Many areas in New South Wales, Victoria, and Queensland have received multiple inches of rain over the last seven days with a number of locations recording about 100 mm (almost four inches).
A heavy rain could come close to putting out some fires but a light rain, depending on the fuel (vegetation), might just pause the spread for a while. And some regions have received little or no rain.
NSW Rural Fire Service commissioner Shane Fitzsimmons says the rain is “breaking the back” of the bushfire season. “The rain is good for business and farms as well as being really good for quenching some of these fires we’ve been dealing with for many, many months,” the commissioner told ABC TV on Friday.
The forecast for Sydney, on the NSW coast, calls for nearly 100 percent chance of precipitation every day over the next eight days.
The Predictive Services section at the National Interagency Fire Center has issued their Wildland Fire Potential Outlook for February through May. The data represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit.
If NIFC’s analysis is correct the only area with above average potential for wildfires during February and March will be Hawaii. However the southern coastal area of California is expected to see above average wildfire potential in April and May.
An excerpt from the NIFC narrative report for the next several months;
More of NIFC’s monthly graphical outlooks;
NOAA’s three-month temperature and precipitation forecasts;
Keetch-Byram Drought Index.
Here is an excerpt from a portion of the report that discusses the possibility of increasing fire potential in southern California in April and May.
“Due to a ridge replacing the trough, the weather has turned very dry since the start of 2020. Precipitation during the past 30 days has been, on average, 30-50% of normal across the Geographic Area. Some places in Southern CA are closer to the 10-25% range in comparison to normal since January 1st . Temperatures have been slightly above normal, especially near the coast, but offshore wind events have been infrequent and of light intensity.
“The drier weather coinciding with what is normally the wettest time of the year is concerning regarding the long term curing and drying cycle of seasonal grasses and other fine fuel types. Long range models are all depicting drier than normal conditions during the February through April timeframe, but some ensemble members point toward a wetter period returning in March. This may be too late to forestall an earlier than normal curing of grasses as subsoil moisture in the first few inches of topsoil will likely be depleted by then. Therefore, we are expecting large fire potential to climb to Above Normal levels due to an early onset of springtime “grassfire season.” Heavier, dead fuels may become involved by the time warmer temperatures arrive in May. Long range models also point toward a warmer than average temperature regime through May which may compound the problem.
“Resource demand will likely increase rapidly across Southern California by the end of March or in April. From there, large fire potential may climb to Above Average across central portions of the state by the late spring or early summer months. At this time, offshore wind events are expected to occur at a near normal rate, but even a quiet offshore pattern may not alleviate the effects of a dry late winter and spring.”
Predicted rain and cooler temperatures this week in Australia could slow the spread of the bushfires in Victoria and New South Wales. The heaviest rain will be on the east coast where some areas could receive over two inches while the forecast on the west side of the two states is for much less or perhaps none.
The rain is the product of a deep inland trough drawing humid air into the system.
Small amounts of rain will not put out the fires, but could make them partially dormant for a period of days, giving firefighters time to regroup and construct firelines on portions of the perimeters. But many of the fires are far too large to ever be completely encircled by firelines.
Some of the rain will come in the form of thunderstorms, leading to the possibility of flash flooding, landslides, and fallen trees.
The rain will be welcomed by residents and especially farmers in the drought-stricken communities.
On Monday and Tuesday local time in New South Wales some areas west of Sydney received rain, which with the higher humidities and lower temperatures slowed the spread of fires in the area. The cooler weather will continue until Friday when the inland areas of NSW will experience temperatures over 100F, 15 percent relative humidity, 15 mph northwest winds, and a chance of dry lightning which could ignite even more fires. The hot, dry, windy weather is expected to last just for the day after which temperatures should drop back into the 80s for several days.
In other bushfire news, Australia’s government is committing an additional $2 billion over two years to a new agency tasked with rebuilding bushfire-ravaged communities.
We have known for a long time that smoke from wildfires can be harmful to humans, but in recent years that knowledge base has increased significantly. And it may have reached a new level with research conducted by fire ecologist Leda Kobziar. After learning that some snow machines use bacteria as condensation nuclei, she started to wonder if bacteria was a component of smoke. Using petri dishes and drones she collected air and smoke samples at a prescribed fire.
Below is an excerpt from an article at KQED.org:
…Then they compared what was collected to the contents of ambient (non-smoky) air. They sampled for abundance and diversity by culturing colonies and analyzing DNA.
Turns out a surprising amount and diversity of bacterial cells and fungal spores gets lofted into wildfire smoke during a fire. The more severe the burn, the more cells it transports. This is a newly emerging area of research, but Kobziar thinks these microbes have the potential to affect human health.
“There are numerous allergens that we’ve found in the smoke. And so it may be that some people who are sensitive to smoke have that sensitivity, not only because of the particulate matter and the smoke, but also because there are some biological organisms in it.” … Possibly, she says, wildfire smoke has been a driving factor in the global distribution of microbial life.
“We think that the role that wildland fire is playing in transporting organisms through smoke has probably had some influence on the evolution of species as well and development of communities,” Kobziar said.