At the end of the heatwave

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).

Please note the differences in estimating the danger level of the weather in relation to nature fires. Please note, that all three indices have air humidity and water content of fuel as most important(and elaborate) parameters.

In my personal opinion, at the moment there is a medium to high fire danger. The position of my anemometer reduces the influence of the wind a bit (but not very much).

The CBI and Angstrom seem to miss the point completely, at least for the environment I am in. In the coniferous forests on the Veluwe, it may be a higher risk, but I definitely do not estimate it as extreme.

In my opinion, the FWI is most to the point. (to be continued).

The table below comes from the PWS De Wilgen (and is made with FWIcalc see footnote [1]) where a similar table is updated every day (at least in season) at 14h00 with a history of 30 days.

Date FWI FWI DC CBI CBI DC Angstrom Angstrom DC
27/07/2019 17.7 HI 41.1 LW 1.5 EX
26/07/2019 15.3 HI 39.4 LW 1.5 EX
25/07/2019 13.6 HI 13.2 LW 2.4 VH
24/07/2019 12.2 MD 30.9 LW 1.4 EX
23/07/2019 3.7 MD 15.5 LW 2.4 VH
22/07/2019 2.1 LW 6.5 LW 3.6 MD
21/07/2019 1.6 LW 2.0 LW 4.7 LW
20/07/2019 1.8 LW 1.2 LW 4.2 LW
19/07/2019 3.9 MD 13.4 LW 3.1 MD
18/07/2019 6.0 MD 10.3 LW 3.2 MD
17/07/2019 2.0 LW 2.2 LW 4.5 LW
16/07/2019 2.5 LW -0.9 LW 5.5 LW
15/07/2019 2.9 LW 3.7 LW 4.5 LW
14/07/2019 1.0 LW 1.8 LW 4.9 LW
13/07/2019 0.6 LW 0.9 LW 4.9 LW

[1] The weather-site of  PWS Meteo-Wagenborgen uses the computer program FWIcalc, which has been developed (from 2002 to 2014) by Graeme Kates in New Zealand on the basis of the FWI (Fire Weather Index), developed in Canada and also used in New-Zealand and France. Some other indices like the Angstrom and the CBI (Chandler Burning Index) are calculated by FWIcalc as well. The software is no longer supported but can still be downloaded and used (freeware). (from The Chandler Burning Index)

Geef een reactie