Australia braces for Cyclone Yasi as it hits Category 5

UPDATE: Live The last radar image from Willis Island added below. The last radar image is truly striking.

Also, see below for the differences between the Australia hurricane scale and the familiar Saffir-Simpson scale used in the USA. They are not equal.

From Australia’s BoM, time to “get outta Dodge” as they say:

Simon at Australian Climate Madness notes this for rebuttal of the inevitable “Yasi caused by global warming” links that will be pushed on the blogs and by the press:

Tropical cyclone Mahina hit on 4 March 1899. It was a Category 5 cyclone, the most powerful of the tropical cyclone severity categories. In addition, Mahina was perhaps one of the most intense cyclones ever observed in the Southern Hemisphere and almost certainly the most intense cyclone ever observed off the East Coast of Australia in living memory. Mahina was named by Government Meteorologist for Queensland Clement Wragge, a pioneer of naming such storms.

Here’s what BoM has to say on their tracking page:

The forecast path shown above is the Bureau’s best estimate of the cyclone’s future movement and intensity. There is always some uncertainty associated with tropical cyclone forecasting and the grey zone indicates the range of likely tracks of the cyclone centre.

Due to the uncertainty in the future movement, the indicated winds will almost certainly extend to regions outside the rings on this map. The extent of the warning and watch zones reflects this.

This product is designed for land-based communities; mariners should read the coastal waters and high seas warnings.




TC Yasi, CATEGORY 5, will continue to move in a west-southwesterly direction during the day. The cyclone is expected to cross the coast in the Innisfail area at about midnight.

Coastal residents within the warning area, and particularly between Cairns and Ayr are specifically warned of an EXTREMELY DANGEROUS SEA LEVEL RISE [i.e. storm tide] as the cyclone approaches, crosses the coast and moves inland. The sea is likely to steadily rise up to a level which will be VERY DANGEROUSLY above the normal tide, with EXTREMELY DAMAGING WAVES, STRONG CURRENTS and FLOODING of low-lying areas extending some way inland. People living in areas likely to be affected by this flooding should take measures to protect their property as much as possible, and be prepared to follow instructions regarding evacuation of the area if advised to do so by authorities.

DAMAGING WINDS with gusts to 90 km/hr that are currently developing on coastal islands, are forecast to develop about the coast by late morning and about the tropical interior overnight.

Between Cape Tribulation and Ingham these winds will become DESTRUCTIVE with gusts in excess of 125km/hr during the afternoon and early evening and VERY DESTRUCTIVE with gusts up to 300 km/hr between Cairns and Ingham during the evening as the cyclone approaches and crosses the coast. These VERY DESTRUCTIVE winds can also occur on the seaward side of hills to the north of the cyclone and are also forecast to reach the Atherton Tablelands.

Winds are forecast to ease about the east coast during Thursday morning as the cyclone moves inland.

FLOODING RAINS will develop from Cooktown to Sarina during the afternoon and then extend inland overnight.

People between Cape Melville and Sarina, extending inland to Croydon and Richmond should complete preparations quickly and be prepared to shelter in a safe place.

– Boats and outside property should be secured.

– For cyclone preparedness and safety advice, visit Queensland’s Disaster Management Services website (

– For emergency assistance call the Queensland State Emergency Service (SES) on 132 500 (for assistance with storm damage, rising flood water, fallen trees on buildings or roof damage).

People about the remaining tropical interior east of Camooweal and north of Winton should consider what action they will need to take if the cyclone threat increases.

– Information is available from your local government

– For cyclone preparedness and safety advice, visit Queensland’s Disaster Management Services website (

– For emergency assistance call the Queensland State Emergency Service (SES) on 132 500 (for assistance with storm damage, rising flood water, fallen trees on buildings or roof damage).

Name: Severe Tropical Cyclone Yasi


Time (EST) Intensity Category Latitude

(decimal deg.)


(decimal deg.)

Estimated Position

Accuracy (km)

0hr 7 am February 2 5 16.1S 150.9E 20
+6hr 1 pm February 2 5 16.7S 149.1E 45
+12hr 7 pm February 2 5 17.2S 147.5E 75
+18hr 1 am February 3 4 17.8S 145.8E 100
+24hr 7 am February 3 2 18.5S 144.1E 130
+36hr 7 pm February 3 1 19.8S 141.1E 190
+48hr 7 am February 4 tropical low 20.9S 138.4E 250

The next Forecast Track Map will be issued by 11:00 am EST Wednesday



Commenter sHx writes:

AS of this moment Yasi is right on top of Willis Island.

Apparently the island has a meteorological post. It even has radar!

click to see the latest image

It must be frightening to be that radar operator looking at this, knowing when that eyewall hits you are going to be subject to Cat5 winds and you have a 30meter tall radar tower right next to you, and there’s really no shelter elsewhere on the island and no place to go. I wonder how long we’ll continue to get a signal from the Willis Island’s radar?

UPDATE2: Just about the time I pressed “update” the radar went out, the radar station is offline. The last image from the station is above. We hope for the best for the BoM employees there. The storm surge must be ferocious. Hopefully BoM evacuated them and they left the radar on “auto”. Given the size and composition of the island versus the size of the hurricane, Willis Island may very well be erased by this storm.

File:Willis Island.JPG

Aerial Photo of Willis Island during Bureau of Meteorology re-development of weather observations facilities 2006. Image Wikipedia


Good luck to our friends in Queensland, especially Dr. Bob Carter and Nigel, who helped during my tour in Townsville last year.


UPDATE 3: Hurricane expert Dr. Ryan Maue brings to our attention the differences in tropical cyclone scales. The Saffir-Simpson scale used maximum sustained one-minute winds while the Australian Region scale uses ten-minute averaged sustained winds.  The convention to convert is (10-minute)*1.14 = 1-minute sustained (units are knots).  This image combined from Wikipedia’s article.

The JTWC advisory intensity at 00Z Feb 2 of 125 knots is a strong Category 4 on the Saffir-Simpson scale.  The Australian Bureau of Meteorology reports central pressure of 930 hPa, and backs out Category 5 winds from that.  Also, feel free to call Yasi a “willy-willy“.


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Why do these big storms always seem to hit at midnight, the worst.
I’m praying for them all……


OMG! Be save!

George E. Smith

Time to boogy Mates, this is not one to arm wrassle with.
Not much we can do to help you all at this time, but we’ll keep our fingers crossed anyway. I think my Aussie Mate Harro is right in the middle of that smash zone too; so get your A*** out of there buddy, and take the lovely lady with you.

val majkus

Yes Good Luck to everyone in the areas to be affected
Someone sent me this link yesterday the Hayden Walker Long range weather site at the link below
there are some amazing further links there. The page linked to is the end page, and to get back to his home page, just scroll back through the links at each page that say previous.
The practice of naming Cyclones was in fact started by a predecessor of Walker’s, Clem Wragge, who started this long range weather forecasting and that is at the second link, also from Hayden Walker’s site.
Link to Hayden Walker Page:
Link to History:
(thanks to TonyfromOz)


Actually, if you check it right now, it looks like the radar loop has stopped. This happened within the last hour, putting it between my reminder and Anthony’s update.
And right now, there is only this message:
Radar service is currently unavailable due to:
Sorry outage information is currently unavailable.

Courier Mail in Brisbane has regular update.
They reported at 10.04 AEST that the weather station may have been destroyed.

Moray Watson

god help them all

Category 5 on the Australian Cyclone Scale, not the familiar Saffir Simpson we use in the Atlantic…
The current intensity is 130 knots (1-minute sustained), and is not forecast to increase. Yasi will likely entrain some dryer continental air prior to landfall and be at 110-120 knots, or a moderate Category 4.
REPLY: Well I learned something today. I thought the Saffir Simpson scale was universally used. I’ll have to make a note now. Thanks -Anthony

Les Francis

According to reports the weather station on Willis Island has stopped reporting.
New reports are estimating expected wind gusts of up to 320Kilometres per hour (200 mph)
Have a look through this graphic PDF
Cyclone PDF
Note the table in the top left hand corner – destructive power of winds in KHM.
380KMH winds and above + total destruction

Gordon Ford

Unfortunately, this will be a wet to remember. Hope all my old mates are well stocked with XXXX and Bundaberg rum.

Ross Brisbane

This cyclone is much FURTHER south then the earlier Cat 5 mentioned here. The 1899 Mahina cyclone also hit a mainly unpopulated Cape York. It went southwest over Cape York Peninsula, emerging over the Gulf of Carpentaria before doubling back and dissipating on 10 March.
Further noting about Mahina it was nearly two months later. The BOM computer modelling along with the CSIRO predicted these cyclones in their modelling. A shift of a 2 degrees latitude in a modelled global WARMING world also predicted the rainfalls QLD has been experiencing.
Here it is word for word PREDICTED in climate models and QLD Government Climate Statement!
Extreme rainfall is defined as the amount of rain falling in the top one per cent of rainfall days. Projections based on 15 climate models and a medium emissions (A1B) scenario indicated that Cape York can expect up to a four per cent increase
in extreme rainfall across all seasons, and that western Queensland and the Gulf Region can expect up to a four per cent increase in summer and autumn (CSIRO & BoM 2007).
Climate change is also likely to affect extreme rainfall in south-east Queensland (Abbs et al. 2007). Projections indicate an increase in two-hour, 24-hour and 72-hour extreme rainfall events for large areas of south-east Queensland, especially
in the McPherson and Great Dividing ranges, west of Brisbane and the Gold Coast. For example, Abbs et al. (2007) found that under the A2 emissions scenario, extreme rainfall intensity averaged over the Gold Coast sub-region is projected to increase
by 48 per cent for a two-hour event, 16 per cent for a 24-hour event and 14 per cent for a 72-hour event by 2070. Therefore despite a projected decrease in rainfall across most of Queensland, the projected increase in rainfall intensity could result in more
flooding events.
It is of course fine to be a climate skeptic – but if may I am in QLD right now. It’s enough to knock the skeptic out of anyone.
Climate Change skeptical extinction may be expected by 2020.


Willis Island is supposed to provide an update every 10 minutes I believe. The transmissions have apparently now ceased. Looking at the pic Anthony provided, I’m not surprised.
The storm surge would put it under water wouldn’t it ?

Robert Smith

Laid back aussies or the worst weather forecast ever?
“Windy later”
Good luck you guys.

King of Cool

The amount of water damage will depend on the exact time that this cyclone affects the coastline. Last I heard was that it would cross around Innisfail (83 kms south of Cairns) at about midnight.
If it accelerates slightly this would put it at the same time at quite a high tide (estimated at 2.38m at 2053 hrs for Cairns) which would be the worst case scenario.


300kmh gusts = 161 knots or 186 mph Ouch!
All of the modern houses are built to cyclone wind standards in FNQ (Far North Queensland) but coastal flooding will be a major issue. Also flying debris such as cars , trees and sharp sheet metal commonly used on roofs can damage structures that could take the wind fine without such structural damage.
The massive Burdekin dam and many others are already overflowing and the rainfall from Yasi is going to be extreme. Expect significant flooding in river systems downstream of all the full dams. My home town of Mt Isa is at the tail end – 800km (497 miles) from the coast and this will still be a category 1 cyclone when it gets there!
If it goes up into the gulf of Carpentaria it could reform…….


According to this page, the weather station on Willis Island last reported CALM conditions with wind at 0 kmh. 🙂
BTW, Anthony, I can’t guarantee you this, but rest assured any living personnel on the island would have been evacuated by now.

Eric (skeptic)

Ross, better get prepared. The bad weather you are talking about is going to happen with or without global warming. It may come more frequently with global warming. It may also be higher intensity although high intensity is also an historical fact. So be prepared!

Baa Humbug

Ross Brisbane says:
February 1, 2011 at 3:45 pm
Piers Corbyn predicted extreme weather for eastern Oz during the period 29th Jan to 2nd Feb and he didn’t include AGW or CO2 in his calculations.
I’ve been telling friends and family of a climate shift accompanied by extreme weather for many months now. Nothing to do with CO2.
What’s happening and been happening in this part of the world is nothing new, just the 35.8yr cycle cycling away as expected. The warm waters around the eastern coast of Oz are a product of La Nina pushing warm waters in a westerly direction against the Oz and PNG coasts.
Why don’t you visit the WUWT Enso page and do a little reading before falling in line with the AGW meme. These extreme weather events would have happened with or without the extra bit of CO2.


For comparison of the scale of this Cyclone with US hurricanes scales see bottom of the page


The 4 BoM employees on Willis Island were evacuated before the cyclone hit,
according to the very informative post be Les Francis.
Seems the only rational move when a storm that size washes over the site.
The rainfall from this system will be a serious blow to the area, which is already suffering from record flooding.

Philip Bradley

Co-incidentally we had a tropical cyclone heading directly for Perth less than a week ago. And in fact the remains of cyclone came directly over downtown Perth. However, the cyclone had rapidly decayed and all we got was 12 hours of drizzle with light winds.
A BoM spokeperson was on TV afterwards telling us how we had ‘dodged a bullet’. No mention of the fact their forecast of 100KPH winds was completely wrong.
Note, no implication the QLD cyclone will be a similar bust.

Nonsense, these predictions were made by models. Until the error bars get narrower I suggest we ignore them


The Courier Mail reported a few hours ago the staff were evacuated:
9.30am Wind gusts are reaching 140km/h at Willis Island off the coast of Queensland. The tiny island is in the direct path of the cyclone and is home to a Bureau of Meteorology weather station. Three bureau staff have been evacuated.


Ryan Maue says:
February 1, 2011 at 3:37 pm
Category 5 on the Australian Cyclone Scale, not the familiar Saffir Simpson we use in the Atlantic…
The current intensity is 130 knots (1-minute sustained), and is not forecast to increase. Yasi will likely entrain some dryer continental air prior to landfall and be at 110-120 knots, or a moderate Category 4.
1 knot = 1.852 km/hr
130 knots = 241 km/hr


Hey Ross of Brisbane,
“It is of course fine to be a climate skeptic – but if may I am in QLD right now. It’s enough to knock the skeptic out of anyone.
Climate Change skeptical extinction may be expected by 2020.”
Ross a lot of readers here might not realise that although you are in Qld if you are in Brisbane then you are a long way away from this storm. I lived in Cairns for 2 years and Trop Cyclones hovered around the coast about 4 per season. Only one touched land just south of Cairns in my time. Mate, it is a weather event not Global Warming or Climate Change. It will be massive, there will be destruction and there could well be deaths. It may also not be the last one for the season which runs for a few more months yet.


The nicest, most civilized people always seem to live in the cruelest, most inhospitable climate. G’day. No worries. I’ll pray for you.

John from CA

Ross Brisbane says:
February 1, 2011 at 3:45 pm
Climate Change skeptical extinction may be expected by 2020.
So I took a look at the linked artile and it presents a document that’s little more than IPCC and UNFCC meme.
The BOM isn’t the best at forecasting seasonal patterns let alone patterns that are decades away.
Could the Australian BOM get it more wrong?
“On August 24 the Australian BOM had pretty much no idea that any unusual wetness was headed their way. Toss a coin, 50:50, yes or no. Spring 2010 was going to be “average”, except in SW Western Australia where they claimed “a wetter than normal spring is favoured.”
What follows were 100 year floods, or at least above average rain to nearly every part of the nation bar the part that was supposed to be getting more rainfall. In the chart below, all shades of “blue” got above average rainfall. The dark blue? That’s the highest rainfall on record.”
BOM Forecasting Skill
from the same article:
Warwick Hughes linked to this unusually candid report of BOM seasonal rain forecasts (Vizard 2005).
“The results indicate that the forecasting system had low skill.”
They go on to explain just how low:
“Brier Skill Score and the receiver operating characteristic values were uniformly close to the no skill value.”
I don’t think I’ll be tendering my Skeptics badge, any time soon, based on Australia Climate Predictions.

Dave N

Ross Brisbane:
“Further noting about Mahina it was nearly two months later”
Since when is March 4th (when Mahina hit), two months later than Feb 2nd?
The latitude shift is bunk, since cyclones have hit lower latitudes many times before, eg Wanda and Zoe.
Having said that, I sincerely hope you’re safe up there (I’m in Adelaide).


Ross Brisbane says:
February 1, 2011 at 3:45 pm
It is of course fine to be a climate skeptic – but if may I am in QLD right now. It’s enough to knock the skeptic out of anyone.
Climate Change skeptical extinction may be expected by 2020.
Ross, serious question
If no one had ever invented global warming/climate change….
….what would you call this?

Geoff Sherrington

At 1000 hrs Australian Eastern Daylight Saving Time on 2 Feb the Premier of Queensland and the 2 IC Police gave a press conference that essentially much that has been said above. The intensity is now 5 on the Australian scale. The eye is 35 km in diameter and the system is tracking slightly south of west at 35 km per hour. It was predicted to be the most severe storm to make landfall in Australia in living memory. Landfall is expected 2200 hrs AEST.
Storm surge depend on local geography and time of tides; high figues of 4 m are quoted, with 2 m expected generally. Some estimates are as high as 6 m.
The entire Cairns Hospital was evacuated to Brisbane last night, over 100 patients who were too ill for discharge.
There must be a high probability of multiple deaths. There will also be a wringing of hands over climate change. As a preamble, see
Not a happy situation.

This may seem like a dumb question but as Queensland is already flooded/moisture laden is the crossing of the cyclone from ocean to land likely to be less of an impact because of the buildup of moisture on the land. In other words how does the effect of a flooded landscape affect the cyclone degenerating as opposed to a parch/dry/drought landscape?

John Silver
Mike McMillan

Willis Island is at
S 16 17 13. E 149 57 50
on Google Earth. There are a few photos.
The reef is to the northeast, but I think the winds will be coming in from the west, so they won’t help soften the impact.


I moved to SW Florida July 4th 2004. Six weeks later we had Charley, made landfall near the island of Cayo Costa, Florida as a 150 mph (240 km/h) Category 4 hurricane with a pressure of 941 mbar (hPa; 27.49 inHg) at approximately 3:45 p.m. EDT on the 13th of August. An hour later, the hurricane struck Punta Gorda as a 145 mph (230 km/h) storm. However, the eye had shrunk before landfall, limiting the most powerful winds to an area within 6 nautical miles (11 km) of the center.3:45 p.m. EDT , 15 miles north of Cape Coral where I live.
I took my mother and I to my brothers house in Fort Lauderdale across Alligator Ally the day before it was scheduled to make landfall. I went back the day after to begin repairs but my mother could not return for a week due to power outages. You do not want to mess with anything greater then a cat3, just get out. I was glad to see the sun going into a sustained solar minimum. I’ve bee going naked on my hurricane insurance the past 2 years.

Philip Bradley

Ross Brisbane, if there are enough predictions you can always find some that turn out to be true. Although I’ll note you are just assuming these forecasts are correct without checking.
FYI, I checked the BoM’s cyclone forecast for the current season
And see their forecast was for,
The largest increase in tropical cyclone numbers is expected to occur in the Western region, where 11-12 tropical cyclones are forecast (4-5 more than the average value of 7 tropical cyclones).
Then checked cyclone activity to date this season and found there have been just 3 Western Region cyclones.
So while the cyclone season has still got a few weeks to go, clearly the BoM’s forecast was far off the mark and we (I live in WA) will have a below average cyclone season. As we have had for the last 7 or 8 years (from memory).

West Houston

Run from the water, hide from the wind. If some authority figure tells you to evacuate, do it. If you won’t, he’ll ask for names of your next of kin. He won’t be joking.


Australian Greens Senator Christine Milne already jumped on the Yasi-caused-by-climate-change bandwagon:
Some people are simply an embarrassment to the species.

Re Willis Island: I was under the impression there were 5 people on the island, and 3 have been evacuated, with 2 remaining. Could be wrong.
All safe and prepared here (near Sarina- on southern edge of gale force winds, so not in any danger), but ready to clear out if it heads south. Best wishes everybody.


“Monster cyclone knocks out weather radar
By Kim Lyell
Category five Cyclone Yasi has knocked out the weather bureau’s radar system on Willis Island, about 450 kilometres east of Cairns in far north Queensland.
The weather bureau’s radar and wind speed measurements on the island failed just before 9am (AEST).
The bureau says the maximum wind speed recorded before the equipment went down was 185 kilometres an hour.
Three weather observers and a technician left the island yesterday.”

Rick Bradford

Poor old Innisfail — it copped a shellacking off Cyclone Larry in 2006, and has slowly been rebuilding over the past 5 years, and it looks as if it’s going to get flattened again.
I was in Cairns when Larry hit, i.e. about 100kms away, and that’s as close I ever want to come to one of these frightening weather events.
Praying that everyone stays safe.

John Cooper

If I’m not mistaken, there aren’t many roads in that part of Australia. Good luck getting out.

John from CA

John Silver says:
February 1, 2011 at 4:41 pm
Rain bands hitting Townsville and just off shore in Cairns:

John from CA

Rain bands in Bowen and Mackay:
128 km Bowen Radar Loop
128 km Mackay Radar Loop

Philip Bradley

It looks like Yasi will dump a lot of rain in the Lake Eyre catchment and we may see the highest recorded level in Eyre (1974) exceeded.
Although to give you an idea of how much water that will require.
The highest recorded level in Lake Eyre was in 1974 but it would take the average flow of Australia’s largest river, the Murray to maintain that level. The Danube River would fill Lake Eyre to the 1974 level in forty-five days; the Mississippi in twenty-two days, and the Amazon in three days.


Hi Ross from Brisbane this is Carrie from Qld. You are new here. Good on ya mate. If you keep coming back and reading the many scientific articles here, plus visit all the blogs linked and listed, you might change your mind. That is of course, if you have a true scientific curiosity and if you are not a person who is benefitting financially via your job or business from the global warming agenda, and/or are not a member of the church of green.


twawki says:
February 1, 2011 at 4:40 pm
This may seem like a dumb question but as Queensland is already flooded/moisture laden is the crossing of the cyclone from ocean to land likely to be less of an impact because of the buildup of moisture on the land. In other words how does the effect of a flooded landscape affect the cyclone degenerating as opposed to a parch/dry/drought landscape?
I’ve forgotten the name, but one recent hurricane in Florida strengthened in the middle of the state.
It crossed south Florida from west to north east, and strengthened when it got over the water in the Everglades, in the middle of the state.

John from CA

Brisbane Times
Too late to leave: drivers told to stay put
Tony Moore
February 2, 2011 – 11:32AM
“Police have urged “frantic” motorists trying to escape Cairns that it is too late to try and outrun Cyclone Yasi.
“Heading south on the highway to outrun the cyclone, it is probably too late for that now,” Regional Traffic Co-ordinator Inspector Robert Waters said.
“Basically if you haven’t already left Cairns, if you haven’t worked out a specific destination within a reasonable driving distance, you have probably left it too late and we suggest you go to the shelters that are advertised by the councils.”

By good fortune I took a copy of the Willis island data to PDF just before is went down.
This appears to show the eye of the cyclone, amazing. If it is valid.
Quickly thrown up this page with a link to the PDF.

Ross Brisbane

Philip Bradley
I am not a BOM “basher” by this cherry picking. Neither am I a CSIRO basher. Where’s that leave you? I do not expect you to think as I do. I do you expect you to be a true sceptic of climate change, keep an open mind to all flows of information and not shut out what you find maybe an unacceptable reach of your understanding.
I do not like cherry picking – read the ENTIRETY of QLD Climate Change Report – it is not only factual, but gives EXTRAORDINARY insight into what climate and type of climate changes QLD will transition into within a global warming context over the next decade.
It also clearly instructs one to better plan their housing location, be selective about the type of house, (an insurance evaluative position, policy and protection) and other named events that QLD will absolutely transition into over the next coming decade.
The key to all this all is not government and political issue but you and me – the daily citizen being able plan with known parameters of foresight rather then hindsight.
The State Government gave an excellent report – it is worthy of anyone reading it for their own well being, to protect their families and plan a better lifestyle with harmful catastrophic event minimisation.

Wayne Delbeke

Stay safe in Australia … but other places too.
Apparently the US is in for a blast from the weather. It was 30 below in Alberta yesterday. There is a huge jet stream mvoing south to Texas right now and affected flights in Texas today. Tonight and tomorrow it will be worse. On the west side of the jet stream it is warm – it was plus 4 C at my farm and 100 km east in Red Deer it was 21 below C today.
The jet stream goes straight south to Texas and then turns north picking up moisture from the Gulf to mix with cold air. Our local weather forecast said there could be 30 cm of snow from a bit east of the Rocky Mountains all the way to Chicago, from Texas to the Canadian border, with 15 to 20 cm on the east coast and tornadoes in the south east. A nasty big weather system covering most of the eastern US and Canada.
The northern jet stream has really been doing its meandering thing this year.
Good luck to all of you in unsettled weather. Stay off the roads.

David L. Hagen

A ham operator friend in the south pacific helping with civil defense said one cyclone he helped out had greater than 230 km/hr winds (142 mph) – because that was when the anemometer blew away!
His rule of thumb to keep metal sheeting on was to use 7 bolts per square meter!