Remember all those details about exactly what Atlantic Hurricane Florence was going to do later this week? Well, the plan has changed in important ways. Mainly, the inland effects will be stronger, more to the south, and more concentrated in space. Read below for details. Continue reading Florence: Change in plan
Hurricane Florence has strengthened as expected. There will likely be some more strengthening, followed by some weakening near the coast. Florence will remain a major and deadly hurricane until after landfall, and then, it will be a deadly flood causing storm with significant winds.
Timing
The best estimate for timing of events is as follows.
On Wednesday morning, Hurricane Florence will likely be looming just off the Carolina coast, with winds of about 140 mph (making it a Category 4 Hurricane).
Tropical storm strength winds will come ashore Wednesday night. Strong surf will have already developed.
The strongest part of Florence will be pounding the Carolina coast at sunup on Friday, and the storm may sit right on the coast for several hours as it winds down to a tropical storm. Landfall and this rapid weakening may happen at about the same time. It is remotely possible that the eye wall will not pass over the coast, thus causing weather reporters and climate disaster deniers to become stupified.
Storm surge
It is important to understand how storm surge warnings work. There are two kinds of estimates that can be made. One is to assume exactly where the eye will come ashore, exactly when (to include the contribution of tieds), estimate the wind speed and forward speed of the storm, and the angle of movement, then use all these variable together with the topography of the coast to estimate how high flooding will be at any given point.
The second is to look at where the storm may go, and how strong it might be, and how those other variables will pan out, but with uncertainty in location and timing being much larger, and produce a map of coastal regions indicating where there might be high flooding, and how high that might be.
The former is generally not what you are looking at when you see a storm surge map. For example, right now there are estimated storm surges of over 9 feet near Kinston and Greenfille North Carolina, but only one foot in and around Albermarle sound. This is based on a combination of the likely track and behavior of the storm but considering that we don’t know exactly where the storm is going to hit. The difference between Greenville and Albermarle sound is a combination of where we think the storm is going and what the storm might do. The two topographies are greatly different, accounting for most of the difference in possible flood height.
In other words, most of the flood levels indicated in most storm surge maps are not going to happen. Only some of them. But, we don’t know which ones.
Anyway, there are storm surges expected to be greater than 9 feet in some places. Even three foot surges are a lot if it is high tide along very low lying barrier islands. If Florence does plow into North Carolina as expected, it is quite likely that the configuration of the barrier islands along that coast will change. Some lines may become dotted lines. Some inlets may be filled, some new inlets created, many tidal channels in the estuaries will shift. Places like the town of Ocracoke may suffer very sever damage, as they lie below the maximum possible food surge.
Flooding
Aside from storm surge, flooding happens inland with hurricanes. The special feature of East Coast hurricanes, especially in “Hurricane Alley”, between Northern Georgia and southern Virginia, is that behind the coastal plain there is a mountain range. So, if tropical storm carried water dumps on that mountain range, a two or three inch rainfall over a very large area can cause significant flooding.
Rainfall of over four inches is expected to fall over most of Virginia, and about half of North Carolina. Delaware, DC, Delmarva, Maryland, southern Pennsylvania, and parts of West Virginia and South Carolina will also get lots of rain. The area of expected landfall, and a few areas in land (like in south-Central Virginia) may see rainfall totals of over 15 inches, maybe two feet right along the coast.
A lot of roads and bridges will be wiped out, immortal doods in large pickups will be obviated, and low lying villages will be flooded. Unless the storm does a zany (and very unlikely) turn to the north before coming ashore, this may be the biggest problem, since it is hard to evacuate five or six states.
Washington DC could get up to a foot of rain. Note: The White House lies on much lower terrain than the Capitol. I’m not promising you a Rose Garden flood, but it could happen.
What if
Florence is just like any other storm of the day: Enhanced by global warming. But note this. Florence will weaken from a strong Category 4 storm to a strong Category 3 storm as it gets near the coast. This will happen because the warm waters on the surface will be churned by the storm itself into the colder water at depth, weakening the storm. Over recent years, however, we’ve seen storms fail to weaken, or even strengthen when they would normally have weakened, because the deeper water is still at “hurricane-strength” temperature. Katrina, Haiyan, and some of last year’s Atlantic storms exhibited this behavior.
With increased warming of the sea, this will eventually start to happen in the US East Coast littoral. Florence ten or twenty years from now would build to Category 5 strength and keep that level of intensity, or nearly, before reaching the shore. And, in ten or twenty years from now, sea levels will be higher. And, by then, a few other hurricanes would have smashed up the barrier islands. In 20 years, North Carolina and Virginia are not likely to be very well protected by those sand features. James Hansen was right.
Spaghetti is as what spaghetti does. At this time, the spaghetti models — that’s what we call the collection of lines emanating out from the location of an existing storm showing many possible future tracks based on many different models — show the Atlantic storm known as Florence coming perilously close to the US.
However, all of these models have the storm still a couple days minimum from hitting something (if it hits something) FIVE DAYS in the future. The collection of models suggesting a tropical storm or hurricane’s track are very accurate, at the level of something the size of a US state, for a couple/few days. Five days out is a long way to predict. If Florence were to hit the US coast, it would be in perhaps six days from now or later.
There is a very high probability that the storm will turn right, north, and entirely avoid the US.
The full range of possible landfalls IF if makes landfall runs from Miami to New Jersey.
So, it is undoubtedly too soon to say anything clear about Florence.
Nonetheless there are two things that compel me two write this premature post. First, the major media are starting to report Florence. I assume this is in part because the Atlantic Hurricane season has been quiet so far and weather-oriented reporters and editors are getting jumpy. I know I am.
The other reason is more important. Just as there are many predicted tracks that have Florence hitting the US, there are also predictions of Florence being rather strong. Most of the intensity predictions suggest that in about 100 to 120 hours from now, the storm will reach Category 3 or possibly Category 4 status.
So, if this is going to be a thing, it might be a big thing.
The intensity predictions don’t say what happens after that, and it is not uncommon for a Category 4 storm out in the middle of the ocean to weaken before it gets near land. So, the news headlines will read “Category Five Storm Heading For Virginia” while what is really happening is “Category Five Storm Will Weaken To Category 3 Storm Before Maybe Hitting Virginia.” The breathless over reporting of strength is dangerous, because the actual Category 3 storm is bad enough, still a major hurricane. But if everyone hears “The Cat Five Weakened to a Cat Three” all they may see is the word “weakened.”
When will we know if Florence is going to hit land? Maybe Tuesday or Wednesday of next week. Stay tuned.
There have been a lot of hurricanes in the Eastern Pacific, none of which hit the west coast. There have been an average to somewhat below average number of hurricanes in the Atlantic. Predictions that this would be a slightly above-average Atlantic season have been replaced by predictions that it will be a slightly below average season, given the high (ca 75%) chance of an El Nino forming later in the year.
Meanwhile, it is easy to forget that the United States spans a third hurricane basin. Hawaii is out there in the middle of the Pacific, but in an area that Hurricanes actually tend to avoid.
But not right now. Hurricane Lane is likely to either directly strike or come very close to one or more of the islands of Hawaii, as a Category 4 hurricane.
The details are complicated because Lane is turning around the same time that the storm is bearing down on the island state. Below is the current info from the National Hurricane Center.
Hurricane Lane is centered as of 2 a.m. HST (8 a.m. EDT) about 230 miles (370 km) south-southwest of Kailua-Kona and about 335 miles (540 km) south of Honolulu. On the forecast track, the center of Lane will move very close to or over the main Hawaiian Islands later today through Friday. Maximum sustained winds are near 130 mph (215 km/h) with higher gusts – a powerful category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast during the next day or so, with more significant weakening thereafter. Lane is expected to remain a hurricane as it approaches the islands.
A Hurricane Warning continues for Oahu, Maui County (including the islands of Maui, Lanai, Molokai and Kahoolawe) and Hawaii County. Preparations to protect life and property should be rushed to completion this morning. A Hurricane Watch continues for Kauai County, including the islands of Kauai and Niihau.
Here are the latest KEY MESSAGES:
1. Lane will pass dangerously close to the main Hawaiian Islands as a hurricane Thursday and Friday, and is expected to bring damaging winds. These winds can be accelerated over and downslope from elevated terrain, and will be higher in high rise buildings.
2. The slow movement of Lane also greatly increases the threat for prolonged heavy rainfall and extreme rainfall totals. This is expected to lead to life-threatening flash flooding and landslides over all Hawaiian Islands.
3. Large and damaging surf can be expected along exposed shorelines, especially along south and west facing coasts, with localized storm surge exacerbating the impacts of a prolonged period of damaging surf.
4. Do not focus on the exact forecast track or intensity of Lane, and be prepared for adjustments to the forecast. Although the official forecast does not explicitly indicate Lane’s center making landfall over any of the islands, this could still occur. Even if the center of Lane remains offshore, severe impacts could still be realized as they extend well away from the center.For storm information specific to your area, please monitor products issued by the National Weather Service office in Honolulu – www.prh.noaa.gov/pr/hnl/
The next complete advisory will be issued by NOAA’s Central Pacific Hurricane Center in Honolulu at 5 a.m. HST (11 a.m. EDT)
Read Making Sense of Weather and Climate: The Science Behind the Forecasts
I know a lot of you are interested in global warming/climate change, so you need to know that this book is not mainly about that (but it is covered). Rather, this book is the Rosetta Stone that allows you to connect a general understanding of the planet (it is round, it spins, it has an atmosphere that includes water vapor, and tends to reside between -50 and +50 degrees C, etc.) and the person on the TV talking about air masses going up and down and what is going to happen during “the overnight” and “the overday” and such. Continue reading Making Sense of Weather and Climate
The phrase “It is almost like praying” is from the song Maria, from the musical West Side Story. The phrase refers to the name itself, if I understand the somg correctly, which makes sense from a Catholic point of view because the name Maria and variants of it thoroughly indurate the prayer-text.
Continue reading Almost Like Praying: Lin-Manuel Miranda and Maria
The news is bad, and is being widely covered. Here I just want to make a remark or two about the link between big fires and global warming.
As of last report, there are 15 known dead and 150 or more missing. Hopefully they are only virtually and not actually missing; there is a lot of confusion and communication resources are in many cases down.
Wild fires are tricky in more ways then one. It is easy to get caught in one (I’ve manage that myself), and it is hard to predict or fully understand why some years have more than others. There has been a long term trend nationally towards fewer wild fires, for several reasons, most of which have to do with human activities. The most significant part of that trend is that humans caused many, huge, often deadly wild fires in the past. The worst wildfire ever in Minnesota, in terms of Death toll, was during World War I and had mainly to do with farming and railroads being a bad mix. Cutting lots of land to farm provides the fuel, and in those days, railroads were travelling tinderboxes sparking fires everywhere they went. Continue reading Tragic and Unprecedented California Deadly Fire
The White House calls the disaster in Puerto Rico a “good news story,” implying that the federal government is doing a great job there.
Meanwhile, Donald Trump put out a tweet today that seems to imply that the US needs to consider whether or not it wants to help Puerto Rico, which, by the way, is actually part of the United States.
Here is the mayor of San Juan, Puerto Rico, responding to some of this:
Hat tip: Media Matters for America
Harvey the Invisible Rabbit: Did not exist.
This is a picture of some men.
Since they are men, they have some abilities. They can, for example, knock each other over, and they can play with balls. This is what men do, and this is what these men can do.
This is a picture of some professional NFL foodball players.
They are also men. They can also knock each other over, and they can also play with balls. But the NFL football players are much better at knocking each other over, and you wouldn’t believe how great they are at playing with balls.
They are NFL enhanced. They are trained, embiggened with special diets, and they are clad with armor and vibrant, often scary, colors.
This is a picture of a hurricane from 1938.
It was a big one; It did lots of damage when it slammed into New England and New York.
A hurricane is a large storm that forms in the tropics, and sometimes hits land. The energy from a hurricane comes from a combination of the earth’s spin, trade winds, and so on, but mainly, from the heat on the surface of the sea. The rain that falls from the hurricane also comes mainly from the sea surface indirectly, and any water that evaporates into the atmosphere.
This is a picture of Harvey the Hurricane, the remnants of which are still circulating around in Texas.
Harvey is a lot like the 1938 hurricane, in that it formed in the tropics, in the Atlantic, and was a big spinny thing. It got its energy in the same way, and formed in the same way, and both slammed into land and scared the crap out of everybody.
But they are different, the 1938 Hurricane and Harvey the Hurricane. How are they different? Have a look at this map:
The pairs of photos above show “then” and “now” for two different things (men and hurricanes). This map shows both then and now in the same graphic. This map represents the current sea surface temperature anomalies, meaning, how much warmer or cooler the current sea temperatures are compared to the same time of year but at some time in the past, averaged over a long period, in this case, from 1971-2000. Global warming was well underway during that period, so present sea surface temperature readings that are above that baseline are not only high but are actually very high, because the baseline is high.
In this map, red is more, blue is less. Look at all the nearly ubiquitous more-ness in sea surface temperatures around the world. That causes the atmosphere across the entire globe to potentially contain much more water vapor than it could have contained during that that baseline period. Look at the sea surface temperature anomalies for the gulf of Mexico, where Harvey formed. They are high. This means that any hurricane that formed over that extra warm water will be stronger, and any tropical storm system that occurs pretty much anywhere on this map (or round the other side of the Earth as well, for that matter) will contain more water, than it would if it existed and all else was equal several decades ago.
This is a picture of a Unicorn.
A unicorn poops rainbows and pees mimosas. Or so I’m told. This is another view of Harvey the Hurricane.
What is the difference between the unicorn and Harvey? Harvey is real, and the unicorn is not.
I won’t quote you or give you links. Why? Because I find this whole thing a bit too embarrassing. But here is the thing. Otherwise intelligent and well informed individuals have stated in various outlets, including major media, and including twitter, that it is simply inappropriate to claim that Harvey the Hurricane is in any way global warming enhanced.
This is wrong. There is no such thing as a storm of any kind that is not a function of the current climatology. The current climatology has widespread and persistent, and in many cases alarmingly high, sea surface temperature anomalies. There will not be a tropical storm, including hurricanes, that escape the physics and poop out rainbows and pee mimosas. They will all be real. They will all have greater power and more moisture than they otherwise would have, had they formed decades ago before the extreme global warming we have experience so far.
There was a time when Harvey was a rabbit, an invisible rabbit only seen by a delusional character in a movie, played by Jimmy Stewart. Today, we have Harvey the Unenhanced Storm, playing that role. It is a fiction, something seen by a few but that is no more real than the above depicted unicorn.
As I was writing this post, Michael Mann posted an item in the Guardian that makes this case.
He says (click here for the whole story):
Sea level rise attributable to climate change – some of which is due to coastal subsidence caused by human disturbance such as oil drilling – is more than half a foot (15cm) over the past few decades … That means the storm surge was half a foot higher than it would have been just decades ago, meaning far more flooding and destruction.
… sea surface temperatures in the region have risen about 0.5C (close to 1F) over the past few decades from roughly 30C (86F) to 30.5C (87F), which contributed to the very warm sea surface temperatures (30.5-31C, or 87-88F).
… there is a roughly 3% increase in average atmospheric moisture content for each 0.5C of warming. Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average … That means 3-5% more moisture in the atmosphere.
That large amount of moisture creates the potential for much greater rainfalls and greater flooding. The combination of coastal flooding and heavy rainfall is responsible for the devastating flooding that Houston is experiencing.
… there is a deep layer of warm water that Harvey was able to feed upon when it intensified at near record pace as it neared the coast….
Harvey was almost certainly more intense than it would have been in the absence of human-caused warming, which means stronger winds, more wind damage and a larger storm surge…
Mann mentions other effects as well, but I’ll let you go read them.
The extra heat at depth Mann mentions is now recognized as responsible for the extra bigness and badness of some other famous hurricanes as well, such as Katrina and Haiyan. Harvey might be a member of a small but growing class of hurricanes, deep-heat hurricanes I’ll call them for now, that simply did not exist prior to global warming of recent decades. Further research is needed on this, but that’s the direction we are heading.
Climate scientist Kevin Trenberth recently noted that “The human contribution can be up to 30 percent or so up to the total rainfall coming out of the storm,”
Aside from Michael Mann’s Guardian article, he has this facebook post making the same argument.
Harvey the Hurricane is real, and so was the 1938 Hurricane. Climate change enhancement of Harvey is real, but unicorns are not. Sadly.
I really thought we had stopped hearing this meme, that “you can never attribute a given weather event to climate change.” But, apparently not. That is a statement that is technically true in the same way that we can’t really attribute an Alberta Clipper (a kind of snow storm) to the spin of the Earth. Yet, somehow, the spin of the Earth is why Alberta Clippers come from Alberta. In other words, the statement is a falsehood that can never be evaluated because it is framed incorrectly. Here is the correct framing:
Climate is weather long term, and weather is climate here and now. The climate has changed. Ergo … you fill in the blank. Hit: Unicorns are not involved.
As has been reported in various places, the death toll from Sidr has slowly and steadily climbed, topping 3,000 according to a fairly recent report from the BBC.The Bangladesh Red Crescent is estimating that the death toll may reach 10,000.A half million homes have been destroyed, and a couple/few million people displaced.Aid is getting to many areas though there are concerns of lack of coordination among agencies and between the aid agencies and the government, according to some reports. The southwest has many regions where supplies and help have not yet arrived.The biggest problem right now seems to be lack of food, and that is also a long term problem with much of the rice crop destroyed in many places.
