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Glenda smashes into Australia

By: Dr. Jeff Masters, 3:36 PM GMT on March 30, 2006

Tropical Cyclone Glenda smashed ashore near Onslow, Western Australia today as a Category 3 storm on the Saffir-Simpson scale, with maximum sustained winds of 115-120 mph, gusting to 155 mph, and a central pressure estimated at 940 mb by the Australian Bureau of Meteorology. A storm surge of at least 10 feet likely accompanied the storm to shore, but fortunately, Glenda missed the most heavily populated city of the region, Karratha, and damage will be far less than the $1 billion inflicted by Tropical Cyclone Larry just 11 days ago. The one-two punch of two major hurricanes hitting Australia in one year is not unprecedented; two Saffir-Simpson Category 4 hurricanes hit Queensland in 1918, killing 147 people, and twin Category 3 storms struck northern Queensland again between March 5 and 15, 1934, killing 64 people and causing $3 million in property and crop losses. The University of Wisconsin has an animation of Glenda hitting the coast.

Figure 1. Tropical Cyclone Glenda near landfall at 7:30 GMT March 30 2006, moving inland near Onslow on the Western Australian coast. This visible light image courtesy of the U.S. Navy.

An interesting article appears in The Australian today, where Dr. Bruce Harper, a consultant to the Bureau of Meteorology, said that Larry had been substantially overestimated in strength. A quote from the article:

Dr. Harper said, "It's not that there's any intention to exaggerate or there's anything wrong with the people at the bureau. It's just that the satellite recognition techniques they use are not accurate."

Bureau of Meteorology weather services supervisor Mike Bergin agreed Larry had not been as strong as the bureau claimed at the time.

"Tracking cyclones is a difficult exercise," Mr Bergin said. "These are dynamic things, changing all the time."

Dr. Harper claimed the bureau was not adequately resourced by the federal Government. He said Australia should follow the example of the US, which flew planes with recording instruments through hurricanes.

If you recall my blog from Monday discussing the problems with estimating hurricane strength in the Southern Hemisphere, these problems continue even today. This makes it very difficult to determine just how many Category 4 and 5 storms there really are, and whether or not they are increasing in number. I'll post part 2 of that discussion Friday, assuming today's severe weather outbreak in the U.S. doesn's grab the headlines. It could be a wild afternoon in the Plains, with the potential of strong F3 tornadoes, particularly in eastern Kansas and northeastern Oklahoma.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Excellent post as always, Dr. Masters. They're very fortunate that some high shear knocked the punch out of Glenda in the leadup to landfall.
Yes,but season is not over yet.April is the last month of activity in Indian Ocean and South Pacific and probably we will see a 2005 North Atlantic season repeat with late storms
Here's a cam, it's either dark or down, below is a surge graph for around the area.
Thanks for another very good update Dr Masters!
Here's the ABC news for the area, scroll down to under Glenda for the link to the ABC radio. They're covering more than Glenda on it. They said they'll be sending the choppers in to Onslow as major road damage is reported. Also they expect it to be downgraded to Cat 2 in a few hours.
"It could be a wild afternoon in the Plains, with the potential of strong F3 tornadoes, particularly in eastern Kansas and northeastern Oklahoma."

I hope there is no tornado outbreak in eastern KS today but we could sure use some good rains. During March 12 we got almost no rain at my house and no bad weather.
seems extadordinarily like rita.........
I think eastern KS/western Mo has more of a chance of severe weather, partly becuase of time of day...hitting KC-area around late afternoon, then turning into a squall line and heading toward StL.
Even more fortunate that that large part of the coast is has very low population.

so it hit in an area of 0 - 0.1 people per square kilometer.
Hope the storm sitution doesn't worsen much for th Aussies. They're certainly not going to move inland.
Cyclone misses population centers at it hits Australian oil and mining region
Some highlights~
Cyclone Glenda hit land about 4:00 pm (0800 GMT) in cattle-grazing territory in the Pilbara region about 200 kilometers (120 miles) southwest of the massive oil and ore shipping center of Karratha, the Bureau of Meteorology said.

Early reports from the region said the storm, classified as a category four cyclone out of a maximum rating of five, ripped up trees and toppled power lines but there was no immediate news of major damage.

Authorities said their main concern was flooding caused by torrential rain and a sea surge of up to 10 meters (33 feet) in an area already soaked by weeks of storms.

But Glenda hit the coast to the southwest over a big cattle station called Mardie and then moved to Onslow, a rural town of about 800 located 1,300 kilometers north of Perth.

Mardie station manager Richard Climas said Glenda was the fourth cyclone to hit his cattle ranch so far this storm season, which runs from November to April.

Meteorologists said Glenda was nearly as powerful as Cyclone Larry which devastated towns on Australia's far northeastern coast 11 days ago.

The Pilbara, Australia's main iron ore producing region and site of major oil and natural gas reserves, lies in what is known as "cyclone alley" because of the frequency of major storms that sweep in from the Indian Ocean each year.

Officials said they were particularly concerned at the danger of flooding, with Glenda's surge coming when tides were already at their highest.

Mining and oil giants BHP Billiton, Rio Tinto, Santos and Woodside Petroleum shut down offshore rigs in the path of the storm and closed port operations around Karratha.

Woodside and Santos sent floating oil rigs from their big Cossack and Mutineer Exeter oilfields out to sea.
We've already had at least 3 radar-indicated tornadoes in NE Kansas, two in Morris county and one in Wabaunsee county. Those three have occurred since I got up 2pm, so if there were any more before that time, I'm not aware of them yet.
One of those tornados has been confirmed by spotters...it's a cloudy day in kansas, so i can't imagine how active things would be if the sun had come out and added more instability.
I just read this interesting article saying that there has been a 90% die-off of coral in the Caribbean because of last summer's record-high SSTs. Some coral colonies over 800 years old are now dead, dealing a devastating blow to tourism and fishing which depend on them. Yet, this report says the Caribbean is actually better off than the Pacific and Indian oceans, where 90% mortality has been routine for several years.

"This is probably a harbinger of things to come," said John Rollino, the chief scientist for the Bahamian Reef Survey. "The coral bleaching is probably more a symptom of disease the widespread global environmental degradation that's going on."
snowski, that is disturbing.

There are some unique martime features off the coast in the area where Glenda hit (And Larry too). Hopefully the impact on the reefs etc is not too bad.

See: http://www.deh.gov.au/heritage/worldheritage/sites/shark/index.html
which is a little bit further south down the coast.
.. particularly:


Stromatolites grow in Hamelin Pool because of the extreme salinity of the seawater, the limited circulation of the water, and the occurrence of calcium carbonate. This environment, which evolved over some 10,000 years to be perfect for microbes to flourish, especially cyanobacteria, depends on the Faure Sill, a sand barrier at the entrance of Hamelin Pool that restricts the flow of seawater into the Pool. This, coupled with high temperatures and increased evaporation, led to a saline environment twice that of normal seawater in which most other living organisms, particularly predators of the microbes, cannot survive.
Snowsky, there has not been a 90% die off of coral. Read the article, it says 1/3.
Cyclones usually do not do too much damage to reefs, at least more than a few feet below the surface. Remember, those reefs have been there thousands of years, they've been hit many times before.
Thanks, I stand corrected.
I am attempting to attach an article from Yahoo.com about the upcoming hurricance season.
Its amazing how many ingredient have to come together for tornadic activity. I have been watching for this breakout for about a week, and it seems everything was coming together..yes, there were a few tornados, but not to the extent I was expecting. Lots of helocity, good cap, but around KC, I was wondering if the CAPE would come around..but remained kinda weak..I think the killer was the lack of surface warming..still nice rain that we need, but fell short of the hype for us in KC
After Hard Lessons, a New Game Plan for Hurricane Seasons


BATON ROUGE, La., March 28 Federal and state emergency officials promised a different approach on Tuesday to the coming hurricane season, saying they would no longer use "last resort" shelters like the Superdome to house displaced residents.

Instead, they said, they will put into effect a better system of communication and evacuation to get residents away from the path of a storm.
On Wednesday, Tyler Smith, coordinator of the U.S. Virgin Islands Coral Reef Monitoring program, dived at a popular spot for tourists in St. Thomas and saw an old chunk of brain coral, about 3 feet in diameter, that was at least 90 percent dead from the disease called "white plague."

"We haven't seen an event of this magnitude in the Caribbean before," said Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's Coral Reef Watch.

The Caribbean is actually better off than areas of the Indian and Pacific ocean where mortality rates mostly from warming waters have been in the 90 percent range in past years, said Tom Goreau of the Global Coral Reef Alliance. Goreau called what's happening worldwide "an underwater holocaust."
The idea of "tunnels" is wacko, but in case of a small tropical atoll it might actually work. Placement of a 4-ft pipe "upstream" of the atoll with the intake 100 ft down into cool water, and routing the pipe over the reef and into the lagoon might moderate the temperature enough to avoid heat damage to the coral. This sounds to me like an inexpensive experiment and probably worth a try, especially given the inestimable value of an 800 year-old reef.
The problem is, cyclone sees the bold:

The idea of "tunnels" is wacko, but in case of a small tropical atoll it might actually work. Placement of a 4-ft pipe "upstream" of the atoll with the intake 100 ft down into cool water, and routing the pipe over the reef and into the lagoon might moderate the temperature enough to avoid heat damage to the coral. This sounds to me like an inexpensive experiment and probably worth a try, especially given the inestimable value of an 800 year-old reef.
I read this article today about how "pork barrel" research is on the rise.

Given that many of our underwater reefs are national treasures administered by the National Park Service, the government might actually try this experiment at a local site. They waste millions on a lot less important research.
32. Inyo
the corals are sensitive to temperature changes, not hurricane damage. Also, any change will harm them... a decrease in temperatures to 70 f would probably kill much more of the coral than an increase from 82 to 84. theres a reason there is no coral off the coasts of New York or Los Angeles.
33. Inyo
also if you are worried about the state of federal land, i would say government 'pork barrel' outsourcing feed barrels for corrupt corporations are way worse than unnecessary studies, although certainly the latter occur as well. (most of them have nothing to do with science and instead involve ridiculous administration 'duties' such as designing a new database for data entry every year then scrapping it.)
Tunnel Talk =

Also, haven't you ever heard of shock? Even a temporary decrease in temperatures can kill coral and fish (if you have ever bought fish for an aquarium, you know that you can't just dump them into the water).
MichaelSTL is ever one ok over there
I just lost power for several seconds, probably from the strong winds (gusts to 40 mph); the main line of storms is still several hours away (see my blog).
Cyclone, a 10 degree drop in water temps for a week certainly WOULD be fatal or at least very harmful.
a selection of tornado & wind reports from storm prediction center~





63 piliminary tornado, hail & wind reports in the last 3 hours.
Wind damagewas reported near me:

0733 PM TSTM WND DMG 4 W MADISON 38.68N 90.22W
291 reports so far for the day. Lotta hail, semi-trailers overturned, damaged houses, destroyed outbuildings. The last 3 hours damage seems to be more harsh than earlier~ destroyed homes, lost roofs.
This radar image shows a TVS (Tornado Vortex Signature) to the southwest of my house and moving directly over it; fortunantly, it lasted for only two frames and no tornado warning was issued:

A sudden drop is fatal for most fish. However, I have 3 fish (used to have 20) in my aquarium that survived 5-6 hour 20 degree temperature swings. These wild fluctuations in temperature resulted from a faulty heater that would not shut off after reaching the set temperature, and the fact that my tank is in a location that is typically around 60 degrees in winter. Whenever I turned the heater on (and forgot to turn it off) the temperature would go up to 80-85 degrees, and when I turned it off (and forgot to turn it back on) the temperature would drop to about 60. The fish that survived are 1 pleco, 1 firemouth cichlid, and 1 red tailed shark (not a real shark).
Also, those problems went on for about a week.
MichaelSTL or any one need help come to my blog for more
46. Inyo
cyclone clearly knows nothing about biology. it certainly will kill the coral. and also, summer water temperatures of 70 certainly do occur off the Southern California coast.
Inyo said "cyclone clearly knows nothing about biology"

Isn't this a given.
just to let you know that there is a lot of damage to come in the future...

Sea levels may be rising faster than expected
Posted: March 30, 2006

Ice sheets across both the Arctic and Antarctic could melt more quickly than expected this century, according to two studies that blend computer modeling with paleoclimate records. The studies, led by scientists at the National Center for Atmospheric Research (NCAR) and the University of Arizona, show that Arctic summers by 2100 may be as warm as they were nearly 130,000 years ago, when sea levels eventually rose up to 20 feet (6 meters) higher than today.

Bette Otto-Bliesner (NCAR) and Jonathan Overpeck (University of Arizona) report on their new work in two papers appearing in the March 24 issue of Science. The research was funded by the National Science Foundation, NCAR's primary sponsor. The study also involved researchers from the universities of Calgary and Colorado, the U.S. Geological Survey, and The Pennsylvania State University.

Otto-Bliesner and Overpeck base their findings on data from ancient coral reefs, ice cores, and other natural climate records, as well as output from the NCAR-based Community Climate System Model (CCSM), a powerful tool for simulating past, present, and future climates.

"Although the focus of our work is polar, the implications are global," says Otto-Bliesner. "These ice sheets have melted before and sea levels rose. The warmth needed isn't that much above present conditions."

The two studies show that greenhouse gas increases over the next century could warm the Arctic by 5-8 degrees Fahrenheit (3-5 degrees Celsius) in summertime. This is roughly as warm as it was 130,000 years ago, between the most recent ice age and the previous one. The warm Arctic summers during the last interglacial period were caused by changes in Earth's tilt and orbit. The CCSM accurately captured that warming, which is mirrored in data from paleoclimate records.

Although simulation results depend on the assumptions and conditions within different models, estimates of warming from the CCSM are within the range projected by other climate models, according to the authors.

"Getting the past climate change correct in these models gives us more confidence in their ability to predict future climate change," says Otto-Bliesner.

The CCSM suggests that during the interglacial period, meltwater from Greenland and other Arctic sources raised sea level by as much as 11 feet (3.5 meters), says Otto-Bliesner. However, coral records indicate that the sea level actually rose 13 to 20 feet (4-6 meters) or more. Overpeck concludes that Antarctic melting must have produced the remainder of the sea-level rise.

These studies are the first to link Arctic and Antarctic melting in the last interglacial period. Marine diatoms and beryllium isotopes found beneath the West Antarctic Ice Sheet indicate that parts of the ice disappeared at some point over the last several hundred thousand years.

Overpeck theorizes that the rise in sea levels produced by Arctic warming and melting could have helped destabilize ice shelves at the edge of the Antarctic ice sheet and led to their collapse. If such a process occurred today, it would be accelerated by global-scale greenhouse-induced warming year round, Overpeck says. In the Arctic, melting would likely be hastened by pollution that darkens snow and enables it to absorb more sunlight.

In the last few years sea level has begun rising more rapidly, now at a rate of about an inch per decade, says Overpeck. Recent studies have also found accelerated rates of glacial retreat along the margins of both the Greenland and West Antarctic ice sheets.

NCAR's primary sponsor is the National Science Foundation. Opinions, findings, conclusions or recommendations contained herein are not necessarily those of NSF.