April 26, 2023
Weather Forecasting for Pilots: Understanding Weather Patterns and Avoiding Dangerous Situations
The sky is a constantly evolving space, with environmental conditions having a significant impact on aviation and pilot decision-making. Pilots are trained to be able to make informed decisions about their flights, avoiding dangerous weather conditions. To effectively do this, pilots need to have a clear understanding of the basics of meteorology, how to read weather maps, and how to utilise weather charts. Here, we’ll cover weather forecasting for pilots: understanding weather patterns and avoiding dangerous situations.
What Should I Be Able to Understand On A Weather Map?
You need to be able to understand the main features of a weather map, and what they mean. This includes:
Isobars are the plain lines curving across the map. They connect points with the same mean sea level air pressure (weight per square area of air above). Some isobars have numbers on them showing this value in hectopascals (hPa).
High and Low Pressure Systems
The number shown on high and low pressure systems indicate the central mean sea level pressure. Standard pressure at sea level is defined as 1013 hPa, but there’s no specific value that defines high vs low pressure—it’s all relative to the surrounding environment. A typical high is around 1020 hPa or higher, while a shallow low is usually above 1000 hPa, a moderate low 980–1000 hPa, and a deep or intense low below 980 hPa. An intense cyclone could even have a central low pressure of around 960 hPa or lower.
A cold front is the boundary between warm air and relatively cooler air. On the weather map it appears as a blue line with small blue triangles (originally chosen because they look like little icicles). On the weather map warm fronts appear as a red line with semi-circles (originally chosen because they look like a sun rising bringing warmth). Warm fronts progressively displace cool air with warmer air. Just like a cold front, the temperature change can be quite large once a warm front moves through, although it tends to happen more gradually than a cold front.
A trough appears on the weather map as a dashed blue line on the chart. It is an elongated area where atmospheric pressure is low relative to its immediate surroundings. Like cold fronts, troughs separate two different air masses (usually more moist air on one side and drier air on the other).
You can read about these basics on the Bureau of Meteorology website, here.
How Do I Avoid Dangerous Weather Situations?
Weather can change quickly. This means that you should never fly in weather you’re unfamiliar with, and you should never fly unless you’re sure that it is safe to do so. To achieve this, you should always rely on as much weather information as possible. We have covered the main weather sources below for you.
Above all, however, you should always check your information and plans with a flying instructor if you have any doubts or questions at all. Similarly, in aviation you may fly through a variety of weather patterns and geographic regions in a single flight. This means it’s imperative that you have correct and current weather information, as well as a thorough understanding of the information.
Where To Access Aviation Weather Information
In order to make informed aviation weather decisions, you’ll first need to ensure you have adequate information and resources to rely upon. Here are some common sources of information that you can refer to. However, note that the most informed decisions will be founded upon multiple sources of information, rather than a singular source.
NAIPs and Airservices
The NAIPs system is overseen by Airservices Australia, the official provider of the Aeronautical Information Service in Australia. This includes the delivery of the Bureau’s aviation meteorological products. Therefore, all information for the purpose of flight planning should be obtained from Airservices Australia.
Radar, Satellite and Weather Maps
Radar, satellite imagery and weather maps are an important part of understanding weather patterns. These visualisation tools help you to understand the behaviour of weather patterns. If you use these tools, you can learn about the weather before, during and after your planned flight. By understanding the weather patterns, you are thinking beyond just the weather forecast, which means you’ll have a more informed understanding of the potential weather you’ll cross.
A mean sea-level pressure analysis, for example, will show you the highs, lows, troughs and fronts. This means you don’t just know what weather is forecast, but you’ll understand why.
Bureau of Meteorology
The Bureau of Meteorology’s Aviation Weather Service provides aviation users with meteorological information necessary for safe and efficient civil aviation operations. The service includes the provision of observations, forecasts, warnings and advisories, and is provided within the technical and regulatory framework of the International Civil Aviation Organization (ICAO) and the World Meteorological Organization (WMO).
Grid Point Wind and Temperature Charts
A grid-point wind and temperature (GPWT) forecast provides a text-based display of forecast wind speed and direction and temperature forecasts at specified heights above mean sea level, presented in a gridded format.
Graphical Area Forecasts (GAFs)
A Graphical Area Forecast is a combination of graphical and textual information. This replaces the ARFOR (area forecast) used previously. The graphic is divided into areas that share common weather characteristics, which are detailed in an associated table.
AWIS services are available at most major airports in Australia via phone or radio. These services provide live aviation weather information and are on a monitored service. An AWIS service won’t allow you to plan very far ahead as it reports current conditions. However, it will help you confirm the weather ahead of you, particularly to assist with runway selection, visibility, and conditions for landing. You will find AWIS information in the ERSA.
Electronic Flight Bag (EFB) Resources
Your EFB, such as OzRunways or AvPlan, integrates into aviation weather data to assist with your flight planning. You should familiarise yourself with your EFB to ensure you know what information is available to you, how the visualisers work, and any limitations of the information (e.g. date and time ranges of validity).
Confirming Weather Forecasts
Any experience pilots will tell you that they always refer to more than one source of weather information. There will be times in your flying career where weather will change beyond the forecast and you may be faced with a decision to make about your planned flight. Beyond the documented weather information we’ve covered, it’s important to understand that you also have additional tools available to you to help inform your choice.
See For Yourself
Regardless of what the weather says, you should always review the live weather yourself – look out the window before flying, and always observe the weather as you fly. You may observe exactly what the weather forecast had told you. If so, that’s great! However, occasionally the weather might appear contrary to the forecast, which is why it’s important to observe yourself.
Many Australian airports have fixed, live weather cameras in place. They are useful as a reference point. However, you should never solely rely on them for flight planning purposes. They should only ever be a secondary or tertiary tool to assist your overall weather and flight planning.
Call Ahead to Confirm
If you’re still unsure of the weather, there is no harm in jumping on the radio or phone to call someone at the destination you’re flying to. There’s not much point calling a day or two before, if you’re looking for live weather information. Again, this shouldn’t be to plan your flight, but it can be useful to confirm the decisions you are making.
Take note, however, that these tools are not official weather forecasting tools. They are merely an additional reference point to help understand the weather you’re flying into. For example, you might ‘see for yourself that your local area appears clear to fly – but if the weather reported an inbound storm, you should definitely reconsider flying.
What Else Should I Know?
We hope this helps you answer some FAQs about aviation medical examinations in Australia!
We’ve also compiled a few useful posts that might help you out. Where ever you are on your aviation journey, the team at Learn To Fly Melbourne are here to help. We want you to pass your exams and have an excellent career, so please reach out if we can help support you through your course and studies!
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