Diminishing Atlantic Hurricane Activity and Potential Upcoming Storms

The Atlantic hurricane season is slowing down, with low probabilities for development of two current disturbances. Hurricane Milton may be the final named storm of October, although the Madden-Julian Oscillation could enhance cyclone formation in November. Significant rainfall is expected from two disturbances, particularly affecting areas in Belize and southeast Mexico, despite low chances of them developing into tropical cyclones. The North Indian Ocean is also anticipated to see activity with potential storm formation in the coming week.

As the month of October progresses, the frequency of tropical cyclones in the Atlantic appears to be decreasing significantly. After a brief period of heightened activity earlier this month, current observations indicate two tropical disturbances, both of which exhibit minimal potential for escalation into named storms. It is anticipated that Hurricane Milton may be the last named storm for October 2024. However, prospects for tropical cyclone formation may improve with the anticipated arrival of the Madden-Julian Oscillation (MJO) in early November, which could stimulate upward air movement and enhance the likelihood of storm formation in the Atlantic. One of the disturbances, labeled as Invest 94L, is approaching the northern Leeward Islands, moving swiftly at around 20 mph. Although it is situated in an environment characterized by light wind shear and exceptionally warm sea surface temperatures of approximately 30 degrees Celsius (86 degrees Fahrenheit), the development of 94L is hindered by the presence of dry air, which limits thunderstorm activity, and by its rapid forward motion, complicating the alignment of its organization. Additionally, an unfavorable MJO configuration currently favors descending air over the region. By Saturday, 94L is expected to encounter significant challenges to its development, including hostile wind shear if it proceeds west-northwest towards Florida, or the mountainous terrain of Hispaniola if it veers west-southwest. Predictive models are largely pessimistic concerning the potential for 94L to intensify, forecasting its failure by Sunday. Nevertheless, the system is anticipated to bring substantial rainfall, with estimates of 1-2 inches (25-50 mm) affecting the Leeward Islands, Virgin Islands, Puerto Rico, and the Dominican Republic during the upcoming Friday and Saturday. The National Hurricane Center has assigned a development probability of 20% over the next two days, increasing to 30% over the next week for Invest 94L. A separate disturbance associated with a Central American gyre is generating concern as it moves toward land, with forecasts suggesting it will make landfall over Belize or the Quintana Roo region of Mexico this weekend. Although the likelihood of this system developing into a tropical cyclone remains low, it is expected to produce heavy rainfall that could exceed 15-20 inches in certain areas, elevating the risks of mudslides and flash floods across parts of Belize, Guatemala, and Honduras. As of Thursday morning, the National Hurricane Center has indicated a limited potential for this system’s development, echoing a 20% chance over two days and seven days, namely before the expected inland transition. International tropical cyclone activity is also drawing attention with the onset of the fall cyclone season in the North Indian Ocean. Projections indicate that a tropical cyclone may emerge in the eastern Bay of Bengal early next week, catalyzed by a conducive phase of the MJO. Historical records highlight the impact of recent major cyclones, such as Cyclone Mocha, which made landfall as a category 4 storm in May 2023, with devastating consequences for the region, including significant loss of life and widespread destruction in Myanmar, where ongoing civil strife complicates disaster aftermath assessments.

The Atlantic hurricane season, typically characterized by heightened tropical cyclone activity, sees cycles of intense storms interspersed with periods of relative quiet. The Madden-Julian Oscillation plays a critical role in influencing weather patterns conducive to storm development. Currently, meteorological observations indicate a shift toward stabilization after a brief surge of storms early in October. Disturbances such as Invest 94L and other systems are monitored closely as specialists assess their potential for growth and impact on land populations.

In summary, while the likelihood of further named storms in the Atlantic diminishes as October nears its end, it remains prudent to remain vigilant, particularly in regard to the potential development of disturbances like Invest 94L and the Central American gyre system. Moreover, the upcoming cycle of the MJO could influence the future trajectory of the hurricane season, warranting continued observation and preparedness, especially in vulnerable coastal areas.

Original Source: yaleclimateconnections.org