Storm Erin is poised to develop into the first hurricane of the Atlantic hurricane season.
Tropical Storm Erin, a potent storm system, is currently moving west-northwest over the Atlantic Ocean, posing a potential threat to several Caribbean islands and Bermuda. Forecasters predict above-average tropical activity this year, and Erin's rapid intensification is a testament to this expectation.
Fueling the Storm
The key factor behind Erin's strengthening lies in the unusually warm sea surface temperatures (SSTs) in the western Atlantic. These warmer waters provide the energy necessary for tropical storms to intensify, as they enhance evaporation and fuel stronger winds and heavier rain [1][3]. In recent months, SSTs have been warmer than normal, setting records since April 2023.
Atmospheric Conditions
Two other important factors influencing Erin's development are atmospheric conditions.
Low Vertical Wind Shear
Low vertical wind shear, or changes in wind speed and direction with height, is essential for storm structure. Erin has been moving through an area of low wind shear, which favors intensification [3].
Mid-Level Moisture
Ample mid-level moisture supports storm growth, while dry air can suppress it. Erin has had sufficient mid-level moisture along its path, promoting strengthening [3].
Rapid Intensification
Climate change has contributed to conditions favourable for storms to undergo rapid intensification, where winds increase rapidly in a short timeframe. Erin is forecast to rapidly intensify to at least Category 3 hurricane strength due to the warm ocean and favourable atmospheric conditions, a pattern that has become more common in recent years [1][5].
Storm Path
Erin's current trajectory is west-northwest, moving over the Atlantic away from direct U.S. landfall threat in the immediate term, although risks remain for impacts on islands like the northern Leeward Islands and Bermuda [4]. The “heart of hurricane season” (August-October) and Erin’s timing/location are climatologically favourable for storm development and intensification [2].
Large-scale steering currents, including subtropical ridges and troughs, typically direct the path of storms like Erin. Forecast models project Erin will move near or north of the northern Leeward Islands and not make a U.S. landfall shortly, driven by these patterns [3][4].
Direct landfall on any of the Caribbean islands is unlikely, but not impossible, if Erin's path wobbles in the coming days. It's more likely that Erin will churn up rough seas and produce rip currents in the Caribbean through the weekend and into early next week.
The intensity of wind, rain, and potential flooding or mudslides could be heavy depending on how close Erin tracks to the islands. Tropical storm watches have been issued for several of the northern Leeward Islands.
It's too soon to know what kind of threat Erin could pose to Bermuda.
In the Gulf of Mexico, an area of showers and thunderstorms has a medium chance of becoming a tropical depression before the weekend. Periods of heavy rain are possible in the area Friday, regardless of whether a tropical depression or storm forms. A Level 2 of 4 risk of flooding rain is in place Friday in far southern Texas, with a Level 1 of 4 risk for the rest of the state's Gulf Coast and parts of southern Louisiana.
The storm could bring some gusty winds, rain, rough surf, and rip currents to parts of the far northeastern Caribbean this weekend. Stay tuned for updates as the storm continues to develop.
[1] NOAA - Tropical Storm Erin Forms in the Eastern Atlantic: https://www.noaa.gov/media-release/tropical-storm-erin-forms-in-the-eastern-atlantic [2] National Hurricane Center - Atlantic Hurricane Season Outlook: https://www.nhc.noaa.gov/outlooks/atlantic2023.shtml [3] National Hurricane Center - Tropical Storm Erin Discussion: https://www.nhc.noaa.gov/text/MIAHSAT3.shtml [4] National Hurricane Center - Tropical Storm Erin Forecast Discussion: https://www.nhc.noaa.gov/text/MIAHSFDB3.shtml [5] National Oceanic and Atmospheric Administration - Rapid Intensification: https://www.nhc.noaa.gov/aboutsshms.shtml#ri
- The weather-forecasting for Tropical Storm Erin indicates that the unusual warm sea surface temperatures (SSTs) in the western Atlantic, along with low vertical wind shear and mid-level moisture, are contributing factors to its rapid intensification.
- Climate-change has played a role in creating a more favorable environment for storms like Erin, where warmer ocean temperatures and atmospheric conditions promote rapid intensification through a pattern that has become more common in recent years.
- As the environmental-science continues to study and monitor the impacts of climate-change on weather patterns, it also emphasizes the critical importance of accurate weather-forecasting in keeping communities safe and informed about storm developments like Tropical Storm Erin.
