Great compass work - Spring Creek Fire - 15 December

I know I already complimented James W on his 15km compass bearing on the Spring Creek fire a week ago, but I just downloaded some photos from my camera - I'd forgotten that I took some shots of the fire from the Gatton-Esk Road when I was trying to locate it.

This is what the fire looked like from 3km away (using some zoom), seeing it against the darker hills behind.  James was taking his bearing from the top of the range further to the right of this photo and five times as far away.

Taking a bearing on it from 15+ km away without that dark background and getting it spot on is a great bit of compass work.

Smoke in the Spring Creek, Adare, Vinegar Hill and Ringwood areas - Saturday 15 December

The smoke in the Spring Creek, Adare, Vinegar Hill and Ringwood areas today (Saturday 15 December) is coming from a controlled burn at the Spring Creek jail.  The Gatton Springdale Rural Fire Brigade was in attendance at 10.00am this morning.

There was a fire in the Spring Creek jail land last weekend, though on that occasion some of the Smokspotters lost a lot of time in identifying the location.  This was because:

• the cross bearings we obtained on the wide front of smoke suggested that it was in either the eastern edge of the Lockyer National Park or in the land owned by the jail;
• the Queensland Rural Fire Service Current Bushfire Incidents web page showed a permitted burn with fire crews in attendance at the junction of Millers Road and the Gatton-Esk Road (the jail is at the other end of Millers Road).  This was approximately 5 km from where we had identified the fire location (were our bearings wrong?);
• when we were unable to contact the Grantham Rural Brigade First Officer we contacted the Deputy, who had not been informed any controlled burn in that area (though from our bearings the fire was in, or on the edge of, the Grantham Rural Fire Brigade area);
• we then spent more time trying to find Smokespotters who could give us a better bearing on the smoke, but without being able to improve the location.

In the end it was decided that the fire was either in the jail land (in which case it was under control) or in the edge of the Lockyer National Park, so a message was left for the QPWS Duty Officer to contact one of the Coordinators. He/she didn't.

It was not until the next morning, when the smoke was still thick in the area, that the source was identified as the jail lands.

Today the Current Bushfire Incidents web page again showed a Permitted Burn at the corner of Millers Road and the Gatton-Esk Road.

The X shows the approximate location as identified by Smokespotter bearings (see image below for a more accurate location), the XX shows the location of the nearest point of the fire to the indicated location.

Here's a picture of the situation this morning (Saturday 15 October) plotted on a Google Earth base - you can click on the image to see a larger version, but unless you open it in a new window you won't be able to see the text at the same time:

The area outlined in yellow is where the fire was burning.  Our bearings (red lines) were within one km of the nearest fire - not bad considering that James W's bearing was taken over a distance of 15km (the other was only 6km) and the smoke was "smeared out" by a northeasterly wind.  The expensive bearing compasses we use are well worth the money.  In fact the projection of James' bearing was right on the fire.  It was my bearing over 6km that was off the mark; I'll blame the wind.

The place pin on the right shows where the Queensland Rural Fire Service's Current Bushfire Incidents map located the permitted burn - over 3km from the nearest point of the burnt area.

I've made efforts in the past to have the Smokespotter Coordinators notified when there is going to be a planned burn on the jail lands because of both their proximity to the Lockyer National Park and the unreliability of the Permitted Burn locations on the Current Bushfire Incidents web page (which means that we waste Smokespotters' time in trying to fix the location of sighted smoke).  Clearly I haven't yet found the key person who will see that this happens, but I'll keep trying.

Smoke in the Vinegar Hill, Adare, Ringwood area

The smoke in the Vinegar Hill, Adare, Ringwood area appears to be likely to be coming from a Permitted Burn in Millers Road, Adare that can be seen on the Current Bushfire Incidents map on the Rural Fire Service website.

Why are there sometimes discrepancies between Fire Danger Rating maps and BOM Fire Weather forecasts

I've done a bit of digging around to try to sort out some discrepancies we have seen over the last few days between the Forest and Grass Fire Danger Ratings maps which are available on the Queensland Rural Fire Service web site and the Fire Danger Ratings included in Bureau of Meteorology District Forecasts.

BOM Fire Danger Ratings (which apply to quite wide areas compared to the QFRS FDR map zones) have sometimes been higher than the mapped ratings within the same area in Southeast Queensland (and apparently across wider areas of the State).

As I understand it, the QRFS FDR maps are constructed on the basis of BOM data, using a computer program to produce the ratings.  There is no human intervention in the production of these ratings, which is what you would expect because the Fire Danger Ratings are in fact what is called the McArthur Fire Danger Indices (Forest and Grassland), and these indices are calculated using a standard formula.  The purpose of the indices (Ratings) is to provide a relative measure of the difficulty of suppression for a standard fuel type.

While these indices generally work well enough in practice, the reality is that not all variables can be included.  For example the calculation assumes a fuel load arranged as a standard continuous pasture.

The BOM FDRs are apparently produced on the basis of the same data set (I have no confirmation of this), but with a degree of human intervention that takes into account actual fire behaviour as reported by fire fighters in particular districts.  This allows for adjustment based on variables which are not allowed for in the calculation of the McArthur indices, such as for example, continuity of fuel.

This produces a more "refined" FDR, but not currently at the detailed scale that is available in the Fire Danger Rating maps.

So, I guess the "take home message" is that you should check the BOM website - in our case their Southeast Coast Forecasts, via the Updated weather Ipswich & Fire Danger link in the right hand column of this web page, and always ask FireComm whether it is safe to burn when you notify them of your intention to light up a permitted burn.

You can find more information on the McArthur fire danger indices on the web.  For a fairly simple account you can read this presentation from the Bushfire CRC, or for more detail this paper from the Centre for Australian Weather and Climate Research which compares the McArthur Forest Fire Danger Index approach with the Canadian Forest Fire Weather Index.

If you have some "inside knowledge" of how the system works and can improve on my attempt at explanation please feel free to contact me so I can share the information with readers of this blog.

Fire Danger Rating - Wednesday 5 December

This morning, after I updated the LVR fire danger rating map, I was puzzling over the fact that the highest rating in our area was "Very High", with most of the Lockyer Valley Region as "High".  This just didn't seem to be consistent with all the media references last night to Fire Weather warnings for today.  In fact I had much the same concerns when I uploaded yesterday's fire danger rating map - the ratings just weren't consistent with either what I was hearing on the media, or with the weather we were experiencing here, which was obviously very dangerous from a fire point of view.

I opened the Bureau of Meteorology's weather forecast page for the Southeast Coast, knowing that they give fire danger ratings. (The BOM link ("Updated weather Ipswich & Fire Danger") is in the column on the right hand side of this blog .

While the BOM doesn't give a separate fire danger rating for the Lockyer Valley Region, they do give ratings for the overall Southeast Coast District and separate ratings for areas within Southeast Coast, including Ipswich.  Our weather forecasts aren't usually too different to those for Ipswich, so presumably the fire danger rating won't be very different either.

Overall, BOM's forecast for the Southeast Coast District (issued at 4.45am this morning) has the Fire Danger as: "Very High to Severe", and for Ipswich it is "Severe".  Gold Coast is "Very High" and Sunshine Coast is "Severe".

These ratings are at odds with the current Rural Fire Service's Forest Fire Danger Ratings map for the area, which shows no areas of Severe rating at all.  Here's the current Forest Fire Danger Rating Map from the RFS web site, downloaded early this morning.  No "Severe" ratings anywhere.

 

Just to be sure, I checked the RFS Grassland Fire Danger Ratings to make sure that they were not "Severe".  In fact they are, in general, more benign than the Forest ratings.

In future, when there are media reports of high fire danger in SEQ, I'll be checking the BOM site as well as the RFS site.