Identifying current and recent weather conditions
“You pray for rain, you gotta deal with the mud too. That's a part of it.” Denzel Washington
While forecasts help with planning a bushwalk, the actual recent weather data helps to decide if you go or stay, or if the route plan needs to be changed or modified. For instance, a pleasant dry day may have been forecasted in the area you have planned to go, but recent heavy rainfall caused landslides on a section of your intended walking track. In this case, it’s clear that at the very least, a route modification is required, but more likely, you’d want to get some local advice from land managers about the condition of the rest of the track, and what they recommend as an alternative route.
Think about where your intended walk goes, and what terrain it crosses as this will help to fine tune what weather forecasts are useful.
For example, if your intended tracks involve steep, rough, slippery terrain, rainfall data of the last few days in the area would help you decide if you should change your route. You can get this from the Australian Government Bureau of Meteorology. The bureau keeps statistics of daily and monthly historical weather observations, rainfall, temperature and solar tables, graphs and data up to the previous 24 hours. Katoomba, for example, has all the daily rainfall data for 2017 published here.
More generally, avoid catchment areas, canyons and slippery terrain if there has been heavy rainfalls in those areas. Remember also that it may be useful to contact local rangers to obtain a better idea of any safety issues, such as fallen trees or broken bridges, in the areas you intend to visit.
River crossings vary with rainfall and temperature conditions and require bushwalkers to think and act carefully to ensure safe crossing. Check out river conditions on Bureau of Meteorology if your track involves river crossing or river activities such as kayaking. Never attempt to cross flooded rivers.
Using BOM forecasts Making use of the Bureau of Meteorology weather forecasts
Traditionally, weather forecasting was done through observations of cloud patterns, temperature changes, wind/rain and so on. In many ways, when we go bushwalking and step away from weather forecasts on our smartphones, we become a lot more aware of these subtle weather changes and what they mean for bushwalking.
Modern-day forecasting is what we’re familiar with from television forecasts, radio reports and forecasts on our phone. These forecasts are based on computer-generated maps that model likely weather outcomes based on learnt patterns. This is called Numerical Weather Prediction (NWP), which is based on mathematical models of the atmosphere. Sophistocated computer programs, also known as forecast models, run on supercomputers and provide predictions on many atmospheric variables such as temperature, pressure, wind, and rainfall.
Many different mathematical forecast models are available for weather prediction. For greater accuracy, the Bureau of Meteorology uses the Combining Models method. However, no weather forecast system is perfect, so it pays to be prepared for unexpected changes in weather when bushwalking.
All of them pride themselves on various features such as attractive graphs, maps and charts. You may want to explore different websites to discover which one appeals to you more.
Before departing, check any weather warnings in your state. The Bureau of Meteorology provides a summary of weather warnings issued in each State, and it is regularly updated throughout the day at the hour indicated at the bottom of the page. Warnings include marine wind warning, flood watch and road weather alert.
How far in advance to trust
Despite the advent of modern technology and improved techniques, weather forecasts still have their limitations. For example, weather forecasts for today or tomorrow are likely to be more reliable than weather predictions 14 days from now.
Forecast accuracy is also affected by the fact that the weather in many parts of the world has become more unpredictable and changeable.
Therefore, it is good practice to check forecasts regularly, as they become more accurate as the date approaches.
Apart from the weather forecast and warnings, there are other types of warnings bushwalkers must pay attention to, such as:
- For bushfire warnings: check with the NSW Rural Fire Service publish details of bushfires and hazard reduction burns online. You can also download the NSW Rural Fire Service Fires Near Me app on iTunes or Android for information on the go in New South Wales and the ACT.
- For park alerts/closures: check with NSW National Parks and Wildlife Service (NPWS) before you set out.
Checking Fire Danger Ratings and TOBANs How to check fire danger ratings and TOBANs before a bushwalk
Bushfire risk changes every day. It is predicted through temperature, wind and humidity conditions, as well as how dry the landscape is. The hotter, drier and windier the conditions, the more likely a fire is to start and spread, and the harder it is to control.
Bushfire danger ratings are a tool used by authorities to quickly convey bushfire risk by describing the possible consequences of a fire, if one were to start. The higher the rating, the more dangerous the conditions are, and the more severe the recommendations become. Instructions on ‘what to do’ in each category of bushfire risk are primarily targeted at homeowners, and behaviours around if and when to stay and defend a property, versus when to leave.
For instance, for a low-moderate bushfire danger rating, the NSW Rural Fire Service recommend “Review your bush fire survival plan with your family. Keep yourself informed and monitor conditions. Be ready to act if necessary”, whereas for a Catastrophic rating, “For your survival, leaving early is the only option”.
For bushwalkers, NSW Rural Fire Service has some simple Fire Safety Brochures for Bushwalkers and Travellers, where they advise “If the conditions aren’t good, don’t go!”. The tricky thing here, however, is that it’s not clear what are ‘good’ or ‘bad’ bushwalking conditions. How do you decide what’s safe or not?
We recommend the following course of action for deciding whether to go on your bushwalk or not:
- NSW is divided into 21 fire areas based. Determine which areas your walk goes through, and use the NSW Rurual Fire Service Fire Danger Rating service to view relevant fire danger ratings. Cancel the walk if high, very high, severe, extreme or catastrophic Fire Danger rating is in place.
- Also check out the BOM weather forecast before departure, particularly for multi-day bushwalks, and cancel the walk if hot wind and extremely high temperature are predicted.
On high to extreme fire days, such as hot, dry and windy days, when fires are more likely to spread and cause damage, the NSW RFS Commissioner may declare a Total Fire Ban (TOBAN) to reduce the risk of fires damaging or destroying life, property and the environment.
In a Total Fire Ban, no fire may be lit in the open and all fire permits are suspended. This includes incinerators and barbecues (BBQ) which burn solid fuel, e.g. wood, charcoal or heat beads. NSW national parks are also closed during a Total Fire Ban.
We strongly recommend canceling your walk if a TOBAN is in place. On multi-day activities, if a Total Fire Ban is unexpectedly declared (or suspected) leave the park early.
Most important, If you are unsure about the conditions, don’t go bushwalking!