#Earthquake in #NC this morning

There was a M5.1 Earthquake near the North Carolina/Virginia border, near Sparta NC, just after 8am this morning. Models and early reports indicate damage was probably light. Here’s a quick look map of the impact area:

Earthquakes on the East Coast are usually felt over a much wider area than those out west. The reason is that the bedrock out here is not nearly as fractured. Out west in California an earthquake like this might not be felt 50 miles away but here it can be felt 100’s of miles away because there aren’t as many intervening faults and fractures to reduce the energy of the seismic waves. This makes an equivalent major earthquake east of the Rockies more dangerous than one on the west coast, and while rare, they can be devastating. (To be clear, this one wasn’t!)

Damaging the truth with the facts

During the Vietnam War, there was a saying that was supposedly serious, but later came to represent the futility of that conflict and how it was conducted: we had to destroy the village to save it. That was the first thing that came to mind when I saw this graphic, created by the Kansas Department of Health and Environment:

Bad Science, don’t do this! Source: State of Kansas DPHE

This chart was presented to the Kansas state legislature last Wednesday by Secretary Lee Norman to make the case that counties that mandated masks are doing dramatically better than counties without masks. His argument was that after Gov. Kelly allowed counties to mandate masks, 15 counties (mostly urban) did so, and 90 counties did not, there was a dramatic change in the cases. Dr. Norman goes on to say that those 90 counties that did not mask are “losing the fight” and “The experimental group (the 15 masked counties) is winning the battle.” There’s just one problem: This graph doesn’t really show that, and it is deceptive in a way that has the potential to further inflame the mistrust of people who are opposed to mask mandates and don’t believe either government or science.

Take a careful look at the graph, which is spreading in the news, politics, and social media worlds. It is presenting the number of cases per 100,000 people for two groups, counties with masks, and those without. The key problem is that this violates a key principle of presenting scientific data. The “Y” axis is not the same for the two groups. The “mask” counties started at over 25 per 100k (possibly a glitch given the sharp drop the following day to just over 19/100k), stabilized between 19 and 21, then dropped to around 16 per 100k. The unmasked counties at first glance seem to be hovering around 20/21 per 100k – but that is deceptive – to read the values for the “no mask” counties you have to look at the right hand legend, which shows they were in fact between 9 and 10 per 100k. In other words, the masked counties are still over 50% higher than the unmasked counties!

There is a lot more be critical of here. I won’t rant about the fact the vertical axis doesn’t start at zero, which is another technique people use to dramatize an otherwise subtle change. Plotted properly the drop isn’t very dramatic relative to the difference between “masked” and “unmasked” (which itself is really more about the difference between rural and urban rates). And we don’t really know enough about what is going on in the “masked” areas. What were the trends prior to this graph? It’s way too short of a snapshot. Given the fact it is a rolling average, the drop could well be related to something that happened before the start of the graph on 12 July.

To be clear, that doesn’t mean masks don’t work, on the contrary, given the timing of the mask mandate, the nature of spread in urban vs rural areas, and a lot of other complex factors, it does seem that the initiation of the mask mandates in early July knocked down the case rates as expected 10-12 days after they came in to effect. But this data set and graph aren’t anywhere near being convincing evidence for that. Sadly, this is a tactic that I’ve seen a lot during the pandemic. It happens in climate science, emergency management, and other fields as well. Noisy or complex data is “spun” and oversimplified by officials and activists to support this or that policy with little regard for the damage they are doing not only to their own credibility, but to the scientific process, when that spin is examined and brought to light by critics as it almost always is.

Addition/update: Just to be clear, I don’t think Dr. Norman and the staff at Kansas DPHE were deliberately being deceptive. My guess is that they were thinking “how to we make this clearer to the average person, much less Kansas politician” and so rather than work on the explanation part, took the easier route and tried to simplify the graph to tell the story, rather than tell the story around a proper graph.

Bottom line: the science is complex but pretty clear, masks work. To those presenting this kind of information to influence the public: Don’t exaggerate the data and provide the anti-mask and anti-science crowd with ammunition by playing games with deceptive graphics and simplistic comments to try to stampede people in to doing the right thing. It won’t work, and in the long run, just kills your credibility. Do the hard work of explaining things to people. Most of them will get it and do the right thing. But only if they trust you, and misguided presentations like this potentially destroys that essential trust.

The Beirut Explosion and Transportation Safety

Every day ports around the world move thousands of tons of hazardous materials, and tons of it move through our streets on rail cars and trucks without notice. The safety and success rate is amazingly good. But sometimes things go terribly wrong, especially when shortcuts are taken or, as seems to be the case in Beirut yesterday, a hazardous situation is allowed to continue and ignored for far too long. The chances of something like that happening in in a place like the Port of Savannah are maybe not impossible, but really really small. To appreciate the scale of what happened there, it’s probably worth examining what it would look like if something similar happened at our Ocean Terminal where, longer term residents of Savannah will recall, there was a large fire involving 5600 tons of rubber in 2014.

The Beirut blast was apparently the result of the detonation of 2750 tons of Nitropril(tm) (Ammonium Nitrate, which is specially formulated as an explosive for use in mining operations). Here’s what the approximate range of significant structural damage would be for a similar event at the Ocean Terminal:

Compared to Beirut, the population density is much smaller, but on the other hand there are no large high-rise or sturdy structures nearby to absorb the blast, so the radius is actually somewhat larger. More than likely the Trade Center would be damaged, as would the bridge. The blast zone includes several neighborhoods in Port Wentworth, as well as Yamacraw Village, parts of SCAD, and downtown Savannah. Here’s a zoom of the Savannah part of the zone:

Windows would likely be broken out and spot damage for a mile outside this radius (which itself is about 0.8 miles in diameter). Again, given the population differences, rather than hundreds killed, thousands injured, and tens of thousands displaced, it would likely be dozens killed and hundreds injured, but imagine if instead of on the fringes of town, it happened in, say, at City Hall and took out the heart of the city. That is what happened in Beirut. The Lebanese Government is estimating $3 Billion in damage – sad to say, that may not be far off.

Again, to be absolutely clear, the chances of something like that happening here are pretty small. Materials are kept on the move, not left to fester for years in an uncontrolled environment while the politics and finances are sorted out, and the safety standards are far higher. Certainly not worth losing any sleep over (heck, we have the Pandemic, Hurricanes, and the Elections for that!). But if I were a local emergency manager, I’d double check my plans and make sure I know what is transiting our area and when. And for the average person, having emergency plans and thinking through what you would do in the event of a major industrial accident at the ports or the LNG terminal are worth thinking about, especially having a contact plan for family members who work in and near these facilities.

#Isaias Wrapup; #Lebanon

Isiaias is blowing itself out over Canada this morning with bluster winds, probably some scattered power outages, and rain. Damage across the US was scattered and almost random, it seems that some of the worst damage was cause by a few tornadoes that were spawned after landfall. NHC has issued their final advisories, and here is the swath-of-doom based on the final real time advisory and prior tracking:

Total economic impact is probably around $2.5 Billion USD, and unlike many storms, that is likely on the order of 80% physical damage and clean-up (usually direct damage is only 50% or so of total impacts). As noted yesterday, that’s one to one and a half Billion lower than it would be in a normal year due the depressed level of economic activity caused by the COVID19 pandemic.

Elsewhere, the invest area in the Atlantic (AL94) is fading without spinning up, Hagupit (WP03) has made landfall near Shanghai, causing some damage and flooding.

We’re also carefully watching the situation in Lebanon; I spent some time there in the 1980’s, during the civil war, Israeli invasion, PLO evacuation, as well as both the US Embassy and Marine Barracks bombings. Watching the shock wave expanding across the city brought back some bad memories of being tossed through the air by one of those events. It is indicative on the ongoing tragedy in that once beautiful city and country to be praying that this is the result of an accident, rather than the start of another round of violence. And that if it is an accident, that it is not exploited by the various players who use Lebanon as their chessboard – and the people who are just trying to live their lives in peace, as pawns.

#Isaias Landfall; did COVID reduce the impact?

Isaias made landfall last night near the SC/NC Border, dropping considerable rain on the South Carolina coast, North Carolina, and in to Virginia overnight. NHC upgraded it to a hurricane just before the 11pm landfall, but by far most of the impact zone only experienced tropical storm conditions, with rain, along with shallow coastal flooding, the biggest risk. The Multi Sensor Multi Radar (MRMS) composite shows some pretty high rainfall totals … fortunately it looks like the heaviest swath of rain missed the flood prone downtown Charleston SC area, :

This morning radar indicates the heaviest rain has moved northward. There were some tornadoes in NC overnight, and several active tornado warnings in Virginia and Maryland as of 7am this morning …

Over the rest of today, sustained tropical storm force winds might be felt right along the coasts of Maryland, New Jersey, and New York. But the biggest risks are gusty winds and heavy rain across the entire region, causing power outages and downed trees. Here’s the damage swath:

For Canada, busy winds and rain, but most likely below the level to be considered hazardous.

The overall estimated economic impact of the storm will likely be right around $2 Billion USD. This includes a “COVID” discount – many of the impacts in Florida such as a hit on tourism were “mitigated” by the fact that sector is already rather depressed. The same applies to the GA/SC/NC coasts. Our early estimate is that the short term impacts would have been on the order of 50% higher in Florida, at least 30% higher elsewhere, and it is likely a few jurisdictions would have ordered at least partial evacuations had it not been for COVID fears. So in total, it is estimated that COVID turned a $3.5 Billion storm in to a $2 Billion event. That’s actually a bad thing, and pretty scary, as it indicates just how depressed the US economy is right now …

#Isaias, #Hagupit updates

Isaias has been following the track NHC has been forecasting for a couple of days, with some minor wobbles. They continue to warn it could become a hurricane before landfall, but that’s really a bit of a technicality. Key Messages regarding Tropical Storm Isaias (en Español: Mensajes Claves)

A lot of scientific classification is ultimately arbitrary. 70mph, it’s a tropical storm. 75mph, it’s a hurricane. Isaias may be getting a bit better organized with stronger convection to the north side, but it still doesn’t have a structure like a typical strong tropical storm on the verge of hurricane status should have at this point. The areas of high winds are small, and transitory. But, if you’re in the wrong place at the wrong time on the immediate coast in northern South Carolina or North Carolina later tonight or in the morning, you could experience hurricane force winds. But it’s not likely to be widespread. This means the storm surge won’t be quite as high as a fully mature hurricane, even one of the same intensity. The main risks from Isaias are still urban and riverine flooding in vulnerable places, power outages, scattered trees down, and isolated tornado, and some wind damage right on the coast. Hazardous, but not dangerous outside of areas that frequently flood, or vulnerable structures like unsecured mobile homes. Here’s the embiggenable swath of doom based on the 5pm forecast:

For the Northeastern US Isaias will bring gusty winds and rain, but hopefully not too much damage; the big risk is localized flooding. For Canada it’s increasingly looking like Isaias won’t be much of a hazard.

On the other side of the world, Typhoon Hagupit is making landfall just south of Shanghai, China. It is likely to cause several billion dollars of damage, and as with any landfall on mainland China, huge numbers of people are in the way. Evacuations are underway, There has been a lot of rain in China this year – so much there are concerns about the stability of the massive Three Gorges Dam. While unrelated to Hagupit, there are ongoing rains to the west, which will end up in the Yangtze river and, ultimately going over (or through) the dam. It’s one of those stories we’re watching that, hopefully, won’t be a major disaster before the year is out …

Elsewhere, there is a blob of clouds in the Atlantic that is being tracked as an Invest area, 93L. NHC gives it a 60% chance of becoming something, but it’s not anything like a threat in the near future (and not likely even beyond that).

#Isaias 11 am Monday update

Here’s the current (just before 11am) satellite picture and surface reports, along with the HRRR surface pressure contours for context … embiggen for details as usual:

None of the land stations are reporting tropical storm force winds – in fact, most winds are pretty light – although a couple of near shore buoys are over 20 knots (34 is tropical storm). That will change for SC/NC north of Charleston, but for Georgia I seriously doubt sustained winds will reach the threshold. Tracking this morning showed the storm was a little left (west) of the forecast track, so NHC “tweaked” the track. What does a tweak look like? Here’s the difference between the 5am and 11am tracks …

That changed the economic impact by a trivial amount, and didn’t change anything of substance in the earlier discussion. Interestingly, the current NHC Forecast Discussion is talking about fresh convection and a shift to the East, away from the direction they just went! BUT … they are talking about the center, not the track, and focusing on these little wobbles and reformations is ultimately self-defeating since unlike a storm with a distinct eyewall, for a storm like this the exact center fix can change 20 miles one way or the other and not make much difference in impacts.

How are the media handling the shift in track and the conflicting NHC Discussion? I don’t know – I’m listening to an iPod mix of Граи (a Russian Folk Metal band) and Warunda while working on closing out a project that is wrapping up …

#Isaias Monday Morning (3 Aug)

Tropical Storm Isaias is now moving northward parallel to the North Florida/Georgia shoreline, with the center just off of the Palm Coast area … here is the 6am IR Satellite view with HRRR model pressure overlay:

As you can see from where the center is, vs where the highest/coldest clouds are (and therefore rain and convection is), compared to yesterday the heaviest rain is now shifted more to the north. The highest winds remain off to the northeast. Speaking of winds, the latest estimates for the highest winds in the storm are just below hurricane strength. Given a reduction in the shear (which is the difference in wind between the lower and middle/upper levels in the atmosphere) and a pool of warm water (the Gulf Stream), NHC is now forecasting Isaias to regain hurricane strength later today: Key Messages regarding Tropical Storm Isaias (en Español: Mensajes Claves). Here is the TAOS/TC impact map based on their forecast:

Hurricane warnings are now up fore parts of SC and the NC/VA border. So is it time to panic? Not really. The area of actual hurricane force winds is pretty small and inconsistent; this wind field for this storm is pretty lopsided, more so than the forecast map indicates. While anyone on the coast north of Cape Island (Bulls Bay) SC should plan for a minimal hurricane conditions later today, and Myrtle Beach to Diamond Shoals (on the Outer Banks) later in to the overnight hours, it’s unlikely you will experience actual hurricane force winds. That said, we’re looking at power outages, trees down, coastal flooding from 2-4 feet of storm surge (above high tide). Given the shifting rain shield the Charleston area and points north have a good chance of heavy downpours, so that means flooding in places that normally flood in heavy rain. Here is the HPC five day cumulative rain forecast – some areas are showing 6 inches or more. You’ll almost certainly have to embiggen to see the details …

I strongly suspect that for the Georgia/low country coast, at worst it will get blustery with some rain, but likely under 2″ unless some training sets up over a limited area. But, take a look around and make sure yard stuff is secure (I took down our porch swing since it can bang against the house in high wind gusts), limit travel this afternoon as there could be street flooding, some branches down, and stupid people running stop lights. Oh, wait, that’s a normal Monday …

#Isaias Sunday Evening Update (2 Aug 2020)

It’s official: Bored Now … ok, not quite, but things seem literally on track. Here is the 5pm satellite view, with the HRRR pressure overlay so you can see the center of the clouds isn’t the center of the storm … yes, of course, you may embiggen:

For the official word … NHC’s Key Messages regarding Tropical Storm Isaias (en Español: Mensajes Claves). For the Enki interpretation, the discussion from this morning is still valid. The only real difference is the chances of the dreaded “Precursor Rainfall Event” seem to be a good bit less for the Savannah/Beaufort area, and less than 2″ of rain is forecast to fall on our increasingly crunchy grass. It will get gusty and windy as the storm gets closer, a few rain bands, but not even tropical storm conditions. Further north towards Charleson, there is a much better chance of some heavy rain, so there is a flash flood watch in effect. And on up towards Myrtle Beach/Wilmington/Outer Banks area, it looks like a landfall for a low to middling tropical storm is in your future. The worst effects will be to the right (east) of the track. Gusty winds and rain, scattered power outages, some flooding in the places it always floods in heavy rains, waves and a couple feet above normal high tides. Nothing catastrophic or dangerous if you’re sensible and prepared. There is always the risk of a tree fall or tornado, so being aware of your surroundings and taking cover as needed is a smart move.

I’ll again flog my post this afternoon on what a real storm can do, and try to dispel the myth that Savannah is “protected.” The continental shelf and Gulf Stream are actually big dangers – it is Florida, acting as a downfield blocker and disrupting influence on re-curving storms as it did with Isaias, that provides the GA and SC Low Country coasts some measure of protection from weaker storms. So all you Dawg fans, sorry, you have to thank a Gator for doing what they do best: being in the way …

The August 1881 Storm and Savannah

Not a lot has changed with the 11am advisory package. Although Isaias has a much better satellite and radar presentation, the comments from 5am still capture the situation, and the biggest threat is likely to be heavy rainfall ahead of the storm, with some potential one to three foot surge in the Myrtle Beach/Wilmington NC area. Will do a more complete discussion of all that this afternoon. But while I’ve got your attention, I’d like to take a quick look at history and channel Cassandra for a moment. Every time there is a bypassing storm like Isaias, or even a more dangerous situation like Floyd (now 20 years ago), I hear lots of people saying that the Savannah and Low Country are “protected” by the Gulf Stream or Georgia bight (the concave shape of the Southeastern US Coast from Cape Canaveral to Hatteras). Let’s be blunt here: that is a myth. In fact, while it somewhat makes the Georgia coast less “risky” (in frequency for weaker storms), it actually makes it more dangerous (in consequences for a strong storm). The issue is that while Florida causes recurving storms to be weaker than they would be without it, the funnel shape makes the Savannah/Beaufort area the second worst place in the world for hurricane storm surges – second only to the northern Indian Ocean/Bangladesh area. Let’s take a look at a real example …

In the late 1880’s a number of very strong hurricanes hit the area. The August 1881 storm was one in this series. Here is the track and wind map using the same system I use to track and model modern storms …

The weather bureau anenometer was destroyed at 80mph, but we think the winds were around 105 sustained (that would mean gusts to 120 or so). The storm arrived at high tide and the storm surge flooding was epic, 20 to 25 feet in places. Here’s the estimated storm surge using the same model …

Over 700 people were known to be killed. At the time the islands were largely inhabited by former slaves, and bodies washed up for days and given the times were naturally not properly accounted for. If this same storm hit today, with proper evacuation the toll in lives would be low, but the economic impacts would be enormous – over $3 Billion in damage in Chatham County alone! The ports would be closed for months at best, as the shipping channel would be filled with silt (not to mention debris from Tybee and Hilton Head :O ). It would be years before anything resembling normal life could resume here.

So while Isaias isn’t that serious, don’t ever think that nature can’t wipe the Savannah/Low Country off the map in just a few hours. It has happened before. It will happen again … just not today.

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