Wednesday, December 1, 2010

Plan Safer Bushwalks: Weather Forecasts and Climate Records

Why check the weather forecast before you go bushwalking? How should you use the weather forecast and climate records to help pack and plan your hike?  How can climate records help you?  How can you check the weather during your walk?
Trip Planning

An essential component of trip planning is to check the climate statistics for the region you will be visiting and for the time of the year. This can be a critical component of your planning because there are enormous variations in the weather both within and between States. I usually look at both last years and average statistics for the month I am intending to visit. Finding the nearest weather station often takes a bit of hunting.

You should check out the climate statistics before you go, so that you take the right clothing, food, water and tent and can allow extra days for extreme weather. The stats will give the likelihood of this happening.
For those of you planning a trip to the Tasmanian Central Highlands, you will need to expect lots of rain and some snow even in summer. A winter trip will require special expertise and equipment, which will beyond the expertise of most hikers.

Check the statistics for Scott Peak Dam, just north of Western Arthurs and near Mt Anne . Long term stats show February would be the best time to go if you wanted the least number of rain days. But what clothing should you take?
Daily records for February show: Max temp 35, minimum temp 3, highest rain 42 mm. Long term averages show: 15 raindays, mean max temp  21, mean min temp 9, mean rain 65 mm
I'd be taking a full range of gear: sun hat, sunburn cream, long shirt and maybe long lightweight trousers for the hot days then overpants, rain jacket, perhaps down vest, thermals for the cold.

If you are planning a trip to northern SA (eg the Gammons) in spring check the forecast carefully as the temperature is often in the high twenties or low thirties, when it is high teens in Adelaide. My experience is that it is often 5 -10 degrees warmer than Adelaide but colder at night. 

Check the climate statistics for Arkarooola the nearest weather station.
Long term averages show May to August look best from a temperature perspective (19-20 deg C). Mean min temp are 3-7 deg C, (lightweight sleeping bag weather). Days of rain 3, mean rain 6-10 mm (you may even risk just a fly depending on the month)
Further north in the Gammons, water can also be short supply after six months with little rain. A spring/summer trip is a no, no! Surprisingly, most rain falls in December-March as the tail ends of monsoons sweep down SE from the Kimberley, so May will still have lots of water in rock holes.

Read more on Trip Planning
Taking Enough Water

The weather stats are useful because you can check rainfall for the current and previous few months. You should be able to work out whether rock holes will be full, creeks flowing and surface water available. In Tasmania in summer in certain locations eg Mt Anne, Frenchmans Cap, you can often rely upon deep "yabbie" holes which will usually contain water even when the surface is dry, and can be drained  with a short piece of tubing.

Expected temperature has a significant bearing on how much water you will need to carry. On a warm day, carrying a full pack I need about 4 L during the day, add to that a dry overnight camp and breakfast and 6 litres becomes the minimum to carry between "wet" campsites. You should hydrate before you leave your source of water each day, to reduce the amount you need to carry. Have a couple of extra cups of tea , even drink your teeth cleaning water if you are short.

Spare days
If you are walking in alpine areas, areas subject to flash flooding or in places which are exposed to weather blowing in from the sea, for example the central highlands of Tasmania or the west coast of the South Island in NZ, allowing extra days to sit out a storm or wait for a river to fall ( Franklin or South Coast Track, Tasmania) is essential for safety.


Risk Avoidance and Response
Most bushwalks require some risk analysis  during the route planning stage and this should automatically involve a check of the weather and climate statistics for the locality.

The Adventure Activity Standards (AAS) specifies two units from the Outdoor Recreation Industry Training Package which are helpful
Bushfire Alert
Many Parks close and evacuate walkers when there is an imminent threat of bushfire or on days of high bushfire danger. While  most of us try to avoid walking in the middle of summer, those of us who walk in Tasmania by choice, have to expect the occasional park closure. A little commonsense helps too... check for Park closures before going, don't walk towards smoke and always have an alternative escape route in case you are cut off by a bushfire.

The Victorian Outdoor Recreation Centre's Newsletter has some excellent advice. A great resource is their Guidance Note Management of Outdoor Activities for Severe Weather Conditions (November 2009) which is available for download.

Check for bushfire alerts:
Try the iPhone apps

FiresAU . For those of you who live in NSW, Tasmania, SA.
This app lists bushfire alerts ranking them according to proximity to your location, using the built-in GPS. Bushfires are also shown on a map by red pins and your current location by a blue pin. In the case of an emergency, a "canned message" can be emailed to a contact giving your location.
Fires Near Me NSW
This is the official iPhone application of the NSW Rural Fire Service. This application provides information on current incidents across NSW attended by the RFS and other agencies. It also provides information on total fire bans.
Lightning Warnings
Thunderstorms can be dangerous if your caught on an exposed ridge or under a tree while its raining. One way to avoid being caught is to try to work out how far the storm is away, using the lightning flash and the time taken for the thunder to be heard.

One iPhone app that does just this is Thunderstorm-Calculator

Tides
Knowing the predicted tides can be invaluable for those bushwalks where you will be walking along the coast. Two walks come to mind: The Great Ocean Walk along the coast near the Otway Ranges in Victoria and the South Coast Track in Tasmania. Both of these walks require decisions to be made about whether it is safe to walk along the shoreline or whether an inland route should be taken. ...and these are decisions not to be taken lightly as both coasts are subject to big waves and strong southerly winds.

There are several iPhone apps which give tide information and in some cases store it on your smartphone so you don't need internet access to view the data:

Moonlight
Well, there have been a few occasions when I would have liked some moonlight to complete a long walk, but most of us like to be in camp by mid-afternoon. If you are an aspiring alpine mountain climber, then moonlight becomes more important, as you often need to make a start in the early hours of the morning to catch the snow while it is hard.

Check out the iPhone Moonlight app.
Moonlight features a photorealistic display. The program takes the observer's  current position and time into account for exact rendering of images. Moonlight not only displays a pretty 3D image but also shows various essential data points: moon phase, distance between earth and moon, julian date or local sideral time.
Monitoring the weather while you walk.
There are many ways to monitor the weather while you walk
  1. wristwatch
  2. portable weather station
  3. smartphone app
  4. GPS with inbuilt barometer/altimeter
    1. Wristwatch Weather

    Suunto Observer
    I have only used Suunto watches (Finland), bought from Paddy Pallin, which have been around for many years and are very reliable. Their only problem is that the batteries have a significantly shortened lifetime if the compass, backlight or GPS are used frequently and having them replaced by Suunto is NOT cheap. Be careful if you have it done at your local jeweller, even if they claim to pressure test. Like me, you may regret it when your very expensive watch fills with water, as mine did after a swim in Lake Vera, near Frenchmans Cap, Tasmania after I had the battery replaced by the local Battery Bar

    They make a great everyday watch and a good bushwalking navigation backup. PS The alarm  is very quiet for me. Must be old age!

    2. Portable Weather Station

    Light weight, compact, weather stations which can be carried in your pack have become available recently at a low cost. I can't vouch for their accuracy, but I would imagine they would be at least as accurate as a wristwatch.Many have an LCD screen so you can watch trends.

    Try Dick Smiths for some ideas. They are much cheaper than a wristwatch "weather station" and there is no need to leave your tent in the morning to check if its raining!

    .... or Kathmandu, for their combined weather station, alarm and clock at sale prices.

    3. Got an iPhone? then try an app

    iBarometer:
    Lets you easily know what is the pressure near you, using the internet. Great for calibrating your altimeter. Contrary to standard applications (with predefined cities), this version of the barometer will give you precisely the pressure of where you are. It integrates its own conversion system.Could be very useful before set out on a walk.
    Pocket-weather-au 

    Pocket Weather AU
    Highly recommended, Australian developers; the one I use!

        Forecast and observation data for hundreds of areas around Australia. Select it via GPS, Map or list.
        - Push current temp, text forecasts and state,regional and local warnings to your iPhone
        - Custom interface for browsing BOM warnings, all nicely formatted for your iPhone
        - Tide graphs for hundreds of locations around Australia
        - National Rain, Satellite and Synoptic Chart
        - Animated weather icons
        - Sunrise/sunset times
        - All of the BOM rain and wind doppler radars with Find/Track me function as well as the ability to have it auto update (see 'Live Radar' in settings)
        - National rain and cloud radars and Synoptic chart
        - Extended forecasts for regional areas
        - Give your locations custom names
        - Shake to refresh, simply shake your phone to refresh the data
        - Realtime UV support for some locations
        - Last update is always cached, so you don't need a network connection to check the weather for the week, once you've got it once.
        - Updates are tiny (less than 10kb) so you don't have to worry about your iPhone data cap.
        - Supports landscape and portrait view, and in landscape you get all the information on a single page. 


        - 7 day forecasts for more than 250 official forecast locations
        - Detailed local observations, typically updated every 10 mins
        - Each forecast location includes up to 6 nearest official observation locations, accessible by side-scrolling action.
        - 50 rain radar locations around Australia
        - The radar view also has a "Locate Me" feature which queries the iPhone's GPS and then centres the radar map on your current location along with an animated cross hair cursor.
        - Radar data delivery has been carefully optimised to arrive quickly on your iPhone  (Free version available)

     It uses GPS to show your location on the radar inf ull screen landscape view. National cloud and synoptic charts.
    Time and Australian Weather, a match made in heaven. Weather sourced directly from the Australian Bureau of Meteorology (BOM) displayed elegantly alongside the current time. 
    Calculate wind chill temperature by simply selecting the air temperature and wind speed. The calculated wind chill temperature is displayed "on the fly". For those who travel by bike, motorcycle, boat, or other means where you find yourself exposed to the elements while in motion, Wooly Wind Chill now has the option to calculate the approximate effective wind chill based your current moving speed (not factoring for actual wind speeds).

       This app brings back the ancient knowledge of former generations:
    Identify conclusively a thundercloud and what kind of weather can be expected in what time frame when you see fleecy clouds.  Find out if  it is going to rain when the spider stops spinning its web and much, much more.  Detailed descriptions of all cloud types and the weather they bring. Complete cloud atlas with all cloud families, species and types according to the  International Cloud Atlas of the WMO (World Meteorological Organization). Large photo gallery with over 70 examples of all cloud types
      4. GPS with Barometer

      Garmin GPS
      Garmin, and no doubt others, have quite a few GPSs which come equipped with a barometer/altimeter eg  the wrist mounted Foretrex 401, the touch screen Oregon 450 -550 series, GPSMAP 62 series, eTrex Summit HC, eTrex Vista

      Get more iPhone  Apps for the Outdoors

      Some Great Uses of the iPhone for Bushwalkers Forums

      Check out some Forums


      Folk Lore

      Creative Commons License
      This article by Bush Walker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

      1 comment:

      1. Which weather sites do you use?

        Do you have a good weather field guide which offers practical advice?

        Do you use a good Symbian or Android weather app?

        Do you have links to other weather sites which help you with planning your hike?

        ReplyDelete