Illustrating Hurricane Paths
Mar. 7th, 2019 08:11 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
ysabetwordsmithTwo different ways of illustrating hurricane paths can be interpreted differently by viewers. Each has its pros and cons.
Neither way gives precise probabilities of storm landing. What you see is either a blob or a bunch of lines showing where it's likely to go. What we need is a tonal map that says something like "90% likely to strike here," "75% likely to strike here," "less than 10% likely to strike here," etc. That's for the center of the storm. It would also be helpful to indicate similar gradients for damage, because the size of those zones will differ for storms based on their size and intensity. (These things are slightly different: you may have a lower probability of a direct hit but a high probability of a sideswipe.) Then use data collected from other storms to set guidelines for what level of response is advisable for towns and individuals. High-risk areas should evacuate at least the vulnerable people. Medium-risk areas should prepare for storm activity and be ready to scramble a higher response if it looks to get worse. Low-risk areas should watch in case it veers suddenly, and do things like make sure their shelters are prepped. If you want to get fancy, ram all that data into a processor that will take your zip code, spit out your hit probability and damage prediction, and give recommendations for different types of people. Remember you need to design the data processing for maximum surge demands, not everyday use.
Neither says anything about the intensity of the storm or its damage quotient. Those are separately measured with metrics that are also in need of upgrade. A direct hit will of course do more harm than a glancing blow from the same storm, but a glancing blow from a bad storm can be much worse than a direct hit from a weak one, and there are multiple factors which can make a storm very bad. These are all things we need to put on hazard forecast maps, separately, and then combine into an estimate of total danger, graduated as described above. Some of our current problems come from people thinking the wind speed is actually a damage quotient, that the cone map means the storm is getting worse, or that being some distance from the center means they can't get hit.
Some things we should do:
* Acknowledge Category 6 because now we are seeing some hurricanes with higher winds. Category 5 "everything bigger than 4" is now a wider range than the other categories, so it needs to be subdivided for accuracy. Be prepared to expand the categories whenever needed to account for worse storms, because they are getting worse. You have seen nothing yet.
* Measure and announce the speed at which the storm is traveling. A slow storm has more time to do more damage while it squats over a target. A fast storm may be bad, but then it's over and recovery can commence.
* Measure and announce the storm surge. Some hurricanes only raise the water a modest amount, while others tow massive amounts of water inland.
* Measure the precipitation coming from the storm and estimate what it is likely to dump on land. Announce this so people can plan ahead for heavy rains. Hurricanes tend to rain plenty, but some also throw hail (rare but possible), and some can drop several feet of water on one spot. Bear in mind that this is the most widespread threat and can overwhelm areas not "technically" in the hazard zone according to current measurements.
* Mark each of these factors on the hazard map: spiral wind speed, forward speed of travel, storm surge, precipitation. Score each of them separately. Then compile an overall danger rating. A hurricane of SWS 4, FST 5, SS 2, P 3 will quite probably do less harm than one of SWS 1, FST 1, SS 4, P5. The first one blasts through and flattens a lot of buildings but is gone in a day or two. It might be D2. The second peels off a few roofs but vomits several feet of water over hundreds of miles for a week. It might be D4. Further note that you should evacuate high locations for SWS 3+ while low ones mayb e sheltered from wind, and low locations for P3+ while high ones may be raised above floods.
* For the love of all good sense, everywhere in hurricane territory should have shelters sufficient for all souls on board, sturdy enough to withstand a direct hit by all the above forces, and stocked with enough food, water, medical supplies, and other necessities for at least two weeks. If you're not willing to do that, you don't get to cry when dead bodies float down the roads. Preferably, all the states bordering hurricane territory should have similar shelter capacity so the coastal states have somewhere to evacuate out of the way of the D4-D5 storms that will wipe everything off the face of the earth. Realistically, every town and state should have this kind of shelter preparation to cope with the barrage of storms, earthquakes, wildfires, and other mayhem we face. Individuals should stock for locally probable emergencies to the best of their ability. Failing to plan is planning to fail.
Neither way gives precise probabilities of storm landing. What you see is either a blob or a bunch of lines showing where it's likely to go. What we need is a tonal map that says something like "90% likely to strike here," "75% likely to strike here," "less than 10% likely to strike here," etc. That's for the center of the storm. It would also be helpful to indicate similar gradients for damage, because the size of those zones will differ for storms based on their size and intensity. (These things are slightly different: you may have a lower probability of a direct hit but a high probability of a sideswipe.) Then use data collected from other storms to set guidelines for what level of response is advisable for towns and individuals. High-risk areas should evacuate at least the vulnerable people. Medium-risk areas should prepare for storm activity and be ready to scramble a higher response if it looks to get worse. Low-risk areas should watch in case it veers suddenly, and do things like make sure their shelters are prepped. If you want to get fancy, ram all that data into a processor that will take your zip code, spit out your hit probability and damage prediction, and give recommendations for different types of people. Remember you need to design the data processing for maximum surge demands, not everyday use.
Neither says anything about the intensity of the storm or its damage quotient. Those are separately measured with metrics that are also in need of upgrade. A direct hit will of course do more harm than a glancing blow from the same storm, but a glancing blow from a bad storm can be much worse than a direct hit from a weak one, and there are multiple factors which can make a storm very bad. These are all things we need to put on hazard forecast maps, separately, and then combine into an estimate of total danger, graduated as described above. Some of our current problems come from people thinking the wind speed is actually a damage quotient, that the cone map means the storm is getting worse, or that being some distance from the center means they can't get hit.
Some things we should do:
* Acknowledge Category 6 because now we are seeing some hurricanes with higher winds. Category 5 "everything bigger than 4" is now a wider range than the other categories, so it needs to be subdivided for accuracy. Be prepared to expand the categories whenever needed to account for worse storms, because they are getting worse. You have seen nothing yet.
* Measure and announce the speed at which the storm is traveling. A slow storm has more time to do more damage while it squats over a target. A fast storm may be bad, but then it's over and recovery can commence.
* Measure and announce the storm surge. Some hurricanes only raise the water a modest amount, while others tow massive amounts of water inland.
* Measure the precipitation coming from the storm and estimate what it is likely to dump on land. Announce this so people can plan ahead for heavy rains. Hurricanes tend to rain plenty, but some also throw hail (rare but possible), and some can drop several feet of water on one spot. Bear in mind that this is the most widespread threat and can overwhelm areas not "technically" in the hazard zone according to current measurements.
* Mark each of these factors on the hazard map: spiral wind speed, forward speed of travel, storm surge, precipitation. Score each of them separately. Then compile an overall danger rating. A hurricane of SWS 4, FST 5, SS 2, P 3 will quite probably do less harm than one of SWS 1, FST 1, SS 4, P5. The first one blasts through and flattens a lot of buildings but is gone in a day or two. It might be D2. The second peels off a few roofs but vomits several feet of water over hundreds of miles for a week. It might be D4. Further note that you should evacuate high locations for SWS 3+ while low ones mayb e sheltered from wind, and low locations for P3+ while high ones may be raised above floods.
* For the love of all good sense, everywhere in hurricane territory should have shelters sufficient for all souls on board, sturdy enough to withstand a direct hit by all the above forces, and stocked with enough food, water, medical supplies, and other necessities for at least two weeks. If you're not willing to do that, you don't get to cry when dead bodies float down the roads. Preferably, all the states bordering hurricane territory should have similar shelter capacity so the coastal states have somewhere to evacuate out of the way of the D4-D5 storms that will wipe everything off the face of the earth. Realistically, every town and state should have this kind of shelter preparation to cope with the barrage of storms, earthquakes, wildfires, and other mayhem we face. Individuals should stock for locally probable emergencies to the best of their ability. Failing to plan is planning to fail.
(no subject)
Date: 2019-03-08 05:24 am (UTC)Thoughts
Date: 2019-03-08 05:43 am (UTC)Rotate batteries too.