Having developed theoretically a Fire Weather Index (see my pwsFWI) and creating a first implementation of it in C for analytical purposes, I needed to take the software a bit further to make it more robust and useful. I had some feedback which made me realize it was urgent to have a good Fire Weather Index (FWI) for Personal Weather Stations (PWSs).
This blog is about the context and the actual programming requirements.
In An effort for a Simpler Fire Weather Index I described my new FWI and the theory behind it. In short, this pwsFWI (as I have baptised it) is meant to be a generic FWI, valid everywhere and independent of geology and vegetation.
The pwsFWI is a (not too) complex measure of local meteorology, an indicator composed of humidity, wind speed and temperature. It fluctuates under ‘normal’ conditions and if it becomes dryer (a longer period without rain, the number becomes higher. As soon as it starts raining, the value starts dropping.
In this blog I will propose a fire weather index for PWSs. The goal is to get fuel parameters out of the equation. This means that species, litter type or geography, will not play a role as they do in the Canadian FWI. As such, it connects with a recent new development described by Goodrick et.al. 2 .
I will describe the Canadian FWI as it appears in (scientific) literature. The basic reason for describing this complex fire-weather index is, that it is heavily used in some big countries, notably Canada, France, Australia and New Zealand and that the description of the method of calculation is not readily available.
Some extensive studies have been made, to measure its performance and its relevance. FWI also contains most parameters relevant to estimating the danger level of the weather in relation to nature fires. In short: the FWI is an important tool for estimating and studying fire weather and fire spreading, with a huge knowledge base spanning almost 100 years.Read More »The Canadian FWI
An example for this top10 approach you will find on the weather site.
As a variation to existing top10 lists, I wrote a small program (in C) which reads dayfile.txt from Cumulus once per day just after midnight and for selected measurements it creates a sorted top10-list. From that list it creates a HTML-table and writes that to a text-file. That file can be included by the user on a website wherever he wants simply by a PHP-include (which is the easy way to include I think).
For amateur meteorologists it is not always easy to calibrate their equipment, unless you yourself are working at a meteorological service or know people who do, it can be difficult to get the readouts correct within the limits of error of the weather station. I described this already a short time ago.
So now I have this new UT330C. I bought it in China and it arrived pretty fast (11 days). It measures temperature, humidity and pressure within reasonable error limits:Read More »PWS – Calibrations: UT330C
In preparation of the blog about the Canadian FWI, it seems a good idea to publish the results of the actual values of three of the indices I intend to discuss. Especially interesting after the recent heatwave with record temperature values (see the blogs on those memorable days).
The Davis Vantage PRO 2+, the hardware which forms the basis of the PWS De Wilgen is not a measurement device without flaws. As any measuring device – a thermometer, hygrometer etc… – it requires calibration and a calibration needs to be checked regularly. I use two types of calibration.
Yesterday I wrote a blog about the high temperatures in the Netherlands and the breaking of all existing temperature records. Today it continued and for the first time ever, temperature in the Netherlands rose above 40 °C. First time ever means since formal measurement began in 1901 and even since historical measurement series spanning almost 300 years.