25 November 2009


The bushfire situation across Australia is currently in a relative state of calm, with fire weather conditions having moderated considerably over the past few days. That said, there is a fire ban has been issued for Thursday in NSW west of the ranges.

Much of the fire activity in QLD and NSW reported over the weekend is controlled or being brought under control. A large area of active fire is noted on NAFI in the central NT. This current activity is a continuation of a fire which began last week (the then smaller western ones, in particular). There is light to moderate activity from those fires westward to the Dampier Peninsula...

The image doesn't really have much of anything to do with fire. If you insist, you can see some general smoke in the NW corner (upper left) of the image. Rather, the midday-from-the-Terra-MODIS image shows a spectacular comma cloud spanning the breadth of the continent. For an idea of size, the image is 2000 x 1600 km. In this case, the cloud structure is spawned by a deep cut-off low pressure system in the mid- and upper-troposphere. A beauty only knowable from space.

This system (and its precursors) has brought a significant amount of precipitation to inland western QLD and northeastern SA. It is forecast to bring more rain to parts of the southeast, mainly VIC and SA...little or no relief for NSW.

24 November 2009

As bad as it gets, too

The dangerous fire weather conditions observed at the end of last week persisted throughout the weekend in NSW. Dangerous conditions peaked on Sunday, as a developing low pressure system over Victoria brought hot westerly winds to the state. The more than100 fires started by lightning on Friday flared, evacuating hospitals and threatening homes, among other things...

Firefighters have gained the upper hand on many of these blazes with the arrival of milder weather on Sunday night, but some of these fires remain out of control as of earlier today (23 Nov). That said, with more moderate weather expected for a few days, they will likely be brought under control soon.

These conditions extended into southern QLD as well, with a relatively widespread, but significant of grass fire activity noted, particularly on Sunday.

Peak temperatures on both days were above 40C in most of northern NSW and southern QLD. On Sunday, these extreme temperatures reached the Sydney region, which saw temperatures in excess of 42 C. Simultaneously, large portions of VIC and SA received a significant amount of rainfall, with over 70 mm in some locales (including Melbourne!). In northern SA (very arid...), rainfall amounts of 3 and 4 times the normal monthly totals were observed.

The image (click to enlarge) shows widespread fire activity and numerous smoke plumes extending from wildfires in Carnarvon National Park (west) and Expedition National Park (or various state forests nearby...) on 21 Nov (Sat.). It's scale is roughly 425 x 250 km, so these fires are burning over an extensive area. (See NAFI more more detail) Those with a long memory may recall that this same park saw significant fire activity in September. Parts that didn't burn then are now going. (There have been a lot of clouds about lately, poor conditions for fire images...). These fires are remote, little threat to immediate human values

20 November 2009

Almost as bad as it gets

In terms of fire weather, most of the southeastern portion of Australia has seen conditions that are about as bad as they get over the past few days. The whole month of November has seen unprecedented levels of heat for late spring, but the last few days have been over the top throughout the area. There have been widespread areas with temperatures well in excess of 40 C. These temperatures are approaching or exceeding all-time, not just for spring, record-high maximum temperatures (and record high-minimum temperatures, too). It was 43C in Adelaide on Thursday, and temperatures were in excess of 45C in northern SA and western NSW. See this post for a description of the heat during the earlier part of the month; the third record heat wave in two years in some places. The last few days have been even hotter, but not as long-lived. Another bad day tomorrow in NSW, but afterward the weather should moderate for the next few days at least. Look for a full description of the event, with all the climatological details, in a Special Climate Statement from the National Climate Centre on Monday.

Of course, with the extreme weather comes the extreme fire danger. The graphic, from the ABC, shows the regions covered by the new 'catastrophic' fire danger rating (FFDI > 100) today (20 Nov). Conditions were similar yesterday, with a focus further to the west. In many ways, Australia has been fortunate this time around; there have been no Black Saturday-level fire events during this period. No massive loss of life, no city-razing fires. There have been numerous fires started by lightning across SA, southern QLD and NSW; a few homes have been destroyed but overall the damage has been minimal. A nice summation of the fires today can be found in this article from the ABC. The firefighters have done a good job at managing this situation to date.

Events of this nature strengthen the evidence for the reality of the impact of climate change. Sure, previous generations saw fire weather events of similar intensity, but not this frequently and not at this strong. Remember, it is not even the nominal start of summer yet. Stick your head and the sand and deny the evidence if you must, but this is our new climate. Yes, climate variability will still exist, and we will see years or perhaps even a decade where conditions moderate, but events of this nature will become more frequent and eventually the norm. Its a record now, but soon enough these conditions are likely to be our average, what we expect every year.

If it makes you feel better, tell yourself it's natural...the natural response to the enhanced climate forcing from increased CO2, land degradation and other human factors. We did it and we have to live with it. Are you ready?

17 November 2009

Central NT

As suggested yesterday, there are huge fires currently going in the central portions of the NT, including the Barkly Tablelands. Many of these fires have been burning for several weeks, and have now affected large areas. Fortunately, the fires are in remote areas and unlikely to have a large human impact.

The image is the True Colour image from the Terra overpass on 17 November at 0145 UTC. Numerous fires are readily visible on the image. The large fire scar on the right, with active hotspots, represents the fires in the Barkly Tablelands noted over 10 days ago. Comparing the older image with this one shows how much the fire has grown. Estimate of the affected area over the whole period are easily in excess of 2 million ha. TO get some sense of scale, the distance from Eliottt (E) and Daly Waters (DW) is roughly 150 km. The linear extend of the fire in the north-south direction exceeds that. Katherine (K) is noted at the top of the image.

Looking at NAFI, some of the detected hotspots are likely efforts by firefighters to control the extent of the blaze. Many line up right along highways, likely attempts to establish firebreaks.

Further west, several active fires are noted in the northern Tanami Desert and close to the Victoria River district. region. These fires are quite intense, and much of this region has burnt in just the last two or three days according to the history on NAFI.

Weather conditions are quite hot, even for the place and time of year. Temperatures are in the low-40s, 5 degrees or so above normal. Afternoon relative humidities are around 20% (dewpoints of 10-15 degrees), but the winds are from the NW and not too strong, although some quite gusty obs are noted at some of the stations.

16 November 2009

Eastern Australia and more

Lots of fire activity reported across Australia today, as generally high temperatures continued to be4 observed across much of the country. This warmth was particularly pronounced in the interior regions of the country; temperatures were in the upper-30s and low-40s across wide areas, in some cases more than 10 degrees C above normal. The SA Riverland region set new records for heat in November.

The image shows a composite true colour image of Australia from two Aqua overpasses today. Widespread fire activity is noted in much of eastern Australia, particularly in QLD. Fire activity continues in the Barkly Tableland region of the NT as well.

Several blazes were reported as threatening homes in QLD and NSW, including near Gympie in QLD and also in the western suburbs of Sydney.

Other fires were reported near Orange in NSW, in the Great Sandy National Park near the Sunshine Coast in QLD and in the Pilbara region of WA.

In QLD, fires are also noted (on the image) in Carnarvon National Park (where they have been burning on and off since October...) and throughout the Cape York Peninsula. Fire bans are in effect through next week in much of the state, are may be extended beyond that date.

Conditions have slightly moderated in VIC and southern SA for a few days. The Cape Conlan blaze in VIC was contained today. However, the end of the week, particularly Thursday and Friday, are likely to be extreme in terms of fire danger in these most populous parts of the country.

11 November 2009

Camooweal QLD

ABC reports today of a wildfire near Camooweal, near the QLD/NT border, which was brought under control earlier today. It's somewhat rare that these fires in the north directly impact human activity and are reported on in the media...

The story reports that the fire came within 10 km of the main township. It was most active last night and yesterday afternoon and was brought under control this morning. No significant losses were reported, but the fire burnt a considerable amount of grazing land. The fire also closed the highway near the town for a while as well.

The image shows a true colour MODIS view of the fire from the Terra overpass this morning around 1045 LT. The immediate vicinity of Camooweal is visible, just to the WNW of the burn scar. The dimensions of the image are about 200 x 150 km. This was already after it had been brought under control. A few hotspots are still apparent on the image, but the fire is clearly subdued. A very thin, darkly coloured smoke plume is just visible streaming off to the west. The western burnt patch is today's fire. The patch to the east looks to have mainly been active during the previous day or two. Both patches of burnt area together encompass 20 000 to 30 000 ha.

Weather conditions have been fairly typical for the region; most likely high or very high fire danger conditions in the afternoon.

09 November 2009

E Gippsland VIC

Noting the first significant fire activity in VIC this evening as the season winds up. The fire is burning in Cape Conran Coastal Park between Cape Conran and Bemm River. It has burnt around 1100 ha as of this evening. The fire is Going but no 'property' is currently under threat at this time. [INFO]

The image is the true colour image from the Aqua MODIS, around 1600 LT. The smoke plume is visible, trailing off toward the north with the sea breeze. No hotspot was detected as this is on the very edge of the swath. The image is garish (to me, anyway...) because I have applied 'Auto Adjust Color' to brighten it up. Bairnsdale and Orbost, 60-70 km apart, are marked on the image.

The fire weather conditions across VIC and in the high to very high range. It is much warmer than normal across the region, with maximum temperature anomalies of 8-12+ degrees over most of the area. In Gippsland, temperatures were in the upper-20s. Further west, in Melbourne and Adelaide (very far west!), temperatures have been in the mid-30s. Hot weather is expected to persist through the end of the week. Fortunately, the winds have remained light to moderate, helping to moderate fire dangers.

While the fire danger situation isn't too drastic now; it's hot, but the season is early. Instead, this hot weather is setting the stage for later in the season – drying the land and the forests and curing the grass, creating fuel for later fires.

06 November 2009

Barkly Tablelands NT

The image shows some several large bushfires burning in the Barklys Tableland, in central NT. The fires here, while burning for a week or so have flared, expanding a great deal in a short amount of time. On the true colour image, the smoke plumes from these fires are quite thick, suggesting vigorous fire activity.

Rather than the more typical true colour image, this is a so-called 721 image -- a different combination of channels from the MODIS. Green is vegetation. The recent burns scars are a dark brown colour, the very recent scars or even open fires are the bright red marks. The darker coloured scars are more recent; they get lighter brown to tan to back to green as a time passes, say 1-2 years. These do NOT have the hotspots marked...they show up quite well on their own with the red and pink.

The reason for the vigour of the fires is not immediately obvious. Weather conditions are not particularly severe; no fire weather warnings are in effect. More likely, the fires have reached an area of abundantly flammable (or is it flammabley abundant?) vegetation and taken off. There was some rain (and likely lightning activity) 4 or 5 days ago in the area, and this may nave been the igniter or reinforcer of these fires.

In general, bushfire has burnt much of the pictured area (about 220 x 390 km). The NAFI fire scars mapper indicates that most of this area burnt during October...looking thru old posts, much of it looks to have been quite recently...Indeed, fuel loads are quite high across the region as a result of abundant precipitation during the past wet season. The strengthening of the El Nino often results in a delayed onset of the wet season across the NT. This means that fire activity could extend further into the year, and perhaps even into January (if fuel is available)...

Finally, these fires are burning in a remote area and are of no threat to the usual concerns. The effects will mostly be on the ecology of the region, as well as a source of greenhouse gases in the atmosphere.