This business aviation blog post continues from our article last week, titled: “Hurricanes and Typhoons vs. Business Aviation – Part 1: Understanding These Weather Events.“

It’s often difficult to accurately predict formation, intensity, and track of hurricanes and typhoons. These weather events, however, must be monitored closely by business aircraft operators, as they could drastically alter routing, destination stops, and safety of operation. The good news is that many resources are available in terms of trip planning to predict and manage negative impacts of hurricane and typhoon activity.

1. How often are weather advisories updated?

For the U.S., the National Hurricane Center (NHC) issues updates every six hours, and more often as a cyclone moves closer to U.S. interests. For other regions of the world, warnings and advisories are issued by Regional Specialized Meteorological Centers (RSMCs) and Tropical Cyclone Warning Centers (TCWCs), in addition to other official warnings issued by respective National Meteorological and Hydrological Services (NMHSs). Also, there is the WMO severe weather information center which contains links to RSMCs and TCWCs.

2. What are the difficulties in forecasting these weather events?

It’s always difficult to forecast the development and tracks of tropical cyclones. Every tropical cyclone needs five basic ingredients to develop: a pre-existing disturbance, warm water, Coriolis force, weak vertical shear, and an exhaust mechanism. If any of these ingredients are missing, it may prevent formation or intensification of a severe weather event. As most cyclones develop in remote ocean regions, there’s usually little in the way of surface and upper-air observations to accurately predict severe tropical activity. Enhanced computer modeling and worldwide satellite coverage have improved forecasting accuracy. It remains a challenge, however, to accurately forecast track or intensity beyond 72 hours.

3. What sources of weather data should operators pay attention to?

Best practice is to keep abreast of local media and government advisories and to contact your weather/3rd-party provider for up-to-date information on tropical cyclones. Always check notices to airmen (NOTAMs) regarding airfield status, and communicate with your ground handler regarding any airfield damage and expected repair times. While in-flight, keep in contact with ATC and your 3rd-party provider for weather updates and to ensure you’re routed away from cyclonic activity. You should also be receiving the latest weather advisories as issued by the relevant MET/ATC service.

4. What advisories are issued ahead of a hurricane or typhoon?

Formation of a tropical cyclone is usually preceded by an advisory or a Tropical Cyclone Formation Alert (TCFA). The Joint Typhoon Warning Center (JTWC) classifies tropical disturbances, listed in Significant Tropical Weather Advisories as “Low, “Med,” or “High,” based on the disturbance’s potential to develop into a significant tropical cyclone within 24 hours. “High” formation potential describes a monitored area that’s expected to develop within 24 hours. NHC highlights areas of potential tropical cyclone development for the Atlantic and eastern Pacific basins. It classifies potential cyclone development as low (less than 30%), medium (30-50%), or high (greater than 50%) within the next 48 hours.

5. What are some tips when faced with such storms?

Operators should be vigilant for potential tropical weather activity. If a trip involves potential severe tropical weather activity, operators should contact their 3rd-party provider for weather updates and keep up to date with local media reports. Be aware that any weather forecasts beyond 72 hours, especially concerning tropical cyclone activity, has significant potential for error.

6. What are additional sources of information?

For the Atlantic and Pacific Basin, the NHC website is http://www.nhc.noaa.gov/.

For the Central Pacific, the site is http://www.prh.noaa.gov/hnl/cphc/.

For Western Pacific – Indian Ocean, including Southern Hemisphere, the JTWC website is http://www.usno.navy.mil/JTWC/.

Other regional government websites:

Australia – http://www.bom.gov.au/cyclone/index.shtml
Japan – http://www.jma.go.jp/en/typh/
Canada – http://www.ec.gc.ca/ouragans-hurricanes/
India – http://www.imd.gov.in/section/nhac/dynamic/cyclone.htm
Central South Pacific – http://www.met.gov.fj/

Conclusion

Hurricanes and typhoons can significantly impact a trip and may require last-minute routing , alternate and destination changes, including the need to revise international overflight and landing permits. If there’s potential for severe tropical cyclone activity along your route, be vigilant, work closely with your 3rd-party provider, and check NOTAMs for airport closures or fuel supply interruptions.

Questions?

If you have any questions about this article, contact me at stevearbogast@univ-wea.com.