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stormtracker

Major Hurricane Irma- STORM MODE

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12 minutes ago, skagen00 said:

Out of pure curiosity (and I have been lurking for hundreds of pages from the last thread) what would we say is the most likely reason to explain why the models have repeatedly shifted reliably westward for the past couple of days?  What influence was the biggest surprise to the models?

Much of the uncertainty has been tied to the ridge/trof combo across North America. Now the focus is shifting towards the specific heights at the base of that trof across the Southeast. Higher heights than modeled would want to prolong the westward motion, lower heights than modeled would suggest a faster turn. 

As an aside, the ensemble members that tracked farther south of the mean were the ones more likely to prolong westward movement and make landfall on the west coast of FL.

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It's going to be interesting tonight especially in the next couple hours. We're in a significant stage now seeing how this evolves later for Florida.

Waiting for the first sign of it north shifting. It looks like it will start to ride up the coast nw soon.

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31 minutes ago, AcePuppy said:

Latest IR

 

hifloat5_None_anim.gif

Notice the northward movement of the clouds off of western Cuba. This appears to be part of the steering motion that will kick Irma toward the FL Keys and FL West Coast. It's the timing of the kick that is causing consternation on this board. With that in mind, I believe we may see the eyewall scrape along the Cuban coast for the next 1-3 hours, maybe even with a brief landfall of textbook definition, before this thing veers back out into warm water of the Florida Strait.

(I am no meteorologist, just observing possible signs on Sat/IR) 

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7 minutes ago, senc30 said:

If that NW movement starts in the next 2-3 hours, wouldn't that be about 10-12 hours sooner then modeled? I'm asking because maybe I'm looking at things wrong but it seems like the NW turn wasn't supposed to happen until about noon tomorrow. 

No it would have to turn nw very soon or it would end up crossing Cuba which no model showed. Its the sharp north turn that happens tomorrow

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A point to make about potential impacts Cuba will have.  If this was a small system brushing up against the coast of a continent, you'd have roughly half the system deprived of TCHP.  However, Irma is brushing up against an island (a large one, I admit) and it's large circulation extents to the south of Cuba, (which has the highest TCHP in the Atlantic basin.  So there is even more of a negating effect, than otherwise would be

...so to summarize...Irma is/was just starting to intensify, is brushing/slightly entering the Cuban coast (relatively low terrain), has 80%+ of her circulation over bath water, (and super bath water to the south of Cuba), and should have a modest residual time over/adjacent to land (12-18 hrs.)

I'd expect a 20mph diminishment of wind and a 20mb rise upon exiting/lifting from the N. Cuban coast. 

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4 minutes ago, geddyweather said:

Notice the northward movement of the clouds off of western Cuba. This appears to be part of the steering motion that will kick Irma toward the FL Keys and FL West Coast. It's the timing of the kick that is causing consternation on this board. With that in mind, I believe we may see the eyewall scrape along the Cuban coast for the next 1-3 hours, maybe even with a brief landfall of textbook definition, before this thing veers back out into warm water of the Florida Strait.

(I am no meteorologist, just observing possible signs on Sat/IR) 

That is just anticyclonic outflow from Irma itself. The larger steering flow if farther north.

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4 minutes ago, LakeEffectKing said:

A point to make about potential impacts Cuba will have.  If this was a small system brushing up against the coast of a continent, you'd have roughly half the system deprived of TCHP.  However, Irma is brushing up against an island (a large one, I admit) and it's large circulation extents to the south of Cuba, (which has the highest TCHP in the Atlantic basin.  So there is even more of a negating effect, than otherwise would be

...so to summarize...Irma is/was just starting to intensify, is brushing/slightly entering the Cuban coast (relatively low terrain), has 80%+ of her circulation over bath water, (and super bath water to the south of Cuba), and should have a modest residual time over/adjacent to land (12-18 hrs.)

I'd expect a 20mph diminishment of wind and a 20mb rise upon exiting/lifting from the N. Cuban coast. 

I'd been saying around 25 mph...that sounds right

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5 minutes ago, Stormlover74 said:

No it would have to turn nw very soon or it would end up crossing Cuba which no model showed. Its the sharp north turn that happens tomorrow

Thank you for the answer! I was going on what the models were showing and it just looked to me that a wnw movement would continue until around noon tomorrow then a NW to N after that. Again thanks for getting back to me with an answer.

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5 minutes ago, LakeEffectKing said:

A point to make about potential impacts Cuba will have.  If this was a small system brushing up against the coast of a continent, you'd have roughly half the system deprived of TCHP.  However, Irma is brushing up against an island (a large one, I admit) and it's large circulation extents to the south of Cuba, (which has the highest TCHP in the Atlantic basin.  So there is even more of a negating effect, than otherwise would be

...so to summarize...Irma is/was just starting to intensify, is brushing/slightly entering the Cuban coast (relatively low terrain), has 80%+ of her circulation over bath water, (and super bath water to the south of Cuba), and should have a modest residual time over/adjacent to land (12-18 hrs.)

I'd expect a 20mph diminishment of wind and a 20mb rise upon exiting/lifting from the N. Cuban coast. 

What would you expect in an increase in winds as it comes off Cuba before it makes landfall into the Keys/SW Florida?

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Meso models like the HRRR and RAP are useful for short term trends in the cyclone (Do not pay attention to intensity). Both models are right on top of each other with track and the turn should be commencing right about now which according to radar and satellite, that seems to be the case. Both runs take the CoC parallel to the northern coast with the eye pretty much bisecting the coastline. This is being modeled unbelievably right now and only deviations we should see at this point are wobbles. We might see some minor weakening due to the land interaction, but it's unanimous that a strong core, once off the coast, will assist in Irma's ability to strengthen with steady pressure falls and develop a deep convective ring around the CoC. Whether or not the wind speeds adjust quick enough to get the storm back to a Cat 5 are unknown, but they will have the ability. If not, high end Cat 4 is well within reason.

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2 minutes ago, LakeEffectKing said:

A point to make about potential impacts Cuba will have.  If this was a small system brushing up against the coast of a continent, you'd have roughly half the system deprived of TCHP.  However, Irma is brushing up against an island (a large one, I admit) and it's large circulation extents to the south of Cuba, (which has the highest TCHP in the Atlantic basin.  So there is even more of a negating effect, than otherwise would be

...so to summarize...Irma is/was just starting to intensify, is brushing/slightly entering the Cuban coast (relatively low terrain), has 80%+ of her circulation over bath water, (and super bath water to the south of Cuba), and should have a modest residual time over/adjacent to land (12-18 hrs.)

I'd expect a 20mph diminishment of wind and a 20mb rise upon exiting/lifting from the N. Cuban coast. 

That's about what I was thinking (loss of intensity wise), but didn't want to say. Certainly a lot more credibility coming from you.  If ever there were a case where prolonged land interaction doesn't cause massive weakening, this is it.

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Just now, AcePuppy said:

What would you expect in an increase in winds as it comes off Cuba before it makes landfall into the Keys/SW Florida?

My earlier thinking (when I created my map) was a robust deepening, but little in the way of max wind increases.

That has changed, and I think the NHC is about right with 160 just prior to LF in the Keys....maybe a touch higher....

...thoughts as of now..

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Looking at Cuban radar is looks like she is turning NW. Right on NHC track. Man...what a forecast.


There has been no turn yet. All recon fixes have had due west movement.
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3 minutes ago, MillvilleWx said:

Meso models like the HRRR and RAP are useful for short term trends in the cyclone (Do not pay attention to intensity). Both models are right on top of each other with track and the turn should be commencing right about now which according to radar and satellite, that seems to be the case. Both runs take the CoC parallel to the northern coast with the eye pretty much bisecting the coastline. This is being modeled unbelievably right now and only deviations we should see at this point are wobbles. We might see some minor weakening due to the land interaction, but it's unanimous that a strong core, once off the coast, will assist in Irma's ability to strengthen with steady pressure falls and develop a deep convective ring around the CoC. Whether or not the wind speeds adjust quick enough to get the storm back to a Cat 5 are unknown, but they will have the ability. If not, high end Cat 4 is well within reason.

What kind of interpolation are you using? Location of Irma is outside of HRRR's domain, at least on TT it is..... 

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1 minute ago, SN_Lover said:

What kind of interpolation are you using? Location of Irma is outside of HRRR's domain, at least on TT it is..... 

HRRR domain on Weatherbell shows very northern coast of Cuba using SE US regional depiction. There's also a 500 Vort panel to use and you can see the northern edge of the CoC at the bottom of screen. Little easier to see on RAP and it shows something very similar. It's at the very end of each model domain, but it's there. I'm in full agreement with LEK. As long as the core isn't ravaged, this should be able to rebound pretty well within Straits waters. 

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I always forget about this site. Very useful. Thanks for the post. So far everything is lining up. 

Yep...anyone who thinks she is just going to continue barreling into Cuba lacks the proper respect for the current state of modeling. We can do pretty good six hours out with large scale features...

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The 3km NAM track and wind depictions don't seem all that bad. A fairly widespread area progged to experience winds over 100 mph, including Miami.IMG_4521.JPG.ead91eb50ce409550a850fe57f65ef96.JPG

Courtesy WeatherBELL.

 

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