Hurricane Florence

[Nate Colbert]

Seems to have strengthened from Cat 2 to Cat 4 in just a matter of hours. If it comes ashore in North Carolina, will be the first hurricane of that strength to hit that state in 60+ years.

Stay safe, Reuben and other North Carolinians.

[das]

This thing means business. It’s somewhat similar to Harvey last year in that it will come ashore very strong with very strong cat4-ish winds and tons of coastal flooding then stall, dropping prodigious rain with lots of inland freshwater flooding. The stall won’t be to the ridiculous effect that Harvey was but still significant nonetheless. The antecedent soil moisture is a problem as there has been 25” of rain in the last 2.5 months in the mid Atlantic. Should be a fair number of downed trees. Flo will have a much larger integrated kinetic energy.  She is getting very large over the next two days. Will be a broad attack area on the coast.

[jbm]

I am curious, could  you expand on a “larger integrated kinetic energy”? 

[Waldo]

I am curious, could  you expand on a “larger integrated kinetic energy”?

I'm no das, but integrated kinetic energy is the way meteorologists measure the total energy output (and, therefore, the destructive potential) of a storm.  It takes into account not just the max wind speed, but also the size of the storm and various data from the storm's four quadrants.

For example, Sandy was only a category 1 storm, but its IKE was measured at over 300 terajoules.  That's double the combined energy of the bombs dropped on Hiroshima and Nagasaki.

[das]

I'm no das, but integrated kinetic energy is the way meteorologists measure the total energy output (and, therefore, the destructive potential) of a storm.  It takes into account not just the max wind speed, but also the size of the storm and various data from the storm's four quadrants.

For example, Sandy was only a category 1 storm, but its IKE was measured at over 300 terajoules.  That's double the combined energy of the bombs dropped on Hiroshima and Nagasaki.

Nice synopsis, Dave. If you or @jbm want a little more light reading, here’s an expanded abstract on the wind/water forcing metric from the Hurricane Research Division at NOAA’s Atlantic Oceanographic & Meteorological Lab:
http://www.aoml.noaa.gov/hrd/Powell/BAMS_IKE_Paper_final.pdf

[HudsonHawk]

And if we’re science geeking out...

Internal energy of a system, including kinetic energy (the energy that a body possesses by virtue of being in motion), is the sum of the energy of all its parts. So be it wind, or a wave on the ocean, the more mass in the system, the more internal energy it possesses. So the IKE is a function of both size and velocity, both forward and angular.

[das]

And if we’re science geeking out...

Internal energy of a system, including kinetic energy (the energy that a body possesses by virtue of being in motion), is the sum of the energy of all its parts. So be it wind, or a wave on the ocean, the more mass in the system, the more internal energy it possesses. So the IKE is a function of both size and velocity, both forward and angular.

That’s right. And that’s why IKE is a superior measure/index to the Saffir Simpson scale. It calculates both the wind and the water forcing mechanisms.

[Limey]

That’s right. And that’s why IKE is a superior measure/index to the Saffir Simpson scale. It calculates both the wind and the water forcing mechanisms.

It’s the difference between trying to block the plate against a charging Altuve, and a charging Gattis.  The former may be moving faster but the latter is going to pack much more of a punch. 

[jbm]

Thanks for all the explanations and the article and sorry for the following uninformed question/observation.  I read it best I could, but my takeaway was that IKE's major relevance is to surge intensity and duration, rather than inland wind damage.  I get that the ocean can store the storm's energy over time, and that energy storage is an important variable in modeling surge, but I'm not grasping an analog for inland wind destruction.  In other words, is the expected wind/damage at an inland location at all affected by the previous strength of the storm? 

[HudsonHawk]

Thanks for all the explanations and the article and sorry for the following uninformed question/observation.  I read it best I could, but my takeaway was that IKE's major relevance is to surge intensity and duration, rather than inland wind damage.  I get that the ocean can store the storm's energy over time, and that energy storage is an important variable in modeling surge, but I'm not grasping an analog for inland wind destruction.  In other words, is the expected wind/damage at an inland location at all affected by the previous strength of the storm?

The damage at a particular location is a function of the strength of the storm at the time it hits.  I'm not sure I understand your question.

[jbm]

The damage at a particular location is a function of the strength of the storm at the time it hits.  I'm not sure I understand your question.

Well, if I have a house on the coast and I hear about a storm coming in, I now realize that the IKE is pretty important in estimating the potential damage to my house.  However, if I live 30 miles inland out of the floodplain and am only worried about wind speed and duration, does the fact that the storm was a monster the previous day or that it is huge in scale matter to me in anticipating damage to my house?

[HudsonHawk]

Well, if I have a house on the coast and I hear about a storm coming in, I now realize that the IKE is pretty important in estimating the potential damage to my house.  However, if I live 30 miles inland out of the floodplain and am only worried about wind speed and duration, does the fact that the storm was a monster the previous day or that it is huge in scale matter to me in anticipating damage to my house?

Of course it matters, but only in the sense of how intense it is when it gets to you.  It's likely to dissipate as it moves inland.  How much it does before it gets to you is what matters to the damage you can expect.  It doesn't matter how intense the storm is somewhere else though, if that's what you're asking.  But IKE is still what matters.  It's not just a term for hurricanes when they make landfall, it's a scientific term for the aggregate energy in any moving system.

[das]

For anyone else interested, the Regional and Mesoscale Meteorology Branch (RAMMB) at NOAA's National Environmental Satellite, Data, and Information Service has a fantastic data presentation layer for all things meteorological, including all sensors and channels (except lightening) for GOES-16 and HIMAWARI-8.  It can be found here:   http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=full_disk&x=10528&y=6960&z=1&im=24&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=16&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

[das]

Here's also a great 1km visible image of the tropic sector.  Shows the storm well today.  It’s Vis do check back to the link during the daytime.
https://whirlwind.aos.wisc.edu/~wxp/goes16/vis/full/latest_full_1.jpg

[das]

IKE update on Florence.  The storm has just passed the 100 TeraJoule threshold.  Two of the largest ever were Katrina at 120TJ and Sandy at 140TJ.  The storm now has three wind maxima (three concentric eyewalls) due to multiple eyewall replacement cycles and hurricane force winds are now out to around 150 miles from the center.  Bib, big, nasty storm.

Of even more concern is that the IKE will promote a very large storm surge since the storm will stay on the coast for a while piling up water in the sounds and up river while massive rain floods the coastal plan with all that water trying to go downriver.  It creates a damming situation with both water forces opposing each other.  Tough situation.

In this graphic loop, each time the hurricane force winds field expands there at the end of the loop, the storm as gone through one of these eyewall replacement cycles.  It may do at least two more prior to reaching the coast.  https://www.nhc.noaa.gov/archive/2018/FLORENCE_graphics.php?product=current_wind

Oh, and, seas were just measured at 59-83ft in the NE quadrant of the storm.  This happens with the winds and storm motion are aligned for a long period of time.

[juliogotay]

IKE update on Florence.  The storm has just passed the 100 TeraJoule threshold.  Two of the largest ever were Katrina at 120TJ and Sandy at 140TJ.  The storm now has three wind maxima (three concentric eyewalls) due to multiple eyewall replacement cycles and hurricane force winds are now out to around 150 miles from the center.  Bib, big, nasty storm.

Of even more concern is that the IKE will promote a very large storm surge since the storm will stay on the coast for a while piling up water in the sounds and up river while massive rain floods the coastal plan with all that water trying to go downriver.  It creates a damming situation with both water forces opposing each other.  Tough situation.

In this graphic loop, each time the hurricane force winds field expands there at the end of the loop, the storm as gone through one of these eyewall replacement cycles.  It may do at least two more prior to reaching the coast.  https://www.nhc.noaa.gov/archive/2018/FLORENCE_graphics.php?product=current_wind

Oh, and, seas were just measured at 59-83ft in the NE quadrant of the storm.  This happens with the winds and storm motion are aligned for a long period of time.

Thanks, Das.

[Bench]

  It creates a damming situation with both water forces opposing each other. 

Damning indeed

[chuck]

What's the scientific metric for measuring a storm's wetness?

[Limey]

What's the scientific metric for measuring a storm's wetness?

$130,000.

[moriartp]

$130,000.

Holy shit

[Craig]

$130,000.

Oh shit.

[MusicMan]

$130,000.

I’m standing and applauding and crying.


Sent from my iPad using Tapatalk

[das]

$130,000.

OMG, ha!  Outstanding.

[Lefty]

OMG, ha!  Outstanding.

What do you know at this point?  Talking about Wilmington and areas...?

[das]

What do you know at this point?  Talking about Wilmington and areas...?

The surge is at or near 10ft, which is devastating for the barrier islands and the sound communities to the west.  As the storm approached land, something called frictional convergence eroded the multiple wind maxima and tightened the core around the eye so winds ticked up at the last minute.  Rainfall estimates are astounding.  Two noteworthy reports are for 24 hour totals of 31.37' in Morehead City and 27.04" at Bogue Sound.  As a reminder, The multi-day Harvey maximums were ~60' so Morehead City got half of the incredible Harvey total in only 24 hours. 

https://nc.water.usgs.gov/realtime/rainfall.php

Freshwater flooding continues to be the most significant threat.

[das]

Also, the training spiral bands that were so evident in Harvey are starting to form on the east side of the storm.  Couple that with the slow movement, there may be some Harvey-esque totals.  The places at or neat 30" are forecast to receive another 20+" over the next 48 hours but, it is nearly impossible to see where (and predict) the exact anomalously high totals will be. 

Wilmington was in the NW eyewall for a considerable amount of time.  Will be interesting to see how they faired.

Here's a livestream of some dude driving around Wilmington.  Roofs off and trees down.
https://livestormchasing.com/stream/charles.peek

[Reuben]

A cousin of mine for some reason decided to take her infant son and go TO Morehead City to stay with her (perfectly capable/mobile) mom.

Here in Durham (about 150 miles from where Florence made landfall) it’s been quiet, some wind, some rain, but nothing too unusual, yet.

[chuck]

Outstanding plan. Get as close as you can to the shore before a major hurricane. With your infant.

I was watching an interview yesterday with one of those I'm gonna ride 'er out on this here sailboat! types. In an hour or two you might look out the window and see parts of his boat floating past. Or blowing past.

[Snuffy]

We were w/o power for 2-3 weeks after hurricane Wilma hit S FL during 24-25 Oct 2005. 

Windows blew out on the front and back of some condos on the upper floors, creating wind tunnels and water damage.  When the windows held, towels had to be used to catch the water that blew in under the windows and doors.  At its peak, the wind temporarily blew out one window in our condo, but thankfully it did not break and there was no damage. 

Nature blacked out the Astros' first WS for us.

We learned to appreciate ICE, sun tea, and peanut butter w/ apples.  Trips to the grocery store required a flashlight the navigate the aisles, while the generators were used for the cash registers and credit card transactions.  Bags of ice were distributed by the City at the clubhouse for our complex.  Many roads were blocked due to debris and intersections were dangerous w/o traffic lights.

After Wilma generators were required for gas stations in S FL....
https://www.local10.com/weather/hurricane-irma/gas-stations-in-south-florida-with-generators-for-after-storm

[Limey]

A cousin of mine for some reason decided to take her infant son and go TO Morehead City to stay with her (perfectly capable/mobile) mom.

A mother and infant child were killed when a tree fell on their house.  I sincerely hope this is not your cousin.

Here in Durham (about 150 miles from where Florence made landfall) it’s been quiet, some wind, some rain, but nothing too unusual, yet.

I hope everything stayed quiet.  Flo is a bitch.

[Reuben]

A mother and infant child were killed when a tree fell on their house.  I sincerely hope this is not your cousin.


I hope everything stayed quiet.  Flo is a bitch.

Thanks, I can report that they are all OK. Lost their dock, apparently (they live on the sound, opposite Atlantic Beach), but did not get water in their house.

Next up in Flo’s path is Charlotte, where my sister and her family live. It will be weaker by then of course; they are expecting 10-15” of rain.

[Limey]

Unless your name is Buffalo Bill, why the fuck would you drive through floodwaters with two people shackled in the back of your van?

[chuck]

All I know is I'm hoping for a hurricane here because I could sure use a new boat.

[Col. Sphinx Drummond]

All I know is I'm hoping for a hurricane here because I could sure use a new boat.

I think it's the Law of The Seas. You get to keep any boat that finds it's way on your land during a flood.

[Knoxbanedoodle]

I think it's the Law of The Seas. You get to keep any boat that finds it's way on your land during a flood.

Would that be flotsam, technically, or jetsam?

[Limey]

Would that be flotsam, technically, or jetsam?

Has to be flotsam, as it wasn’t thrown overboard. 

All that’s left is to decide whether the insurance claim is subject to general average.

[Bench]

Michael seems like a hell of a storm. 

[jbm]

Michael seems like a hell of a storm.

Sadly, it appears to be a scenario where people are legitimately caught off guard.  Rapidly strengthening storms are becoming the norm it seems, and it will present a difficult problem for public officials: call for evacuations for every storm as it might quickly become a monster and risk losing the public's confidence when they don't.