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Concept for New Hurricane Rating System

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CoreySamson:
So I mentioned this in the "Minor Things that Bother You" thread, and I thought it would be interesting enough to share. The current Saffir-Simpson Wind Scale, while very good at indicating a hurricane's strength, is not very good at informing the public of all the hazards a hurricane can bring. Most deaths in hurricanes are due to water (either flooding or storm surge), not wind, which is what the SS scale measures. This scale is designed to incorporate more of the other hazards a hurricane can bring into account in order to give the public more balanced information of the total picture, but it is meant to be used in conjunction with the SS scale, not as a replacement. I acknowledge that the scale is very unbalanced at the moment, so bear with me. Suggestions are highly encouraged!


Scoring System:
Generally, hurricanes will be rated on a scale of 1-100, but storms may exceed 100 if they are bad enough. There is no true “cap” to the scale, but there are obvious limits to how high the scale goes. Each category contributes to the overall point total of the hurricane overall. Each category is added together to get a complete max rating for the storm. In addition, I envision graphics that give certain areas risk factors using this system (I envision them looking much like how the SPC's severe weather outlooks appear).

Scale
0-20: [TC1] Mild (mild impacts, minor damage)
20-40: [TC2] Moderate (localized impacts, medium damage)
40-60: [TC3] Damaging (more widespread impacts, somewhat mid-high range damage)
60-80: [TC4] Destructive (widespread destructive impacts, high damage, possible retiring)
80-100: [TC5] Devastating (widespread devastating impacts, devastating damage, likely retiring)
100+: [TC6] Catastrophic (ultra-widespread catastrophic impacts, cataclysmic damage, certain retiring)

Max Rainfall:
If below 3”: Multiply total times 0.5
If between 3” and 10”: Multiply total times 1
If over 10”: Multiply total times 1.5

Wind Speed:
(Max 1-minute Sustained Winds in mph times 0.1) + (1020 - Minimum Storm Pressure in mb times 0.1)

Storm Surge:
Multiply projected storm surge heights in feet by 1, if above 5 ft, multiply by 1.5

Storm Size:
Storm TS Wind Field Diameter in miles multiplied by 0.02

Additional Factors:
These are not the only factors that can contribute to how bad a hurricane is or was. Tornadoes, the explosivity of a storm, and human factors (evacuation problems, levee breaches, etc.) can also contribute. I envision each of these categories adding 0-5 points to the overall total.

I ran some of the numbers with information I could find (estimating in certain cases), so this is how the landfalling storms of 2021 in the Atlantic hurricane season scored on the scale as an example:

TS Claudette: 40.2 (TC3)
TS Danny: 15.6 (TC1)
Hurricane Elsa: 38.3 (TC2)
TS Fred: 36.3 (TC2)
Hurricane Grace 51.8 (TC3)
Hurricane Henri 29.8 (TC2)
Hurricane Ida 79.6 (TC4)
TS Mindy 20 (TC2)
Hurricane Nicholas 48.2 (TC3)


Please comment with feedback!

SectorZ:
I would like that as an add-on to the current system, as more of a point forecast for a specific area while leaving Saffir-Simpson for a broader overview of a tropical system.

Storm surge is a big problem because it is so ultra-specific to a location, mostly due to the chaotic nature of shorelines where they aren't some straight-line beach in most places. The National Hurricane Center has a model for storm surge for storms making landfall, and I can tell you loading it will damn near run all the ram on your computer to load the animation of it because it is quite data-heavy.

One of the interesting things with your scale is the interplay between rainfall and the other factors. Rainfall takes a back seat to the enormous storms but becomes the headline with weaker storms, especially ones that have drifted inland and find their way into the mountains.

This is a really good thought experiment and concept. Warning systems can always be improved, especially when computer technology is enabling more accurate forecasts, and therefore more refined warning systems that match the increased accuracy.

1:
Does the scale work in a useful way with things that aren't hurricanes or tropical storms? For example, could a severe thunderstorm in New England get a rating of 8?

CoreySamson:

--- Quote from: 1 on September 09, 2022, 07:36:02 PM ---Does the scale work in a useful way with things that aren't hurricanes or tropical storms? For example, could a severe thunderstorm in New England get a rating of 8?

--- End quote ---
No, it doesn't. This is only meant for tropical systems.

US 89:

--- Quote from: SectorZ on September 09, 2022, 07:32:40 PM ---Storm surge is a big problem because it is so ultra-specific to a location, mostly due to the chaotic nature of shorelines where they aren't some straight-line beach in most places. The National Hurricane Center has a model for storm surge for storms making landfall, and I can tell you loading it will damn near run all the ram on your computer to load the animation of it because it is quite data-heavy.

--- End quote ---

The other thing about storm surge is the damage it causes is hugely dependent on local geography, so your scale isn't really comparable in different areas. 10 feet of storm surge will do a whole lot more damage in flat coastal Florida than it will in hilly Bermuda, for example.

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