Making good weather-based decisions*

Abstract

Processes in good weather-based decision making:

1. Understand the threat. While wind and rainfall threats are generally well understood, some other events—such as negative storm surge, long distance lightning strikes, or tsunami—are often not considered. Although these events are not as frequent, they can be devastating.

2. Be aware of resources. An awareness of products, and making appropriate use of these products, contributes greatly to good decision making. The use of probabilities is growing in popularity; however, the uptake of these products has been limited because of the desire to make yes/no decisions.

3. Understand the products. The meanings of products, and terms within the products, are not always well understood. This can be seen in cone of uncertainty TC forecasts and significant wave height forecasts where the potential risks are often underestimated. There is an evolving need to provide educational material and resources to decision makers.

4. Understand the spread of possibilities. It can be easy to just look at a deterministic forecast—the most likely weather conditions—without considering alternative outcomes. The best strategy is to work with the weather service provider to determine the likelihood of the worst case scenario at any given time.

5. Use good sources of information.

   Too often we hear that alternative opinions have been sourced from the internet. There can be very good reasons for having more than one service provider, but using unverified sources or raw model data can have calamitous results.

6. Have well understood response procedures. When developing response plans, work with a skilled meteorologist to identify potential weaknesses. As an example, we see many strategies that rely on only observed TC characteristics rather than forecast characteristics.

   Make sure false alarm and probability of detection ratios of response plans are known. This can alleviate concern among senior management if they accept that a number of false alarm responses are a normal part of safe operations.

7. Report the weather. Reporting onsite weather in a standardised manner has a tremendous impact on the overall skill of forecasts. Forecasts are usually tuned to match the prevailing site idiosyncrasies, especially in remote or terrain-influenced locations. Additionally, weather usually moves from point A to point B, so if there is a culture of sharing information then the community in general benefits.