30 December 2009

Toodyay, WA plus

Still mostly in holiday mode here, but a few of items of note...

1. At least 37 homes have been destroyed in a bushfire, apparently ignited by a fallen power pole.in Toodyay, WA, approximately 80 km northeast of Perth. The fire started around noon yesterday (29 Dec) and has burnt over 2900 ha. Nearby observations suggest that fire weather conditions were 'catastrophic', with max temperatures in the low 40s, RH below 10% and 40 km/h sustained winds. Cloudy conditions prevented a satellite view of the fire.

2. Just before Xmas saw a significant bushfire near Pt Lincoln, SA. 13 homes and a State Emergency Service base amongst other things were destroyed in the 650 ha blaze. Hot (43C), dry windy conditions prevailed.

3. The rise and fall of TC Laurence has proceeded mostly in line with the general scenario outlined around 2 weeks ago...Lingered in the Pilbara before striking an eastward path across the country, culminating in a large rain event in NSW. The storm made three (I think) landfalls and the subsequent re-intensifications reached category 5 on two occasions. Significant rain in the Pilbara, across northern SA and into NSW. Northeastern NSW in particular saw a good deal of precipitation, although 50+ mm were widespread in the eastern part of the state.

This rain should dampen the fire danger in those areas for at least a week or two anyway. In the north, maybe enough to end the season? More rain in the near future would help this a reality...Northern SA saw a wet Spring, particularly November. These normally arid regions could see a 'green up' in the coming seasons, potential fuel for next year's bushfire season.

19 December 2009

Southern NSW

As briefly noted earlier, nine houses were destroyed in 3 separate fires in southern NSW on 17 December, on a highly dangerous fire weather day. However, a cool change has brought relief to much of NSW; while numerous fires remain burning, the immediate threat has subsided.

The image, is from the 18 Dec 2009 Aqua satellite overpass with a false-colour '721' enhancement, which captures (among other things...) vegetation differences and effectively highlights burn scars on the land. These appear as reddish, brownish blotches and represent the fire's path and the area it burned.

About 30km north of Albany (A) is the Gerogery fire; 4 houses and 5200 ha burnt. In the centre of the image is the Tooma fire scar, where 2 houses and over 10 000 ha were burnt. These two fires are under control. Furthest east is the Michelago scar, 40-50 km from Canberra (C); three houses and 9000 ha burnt there. This fire is being controlled but is no longer threatening 'property'.

17 December 2009

Southeast Australia

Parts of southeastern Australia saw a a second consecutive day of dangerous fire weather conditions, with several destructive bushfires reported in the region. Most destructive was a fire in Gerogery (north of Albury) that destroyed four homes among other things. Other large fires were reported near Tooma in southern NSW, to the south of Canberra and in northwestern areas of Greater Sydney. In East Gippsland, a fire near Cann River started yesterday and expanded rapidly during the day.

This last fire is the most apparent in the image, a Terra satellite from 1120 LT, the morning of 17 Dec. The Cann River fire has a sharp dense smoke plume streaming off towards the southeast. The other fires noted above are not apparently detectable in the image. The locations of Canberra (C) and Albury (A) are noted. At the time of the later Aqua image, more likely to show the fires, the region is generally obscured by cloud...Careful examination shows a few plumes are visible, mixed in with the clouds.

Fire weather conditions across this region were quite dangerous today; It was hot and dry, with afternoon temperatures in the mid-upper 30s and very low relative humidity. Strong and gusty NW winds as well. Catastrophic fire dangers were forecast in southern NSW; conditions indicate that this was likely met. A strong cool change and associated rainband is moderating conditions this evening, which should allow firefighters to bring these fires under control.
A nice summary of the recent fire activity in rural NSW and its impact on farmers can be found at the link.

UPDATE: Nine homes destroyed in these bushfires  -- 4 in Gerogery; two in Tooma and three in Michelago (south of Canberra).

15 December 2009

The little storm that could

That would be TC Laurence, currently menacing the Kimberley region of WA. It is currently a Category 3 storm, with a central pressure of 975 mb. This same system brought a month's worth of rain to Darwin and strengthened into a full blown TC. It is expected to finally move ashore on the afternoon of the 16 Dec, a big (and surprising!) start to the Wet in the western Top End and the Kimberley.  Atypically, the onset of this Wet is not part of the northern monsoon; winds remain easterly across most of the region.

The image, from Aqua MODIS, shows TC Laurence in its full glory on the afternoon of 15 Dec. A cloud-filled but obvious eye is present as are extensive spiral bands swirling in towards the centre.

Initially not expected to have much more than a short-lived regional impact, this TC could  have a major impact on the seasonal climate across a good portion of the continent. The interest here is the effects on the fire weather and climate. The immediate forecast is for the TC to weaken but linger in NW WA for a while, likely finishing off the fire season in the Pilbara and Kimberley.  After that, the forecast becomes uncertain. It's entirely possible, but by no means guaranteed, that this storm (or it remnants...) will effect central and SE Aust, drifting slowly towards the ESE. One 10-day NWP model forecast (unreliable!!) I saw earlier today predicts a major rain event in NSW (on Xmas eve) as the remnants of the TC were absorbed into the extratropics.

It goes without saying that a major widerspread rain event in eastern Australia would be entirely welcome, and help dampen fire activity in those regions. (Of course, high-based thunderstorms with dry lightning would be a disaster...). 'Enough' rain along the storm's path would also reduce fire dangers for the next few weeks. It could also provide soil moisture for abundant growth (fuel for next season) in affected northern areas.

Cape York and the Gulf regions are unlikely to be directly affected from the storm. They will still likely need monsoon onset for the wet season to begin.

14 December 2009

Southwest WA

An out-of-control fire was reported earlier today in Southwest WA, near the town of Harvey. While the fire is not directly threatening 'property' or lives. It nonetheless is having an impact in that it 'smoked out' Perth this morning, and remains a chance to do so again on Tuesday morning. The first image, taken from the linked story, shows a spectacualr aerial photo of the smopke over the city.

The second image, from the Aqua satellite around 1500 LT Monday afternoon, shows this fire roughly 130 km to the SSW of Perth (P...my P is on the southern side of Perth, away from the city centre...). At the time of this image, the smoke is not impacting the city, having cleared out with the sea breeze. The Terra image earlier in the day shows the smoke impacting the city more clearly, but the swath edge is inconveniently placed in that one...The smoke plume is quite dense and extend for some distance downstream. It has been suggested that this fire was started by an illegal campfire.

Further south, near Walpole a second set of hotspots and smoke is noted. This fire is a result of an escaped prescribed burn. AS of this evening, it has burned roughly 3000 ha, and is expected to consume near 10 000 ha before it is brought under control.

13 December 2009

Northern NSW 2

Numerous fires remain burning across NSW, particularly in the northern reaches of the state. No immediate threat to human values is present at this time, but the RFS current incidents page suggests that several fire these fires have burned out areas in excess of 15 000 ha in some cases. Many of these areas have seen fire activity for at least a week.

The image is from the Aqua MODIS instrument shows eastern NSW, from the QLD border in the north to the VIC border in the south. Most striking is the activity in the north, where numerous hotspots and widespread smoke are apparent. Interestingly, the fires noted in the Blue Mountains near Sydney (the 'S') are not apparent from space, nor have they really been in the previous few days. One possible reason is that the fires are in valleys and hence not viewable to the satellite; this occurs regularly in rugged terrain

Fire weather conditions remain dangerous, but not so much that a fire ban has been warranted. In the north, temperatures are in the low to mid-30s and humidity is low, but the relative lack of wind is currently moderating fire dangers. That said, conditions are likely to worsen mid-week, with temperatures near 40C and strong northwesterly winds forecast for a large portion of southeastern Australia.

09 December 2009

Eastern Australia

Another active fire day throughout the eastern portion of Australia again today, as fires raged from the Cape York Peninsula in far north QLD down into northern and central portions of NSW.

The image (click to enlarge), from the Aqua satellite showing much of the eastern coast of Australia, summarizes this activity. Looking back to earlier in the season, the image is surprisingly reminiscent of the situation in September; the long fire season drags on and on...If you look carefully, there is even a dust storm apparent (a faint band in northern NSW...), although not as strong as those noted in September.

In the far north, several large fires are noted on Cape York. One home was reported destroyed near Mareeba, just to the west of Cairns, but later reports indicate that it was merely a shed. This fire is actually one of the smaller areas of hotspots on the image. The larger one just to the west of the Mareeba example (presumably in more remote areas, so no reports) have burnt on the order of 200 000+ ha (or more), and just off image is a fire with an even larger area burnt.

Extensive fire activity continues in Carnarvon National Park and Expedition National Park and in the state forests in the general area. The second round of these fires have been going for some time now after widespread activity in September.

The northeastern region of NSW is also showing widespread activity. There are numerous fires of concern noted on the RFS Current Incidents page...too many to list here. Some of these fires are producing some quite striking smoke plumes when this image was captured. The Tweed Heads fire reported earlier is not particularly noticeable on the image, but was reported as threatening properties earlier in the day. Tragically, one person died when a helicopter being used to map bushfires crashed earlier today in this area as well.

The weather conditions were very dangerous again today, particularly in southern QLD and northern NSW, with temperatures in the upper-30s/low-40s and low RH...the winds weren't terribly strong and so moderated the danger to some (small) degree. Fire weather conditions are expected to remain poor tomorrow, and a fire ban is again in effect for much of southern QLD and northern NSW.

07 December 2009

Northern NSW

A few fires burning in northern NSW and southern QLD today. The most serious is reported near Tweed Heads, at the QLD-NSW border. At this time, none of these fires are posing a particular threat to property and other human values, but the situation bears watching; the fire is to be declared an emergency. 600 ha are reported burnt at this time

The true colour MODIS image is from the afternoon Aqua overpass (7dec 2009), around 1500 LT. The image is about 380 x 250 km. The approximate locale of Tweed Heads is marked (TH), the hot spot just to the south is the fire noted above.

On the image, several other regions of hotspot activity are noted in northern NSW and southern QLD. Several areas of hotspots and smoke are noted in state forest areas in NSW. In southern QLD, near the upper left corner,the fire burning there looks to be producing a pyrocumulus cloud.

Much of this area saw dangerous fire weather conditions today, with moderate northerly winds and temperatures in the inland areas in the upper-30s/low-40s. Fire weather conditions are expected to remain poor tomorrow (8 Dec) throughout QLD and NSW with hot, dry conditions and gusty northerly winds ahead of a cool change. Fire bans are in effect for large portions of both of these states.

03 December 2009

Welcome to Summer

With the beginning of December also comes summer which is peak bushfire season in southern Australia. If it is anything like the spring in terms of weather it will be a bumpy ride.

In particular, QLD and NSW have seen unusual levels of fire activity over the spring. In QLD, abundant rainfall the previous two years produced abundant fuel. This year has seen development of an El Nino in the central Pacific and two heat waves of unprecedented magnitude to much of eastern Australia. Extended periods of significant fire activity were seen in much of the east, with the city of Rockhampton being directly threatened. Across the season, northern regions of Australia, including the Top End, Cape York, the Kimberley and such, observed normally high amounts of fire activity. More recently, unusual fire activity has been observed in central NT. Fires continue in this general area.

And who can forget not just one, but two large dust storms.

The latest extreme heat event has broken, and with it the fire threat has eased temporarily. A few fires linger in NSW and southern QLD, but the break in the weather has allowed firefighters to acquire and maintain control over the most threatening (to human values...) fires.

That said, the image, from Aqua MODIS shows northern QLD on 2 Dec 2009. Widespread fire activity is still noted, particularly on the Cape York Peninsula. Conditions are hot and dry; the wet season has yet to start in earnest. But the winds are not particularly strong, so fire dangers remain lower than they otherwise could be. Whatever fuel is present is undoubtedly ready to burn; grass is cured, forests are dry.

Historically, the wet season onset is late during El Nino years. Current observations suggest that the active phase of so-called MJO, frequently a trigger of the monsoon in the north, has passed our longitude in the last week or so and hence not expected for a few weeks at least. That suggests that conditions could remain ripe for fire in the north for several more weeks, perhaps even into January in a worst-case. Conditions remain dry throughout the eastern states, meaning any hot, windy day will easily see a rise in fire dangers in those areas. The moderate-strong El Nino historically means a bad fire year for southern and eastern Australia, suggest the need for special caution throughout the upcoming season.