Atlantic Hurricane Season: Dates, Seasonal Outlook and Weather Forecast

The Atlantic hurricane season is the period when tropical cyclones typically occur more frequently in the North Atlantic. It officially begins on June 1 and ends on November 30; the area covered also includes the Caribbean and the Gulf of Mexico. The calendar describes the seasonal timeframe for an entire ocean basin. Seasonal outlooks and short-term weather forecasts provide different kinds of information.

Season dates and seasonal outlook

A seasonal outlook estimates overall activity in the Atlantic basin, such as the expected number of tropical storms and hurricanes. NOAA bases these outlooks on large-scale influences and models. These include sea surface temperatures, vertical wind shear, atmospheric moisture and stability. These factors help estimate activity across an entire basin; they do not determine the path of an individual storm or its effects on a particular coast.

A seasonal outlook is also a statement of probability: expected activity is given as a range, not an exact number. Similar large-scale weather patterns can result in different combinations of many short-lived storms or a few longer-lasting ones. That is why a forecast of a quiet or active season does not mean that every route in the Atlantic will experience the same weather conditions.

Seasonal outlook versus a specific forecast

A specific forecast concerns a weather system that has already been observed and its possible track, intensity and hazards. NOAA notes that landfalls depend greatly on the weather patterns in place as a storm approaches the coast; these patterns can generally only be narrowed down a few days in advance. A seasonal calendar, a seasonal activity outlook and short-term warnings therefore answer different questions. Wind strength and sea state are additional aspects of the marine weather conditions and are reflected in sea conditions.

Context for Atlantic routes

Atlantic routes pass through a wide variety of coastal and ocean areas. The time of year is therefore part of the broader context for a voyage, while conditions on any given day depend on how the weather develops. Seasonal statistics describe the expected activity across the basin; they do not make a prediction about an individual port, a particular ship or the precise route. Offshore cruising areas show how far routes can extend across coastlines, islands and open sea.