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#1
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![]() Rank: F5 Superstorm ![]() ![]() ![]() Group: Member Posts: 1,571 Joined: 8-April 10 From: Baltimore, MD Member No.: 22,491 ![]() |
This was posted Thursday.
QUOTE NOUS41 KWBC 011848 PNSWSH Public Information Statement National Weather Service Headquarters Washington DC 148 PM EST Thu Mar 1 2012 To: Subscribers: -Family of Services -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPORT Other NWS partners and NWS employees From: Mark Tew Chief, Marine and Coastal Services Branch Subject: Minor Modification of Saffir-Simpson Hurricane Wind Scale Thresholds Effective May 15, 2012 Effective May 15, 2012, the Saffir-Simpson Hurricane Wind Scale (SSHWS) will be adjusted slightly to resolve issues associated with the conversion of units used for wind speed. This change follows a public comment period conducted in 2011. The National Hurricane Center (NHC) and Central Pacific Hurricane (CPHC) assign intensities of hurricanes in 5-knot (kt) increments. For advisory products, these intensities are converted to miles per hour (mph) and kilometers per hour (km/h), and then rounded to the nearest 5-mph or 5-km/h increments. Challenges occur when the current Category 4 intensity is 115 kt (132.3 mph). Although 115 kt is within the Category 4 range, the equivalent rounded wind speed in mph is 130 mph, which is in the Category 3 range. To classify the hurricane as a Category 4 in both sets of units (kt and mph), NHC and CPHC must incorrectly convert 115 kt to 135 mph in the advisory products. A similar issue occurs when the current Category 4 intensity of 135 kt is converted to km/h. Effective May 15, 2012, to resolve these rounding issues, Category 4 on the SSHWS will be broadened by one mph at each end of the range, yielding a new range of 130-156 mph. This will also result in a minor modification of the Category 3 and 5 wind speed thresholds. The SSHWS will change as follows: From: Category 3: 111-130 mph (96-113 kt, 178-209 km/h) Category 4: 131-155 mph (114-135 kt, 210-249 km/h) Category 5: 156 mph or higher (136 kt or higher, 250 km/h or higher) To: Category 3: 111-129 mph (96-112 kt, 178-208 km/h) Category 4: 130-156 mph (113-136 kt, 209-251 km/h) Category 5: 157 mph or higher (137 kt or higher, 252 km/h or higher) There will be no change to the wind speeds currently assigned to Categories 1 and 2. With this change, a 115-kt Category 4 hurricane will have its intensity properly converted to mph and rounded to the nearest 5 mph (130 mph) and remain within the Category 4 mph range. Important note: Since intensities are assigned using 5-kt increments, neither storms in the historical record nor any future storms will have their SSHWS category changed as a result of this modification to the scale. The NWS wishes to remind media, partners, and the public the Saffir-Simpson Hurricane Wind Scale provides information on wind impacts only. The scale does not provide commentary or information on other impacts or characteristics of tropical cyclones. Additional information on this change can be found at: http://www.nhc.noaa.gov/aboutsshws.php If you have any questions, please contact John Kuhn National Weather Service Silver Spring, Maryland 20910 301 713 1677 ext. 121 john.f.kuhn@noaa.gov National Public Information Notices are online at: http://www.weather.gov/om/notif.htm $$ source -------------------- You can lead a horse to water but a pencil must be lead. - Stan Laurel
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#2
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![]() Rank: Tornado ![]() ![]() Group: Member Posts: 251 Joined: 19-June 10 From: Clear lake Shores, TX Member No.: 23,001 ![]() |
This was posted Thursday. source This might be slightly off topic, but are they ever going to fix the issue of the scale not accounting for size? I am referring to the inaccurate measurements when they predicted Hurricane Ike, September 2008, and the storm surge was off by upwards of 5 feet in many places, due to the sheer size of the storm. |
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#3
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Rank: F5 Superstorm ![]() ![]() ![]() Group: Member Posts: 33,603 Joined: 29-August 08 Member No.: 15,491 ![]() |
This might be slightly off topic, but are they ever going to fix the issue of the scale not accounting for size? I am referring to the inaccurate measurements when they predicted Hurricane Ike, September 2008, and the storm surge was off by upwards of 5 feet in many places, due to the sheer size of the storm. That's why its name has been changed not long ago to the "Saffir-Simpson Hurricane Wind Scale". Ike was one of the reasons that resulted in the changing of the scale to wind, not including other factors. Still, I would think that an additional scale including size/wave impact may be needed. |
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#4
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![]() Rank: Tornado ![]() ![]() Group: Member Posts: 251 Joined: 19-June 10 From: Clear lake Shores, TX Member No.: 23,001 ![]() |
That's why its name has been changed not long ago to the "Saffir-Simpson Hurricane Wind Scale". Ike was one of the reasons that resulted in the changing of the scale to wind, not including other factors. Still, I would think that an additional scale including size/wave impact may be needed. I agree, i lost some property because of the inaccurate measurements, and i think a scale is needed, at least in that area. This post has been edited by weather-major94: Mar 25 2012, 05:59 PM |
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#5
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![]() Rank: F5 Superstorm ![]() ![]() ![]() Group: Member Posts: 8,938 Joined: 24-January 08 From: Nowhere, ND Member No.: 13,040 ![]() |
There actually is a scale that accounts surge and size of a hurricane.
It's called the "IKE" scale and believe it or not, Hurricane Ike had the highest numbers on it. EDIT: Link to the IKE scale that was patented in 2007 This post has been edited by Superstorm93: Mar 25 2012, 06:40 PM -------------------- Millersville University Meteorology Major
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#6
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Rank: F5 Superstorm ![]() ![]() ![]() Group: Member Posts: 7,695 Joined: 7-January 08 From: Mount Vernon, NY Member No.: 12,006 ![]() |
There actually is a scale that accounts surge and size of a hurricane. It's called the "IKE" scale and believe it or not, Hurricane Ike had the highest numbers on it. ![]() ![]() This post has been edited by Niyologist: Mar 25 2012, 06:07 PM |
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#7
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![]() Rank: Tornado ![]() ![]() Group: Member Posts: 251 Joined: 19-June 10 From: Clear lake Shores, TX Member No.: 23,001 ![]() |
There actually is a scale that accounts surge and size of a hurricane. It's called the "IKE" scale and believe it or not, Hurricane Ike had the highest numbers on it. EDIT: Link to the IKE scale that was patented in 2007 they need to use this scale more than the saffir simpson. this scale has a bit less margin for error, and the calculation is pretty much foolproof. |
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