workweek, Erin’s thunderstorms were largely displaced from its center. However, by early Tuesday, the storm's circulation had become more symmetrical, with thunderstorms clustering around the low-pressure center. This organization is crucial as it facilitates the upward movement of air, which will help intensify Erin’s core pressure and pave the way for further strengthening.
Several factors are at play that will determine the path of Tropical Storm Erin. The principal uncertainty lies in the strength and shape of the Bermuda high, a significant high-pressure system that stretches from the Azores to near Bermuda. This system typically acts as a barrier for hurricanes, and its current configuration is keeping Erin on a southerly path.
In the coming days, Erin is expected to navigate around the western side of the Bermuda high as it shifts northward. If the Bermuda high proves strong and situated further west, Erin may veer closer to the Bahamas and the eastern United States. Conversely, if the Bermuda high weakens, Erin could be steered out to sea, reducing the risk of impact on North America.
Currently, Bermuda and the Canadian Maritimes appear to be at the highest risk for impacts from Erin. The shape of the Bermuda high will be influenced by two upper-level disturbances, or pockets of cold air, forecasted to move across North America. One of these disturbances is expected to arrive by Friday, while the other is currently situated over Yukon, Canada. As this second disturbance progresses over land, meteorologists will deploy weather balloons to gather data, which will enhance forecasting models.
Erin is set to encounter exceptionally warm ocean waters north of the Caribbean Islands later this week, which could boost its intensification prospects. A marine heat wave is currently affecting the western Atlantic Ocean, creating an environment that is conducive to strong storm development. Forecasts suggest that Erin could reach at least Category 3 hurricane status, if not stronger, as it traverses these unusually warm waters.
As Erin progresses, several additional waves of energy are expected to follow, each possessing the potential for strengthening. These disturbances, known as African Easterly Waves, originate from Africa’s Sahel region and play a critical role in hurricane development from June to October. Residents and visitors in the Caribbean Islands should maintain a heightened level of vigilance, as the likelihood of further storm activity is elevated in the coming week.
Following Erin, the next storm names on the list are Fernand, Gabrielle, and Humberto.
