Guide #1: Atlantic Hurricane Season

Information

• Info on hurricane season dates
• General hurricane info
• Summary of 2022 season
• Predictions for 2023 season
• Aviation impact analysis
• Resources for aviation planning and weather awareness

What?

The Atlantic Hurricane Season produces some of the most ferocious storm both in intensity and often impact.

It runs from June 1 – November 30 (give or take – because storms don’t always follow our calendars).

The Eastern Pacific Hurricane season starts a little earlier – May 15, and the Central Pacific season from June 1, with both running through to November 30 as well.

The southern hemisphere has a season from November – April.

Hurricane Info

Hurricanes are ranked according to their maximum sustained windspeed (using the Saffir-Simpson Hurricane Wind Scale) and level of damage this is expected to cause. It does not take into account secondary impacts such as flooding or rainfall.

• Category 5 (Major): Catastrophic damage. Sustained winds of 137kt or higher
• Category 4 (Major): Catastrophic damage. Sustained winds of 113-136kt
• Category 3 (Major): Devastating damage. Sustained winds of 96-112kt
• Category 2: Extremely dangerous, extensive damage. Sustained winds of 83-95kt
• Category 1: Very dangerous, some damage. Sustained winds of 64-82kt.

Hurricanes develop in areas of low pressure, starting out as storms, tropical storms, cyclones are becoming hurricanes as their size and windspeed develops. In the northern hemisphere the winds circulate anti-clockwise.

They can achieve sizes of 300-400 miles wide, and potentially 5-6 miles vertically. They typically moves at speeds of 10-15mph but can travel as fast as 40mph. The area of severe weather can extend significant distances from the eye of the storms.

They are fed by warm, moist air and so develop over water and tend to dissipate once they make landfall, however, if they carry enough energy they may move significant distances over land before this occurs. If their track moves them over bodies of water they may re-intensify.

Forecasting the track and ‘lifespan’ of a hurricane is difficult, and many factors affect the intensity of a hurricane.

Last year’s season

2022 was considered an average season with 14 named storms, 8 strengthening to hurricanes and 2 reaching major hurricane status. This is slightly above average in overall number, but less in major hurricanes (greater than category 3). The level of destruction was high though.

• Hurricane Ian
  • Category 5
  • Highest winds of 160mph and lowest pressure 937hPa / 27.67inHg
  • Major impact across Florida, Cuba, Trinidad and Tobago regions
• Hurricane Fiona
  • Category 4
  • Highest winds of 140mph and lowest pressure 931hPa / 27.47 inHg
  • Major impact along east coast USA and Canada (most intense on record to impact Canada)
• Hurricane Nicole
  • Category 1
  • Highest winds of 75mph and lowest pressure 980 hPa / 28.94 inHg
  • Major impact over Florida region

2023 forecast

The forecast for 2023 is provided by NOAA NWS Climate Prediction Center (with 70% confidence apparently).

They are predicting a ‘near normal’ season, potentially less active than the last 3 years.

Aviation Impact

The major impacts on aviation are as follows:

• Delays. Significant delays cause ground and airborne issues:
  • Fuel planning and inflight management
  • Tarmac delays
  • Parking availability and ground congestion
  • Congestion leading to conflict avoidance and separation
• Re-routes:
  • Significant increased fuel burn
  • Potential FTL issues
  • Contingency procedure application (oceanic)
• Airport closures:
  • Diversion airports may be impacted as well
  • Fuel planning and inflight management
  • ETOPS planning
  • Knock-on delays at departure airports (ground stops)
• Performance and handling limitations:
  • Takeoff and landing performance (runway excursion prevention)
  • Windshear and severe weather handling
  • Low pressure and altimetry considerations
• Fuel:
  • Availability may be reduced
  • Costs may increase
• Staffing:
  • Air crew maybe unable to reach bases
• Infrastructure:
  • Power outages
  • No fuelling or handling
  • Flooding are other secondary impacts

The USA sees a significant level of impact from hurricanes along its east coast and southern region.

• In the USA, all weather accounts for 75.48% percent of system-impacting delays of greater than 15 minutes
  • The 6 worst affected are KEWR/Newark and KLGA/La Guardia, KORD/Chicago, KSFO/San Francisco, KBOS/Boston and KSEA/Seattle
    • These airports are most significantly impacted due to the volume of traffic in the airspace and the impact on flow management
  • The Florida Metroplex region sees a high level of impact from hurricanes due to its position, high traffic volumes and number of major airports in a general impact area
  • Summer delays are most commonly due to thunderstorms, winter delays due snow and winter ops, but hurricanes have a significantly costly and long lasting impact to infrastructure.

Resources

These provide links to information and sites providing hurricane monitoring and awareness, and to FAA sites providing flight planning awareness and monitoring:

• FAA website monitors delays at major airports in real time
• FAA Playbook provides info on planned severe weather re-routes based on airport closures, airspace and region closures and includes plans for space weather activity as well
• FAA NASS provides real time updates and access to applicable NOTAMs for US airport, en-route and forecast delays and events
• NOAA NWS monitors active and developing storms in the Atlantic and Pacific regions
• TCAC (Tropical Cyclone Advisory Centre) links can be found here
• Cyclocane provides forecasts on developing hurricanes/cyclones/typhoons and current warnings worldwide
• National Hurricane Centre info
• EASA info on Medicanes (tropical storms in the meditteranean area)
• IATA Hurricane Economic impact reports