Hurricane Maria

[Ginx snewx]

13 hours ago, ncforecaster89 said:

Concerning all this discussion regarding estimated/presumed wind speeds and categorical damage relative to Maria's intensity, I would add that each hurricane is unique and there's not necessarily a one to one correlation between Recon estimated MSW at the surface and the actual winds that occur on land.  

In most cases, and in general, one should expect to see wind gusts equal to the MSW value contained in the NHC advisory in the area of the RMW, as the advisory intensity is the absolute maximum estimated surface wind found anywhere in the storm; which is a single point.   

OTOH, there have been much weaker hurricanes (such as Katrina and Irma), which were also weakening at their respective landfalls, but generated extreme wind gusts that far exceeded the typical sustained to wind gust ratio.  

Taking into consideration various factors such as how an EWRC might effect wind transport from FLvl to the surface, land friction, influences of orography and topography, an objects exposure to the strongest winds, and the quality and durability of said onjects, are just a few reasons why we shouldn't presume a one to one correlation between the NHC advisory MSW and the damage that occurs or similar assumptions comparing storms of similar intensity.         

Although one can reasonably argue that Maria may have weakened  below 135 kt at landfall (for which I agree), I think all the respective data strongly suggests that Maria was most certainly still a very powerful category-four hurricane, regardless of the extent or severity of the damage that has been left in its wake.    

Velocity data at LF suggests otherwise highlighted is a 155 but the color bar for radarscope suggests 175 just offshore and oh man, the flashflooding  in Dominica created Mt St Helens flood like debris fields, excellent long walk through the Western End of Dominica, which was on the weaker side! https://youtu.be/QH1vPCoHYbc 

[klw]

Looks like the eye is clearing out again:

http://www.ssd.noaa.gov/PS/TROP/floaters/15L/imagery/vis_lalo-animated.gif

[bluewave]

It's the combination of wind damage and flash flooding that makes this a really difficult recovery for Puerto Rico.

 

 

[Hazey]

Ensembles are between St. John's and the Grand Banks..moved east over the last 3 days, out of your hood for almost certain.  

 

That's what I figured. I'm cool with that. Maria has caused enough mayhem. Time for it to ride off into the North Atlantic abyss.

[wxmx]

11 minutes ago, klw said:

Looks like the eye is clearing out again:

 

http://www.ssd.noaa.gov/PS/TROP/floaters/15L/imagery/vis_lalo-animated.gif

 

Shear increased temporarily according to CIMSS to between 20-30 kts very early this morning, then went down to around 20kts, but it's on the rise again.

[Hazey]

Aren't land obstacles and obstructions(natural and manmade) taken into account when wind velocity is measured during landfall? I mean if a hurricane has a sustained wind of say 160mph, it's out in the wide open ocean. No impediments to the strength of the winds. When a anemometer on land measures the wind has been disrupted by land(hills,mountains, trees) as well as man made infrastructure(buildings etc). Makes me think you'll never get a true representation of the max wind speeds, atleast on land anyway. Perhaps this is all factored in? Always been curious about this.

[SnoSki14]

15 minutes ago, Hazey said:

That's what I figured. I'm cool with that. Maria has caused enough mayhem. Time for it to ride off into the North Atlantic abyss.

Not before it gives the Outer Banks a scare, it wouldn't take much to send it onshore.

[wxmx]

Just now, Hazey said:

Aren't land obstacles and obstructions(natural and manmade) taken into account when wind velocity is measured during landfall? I mean if a hurricane has a sustained wind of say 160mph, it's out in the wide open ocean. No impediments to the strength of the winds. When a anemometer on land measures the wind has been disrupted by land(hills,mountains, trees) as well as man made infrastructure(buildings etc). Makes me think you'll never get a true representation of the max wind speeds, atleast on land anyway. Perhaps this is all factored in? Always been curious about this.

It is factored in, other than the immediate coast, maximum winds are never expected inland, unless it's at an unimpeded height, but those winds are not representative of the near surface winds.

[ncforecaster89]

18 minutes ago, Ginx snewx said:

Velocity data at LF suggests otherwise highlighted is a 155 but the color bar for radarscope suggests 175 just offshore and oh man, the flashflooding  in Dominica created Mt St Helens flood like debris fields, excellent long walk through the Western End of Dominica, which was on the weaker side! https://youtu.be/QH1vPCoHYbc 

Hi Steve!  Thanks for posting this velocity data.  Please let me clarify that my post was intended to rebutt the suggestion that Maria was anything less than a very powerful category-four hurricane, at landfall.  The part about possibly having weakened below 135 kts is based on the Recon data, continued rise in the central pressure, and satellite presentation at landfall.   My best guess is 130 kts.; the same estimate I had for Patricia.  However,  it's just as conceivable that it retained that extra 5 kts, as well.  Either way, a very intense upper-end category-four hurricane, which was the intent of my post.  

[Ginx snewx]

3 minutes ago, ncforecaster89 said:

Hi Steve!  Thanks for posting this velocity data.  Please let me clarify that my post was intended to rebutt the suggestion that Maria was anything less than a very powerful category-four hurricane, at landfall.  The part about possibly having weakened below 135 kts is based on the Recon data, continued rise in the central pressure, and satellite presentation at landfall.   My best guess is 130 kts.; the same estimate I had for Patricia.  However,  it's just as conceivable that it retained that extra 5 kts, as well.  Either way, a very intense upper-end category-four hurricane, which was the intent of my post.  

Post by Harvey leonard was odd, there is aerial video out of Humacao now where Josh was 

rial

[Sportybx]

12z gfs brings it closer to the coast slightly burshes NC then it pulls directly east OTS 

[ncforecaster89]

Just now, Ginx snewx said:

Post by Harvey leonard was odd, there is aerial video out of Humaco now where Josh was 

rial

I agree. Excellent footage!  Definitely one of Josh's best/most intense chases (maybe top 3 after Hyian and Patricia?).  The extreme wind damage and incredible flooding, as you noted, make this a rather catastrophic event for too many on the island.  Thoughts and prayers are with them all.    

[Sportybx]

Alot slower on this run to 

[Ginx snewx]

6 minutes ago, ncforecaster89 said:

I agree. Excellent footage!  Definitely one of Josh's best/most intense chases (maybe top 3 after Hyian and Patricia?).  The extreme wind damage and incredible flooding, as you noted, make this a rather catastrophic event for too many on the island.  Thoughts and prayers are with them all.    

This is where that wildly gyrating collapsing inner eye came ashore, you can see the Tornadic pockets of Cat 4/5 damage, stripped bark in some spots too

https://twitter.com/WeatherNation/status/911097939132477440

.

[ncforecaster89]

2 hours ago, CheeselandSkies said:

Slightly OT (mods, move to a new thread if you feel necessary but please don't delete) but is this how Andrew was so badly underestimated? This blog suggests that the extreme winds being mixed down over land in small pockets of Andrew's eyewall may have been caused by unusual (for TCs) convective processes within the hurricane.

Obviously it couldn't be in 1992, but is there any way this sort of thing could be predicted (other factors such as oceanic TCHP, shear, max potential intensity, etc in the path toward landfall being favorable to maintain a high-end hurricane) with enough lead time to add extra urgency to forecasts and thus evacuation orders?

Hi cheeseland!  The technology and data available is greatly improved from 1992, as you alluded to, which would have certainly helped.  OTOH, the main reason Andrew rapidly intensified shortly before and through landfall was the completion of an EWRC that had caused it to weaken, beforehand.  The underestimate of the MSW, at the time, was due to the more limited knowledge of the proper ratio between FLvl to surface winds. 

[mappy]

 

[MJO812]

Gefs west of previous runs

 

[HoarfrostHubb]

Any analogs to the odd due east track the 12z GFS has for Maria once it is abeam of the Carolinas?

[gymengineer]

3 minutes ago, HoarfrostHubb said:

Any analogs to the odd due east track the 12z GFS has for Maria once it is abeam of the Carolinas?

Starting from a different longitude, but Cleo 1964:

[Jfreebird]

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...22.8N 71.2W
ABOUT 90 MI...145 KM N OF GRAND TURK ISLAND
ABOUT 420 MI...675 KM ESE OF NASSAU
MAXIMUM SUSTAINED WINDS...125 MPH...205 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...959 MB...28.32 INCHES

[Windspeed]

Palmas Del Mar in the first video is a big wealthy resort area with very well-constructed concrete buildings, complexes and hotels. Not surprisingly, those structures faired well, but as the footage goes on you can see structural damage and deroofed houses.

 

 

Yubacoa, Emajugua, Patallis, Arroya and the South Coast, you can definitely see the houses that faired better with good building codes. Still immense destruction.

 

 

Levitown looks like a war zone, but again, you can see good building codes at work. Some well-built structures look severely damaged.

 

 

Obviously, officials may need ground surveys to confirm codes, severity of structural damage, etc., but I have little doubt this was a Category 4 at landfall. The vast spread of extreme winds is impressive far inland. In retrospect, the ERC may have saved a small area near the coast from receiving catastrophic wind damage, but the larger eyewall took its toll.

[NJwx85]

The 12z ECMWF should come West, the trough coming into the Plains is much flatter, similar to what the 12z GFS showed. And this run also shows a faster dissipation of Jose, leading to a quicker rebuild of the WAR. 

It's debatable if any of this even matters or if we're just delaying the inevitable, however it wouldn't take much more of a Westward trend in order to get OBX into play.

[yoda]

12 minutes ago, NJwx85 said:

The 12z ECMWF should come West, the trough coming into the Plains is much flatter, similar to what the 12z GFS showed. And this run also shows a faster dissipation of Jose, leading to a quicker rebuild of the WAR. 

It's debatable if any of this even matters or if we're just delaying the inevitable, however it wouldn't take much more of a Westward trend in order to get OBX into play.

Doesn't look like it... 96 to 120 Maria is moving due north

and 144 says goodbye... so no westward movement from 12z EURO

[NJwx85]

4 minutes ago, yoda said:

Doesn't look like it... 96 to 120 Maria is moving due north

That's correct, even though the trough itself was flatter this run, it was actually more progressive, so Maria felt the weakness and turned North sooner. Then the Westerlies take over around hr 138 and that's all she wrote. 

I still believe that this isn't a slam dunk OTS storm. Particularly for the OBX area. We've seen a trend today towards a flatter trough and a quicker dissipation of Jose. Should the globals end up too progressive with that trough, I could see Maria making a very close pass near the Outer Banks before eventually heading OTS.

[Juliancolton]

2 minutes ago, NJwx85 said:

That's correct, even though the trough itself was flatter this run, it was actually more progressive, so Maria felt the weakness and turned North sooner. Then the Westerlies take over around hr 138 and that's all she wrote. 

I still believe that this isn't a slam dunk OTS storm. Particularly for the OBX area. We've seen a trend today towards a flatter trough and a quicker dissipation of Jose. Should the globals end up too progressive with that trough, I could see Maria making a very close pass near the Outer Banks before eventually heading OTS.

Isn't that pretty much the way it always works?

[jm1220]

The ranting about moderation, blah blah blah, posts will be deleted. There's a banter thread for that. 

[jburns]

11 minutes ago, jm1220 said:

The ranting about moderation, blah blah blah, posts will be deleted. There's a banter thread for that. 

Not to worry.  He just got Brubecked. 

[Ginx snewx]

NOAA AOC at 1923

[Windspeed]

Hopefully, the people in these areas can get out in time.

 

215PM FLASH FLOOD EMERGENCY for A Dam Failure in Isabela Municipality y Quebradillas Municipality in Puerto Rico.

At 210 PM, dam operators reported the Guajataca Dam is failing causing flash flooding downstream on the Rio Guajataca

This is an EXTREMELY DANGEROUS SITUATION. Busses are currently evacuating people from the area as quickly as they can

https://mobile.twitter.com/NWSSanJuan?p=s

USGS page for info about the watershed and dam:

https://pr.water.usgs.gov/public/rt/pr_lakes/lake_50010800.html

[gymengineer]

The damage videos show widespread roof-off/collapsed buildings across the entire width of the island. It's hard to find examples of Atlantic storms that have caused this type of high-end wind damage upon as large a population.