How strong was Irma?

Peter NJ

Senior Insider
This beach bar sign from SXM was found in the debris at the little airport on Virgin Gorda



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We were told 200MPH winds in Pte. Milou!

Had a long talk with a former local fireman,who has a friend at the nhc,who looked at the satellite data.Winds reached 450 km/h ,and some tornadoes near the eye had winds near 650 km/h (this would explain damages in some areas..the worst hit (hauts de st jean,colombier and so on )
Collectivity with president Magras Is now taking active steps to prepare the island for such events (underground networks ,new shelters,etc).Edf is also planning changes to get generators safe .
It should be noted that sea levels didn't rise (by far) as much as expected..which is scary,when you see sustained damages on the coastline
Japan is the way to go.Typhoons and earthquakes require major planning .and big/strong is never too big or strong
 
• Irma’s maximum intensity of 185 mph was the greatest for an Atlantic hurricane outside of the Gulf of Mexico and Caribbean on record, and is tied as the second strongest Atlantic hurricane, topped only by Allen (1980) in the Caribbean (190 mph). Two other hurricanes have notched 185-mph winds in the Caribbean: Gilbert (1988) and Wilma (2005). The Labor Day hurricane of 1935 hit the same peak winds in the Florida Straits.
• Irma maintained an intensity of 185 mph for 37 hours – the longest any cyclone around the globe has maintained that intensity on record (old record: 24 hours set by Haiyan in 2013.)
• Irma and Harvey marked the first time that two Category 4 hurricanes have made continental United States landfall in the same year.
• Irma’s Florida Keys’ landfall pressure of 929 mb was tied with the Lake Okeechobee Hurricane of 1928 for the 7th lowest on record for a continental US hurricane.
• Irma effectively destroyed the island of Barbuda in the Leeward Islands, forcing all 1,800 inhabitants to leave, making the island unpopulated for the first time in 300 years.
• Maria’s lowest central pressure of 908 mb was the lowest on record for a hurricane in the eastern Caribbean (<=20°N, 75-60°W).
• Maria intensified 70 mph in 18 hours. Only Wilma (2005), Felix (2007) and Ike (2008) have intensified more in 18 hours.
• Maria was the first Category 5 hurricane on record to make landfall in Dominica.
• Maria was the first Category 4 hurricane to make landfall in Puerto Rico since 1932, and the strongest hurricane to make landfall in Puerto Rico since 1928.
• Maria caused the largest and longest power outage in U.S. history: an island-wide power outage for all of Puerto Rico’s 3.4 million people and the 103,000 people in the U.S. Virgin Islands. As of November 30, 35% of Puerto Rico’s 1.5 million customers still did not have power, 6% had no water service, and 27% of the island’s cell phone towers were not working. In the U.S. Virgin Islands, more than half of the residents had no power.
 
Had a long talk with a former local fireman,who has a friend at the nhc,who looked at the satellite data.Winds reached 450 km/h ,and some tornadoes near the eye had winds near 650 km/h (this would explain damages in some areas..the worst hit (hauts de st jean,colombier and so on )
Collectivity with president Magras Is now taking active steps to prepare the island for such events (underground networks ,new shelters,etc).Edf is also planning changes to get generators safe .
It should be noted that sea levels didn't rise (by far) as much as expected..which is scary,when you see sustained damages on the coastline
Japan is the way to go.Typhoons and earthquakes require major planning .and big/strong is never too big or strong

450 km/h is 280 mph.
650 km/h is 404 mph.

The fastest non-tornado wind gust ever previously recorded is 253 mph. https://weather.com/storms/severe/news/most-extreme-winds-earth
The fastest tornado wind speed ever previously recorded is 318 mph. http://www.crh.noaa.gov/Image/dvn/downloads/quickfacts_Tornadoes.pdf

If the above numbers are accurate then the world meteorological community should be very interested.
 
450 km/h is 280 mph.
650 km/h is 404 mph.

The fastest non-tornado wind gust ever previously recorded is 253 mph. https://weather.com/storms/severe/news/most-extreme-winds-earth
The fastest tornado wind speed ever previously recorded is 318 mph. http://www.crh.noaa.gov/Image/dvn/downloads/quickfacts_Tornadoes.pdf

If the above numbers are accurate then the world meteorological community should be very interested.

You should give Adolphe Brin a call.He used to be first respondent on the island for years.he's also a keen "radio amateur",with this friend at NHC.They do mathematical assessments on satellite images (if i understood correctly)
The wind is also measured on the ground level.Wind is 20% stronger 80 meters higher.This might explain the damage on the top of the "mornes".In Colombier,some huge Bismarckia palm trees simply vanished.Those weigh over 4 tons.
Anyway,Adolphe is your man for that talk on the island.
We also discussed the mystery of the sea level not rising as much as expected.(thank God).You can read the journal de Saint Barth to see that Bruno Magras also took notice and is now planning to build new shelters on higher ground.
Irma was pushing over 14 meters of water.But sea level in town only went up 3 meters.
But in my opinion,Maria is the real game changer.And all planning/regulation should be based on Maria's data.
 
Lots of Brin on the island..))and that's not Adolphe
But he is right about one thing..a lot of the equipment breaks and the highest measure is usually when it fails.NHC also uses satellite to monitor the storm strength
The same debate is on about Maria and rainfall,as the numbers are so high many believe the aquipment failed.(and altitude also a factor)
There is an agreement (almost) that a 96 inches is a real possibility for 1 station
That is a 2.5 meters of rain in 24 hours.
This means Sbh and homeowners need to plan for such rain,in my opinion.(because of the numerous hills)...
And they need to plan quickly
 
The warning signs are clear

But this year’s intense Atlantic storm season had another element tying its biggest events together: a monstrous, and sometimes deadly, amount of rain.
Images of the flooded metropolises of Houston, Jacksonville, and San Juan with overtopped dams, billowing sewage, and flooded homes show that torrential rain can be one of the most devastating consequences of hurricanes, especially in urban areas where concrete makes it harder for water to drain and where people can drown.
Scientists say the extreme rainfall events that feed these floods are on the rise for many parts of the world, and this year’s hurricanes fit that trend. In particular, rising temperatures in the ocean and the air alongside booming construction in vulnerable areas are fueling the increased risk from massive deluges.
Satellite measurements already show that it poured as much as 6.44 inches of rain per hour and has left Puerto Rico shrouded in darkness.

This is crucial for EDF and the location of the new generators,for example.
If your neighbor uphill is building,it is worth checking his draining system (just saying)
If you have lots of rocks uphill,it might be worth spending money checking the area and using steel rods to block them.
Climate change is going to be costly.People are slowly waking up to that reality.

People living in Saline should also reflect on this,in my opinion

 
I was thinking the same thing. Some of the new megavillas are being built into lots carved out of hillsides. There may be concerns not only about the rocks from above, but the runoff to villas and residences below.

Much of Saline is a different problem. It's on low ground.
 
Much of Saline is a different problem. It's on low ground.

Did you ever drive on the new saline road when it is raining really heavily ? The amount of water running down is truly spectacular ...what would happen with an 8 inches of rain/hour ?
I wouldn't stay in saline during a major ,moving slowly
 
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