Major Hurricane Irma- STORM MODE

[JC-CT]

2 minutes ago, donsutherland1 said:

The 12z ECMWF takes Irma across Key West into southwest Florida. That portion of the state appears likely to experience the most severe conditions from Irma. At this time, there may be some reason for cautious optimism that Miami will experience a rough but not catastrophic impact. Caution is still advisable, as the ECMWF has averaged 48-hour errors in its track forecast of just over 50 miles. A 50-mile shift to the East would be devastating for Miami. Hopefully, tonight's and tomorrow's runs and the storm tracks will allow one to have greater confidence in where things currently stand.

Courtesy of Weather.US:

 

Thanks Don for reminding everyone just how much uncertainty still remains in the exact location of landfall.

And that is average track error. I'm sure a much bigger variance would still fit under the bell curve.

[SnowGoose69]

1 minute ago, NJwx85 said:

If the Euro track verified, even Orlando could experience gusts to hurricane strength. If I recall correctly, they took a pretty good beating from Charley there.

They gusted to 105 but easily had 70-90 for 3/4 hours 

[The Iceman]

This may just be anecdotal but I can recall several times that a storm was projected to graze the coast before turning away N that the storm almost always turned quicker than anticipated. Like Matthew was supposed to get much closer to the coast than it did before turning N but it ended up turning earlier than expected. Even on Irma's track several times it seemed to wobble around making landfall at a few islands. Are there any studies out there that confirm this phenomenon or are these just coincidences? I would think that with the models that show it making landfall being just coastal grazes, that there is a pretty good chance it turns north earlier than expected to avoid landfall with Cuba and escapes NW as soon as it can. Was Matthew and a few other cases just extremely good timing and the steering mechanisms arrived earlier than anticipated that made the storm turn N sooner than expected or is there a noted tendency for storms to 'avoid' landfall if possible? It seems like Irma would be a solid candidate to make this turn earlier if there is that tendency for storms to avoid landfall and stay over water due to the fact it just barely grazes Cuba on every model that makes landfall. Can anyone chime in on this?

[Jfreebird]

Here is a pretty good simulated IR image from the euro 12z run

[McQuackleton]

 

[40/70 Benchmark]

15 minutes ago, CoastalWx said:

It's an interesting solution on the euro. The storm obviously would weaken over cstl Cuba, but if the euro is right, that is rapidly intensifying into SW FL where the importance of this storm was more centered for MIA-FLL area. 

I think MIA is dodging yet another bullet....RELATIVELY SPEAKING.

West shift and land interaction...its always a wild card how these systems recover, but I do wonder if the delay in latitude buys it more time before shear impacts??

[Paragon]

1 minute ago, 40/70 Benchmark said:

I think MIA is dodging yet another bullet....RELATIVELY SPEAKING.

West shift and land interaction...its always a wild card how these systems recover, but I do wonder if the delay in latitude buys it more time before shear impacts??

It's also going to pass over some super warm water- maybe near The Loop Current that we discussed earlier.  West coast of Fla is much more vulnerable to surge than the east coast is.

 

[wawayanda]

Simulated radar from the Euro run as Irma slides along Cuba

[Papa Joe]

http://www.met.inf.cu/asp/genesis.asp?TB0=PLANTILLAS&TB1=RADAR&TB2=../Radar/07Holguin/hlgMAXw01a.gif

 

Holguin Cu Radar Loop has the entire eye

 

A Google map of the area, with Satellite background shows the underseas topology

https://www.google.com/maps/@22.0707218,-76.8645963,792785m/data=!3m1!1e3

By coming close to Cuba, Irma is avoiding the shallower waters of the Bahamas. Then you can see how deep the Florida Straits are (6000')

 

[RUNNAWAYICEBERG]

I thought the trough was a tad progressive on WV imagery last night compared to guidance. The west shifts make sense. 

[Paragon]

2 minutes ago, Walrus said:

There are no coincidences. 

Some of that might be due to resistance, I've seen that with TC, their forward momentum slows down when they approach land (provided there aren't any strong steering currents around.)

[SnowGoose69]

3 minutes ago, 40/70 Benchmark said:

I think MIA is dodging yet another bullet....RELATIVELY SPEAKING.

West shift and land interaction...its always a wild card how these systems recover, but I do wonder if the delay in latitude buys it more time before shear impacts??

The Euro showed about what I said MIA and north would see IF that track verified.  70-80 gusts to 100.

[CoastalWx]

6 minutes ago, 40/70 Benchmark said:

I think MIA is dodging yet another bullet....RELATIVELY SPEAKING.

West shift and land interaction...its always a wild card how these systems recover, but I do wonder if the delay in latitude buys it more time before shear impacts??

It's going over rocket fuel and low shear after Cuba, so as long as core isn't shredded, don't see why euro solution is tossed.

[olafminesaw]

3 minutes ago, Papa Joe said:

http://www.met.inf.cu/asp/genesis.asp?TB0=PLANTILLAS&TB1=RADAR&TB2=../Radar/07Holguin/hlgMAXw01a.gif

 

Holguin Cu Radar Loop has the entire eye

 

So the ERC looks like it's complete based on that.

[Michigander]

112 terajoules...

 

[hooralph]

how far up the west coast does surge become a real risk with that track?

[rockchalk83]

Saying a major metro area has "dodged a bullet" ~36 hours before landfall is premature. We've seen models over correct one way and then revert back to a previous solution. No model can be expected to have the eye of the storm within 20 miles of verification ~36 hours before landfall. 

That said, the trend is the trend...but caveat emptor when it comes to extrapolating said trend. 

[SnowGoose69]

Just now, CoastalWx said:

It's going over rocket fuel and low shear after Cuba, so as long as core isn't shredded, don't see why euro solution is tossed.

I think it may be disrupted enough that it doesn't really strengthen a whole lot.  The one if may be continued west track adjustments that keep it over water way longer off SW Florida.  If that happens it may have another 12-18 hours to ramp back up. 

[dan11295]

If the track is vertabim what the Euro Sim IR showed, you would think Irma at least get knocked down to a category 3 storm. Needless to say there are a lot of wild cards regarding how exactly the circulation interacts with the coast.

[Paragon]

2 minutes ago, Michigander said:

112 terajoules...

 

I wonder what the record is in the Atlantic basin- Ike? Sandy?

[mappy]

2 minutes ago, hooralph said:

how far up the west coast does surge become a real risk with that track?

this may help

http://www.nhc.noaa.gov/surge/psurge.php

 

[CoastalWx]

Just now, SnowGoose69 said:

I think it may be disrupted enough that it doesn't really strengthen a whole lot.  The one if may be continued west track adjustments that keep it over water way longer off SW Florida.  If that happens it may have another 12-18 hours to ramp back up. 

Right, land interaction is key. I'm usually never a fan of tropical systems getting all fired up after being on land for a time, but Irma does have a large circulation which may help.

[Stormlover74]

Just now, Paragon said:

I wonder what the record is in the Atlantic basin- Ike? Sandy?

Also how much more energy will it have when its approaching the Keys?

[the ghost of leroy]

4 minutes ago, olafminesaw said:

So the ERC looks like it's complete based on that.

nice spiral banding into the eyewall.  this is the best the inner structure has looked in 30 hours.

[NYC10023]

2 minutes ago, hooralph said:

how far up the west coast does surge become a real risk with that track?

Good question. Flying down to Ft. Myers tonight, helping my family in Cape Coral who couldn't evacuate. I just talked to them, they're not concerned about surge AT ALL. Yet they live on Gulf access canal .5 mile from Pine Island Sound (basically the Gulf)

[ag3]

Motion on latest loop looks more NW then W. Maybe it will avoid Cuba.

[klw]

for the new thread: Current state of things as of 2PM update

[McQuackleton]

Latest Guidance

 

[bdgwx]

Here's the SHIPS diagnostic header. As you can see it's not very bullish on intensification though it does at least maintain 135 knot wind speeds up to LF. However, most other dynamic models are suggesting intensification during the lead up to LF including the GFS, Euro, and HWRF with the notable exception of COAMPS which shows weakening even though it keeps Irma just off the coast of Cuba. HMON has been subpar both in terms of track and intensity (obviously) so discounting it seems prudent. Though, despite it not being ocean coupled in the Atlantic basin it is seeing an otherwise favorable environment for intensification. HWRF and COAMPS have been exhibiting equal skill (HWRF better at short range and COAMPS better at long range) and both are beating the IVCN and OFCL forecasts. Conceptually it does seem reasonable that some intensification is possible in the Straights of Florida because SST and TCHP are high, shear is modest up to LF, and there's dynamic model consensus for deepening. Right now my best guess on when the trough interaction will begin is at 06-12Z on Saturday morning. The outflow to the NW may get shunted by the trough, but a wide open channel should open to the NE as a result of Irma getting captured into the RER of an 80-110 kt jet streak. There's a short window in which Irma may get an upper level divergence boost without being impacted too much by shear. A big wild card on intensity will obviously be the land interaction or even landfall with Cuba.

 

                    * ATLANTIC     SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  IRMA        AL112017  09/08/17  12 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND   130   127   129   133   134   137   135   128   117   100    83    61    47
V (KT) LAND      130   127   129   133   134   137   119    68    41    31    28    27    27
V (KT) LGEM      130   124   121   122   124   130   129    67    40    31    28    27    27
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)         6     5     7     6     7     9    15    24    29    41    42    38    34
SHEAR ADJ (KT)     1     1    -3    -2     1     0     6     2     5     2    -9     2     5
SHEAR DIR        303   288   270   272   308   255   245   224   210   204   206   215   223
SST (C)         29.7  29.7  29.8  29.9  30.0  29.9  30.0  29.9  29.4  28.5  26.9  25.8  24.9
POT. INT. (KT)   165   164   166   167   169   167   169   168   159   146   124   111   102
ADJ. POT. INT.   157   153   153   153   152   149   150   149   141   128   106    92    86
200 MB T (C)   -51.1 -50.4 -50.5 -50.5 -50.5 -50.1 -49.7 -48.9 -48.7 -47.9 -48.1 -48.9 -50.3
200 MB VXT (C)   1.4   1.1   1.0   1.0   0.9   1.1   1.5   1.9   1.7   2.0   1.5   2.3   1.9
TH_E DEV (C)      13    13    13    13    12    11     8     6     1     1     0     1     0
700-500 MB RH     56    59    62    65    66    65    63    61    60    55    48    42    37
MODEL VTX (KT)    37    36    38    39    39    44    50    52    50    42    33    20    13
850 MB ENV VOR    55    73    79    86    94   131   141   149   165   158   169   139   101
200 MB DIV        29    49    66    54    59    76    98    57   122    83    45    -4   -13
700-850 TADV      11     6     7     7     8    14    31    35    60    61     6    11     6
LAND (KM)        128   112    87    61    66   102    -4   -76   -71  -183  -434  -570  -622
LAT (DEG N)     21.8  22.1  22.4  22.7  22.9  23.9  25.2  27.0  29.2  31.6  34.3  35.7  36.3
LONG(DEG W)     74.7  75.9  77.0  78.0  78.9  80.2  80.9  81.4  82.1  83.3  85.2  86.6  87.8
STM SPEED (KT)    13    11    10     9     8     8     8    10    12    14    12     7     6
HEAT CONTENT      59    53    60    49    70    59    83    53    31    13     0     0     0

[WintersComing]

3 minutes ago, CoastalWx said:

Right, land interaction is key. I'm usually never a fan of tropical systems getting all fired up after being on land for a time, but Irma does have a large circulation which may help.

And to be honest I don't completely buy the Euro solution.  Looking at satellite and radar it looks to be heading slightly north of due west. Don't think a glancing blow will degrade it that much.  A direct hit on Cuba would obviously change things a bit.