FWI

Analysis of pwsFWI prediction

HansR
11/08/201911/08/2019

Introduction

In my previous blog I described why and how the predictions on pwsFWI were implemented. Also I promised a short analysis:

We’re now in version 1.8.3 and it seems all to be working OK. The testing is back on the meteorological level, trying to find out how much a two day ahead prediction will differ from the actual calculation when the day has past.

In this blog I will show the results and try to interpret them.
Please note that this is not a scientific or even a full analysis as I am lacking the resources and the data for that.

Behaviour of pwsFWI with first rain

HansR
10/06/201911/02/2019

One of the goals of the current implementation of pwsFWI is to see its behaviour under all conditions. It is therefore very interesting to see that behaviour in the two stations in semi-arid zones (in Australia and in Spain) where long dry periods may suddenly alternate with rain after which the drought returns. Read More »Behaviour of pwsFWI with first rain

Corrections to the August-Roche-Magnus equation in pwsFWI

HansR
09/26/201911/02/2019

Now that version 0.9.0 of my Fire Weather Index for personal weather stations (pwsFWI) has been released in the context of CumulusUtils (I may separate it later into an independent program), it is time to look at formula corrections.

Evaluating FWI for Personal Weather Station

HansR
08/30/201911/02/2019

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.

An effort for a simpler fire weather index

HansR
08/19/201911/02/2019

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 .

The Canadian FWI

HansR
08/11/201908/14/2019

Introduction

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.

The FWI also has been introduced in 2007 [1] as the method to assess the fire danger level in a harmonized way throughout Europe.

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

At the end of the heatwave

HansR
07/27/201908/12/2019

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 Ångström index and the FMI index

HansR
07/10/201908/29/2019

The indices

The Ångström index and the FMI index are highly similar indices in understanding, functioning and behaviour using only two meteorological parameters: temperature and humidity.

These indices are interesting because they are historically important, they are still in use and because, in discussing these indices, they shed some light on the understanding of the what and how of trying to understand estimating fire weather danger.Read More »The Ångström index and the FMI index

The Chandler Burning Index

HansR
07/08/201911/02/2019

Introduction

One of the practical applications of meteorology is the objectivation of nature fire risks on the basis of different meteorological parameters (actual or from the past). Rainfall, humidity, temperature and windspeed are typically parameters to calculate a number indicating the risk on nature fire.