Florence Update for Monday Morning, 10 September 2018

Short version: The SC coast north of Charleston, all of North Carolina, and Virginia/DelMarVa  Peninsula really need to take this storm seriously and be ready to act today. Georgia should keep an eye on it, but things are looking ok at this point. Watches and warnings, and the attendant evacuations, etc. are just about inevitable for SC/NC and maybe VA at this point. A reminder, be very careful when using social media like Facebook that uses algorithms to display information, since it does not always work chronologically, and you may be seeing old data!

The steering environment is still somewhat fuzzy, but as expected has come in to much better focus over the last 24 hours.  Starting with the track guidance, it is fairly stable pointing to a landfall along the southern North Carolina coast (Wilmington area).  Here’s the current track forecast maps:

Florence is intensifying and now looks like a serious hurricane as it moves over warmer waters, and more favorable wind environment.  It may well be a strong category 3 or even category 4 before landfall.  Here’s the satellite view as the sun comes up (just before 7 am ET):

So, what might happen?  It’s not good.  Here’s the impact graphic using the official NHC track and intensity as estimated by my Haetta/TC model.

Damage right at the eyewall at landfall and inland could be epic if this intensity forecast holds up.  Storm surges of 5 to 6 meters (upwards of 20 feet) are likely to the right of the landfall, and depending on the exact storm configurations, 25 feet are not out of the question.  Using the 5am NHC forecast track/intensity, Florence is shaping up to be about a $15 to $20 Billion storm. A BIG question on this track is how intense the storm remains over the Research Triangle area of NC (Raleigh-Durham-Chapel Hill). The NHC forecast has it decaying to a tropical storm before crossing the triangle, but storms like Hugo stayed as hurricanes to that point, and if so the damage racks up pretty quickly. The tops of pine trees shear off on average at 70mph or so – and NC has lots of pine trees to end up in the living rooms and business in the triangle. Subtle changes in how fast the storm decays, a 20 or 30 mile wobble as it moves inland, or a tornado or two in a bad place and this *easily* turns into a $30 Billion storm. Wobbles or shifts towards Virginia and the “target rich” environment of the Norfolk and DelMarVa penensula (and the Washington DC area, even as a decaying tropical storm) could also up the totals.

Bottom line: if you are in the swath of this storm, take is seriously.  Don’t panic, but pay attention to National Hurricane Center advisories and your local emergency management, and take appropriate action.  Along the rest of the coast, beware high waves and rip currents.  Surf might be good for another day or so, but be aware of your limitations and don’t get in to trouble!

Hurricane Florence: Implications for the East Coast as of Sunday, 9 Sept

Sorry this is a long post, but lots of stuff to cover! For many places it takes a minimum of 36 hours (and for some coastal metro areas, much longer) from the time you decide you want to launch an evacuation to the time everybody that is going to leave is out of the danger zone.  But of course that’s not 36 hours before landfall – you want people out of the way before conditions become hazardous for travel.  For a big storm, that can be up to 24 hours before actual landfall.  Add in safety margins to account for delays, factor in time of day (doing an announcement at midnight doesn’t help since most folks won’t see it for another 6 hours or so), and we are now up to 4 days prior to landfall for having to make the big decision.  Although Florence has slowed down her forward speed this morning, on the current National Hurricane Forecast official track, we are likely less than 5 days before landfall for a major category 3 hurricane (and certainly less than that for impacts like high winds and waves along the shore).  So we’re now entering the time frame where emergency managers have to begin making hard decisions.  Here’s what they have to work with …

First and most important, there is the official NHC track. It is critical, as they preach, not to focus on the track line because storms are not points but big blobs, so here is the current forecast with the damage swath depicted using my Haetta/TC model used to show areas that will be impacted over the next five days assuming the storm follows this track. 

Now, NHC are the experts at this sort of thing – but at five days it would not be surprising to see the actual landfall location as much as 200 miles either side of this track.  That means a direct hit is possible from Charleston SC to the DelMarVa penensula (with the band of severe impacts extending 100 miles to the right/north, and 60 miles to the left/south, of that spot).  But as with most things it’s more complicated than that.  The average doesn’t tell you much about the bias.  For a storm in this location, and error to the right (north) is more likely than an error to the south.  Is that true for Florence?  Well NHC talks about this kind of thing in their forecast discussions, and we can look at the forecast model tracks to see where the biases might be …

Most of the models, and most of the models doing well on this storm, say somewhere on the Grand Strand of SC (Myrtle Beach area) up through Chesapeake Bay, most likely to be the WIlmington NC or Outer Banks.

So we’ve got a handle on where, but how strong?  That’s a hard question.  Again, NHC is forecasting rapid intensification, with good reason.  The storm is showing signs of better organization, and is moving towards the warm waters of the Gulf Stream, a great energy source.  Intensity is a very complex subject, but let’s go with NHC’s forecast (even if it may be a bit on the strong side).

Bottom line for decision makers: Category 3 hurricane likely to make landfall Friday, with damaging impacts starting late Thursday.  Landfall is probably going to be somewhere  on the North Carolina coast, meaning the area of damaging impacts is more than likely going to be somewhere from Charleston to the DelMarVa Penensula, but the most likely area of severe impacts is the North Carolina coast.  Georgia is on the outside edge and trending better.  North of DelMarVa (eg New Jersey) is not in the worry zone – for now – but that may change later when we figure out what the thing is going to do if it stalls at or near the North Carolina coast as the long range models are implying.  On the present NHC forecast, Florence is on track to cause over 15 Billion dollars in damage.  Using an extended forecast, I would not surprised to see Florence top out at over $25 Billion in impacts, putting it in the top 10 most expensive hurricane to make US landfall.

So what do you personally do?  If you live in coastal SC, NC, VA, MD, or De, you should have your hurricane plan ready to execute.  It is likely that emergency managers will begin recommending actions today, early tomorrow at the latest.  Unlike some past storms on the East Coast the last few years, this is a hard core straight in off the water storm more like a Hugo or Andrew.  Take it seriously.  Georgia, Hilton Head (my “home turf”)  Keep an eye and be alert, but this one is very likely to be north of us, and aside from some waves, not a big deal.  But the next day will tell.

Sunday Morning: Florence decision time approaches

Things actually didn’t change too much overnight, and I’ll post a full analysis as the 11am NHC package is released since that will be used by most emergency managers for decisions today, so here’s some thoughts on information sources and the process. I want to again caution everyone using social media like Facebook: the Facebook algorithms do not show you posts chronologically, but by popularity!  Be absolutely sure you are looking at the most recent information!

As decision time approaches for taking action on Tropical Storm (likely to be a Hurricane again some time today, possibly this morning) Florence, it’s time to review some information sources and toss out some words on the overall storm response process.  First, information.  There’s really only one source of hurricane track and intensity forecasts: the National Hurricane Center. Your best bet, quick overview, TLDR product is the “Key Messages” graphic.  Here’s the one for Florence.  If your local TV folks are scaring the beejesus out of you, go check the NHC site and see how closely their big picture message matches the NHC message and if not, go somewhere  else.

Everybody uses NHC’s products as a starting point.  The problem is that increasingly other people with far less experience and expertise, especially in the news media, are using the raw track forecasts and data to put their own opinions out there and diluting NHC’s message. Was watching CNN yesterday, and they spent only about 10% of the air time talking about the NHC track and reasoning and the rest talking about track models.  That’s irresponsible – the emphasis should always be on the NHC forecast.  On social media I see people with zero tropical cyclone experience talking about this or that model.  It’s interesting and exciting to discuss the models, especially beyond the 5 day limit of the NHC forecasts.  But NHC only forecasts to five days for a reason, and if someone can’t answer basic questions like what are the components of the TVCN model and what is its current 96 hour cross-track error as of the latest forecast package ( 103 nautical miles if you’re curious), laugh condescendingly and move on.

It is important to realize the roles various parties play in this process, and what their agendas are.  Of course everyone wants you to be safe – but they also want other things and it’s important to realize what those things are, and how it influences their point of view. NHC’s purpose is forecasting with an eye towards issuing watches and warnings.  They want to be “right” – but they also really really don’t want to be “wrong.”  This means they tend to be “conservative.”  What does that mean exactly?  It means they would rather, on average, overestimate things like storm wind speeds and impacts, because they don’t want people to be surprised by a worse storm than predicted (which potentially leads to more casualties and congressional hearings).  So you will often see NHC use the phrase “forecast of least regret”.  However, they are of course aware of that, and strive for a balance.  It’s a tough job.  The bottom line here is that NHC has the best mix of experience and resources to make those watch and warning calls.

Unfortunately, the people involved in the actual evacuation decisions are a) less experienced and b) often have political, legal, and experiential biases that lead to problems.  Key among these are two trends: politicians (especially Governors) making evacuation decisions, and local emergency managers coming from a law enforcement rather than a civil defense background.  I ranted a bit about this in a Facebook post this spring if you’re curious.

The News Media also has some biases and agendas that make information from them sometimes problematic. The first is they want to have a local focus.  That’s great, but in a situation like Florence the stations in each market want to talk about what would happen if the storm hit their viewing area.  So if you review the weathercasts from outlets from Jacksonville FL to Wilmington NC, with a few exceptions you’d think the storm was headed to each one, without a lot of perspective on what the probability of any given area being hit.  The time limitations of newscasts just doesn’t allow for that kind of nuance, even if the on air meteorologist had that kind of background and experience.  Weather is a key “grab” for local markets in the competition for market share.  So they want to make their weathercasts flashy, interesting, and make you want to come back for more.  It’s not that they want to intentionally mislead you, but in their efforts to play on your emotions to make you stay tuned, download their app (which are designed as much as marketing tools as information sources – be very careful with them as they often siphon off your contact lists, browsing history, and other privacy related info!), combined with the time limitations, the net effect is that they are often quite misleading as to the actual likely impacts of a storm on you personally.

The net effect of all this is that NHC is conservative (which is reasonable), emergency managers exaggerate a bit to try to get you to take action and follow their directions (I have a problem with this), Politicians often want to use disasters to make themselves look authoritative (this is disgusting), your local news media is basing their reports towards the dramatic (this makes me want to beat up grass), so the information you get is not just worst case, it’s often blown completely out of proportion across the board to the point where the message that needs to get to people who are often at real, life threatening risk is diluted, and the risk to everyone else distorted.

So what about Enki Research?  As a scientist, I’m looking for some kind of objective truth with respect to the economic and humanitarian impacts of hurricanes.  In my analyses, I don’t care so much if I’m high or low on any given storm, only that on average over many events (and note I often analyze 50 or 60 storms and dozens of earthquakes a year), that the errors in the estimates of economic and humanitarian impacts are minimized.  This is very different from virtually every other analyst you are likely to encounter outside the academic world, especially available to the general public.  As noted above, most other sources have a built in bias towards the high end on impacts – they would rather overestimate the impacts than underestimate them.  But that carries with it some risks.  Overwarning (“boy who cried wolf” effect) is one, increased economic impacts are another.  In one sense I don’t care if you read this or not (in fact, I sort of wish you wouldn’t so I could just do research and not have to spend an hour typing up this crap!).  But I’m also glad folks find it helpful, and as long as you, the unwashed masses 😛 want me to continue posting my analyses, I will …

Florence terrorizes east coast, Olivia threatens Hawai’i

Lots of stuff going on out there, but I have to feed the cats and go cook dinner so here’s the quick summary.  First, let’s not overlook the fact that Olivia is expected to pass over Hawai’i in about four days as a tropical storm … given all the rain there in recent weeks, not a great situation even if the winds aren’t that strong.  CPHC doesn’t have a lot of confidence in this forecast, it could well miss, but here’s the latest track if you want to take a look.  Will post more on Olivia tomorrow.

There are a bunch of storms in the Atlantic:

Finally, here’s the latest (4pm East Coast Time Saturday) track guidance for Florence.  The tracks are shifting north a bit, with GFS doing what can only be called a funky move off the coast of North Carolina in the long range forecast.  This map show the little hook in deep blue – after that, the model has Florence doing a full 360 loop offshore, spending nearly 4 days in the same general area before taking off to the north northeast.  That will cause a full blown meltdown of the news media and local emergency managers across the east coast!  I’m not sure I believe that simulation, especially that Florence would stay as strong and organized as the model indicates, because looping on it’s own wake isn’t healthy for a storm because it churns up cold water and chokes off it’s own energy supply.  On the other hand the Gulf Stream is constantly moving four billion cubic feet of warm water a second up that way, and storms have done loops like that in the past so maybe …

The European models are mixed, with tracks from North Florida to North Carolina. NHC has sort of split the difference, kept the official track about the same, and adopted a wait and see attitude, which is fine because there is still plenty of time to figure out who needs to be warned and get them out of harm’s way.  So what should you do about this?  As noted earlier, not really worth getting too excited (aside from checking your emergency supply of coffee, assuming you already have a good plan in place) until the storm we know more, which will be tomorrow afternoon or Monday morning.  Then we can start to see who needs to start seriously preparing.

#Florence Track Notes for Saturday 8 Sept 2018

First, a reminder of a great “one stop shop” for the official word on what a given storm is up to, the National Hurricane Center’s “Key Messages” graphic. It’s pretty straightforward, to the point, and part of the official package on a storm.  Worth watching.

Anybody remember the days when hurricane forecasts only went out three days, and the forecast track models were labeled “for intergovernmental use only”?  It’s great that more data is easily available for both researchers, planners, and the public alike, but it’s also fostered a cherry picking attitude among some who are at least as concerned with hits, viewers, and visuals as they are with accurate forecasts, and for the vast majority of people (including most TV meteorologists and government officials) these things can be scary if you don’t know how to interpret them.  Here’s the forecast track model map as of this morning; some important models are highlighted, as is the official NHC forecast:

Interpreting “spaghetti maps” takes years of training and experience.  It’s one reason why you should be watching that red line (the official NHC track) and not worrying so much about all the other clutter.  It’s like going to the doctor – you have lab work with all kinds of scary numbers, MRI scans, etc.  What matters, and what doesn’t?  It takes an expert.

With hurricanes there are always two related questions: where is it going, and how bad will it be when it gets there.  We’ve gotten somewhat better at the “where is it going” (although better is a relative term; average day 5 forecast errors for the official forecast are around 200 miles). For Florence, there is a big question about the steering Tuesday and later.  There will be high pressure to the north and east of the storm.  Exactly where and how strong is uncertain, and that is causing the reasonable day 6 (Thursday)  forecast location to be within a 800 mile wide swath ranging from the GA/SC  border to out between NC and Bermuda!  The “how bad” part is even harder.  Florence is currently a tropical storm.  It should strengthen, and could be as strong as a category 3 storm at landfall.  However, intensity is tied closely to track, so with so much uncertainty in the track, the intensity forecast is also uncertain.

So what’s the short version as of Saturday AM?  Florence has the potential to be a bad storm for somebody on the US East Coast, Bermuda, and/or Canada later in the upcoming week (Wed/Thu/Fri).  Most likely estimate at this point for hazardous impacts is the North Carolina coast, with points northward (DelMarVa, etc) also likely to see impacts, but South Carolina is not out of the question, and even the Georgia Coast in theory is within the “cone of uncertainty.”  HOWEVER, the storm is still beyond the range of the primary hurricane models.  Forecasts beyond 4-5 days are fraught with error.  For technical reasons noted above there is a lot of uncertainty as to when and where the storm will make its northward turn.

What should you do?  Well, if you have a hurricane plan just watch the theatrics (and if you live on the coast you’re crazy not to have thought about what you would do, but if you procrastinated again this year look at the FEMA site for some checklists).  Still plenty of time to wait and see, then act if it turns out to really be headed your way.  It will be tomorrow before we have some clarity as to the future path (and even then there will be some fuzziness – there always is – but at least it will be actionable fuzziness).  It is possible some state and local officials will “jump the gun” and start actions this weekend, but if I were them I would be watching, getting things ready in the background, reassuring (not scaring) the public, and getting ready to kick off actions first thing Monday morning.

Florence Notes for Friday Morning, 7 Sept 2018

First the big picture (literally), the 6am IR satellite shot with storms labeled …

The three “invest” (investigation areas) will likely develop into storms over the weekend or early next week.  Of the two actual tropical cyclones, Olivia, currently a Category 3 storm, is forecast to weaken and may threaten Hawai’i as a tropical storm by early next week.  Worth watching but still a long way out.  The big focus today, competing with the shenanigans in the US political realm, is of course Tropical Storm Florence.

Florence is currently in a region of unfavorable upper level winds – you will hear weather forecasters talk about shear.  That means the winds at different levels of the atmosphere are moving in different directions and trying to tear the storm apart.  In this case it’s working – Florence is now below hurricane strength.  However, these winds are forecast to subside by tomorrow, and by Sunday Florence is expected to recover somewhat, perhaps becoming a Category 3 storm by Tuesday if it follows the forecast track … which is of course the big question. In simple terms, the future of Florence depends on high pressure to the north of the storm.  The exact location and configuration of this ridge of air will govern how far west, how much shear, and when the storm will turn northward.  The various global models that predict this sort of thing differ, thus the tracks differ a lot.  The bottom line is, as NHC emphasizes in their excellent “Key Messages” graphics, aside from increasing waves (swell, which has my surfer friends excited, but beware rip currents!) along the east coast , we just don’t know what the potential impact on the US East Coast will be. So if you live in a hurricane prone area from South Carolina northwards, especially NC and up, and have a plan, it’s not time to panic or be afraid.  Unless you are watching the news out of Washington.  Feel free to panic over that!

Here is this morning’s guidance, with a few models used by NHC highlighted …

 

Hurricane Florence – ok smart guys, where’s it gonna go?

Here’s the forecast track model plot as is available when the NHC forecasters are preparing the 5pm advisory, with a few models highlighted.  Their last forecast (at 11am) is in red …

Well?  Clock’s ticking … 😛

In all seriousness, tropical cyclone track forecasting is both a science and an art.  You can’t just “cherry pick” a model, especially just pluck one out because it happens to show the storm passing near your viewing area.  If NHC, who do this every day, and are arguably the best and most experienced at this, why not pay attention to what they are saying?  Yes, I sometimes have issues with their forecasts (especially intensity) on technical grounds, but the biggest problem I see with the current process is how raw NOAA and ECMRF data are (mis) used by the media, and how state and local politicians and some EMA’s screw up the process.  Five days is plenty of time to prepare for a storm if you’ve done your pre-season homework.  If you haven’t, check out the FEMA hurricane checklists.  It’s too late for insurance, but otherwise time to think about what you are going to do.  No need for drama, or hanging on every forecast, unless you just need the exercise.

Japan: One Disaster After Another …

Japan isn’t really in a good place from a natural hazard standpoint.  Located on a major plate boundary, it is prone to major earthquakes.  It is also in the crossroads of Typhoons as they start their northward turns, meaning they often sweep over or by the islands, dumping tremendous rain as they decay even if they do not make direct hits with high winds (which they do as well from time to time).

This map shows the damage swaths of natural disasters in Japan just in the last 72 hours:

Typhoon Jebi made landfall earlier this week, with at least $15 Billion in impacts, and causing additional deaths and in particular more flood damage on the top of catastrophic flooding earlier this year which is responsible for at least 300 fatalities.  This summer also saw a deadly heat wave.  And now there has been a 6.6 magnitude earthquake on the northern island of Hokkaido.  Landslides (mudslides actually) are responsible for much of the damage and fatalities as the ground all across Japan is saturated.

Hurricane Update for 5 Sept 2018 …

Here’s a satellite image from this morning showing the parade across the Atlantic …

The blob-of-clouds on the far right (topmost of the group of three) is a tropical wave off of Africa that will likely become the next storm in a few days.  Hurricane Florence, now a category 3 storm, is clearly visible as the mature hurricane in the middle right. Neither is a threat to land at the moment, Florence may be a problem for Bermuda early next week, and the wave, if it develops, the Caribbean.   On the left, the swirl of clouds on the LA/AK/MS border and across Alabama is the decaying  (but still causing flooding and tornadoes) Gordon.

Gordon made landfall on the Gulf Coast yesterday, as expected did not make it to hurricane strength.  Still causing rain and possible tornadoes across Alabama and parts of Mississippi, as well as south Alabama, aka the panhandle of Florida.  Joking aside, a quick review of the damage reports seem to be mostly of the coastal flooding, flash flood in known vulnerable areas, trees down, and roof damage variety.  Sadly, a tree fell on a mobile home and killed a child in Escambia County Florida, showing that even weak storms can cause deep personal tragedy even if, in the big picture, they are not catastrophic events.  Impacts likely in the 100’s of millions of dollars, very little impact on the Insurance industry.  Homeowners likely to get a nasty surprise when they find higher deductibles due to “named storm” clauses in their policies …

There are also two storms (Norman, Olivia) in the Eastern Pacific, both of which are expected to pass to the north of Hawai’i, waves on the north shores being the only impacts.

Typhoon Jebi made landfall and cause a lot of damage in Japan.  Our models estimate impacts at around $14 Billion.

Gordon over south Florida, headed towards Gulf States

The National Hurricane Center started formally tracking Tropical Storm Gordon this morning.  It continues to organize during the day, and as of around 2:00pm Eastern Time even seems to be trying to form a radar eye, although the satellite presentation was not so clear … click for the animated version (reflectivity on the left, velocity on the right, from the Key West radar):

Here’s a static regional composite.  It remains to be seen how much strength Gordon can gain over the Gulf.  Either way, areas of the Gulf Coast are already saturated so more rain, even if from an otherwise weak storm, would be unwelcome.