Trends or Noise? A brief review of how to look at data …

ZOMG! TODAY IS ANOTHER RECORD DAILY INCREASE IN COVID CASES AND THE SECOND RECORD IN A ROW!  Or, it’s a leveling off of the increase.  Or … well, what is it?  It sort of depends on how you look at the data.  I’ve spilled lots of electrons on how the “case” data is really problematic, but that’s what people are using for decision making, and it’s closer to what the virus is doing in “real time” (only about two weeks behind reality, vs. the mortality rate, which lags about a month).  So let’s dig in … sorry, no equations.  

First, the raw numbers and “death counters” you are seeing everywhere can be very misleading.  The spread of a virus through a population depends on a lot of factors, but one of the biggest is population density.   You HAVE to normalize these numbers for population for this to make sense.  100 people in New York City is a blip.  100 people in rural Georgia is a catastrophe. Likewise, two months ago when there were over 20,000 new cases a day, they were mostly in New York and New Jersey; today, they are scattered across a dozen states.  So here is what we are seeing in representative states for the rate of new positive tests (people are calling these a “case” but that’s a misnomer).  This graph shows new positives per 10,000 of population.  Yes, there are some negative numbers and zeros due to reporting issues … (SC and LA are really crummy data sets).  Click to embiggen.

So in relative terms, most states are seeing a spread of the virus on the order of 1/3 the rate of what was seen in NY/NJ at its peak.  Note that’s not a good thing … but, again, 30k people infected in NY/NJ (and most of that in the Metro NYC area, population of about 20 million) vs 30k people across the entire US (population 321 million) is a very different thing. But … we are seeing some states (TX, GA, SC) doing much worse, not only moving in the wrong direction, but into the realm where you have to start worrying about the health care system getting stressed.

Let’s look now at the country as a whole:

Notice how flat this curve looks compared to the state level.  That said, there is a disturbing trend over the last 10 days, however, it’s not really the dramatic upward spike that seems to be the perception in some circles. And as I have often said, single day trends, even week trends, can be misleading.  Is today a plateau, followed by a downward trend, or will the rate increase?  My guess is it will wobble a bit higher then trend back down, and the “stable” point nationally over the summer will be around 1 per 10,000 per day in a “somewhat open, but with most people being sensible” paradigm. That’s not as good as the previous somewhat “stable” point of around ~0.75 per 10k for the last two months, but not horrific.  The trick in looking at this data – and creating policy to address the pandemic – is figuring out the trends, with the knowledge that with new positives you are two weeks behind the curve.  The data point for tomorrow depends on what people did 7-14 days ago.

In short: absolute numbers may be dramatic, but it’s the trends in rate per capita that matters.  Speaking of which, absolute hospitalization and death numbers, while vital to gauge the stress on the health care system (which is getting worse in many states, especially where the positive rate is moving above 1.5 per 10,000), aren’t telling you how deadly or dangerous the virus is.  As noted yesterday, the rate of people who are positive that end up in the hospital, and the rate of people who are dying from the virus, is actually decreasing slightly.  This is likely because more people in the 20-50 year old range are the bulk of the new positives.  So while the news coverage has shifted this week, what we are seeing isn’t a dramatic change in the virus.

The trend over the last 10 days is of course being blamed on reopening, and that is a big factor, but more importantly these trends are a direct result of people relaxing basic precautions – especially not wearing masks in public places and gathering inappropriately.  The reopening didn’t have to cause this increase.  In my view it is an urgent call to take more precautions on an individual level. (Update: and, an hour or so after I posted this, guess who said the same thing, but obviously a bit better …)  I don’t think it’s a call to close things down again; our economy is very fragile (likely in an ongoing collapse with the worst yet to come) and just can’t handle that.

Finally, I’m not trying to minimize how bad this is, or get into the partisan poo flinging over it.  As for those saying that the positives are related to testing; the argument that more testing is the reason we are seeing more positives  is “not even wrong.”  But that said, we need to have some context about this pandemic, and chart a careful path between over-reaction and under-reaction.  Sadly, all we seem to be doing is a random weave between the extremes … and that has severely damaged our economy, and maybe even our society as people are increasingly frustrated and angry as pre-existing fault lines are exposed and aggravated.

The Second Phase of the First Wave (COVID Update 25 June)

The last day or so have seen disturbing headlines about the “surge” in COVID-19 cases, “record new US cases,” and the NYT this morning has the calm and rational headline “How the Virus Won.”  So how bad is this?  Like so many aspects of this pandemic, the answer is “it depends on how you look at it.”  But it’s not good, that’s for sure.  Let’s look at the data which, as I have ranted, are embarrassingly  bad for a so called developed country, and see what we can see.

First, let’s look at the trends in people testing positive for the active virus.  With the caveat the data is still a mess (antibody and active virus tests are still not clearly split in some jurisdictions, and testing positive isn’t necessarily a “case” in the classical definition due the high asymptomatic rate with this thing, etc), it’s not headed in a good direction in many states:

I’m deliberately not smoothing this because I think smoothing makes you think the data is better than it is, and masks how this virus seems to work (super-spreaders, big jumps up and down in the spread rate).  But you can clearly see two groups of states: the initial outbreak, rapid spread states of NY, NJ, Louisiana (mainly New Orleans), and the “slow burn” states (everybody else).   In the “slow burn” states like Georgia and South Carolina we are seeing a really bad trend over the last 10 days. We aren’t seeing New York/NJ/LA kinds of spread – largely due to the much lower population densities, and the fact that 30-40 percent of the population are still taking mitigation measures.  But let’s pull out the overall national trend …

It’s disturbing, but not panic-worthy yet.  As can be seen, other than the initial run-up in NY/NJ, there have been previous quick jumps similar to this. I *think* it’s real, and *potentially* the start of another run-up, *definitely* a wake up call, but the data is so bad I’m not willing to jump on that bandwagon that this is the start of another NY style out-of-control phase 2 of the outbreak just yet.  If it persists through the weekend then we can start to freak out.  Here’s the overall confirmed positive (viral only, with some contamination):

In the “good” news category, the hospitalization rate (how many end up in the hospital) and mortality rate (how many who catch the virus die) are pretty stable, and the trend is not bad.  Note that in absolute numbers, yes, the numbers are headed higher – Georgia reported 1124 COVID-19 patients in-hospital yesterday – the highest since May 16 (and it is likely higher given the delayed/bad reporting).  But the probability of the virus being fatal, if you test positive and end up in the hospital, is actually down slightly.  This is likely because many of the most vulnerable have already fallen, or are being protected somewhat.  So the virus isn’t getting worse, it’s just spreading.

Cautionary note: I’m seeing folks looking at ZIP code level and city level data, such as in the Savannah GA area.  Don’t waste your time.  At that level it is so noisy and contaminated it is worthless.  County level you can sort of maybe draw some conclusions from, but with a lot of caveats.

Internationally, the story is mixed.  Much of Europe has leveled off. The big outbreaks, Spain, Italy, UK, are leveling off (albeit beware data issues in Spain).  Sweden continues a jumpy climb but the rest of the Nordic countries have leveled off and have things under control. Russia’s trajectory is still in the “slow burn” category nationally; Moscow Oblast, which is driving their numbers, seems to be leveling off, so in that sense is similar to the US with a couple of big cities driving the overall numbers. Data issues really cloud the picture in most of the rest of the world.  On the surface, the US is in the lower tier of countries when normalized by population, but as seen above, the virus is in the details.

So what do you do?  The advice hasn’t changed much.  Mask up in public, social distancing, good hygiene.  Avoid distant travel if at all possible, avoid groups, stay in your social “bubble.”

Administrative note: I’ve set up a dedicated Twitter feed for Enki Research if you prefer to get your doom that way: @EnkiResearch

Enter Sandman

This year is really shaping up to be like the lyrics from an apocalyptic death metal band. Let’s look at the day so far in pictures (which you can click to embiggen of course): the morning starts with a review of the tropics, and three low grade systems that are a harbinger of doom to come, and a scattering of earthquakes in Iceland …

Next up is a look at the new COVID19 stats, which are almost worthless hash from a scientific standpoint but are trending in a doubleplusungood direction.

That was interrupted by a really lovely discussion about <REDACTED>, which you will likely be seeing hitting the news at some point, if you’re lucky.  Here’s a pic of that:

Which was followed by a major earthquake in Mexico:

Did I mention the Giant Deathtongue of Doom has reached the Caribbean?  With another blob off the coast of Africa behind that one?

But despite all these disasters, real (COVID, Mexico, <redacted>) and imagined (dust- although it is causing respiratory problems across the region, I wouldn’t call it a disaster), we always have cats to correct our mistakes …

Major M7.4 earthquake in Mexico

A shallow magnitude 7.4 earthquake has hit southern Mexico about 11:30 Eastern Time.  Here is the potential disaster area …

Damage reports are coming in, it is likely there are about 1 million people in the area of highest risk, and perhaps 90 thousand people in structures with a significant risk of collapse.  Economic impact is likely to reach into the Billions of US Dollars, with an early best estimate of approximately $3 Billion USD.

Giant Sandstorm to hit US Southeast next week

Good thing you guys are all wearing your masks!  Yes, like a giant Death Tongue of Doom, a massive plume of dust is making its way across the Atlantic and will sweep across the US early next week.  Here is the view from GOES 16 at just before 7am Friday morning (19 June), infrared on the left, visual on the right …

Notice anything interesting?  On the IR image you can see the dust as a faint white dusting.  Recall that colder, likely convective tropical clouds are colored with yellow/red/orange being thunderstorms that, under the right conditions, can form the basis for tropical storms.  The dust itself isn’t so much a factor, it is the dry air it is carried in that suppresses formation of these storms, which means tropical systems are inhibited from forming.  This isn’t terribly unusual.  A NASA study estimated that winds over the Sahara pick up and carry around 182 million tons of sand across the ocean and dump it on the Western Hemisphere.  With the newer satellites we get better pictures, so that probably equates to more media coverage.

Here is the visual view of the sandstorm in all its glory.  On the ground  you probably won’t notice much other than the fact that sunrise/sets next week should be especially colorful. You’ll have to provide your own Tuba solo.

The Data Went Down to Georgia …

For anyone seriously trying to figure out what is going on with the COVID-19 pandemic, it’s still hard to get a handle on what is going on.  It’s clearly not at the “people dropping dead in the streets” stage, and given what we know about the disease isn’t likely to get that bad.  But it also continues to do a slow burn through the population, and in many states like Georgia the trends are hard to figure out.

The testing data is still a mess.  Maybe someone has better data sets (although there was a scandal over one of the commercial data sets, so I have my doubts), but from what I have seen various types of tests are being convolved, and the wide range of accuracy/sensitivity between tests on the market means even when tests are grouped appropriately (viral vs antibody), there is a lot of noise.  Reported deaths are still subject to state-by-state (and even county-by-county) criteria differences.  I can’t rant enough that our public health reporting system in the US is just broken.  Individual practitioners are, of course, trying to do their best for individual patients; but the data when aggregated it seems inconsistent so we don’t really know what is going on with the required degree of certainty.

It does seem that the virus continues to spread in Georgia.  The hospitalization trends appear slightly upward this week after a solid downward trend over the previous two or three weeks …

If you break it down by day of week (there is a clear bias in reporting and operations on the weekends), the trend is consistent in that every day the last week the totals were higher than one week prior.  Reported positive viral tests, normalized for testing penetration, are also at ratios similar to early May.  But that’s not really all that much of a “trend”.  Hospitalization rates for those testing positive, along with serious complication rates and mortality rates, appears to be consistent.  I could deluge you with plots and analysis (including a really cool set of linear algebra equations looking at the hospitalization data), but the short version is within the noise levels, it looks like it’s not better, but it’s not getting rapidly worse, either.

So what does it all mean?  Well, it looks like the reopening hasn’t cause a distinct spike in cases or complications.  How much of that is due to the virus not being as deadly for the general population as feared, and now much of that is due to the fact lots of people are paranoid and still taking precautions, is unknown.  In any event, the guidance really hasn’t changed that much, so continue to use good hand hygiene (even though it increasingly looks like surface spread isn’t a major transmission mode with this thing), use masks, and just stay home if you don’t feel good.  If you are in the vulnerable population (over 65, health issues), be paranoid and isolate to the degree you can.  Wish it was better news.  But at least it’s not worse news.  If you want that, we can talk about the economy. Or social unrest.  Or … politics (shudder)?

Doomwatch, Monday 8 June 2020

The now somewhat ill-defined center of Tropical Depression Cristobal is now inland along the LA/MS border.  As expected it caused (and is still causing) some coastal and riverine flooding in places that usually flood, there was a possible tornado in Florida, and scattered wind damage. Here’s the radar view as of just before 7am Monday Morning …

Interestingly, as it merges with another system tomorrow and Wednesday, the remains of Cristobal will enhance that system and likely cause high winds over the great lakes and upper Midwest (especially Michigan and Ontario).

Elsewhere, pretty quiet – no other tropical systems, no recent earthquakes, only pestilence, economic collapse, and social unrest stalking the land.  So that’s nice …

Cristobal makes landfall (Sun 7 June 2020)

Tropical “Storm” Cristobal should make landfall in a later today.  I put “storm” in quotes because it really is more like a broad sub-tropical cyclone or nor’easter than a traditional tropical storm.  The main impacts right now are over Florida, although an area of convection near the center is about to make landfall near New Orleans.  Here’s the 7:30am Infrared satellite image (click to embiggen) …

IR images show temperature.  In this case, the bright orange/reds are coldest cloud tops, below -60 Celsius.  That matters because for thunderstorms, the colder the cloud tops the more intense the storms.  For a real tropical storm, you can even estimate the wind speeds pretty well just from cloud top temperatures.

Here is the estimated impact swath, but the damage estimate in the interior is overblown.  The reason is that NHC, by their own admission, is overestimating the intensity of Cristobal.

It’s not likely this storm will cause much damage aside from some rain-induced flooding (storm surge should be minor), maybe a few trees down.  A tornado or two isn’t out of the question, but as of 8am the only warnings (aside from the general Tropical Storm Warning) are for flash floods east of Tallahassee.  Still, all that could reach $100 million here in the US, added to the $100 Million or more (due to mudslides and associated rain) in Central America.  Because this is a “named” storm, unfortunately catastrophe deductibles apply.  It isn’t fair, but it’s the system your elected state insurance commissioners (both D and R) created.  Maybe you ought to see about that come November …

Cristobal caused a fair amount of damage in Mexico and Guatemala.  In past years, damage to the PEMEX oil fields in the Bay of Campeche would have triggered spikes in oil and gas prices, along with breathless reports of shortages.  But Cristobal is barely even a blip in global oil/gas futures compared to all the other factors.  My how times change …

Tropical Storm Cristobal, Saturday 6 June 2020

Before discussing Cristobal … I’ve re-established the link to Facebook because so many get their information that way.  While it is a problematic platform in many ways, the simple fact is many people use it.  I would again caution that for real time hazards and news, Facebook can even be dangerous because it does not show you things chronologically.  It also does not show you every post, because it aggressively wants corporate and even non-profit users to pay them to “boost” posts.  So if you really want live data from Enki, bookmark the blog directly.  Another thing I dislike is people profiting from disasters.  As I get time I’m considering options like creating an app,  but I may have to set up a Patreon type thing to sponsor that.  Either way, I really appreciate everyone who has contacted me with well wishes and ideas for how to sort through this.  Note going forward I am not reading or responding to comments on FB.  This is purely an echo of what goes on to the site as a convenience for FB users.

Cristobal has re-emerged into the Gulf of Mexico, and tropical storm force winds should make landfall on the Louisiana coast tomorrow morning – but the impacts will be felt starting later today/tonight.  NHC’s key messages are pretty straightforward, and there are tropical storm warnings up for the Louisiana/Florida Coast, including New Orleans.  Here is the forecast damage swath …

Two things about Cristibal:  first, it isn’t likely to get very strong.  It has a very broad structure, and is dragging in dry air, limiting how intense it can get.  Here is a water vapor image from this morning, you can see the dry air in orange … as always, click any graphic to embiggen.

The second (related) thing is how large the system is.  Normally tropical cyclones get smaller as they get more intense.  It’s a lot like an ice skater who spins faster as she draws her arms in, and slows down when they are extended.  The circulation of Cristobal is quite large.  That means the area of winds and somewhat elevated water is also large – but it also means the storm won’t intensify as fast, even given warm water.  There is also some shear (winds moving in different directions in the middle and upper levels of the atmosphere).  Here’s the 850mb (about 5000 feet up) wind speeds … so even the Florida coast might see gusty (but not dangerous) winds.  Water elevations will run a bit above normal across the Northern Gulf Coast – but only structures right on the coast are at risk.  However, soil moistures are high, and there will likely be a lot of rain, meaning there will be river/creek flooding, so if you live near one along the Gulf Coast beware.  Aside from the odd tree down and scattered power outages, that should be about it for Cristibal.



Tropical Storm Cristobal (Friday 5 June)

Well, technically still Tropical Depression Cristobal as of 11am … for a while it was not much of a system, but NHC continued tracking and advisories since it was expected to re-emerge over the Gulf of Mexico.  That seems to be happening today, the center of circulation is moving north and should move back over water later today.  The part that is over water seems to be intensifying, so there is a good chance Cristobal will become a “real” tropical storm before it strikes the Gulf Coast of the US on Sunday Morning.  Here’s the satellite view as of 10:40am …

Left side is infrared (colder, higher clouds indicating convection in color), right is visual.

Here is the TAOS(tm) TC impact estimate based on the official 11am NHC forecast:

Cristobal has caused a lot of flooding and mudslides in southern Mexico and in Central America, but with all the other news hard to find any good summaries.  Oil refineries and offshore rigs are starting to take action to protect their assets … although the Gulf isn’t nearly as important to US energy and prices as it was 10 years ago.  While it may cause a brief spike (based more on trading dynamics than reality), Cristibal isn’t likely to cause any significant damage offshore.  Onshore, the main risks are flooding, with some minor wind damage and coastal flooding.  NHC is forecasting a very broad wind field – I suspect overly broad – but the Louisiana, Alabama, and parts of the Florida Coast will certainly be gusty Saturday Night in to Sunday.