General Discussion >> Hurricane Ask/Tell

danielwAdministrator
Moderator


Reged: Wed
Posts: 3525
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: HurriScale
      Thu May 03 2007 01:58 AM

It's is something that literally jumped out at me while doing some spreadsheet work.
I took the standard Saffir-Simpson Category numbers. Placed them on a spreadsheet. And filled in the gaps at 5mb intervals.


(NHC/TPC No longer uses minimum central pressure to classify Tropical Cyclones. That practice ended in the mid 1990s)

Using the above table:
980mb= 95mph or 82 knots
965mb=110mph or 95 knots__(15mb drop = 15mph increase)
945mb=130mph or 113 knots_(20mb drop =20mph increase)
920mb=155mph or 135 knots_(25mb drop = 25 mph increase)

After a Storm reaches 75mph. There is roughly a 1mph increase in windspeed for every 1mb drop in pressure.
This is what I call the "Maximum Possible Windspeed" in relation to pressure and wind Only.
Both Katrina and Rita had Maximum Windspeeds OVER the Max Possible Windspeed.
In other words Katrina and Rita went above the Pressure : Wind curve.

For those that have a spreadsheet. Excel or other versions.
Row 1,First Column- 1013 (mb is column name)
Row 1, Second column-10 (mph is column name)
Row 2,First Column- 1012
Row 2,Second column- 15
Now use the "add" function to take Column 1 down to 875mb, and Column 2 to 200 mph.

You should now have the HurriScale table.

This is Not a proven formula. But you can compare it to The Supercanes of 2005. The basis for the formula is the Atkinson-Holliday formulas and theories of the early 1970's. And some other authors over the last 30 years.

I'm working on an easy spreadsheet that I can post.

http://www.google.com/search?hl=en&q=pressure+wind+relationship

http://ams.allenpress.com/archive/1520-0493/105/4/pdf/i1520-0493-105-4-421.pdf

http://www.aoml.noaa.gov/hrd/tcfaq/D1.html

http://www.unc.edu/~rowlett/units/scales/saffir.html

Post Extras Print Post   Remind Me!     Notify Moderator


Entire topic
Subject Posted by Posted on
* HurriSheet... Intensity and Surge Estimations from Pressure danielwAdministrator Thu May 03 2007 01:58 AM
. * * Re: HurriScale dem05   Mon Jul 23 2007 01:08 AM
. * * Re: HurriScale Hootowl   Thu May 03 2007 07:10 AM
. * * Re: HurriScale Lamar-Plant City   Tue May 01 2007 04:55 PM
. * * Re: HurriScale IMTechspec   Sat Jul 21 2007 11:48 PM
. * * Re: HurriScale RevUp   Tue Jul 24 2007 12:17 PM
. * * Experimental Wind Loading Data CoconutCandy   Tue Jul 24 2007 08:40 PM
. * * Re: HurriSheet... Intensity and Surge Estimations from Pressure danielwAdministrator   Tue Apr 14 2009 08:01 PM
. * * Re: HurriSheet... Intensity and Surge Estimations from Pressure danielwAdministrator   Wed Apr 22 2009 02:16 PM
. * * Re: HurriSheet... Intensity and Surge Estimations from Pressure Storm Hunter   Sat May 16 2009 01:53 PM
. * * Re: HurriSheet... Intensity and Surge Estimations from Pressure danielwAdministrator   Sun May 17 2009 10:00 AM
. * * Re: HurriScale danielwAdministrator   Thu May 03 2007 01:58 AM
. * * Wind Loading and the Saffir-Simpson Scale CoconutCandy   Fri Jul 20 2007 09:05 AM
. * * Re: Wind Loading and the Saffir-Simpson Scale audienceofone   Fri Jul 20 2007 10:01 AM
. * * Re: Wind Loading and the Saffir-Simpson Scale Ed DunhamAdministrator   Fri Jul 20 2007 05:54 PM
. * * Wind Loading and the Saffir-Simpson Scale CoconutCandy   Mon Jul 23 2007 07:43 PM
. * * Re: Wind Loading and the Saffir-Simpson Scale danielwAdministrator   Mon Jul 23 2007 08:25 PM

Extra information
0 registered and 0 anonymous users are browsing this forum.

Moderator:  CFHC, Ed Dunham, Colleen A., danielw, Clark, RedingtonBeachGuy, Bloodstar, tpratch, typhoon_tip, cieldumort 



Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating:
Thread views: 13871

Rate this thread

Jump to

Mobile Home - Login - Normal Flhurricane Site
This is NOT an official page. It is run by weather hobbyists and should not be used as a replacement for official sources.
Generated May 18, 2024, 6:40:13 PM EDT
When in doubt, take the word of the National Hurricane Center