Typhoon 4/Man-yi

[Tom Mitchell]

Typhoon 4 is sneaking up on Okinawa. As usual, the JTWC has predicted a Cat 4 monster. JMA uses much longer periods for their wind measurements, so they are predicting 85 knot winds vs. 120 knots for JTWC. Regardless, at 2 days out the tracks are usually accurate, so it looks like the kids might just get a Typhoon day for at least part of the day on Friday.

Japan Meteorological Agency English Site
http://www.jma.go.jp/en/typh/0704.html

Joint Typhoon Warning Center
https://metocph.nmci.navy.mil/jtwc.php

The timing is such that I might actually get to take some video of the trees bending in the 80-100 knot breeze, some big waves, and the people who seem to think that umbrellas are some kind of magic force field (it blows my mind to see people try and use umbrellas in a 50 mph wind.) To be honest, not much else happens during typhoons in Okinawa, unless the are really strong. Of course, the farmers take the brunt of the losses, but 90% have insurance to cover their losses. Hopefully nobody gets hurt. We usually don't even loose electricity, although winds over 100 knots can cause some disruption, usually about 25%.

I keep you all posted, for those that are interested...

Have a great day!

Tom

 

[Jim Leonard]

Japan meteorological agency along with many other agencies around the world use the 10 minute average for maximum sustained winds. I think the one minute average is much better with tropical cyclones. In reality it is those instantanious gusts that do most of the damage which is much stronger than the sustained value. In the west pacific a 125kt typhoon has an average central pressure of around 925mb pressure. The same storm will have a 10 minute average wind of 85kts.
Tom if you take some video of this or any other typhoon let me know, just PM me, thanks.

 

[Tom Mitchell]

I agree with you completely. After seeing first hand how things get battered in typhoons, I think the one minute averages are a better indication of the intensity of the winds. Just imagine if they wind speeds of torandoes were reported as 10 minute averages. Regardless, the Japan Weather Agency local anemometer is about 200 meters from my house, so I will have a pretty good idea of what the winds are here.

Sky and sea here are definitely pre-typhoon...heavy surf rolling in, upper level clouds speeding east, lower level speeding west, with the largest component of the surf coming in perpendicular to the winds. Most importantly, my wife's mother, who comes from a farming family, called us yesterday to tell us that she thinks a typhoon is "coming on friday." She is always right.

 

[Derrick Herndon]

Japan meteorological agency along with many other agencies around the world use the 10 minute average for maximum sustained winds. I think the one minute average is much better with tropical cyclones. In reality it is those instantanious gusts that do most of the damage which is much stronger than the sustained value. In the west pacific a 125kt typhoon has an average central pressure of around 925mb pressure. The same storm will have a 10 minute average wind of 85kts.
Tom if you take some video of this or any other typhoon let me know, just PM me, thanks.

Jim are you getting 85 kts by converting the 125 kts to a 10-minute MSW? I think the normal conversion is 90% of the 1-minute MSW which would make a 125 kt (1-minute) MSW about 110 kts.

 

[Jim Leonard]

Jim are you getting 85 kts by converting the 125 kts to a 10-minute MSW? I think the normal conversion is 90% of the 1-minute MSW which would make a 125 kt (1-minute) MSW about 110 kts.

The Japan agency in their outlook this afternoon was showing an intensity of 85kts in their 36 hour forecast the same time JTWC was giving 125kts.

 

[Jim Leonard]

Tom
It appears now you will see CPA around late morning or noontime as it looks now so you should get some good video. Make sure your car is on the lee side of a strong building and away from any trees. I know Okinowa is built to withstand typhoons, I chased one back in 1992.

 

[Derrick Herndon]

The Japan agency in their outlook this afternoon was showing an intensity of 85kts in their 36 hour forecast the same time JTWC was giving 125kts.

Yeah, I was stationed in WPAC in the Navy for 3 years and we had to deal with these discrepencies a lot. The 85 kts would convert to a 1 minute MSW of about 94 kts so they appear to think that it will not strengthen as much as JTWC does. However right now at 12/00Z the CIMSS ADT is at 140 kts, the 2 AMSU-based techniques are at 105-110 kts and the subjective Dvorak from SAB is at 115 kts. Thats a pretty good consensus of estimates > 105 kts. Even the Tokyo estimates for current intensity were 102 kts at 18Z and 127 kts at 00Z. Apparently the JMA folks doing the forecasts do not put a lot of trust in the Dvorak estimates from their folks down the hall.

 

[Derrick Herndon]

Yeah, I was stationed in WPAC in the Navy for 3 years and we had to deal with these discrepencies a lot. The 85 kts would convert to a 1 minute MSW of about 94 kts so they appear to think that it will not strengthen as much as JTWC does. However right now at 12/00Z the CIMSS ADT is at 140 kts, the 2 AMSU-based techniques are at 105-110 kts and the subjective Dvorak from SAB is at 115 kts. Thats a pretty good consensus of estimates > 105 kts. Even the Tokyo estimates for current intensity were 102 kts at 18Z and 127 kts at 00Z. Apparently the JMA folks doing the forecasts do not put a lot of trust in the Dvorak estimates from their folks down the hall.

Hmm, on the otherhand it appears Tokyo uses a different Dvorak scale. So what would be a T6.0 is 93 kts and T6.5 is 102 kts, still both higher than their advisory intensities.

 

[Tom Mitchell]

Sorry for no updates, but there hasn't been much to say. The northwest quadrant of the storm was fairly inactive, but now things are starting to pick up with winds steady at about 40 knots.

The other exciting news is that I was diagnosed with Infuenza type A. Fever, general malaise...just my luck. Anyway, I am going to step outside to feel the wind on my face...nothing like near hurricane force gusts to freshen you up.

Radar (sorry for the link, but I can't get the image to show...)

http://farm2.static.flickr.com/1136/787603337_2d917842e6.jpg?v=0

 

[Derrick Herndon]

Sorry for no updates, but there hasn't been much to say. The northwest quadrant of the storm was fairly inactive, but now things are starting to pick up with winds steady at about 40 knots.

The other exciting news is that I was diagnosed with Infuenza type A. Fever, general malaise...just my luck. Anyway, I am going to step outside to feel the wind on my face...nothing like near hurricane force gusts to freshen you up.

Radar (sorry for the link, but I can't get the image to show...)

http://farm2.static.flickr.com/1136/787603337_2d917842e6.jpg?v=0

Hey Tom. Why are you in Okinawa? Are you stationed there? If so where at? Looks like the island will be in the dangerous semi-circle.

 

[MatthewCarman]

Looks like the small island of Naha could take a hit. A cat4 Typhoon is the same as a Cat4 hurricane correct?

 

[Jim Leonard]

The power maybe out by now so Tom won't be able to send any updates. He is probably in the airforce stationed at Kadena AFB. Okinowa

 

[Jeff Lawson]

Looks like the small island of Naha could take a hit.

Just a note, Matthew... the island marked as "Naha" on the map is actually Okinawa. Naha is the largest city on the island.

 

[MatthewCarman]

I see that now thanks Jeff. Was wondering where Okinawa was. This Typhoon is heading strait for Okinawa I hope we do not have much loss of life from this hurricane.

 

[Jim Leonard]

The typhoon's eyewall is now entering the south shore of Okinowa. The island should be experiencing the full force of its 100kt+ winds. The entire island should get the eastern eyewall during the next several hours. Tom should have a interesting story to tell once he has electricity.
http://weather.noaa.gov/weather/current/RODN.html