F-5 Posted September 7, 2017 Share Posted September 7, 2017 ERC or not aside, the OEW has contracted about 12 or so miles in the past two four hours based on radar loop out of TJUA. Link to comment Share on other sites More sharing options...
canderson Posted September 7, 2017 Share Posted September 7, 2017 3 minutes ago, Bostonseminole said: yahoo... come on.. It quotes Guadeloupe prefect Eric Maire on that data and is an AFP story. Read first. Link to comment Share on other sites More sharing options...
WishingForWarmWeather Posted September 7, 2017 Share Posted September 7, 2017 3 minutes ago, Bostonseminole said: there are a couple of links up top.. but so much info coming from all direction, looking fro something official from the Gov.. not easy.. don't speak french. Sorry about that. I was about 1 page behind, trying to keep up and do bed time at the same time. I've seen the links now. Thanks for the info. Link to comment Share on other sites More sharing options...
TalcottWx Posted September 7, 2017 Share Posted September 7, 2017 59 minutes ago, Ralph Wiggum said: The whole argument about "it's weakening", "its an ERC", "dry air is entering Irma", "clearly it is losing it's structure", "the eye wall on the NE side is deteriorating rapidly", "the eye just winked at me", etc are almost all moot points. Anyone who has studied or tracked tropical systems will know there are always fluctuations and there are always random imperfections in even the most perfect looking storms. They dont remain textbook/ meteo 101 hardback cover photo worthy the entire life cycle of the TC. It's not how it works. Some of you guys seriously need to step away from the maps for a couple of hours. This was my entire point earlier. It's banter thread stuff. I'm not helping, my complaint is off topic. But maybe that's stuff better suited for the banter thread. Link to comment Share on other sites More sharing options...
WishingForWarmWeather Posted September 7, 2017 Share Posted September 7, 2017 T# down to 7.0 -- regardless of the argument why, something is affecting presentation. When's the next time we get recon data -- matter of fact, I keep asking this, so, where can I follow along on my own so I don't need to rely on asking you all? And when do next model cycles run? Sorry, I know I should have this bookmarked by now, but it's a new computer and lost all my bookmarks. Link to comment Share on other sites More sharing options...
ncskywarn Posted September 7, 2017 Share Posted September 7, 2017 18 minutes ago, Enzedel92 said: Last few radar loops has track heading NW???? Putting the eye in line in Turks and Caicos?? Shooting way north.... It does have a little bit more of a Northerly component at the 5 PM update the NHC said 285 degrees at 14 knots. On the 8 PM advisory it showed 290 degrees at the same speed. Not sure how much if any difference that will make as far as model runs though if any. Link to comment Share on other sites More sharing options...
danny007 Posted September 7, 2017 Share Posted September 7, 2017 1 minute ago, WishingForWarmWeather said: T# down to 7.0 -- regardless of the argument why, something is affecting presentation. When's the next time we get recon data -- matter of fact, I keep asking this, so, where can I follow along on my own so I don't need to rely on asking you all? And when do next model cycles run? Sorry, I know I should have this bookmarked by now, but it's a new computer and lost all my bookmarks. https://www.tropicaltidbits.com/recon/ Link to comment Share on other sites More sharing options...
CamSE-Wx Posted September 7, 2017 Share Posted September 7, 2017 Kind of late to noticing this, but what're opinions on the EPS model run? Seems to be pretty heavy with ensembles running into the GOM. Link to comment Share on other sites More sharing options...
TalcottWx Posted September 7, 2017 Share Posted September 7, 2017 Recent dropsonde in NE quad found 163kt mean wind in lowest 150m Link to comment Share on other sites More sharing options...
TalcottWx Posted September 7, 2017 Share Posted September 7, 2017 Just now, cdhay17 said: Kind of late to noticing this, but what're opinions on the EPS model run? Seems to be pretty heavy with ensembles running into the GOM. Seemed to have two clusters- split east and west Link to comment Share on other sites More sharing options...
Jfreebird Posted September 7, 2017 Share Posted September 7, 2017 Now that the NAM is picking up Irma how reliable is it for hurricanes? Link to comment Share on other sites More sharing options...
yoda Posted September 7, 2017 Share Posted September 7, 2017 Just now, Jfreebird said: Now that the NAM is picking up Irma how reliable is it for hurricanes? Not really very much if at all Link to comment Share on other sites More sharing options...
TalcottWx Posted September 7, 2017 Share Posted September 7, 2017 1 minute ago, Jfreebird said: Now that the NAM is picking up Irma how reliable is it for hurricanes? It's really not Link to comment Share on other sites More sharing options...
jojo762 Posted September 7, 2017 Share Posted September 7, 2017 4 minutes ago, sbos_wx said: Recent dropsonde in NE quad found 163kt mean wind in lowest 150m And 186kt at 927mb... Link to comment Share on other sites More sharing options...
No snow for you Posted September 7, 2017 Share Posted September 7, 2017 ``` Update by Dutch Military Minister... update deputy representative en Rita Rhaman on the scene. Ships are on their way. Infrastructure very badly affected. Situation on the ground sxm is very serious. Port very badly damaged. Dock Coast guard Airport Telecommunications Electricity and utilities Briefly. We have to prepare for the serious Appearances were insufficient No info on victims yet This afternoon 16.00 is being watched from the air by helicopter. [2:26 pm, 9/6/2017]: update from the crisis team where rst is part of: Sxm is completely unreachable. Dod is leading and is going to fly a helicopter tonight at 20 to determine where to land. At present the cruiseterminal / Piers is completely destroyed and the airport is unreachable because the runway is still severely damaged. [2:26 pm, 9/6/2017]: the control tower of the French airport has fallen above the runway and is expected to take weeks before the French have their own job. Defence has indicated that it is not possible for civil aviation to be available for the time being, and an airlift will be launched between Curacao and st. Maarten as soon as defence is free [2:26 pm, 9/6/2017] there will be additional pilots from NL to continue to fly this airlift. [2:26 pm, 9/6/2017]: there are currently 10 shelters, of which 5 are in operation. One of the first priorities is also to extend the number of operational shelter with a view to the new hurricane Jose, which Saturday / Sunday at sxm.. #Sxmstaysafe ``` Link to comment Share on other sites More sharing options...
Windspeed Posted September 7, 2017 Share Posted September 7, 2017 Recent dropsonde in NE quad found 163kt mean wind in lowest 150m The northeast side of this cyclone is the most impressive expanse of Category 2+ sustained hurricane force wind I have ever observed. I thought Isabel was massive but this is extending well out over 75 miles from the eye. This has to be due to the extreme pressure gradient between the high surface pressure and 500mb ridge against Irma. I am sure there have been large cyclones with a more impressive range against a strong ridge (Haiyan comes to mind), but there wasn't recon to verify. EDIT: I should have clarified this is at flight level, but still, it's beyond impressive. Link to comment Share on other sites More sharing options...
SN_Lover Posted September 7, 2017 Share Posted September 7, 2017 Irma is heading NW per radar.... Link to comment Share on other sites More sharing options...
No snow for you Posted September 7, 2017 Share Posted September 7, 2017 1 hour ago, NWLinnCountyIA said: Whats that thing spinning around inside the eye? CC and ZDR say its hydrometeorological, but why is it there? That is birds trapped in the eye Link to comment Share on other sites More sharing options...
aperson Posted September 7, 2017 Share Posted September 7, 2017 What is the minimum time frame where it's feasible to make these "Irma is going X direction" claims? From what I can see, the system seems to have gyroscopic motion like a smaller circle is rotating inside of a larger circle. Given this, you would need to average the motion track out over a longer time. I would love more insight into this motion behavior because I saw similar with Harvey but I'm pretty naive as to the underlying mechanism of action. Link to comment Share on other sites More sharing options...
Z-Cast Posted September 7, 2017 Share Posted September 7, 2017 3 minutes ago, SN_Lover said: Irma is heading NW per radar.... Still heading a long the NHC forecast path per AVN Irma Long Floater overlay. Link to comment Share on other sites More sharing options...
4waresnowcone Posted September 7, 2017 Share Posted September 7, 2017 Just now, No snow for you said: That is birds trapped in the eye Well I'll be damned. That sucks. Link to comment Share on other sites More sharing options...
jojo762 Posted September 7, 2017 Share Posted September 7, 2017 3 minutes ago, SN_Lover said: Irma is heading NW per radar.... Looks WNW to me. I have it heading at about 290 degrees, slightly above 15mph. Link to comment Share on other sites More sharing options...
OUGrad05 Posted September 7, 2017 Share Posted September 7, 2017 Just now, jojo762 said: Looks WNW to me. I have it heading at about 290 degrees, slightly above 15mph. 1 minute ago, Enzedel92 said: This..... All these bs acrononyms being thrown out and nothing more immportant than change in direction!!! I clearly see it. Current track puts it on the north side of Turks. Which model had that!! NONE WNW, don't look at just one or two frames, bobbles can be misleading. Link to comment Share on other sites More sharing options...
hlcater Posted September 7, 2017 Share Posted September 7, 2017 2 minutes ago, No snow for you said: That is birds trapped in the eye No it wasnt, it had high CC and ZDR near one meaning it was a met phenomenon. Was probably some sort of weird mesovortex as others have said. Link to comment Share on other sites More sharing options...
No snow for you Posted September 7, 2017 Share Posted September 7, 2017 2 minutes ago, NWLinnCountyIA said: No it wasnt, it had high CC and ZDR near one meaning it was a met phenomenon. Was probably some sort of weird mesovortex as others have said. You have your theory I have mine. I have seen it happen before on large eyes. But ok Link to comment Share on other sites More sharing options...
Hoosier Posted September 7, 2017 Share Posted September 7, 2017 Ah yes, the radar hallucination stage. If you're going to definitively state that it has changed direction/is running north of NHC track, back it up with some evidence. Link to comment Share on other sites More sharing options...
jojo762 Posted September 7, 2017 Share Posted September 7, 2017 Eye wall is starting to become wrapped entirely in deep convection again, evident on radar as well as satellite. Won't happen immediately though, as it is a process... Believe one of our red-tags mentioned this was probably going to happen earlier. Link to comment Share on other sites More sharing options...
OUGrad05 Posted September 7, 2017 Share Posted September 7, 2017 1 minute ago, jojo762 said: Eye wall is starting to become wrapped entirely in deep convection again, evident on radar as well as satellite. Won't happen immediately though, as it is a process... Believe one of our red-tags mentioned this was probably going to happen earlier. Yeah the presentation is definitely down a couple notches from earlier, dry air I suspect combined with ERC. We'll see how it ramps back up over night. Link to comment Share on other sites More sharing options...
LakeEffectKing Posted September 7, 2017 Share Posted September 7, 2017 Can't say that I differ too much from NHC...I think Irma will move a tad quicker initially, but, overall, the only subtle differences is wind speed at LF and a slightly western position at LF. Link to comment Share on other sites More sharing options...
USCG RS Posted September 7, 2017 Share Posted September 7, 2017 The ERC may have been disrupted due to some land interaction thanks to the close pass to PR. With that being said, it still has 3 more days over very warm water with nearly optimal atmospheric conditions to work with. All guidance shows Irma strengthening in the Southern Bahamas, so current intensity is irrelevant now that we temporarily don't have any threats to land.OK.. So this has been bothering me the whole night. Therefore i spent the past three hours working and researching eyewall replacement cycle s (ERC) . I will preference with this: ERC are very poorly understood and research on them is just beginning. However, I found a theory about ERC which not only makes sense, but I was likewise able to extrapolate an answer for which I believe fits why these ERC are doing nothing to weaken Irma.Terms:ERC : Eyewall replacement cycle. HBL : Hurricane boundary layer. NRF : Net radial force. PGF : Pressure Gradient Force.I will also preferance with the fact that I view weather as the earth's immune system and really all weather is is an attempt for the atmosphere to find an equilibrium (much like our immune system is to bring homeostasis to the body).So let's get to it. ERC, in this theory, are believed to take place due to a set of complicated physics. As a hurricane is born, there are three main components, physics wise, which make up the storm (at least as it pertains to ERC). The first is the HBL which extends approximately 1 km into the atmosphere, from the surface. It interacts with most of the surface friction. The second is the PGF, which essentially forces particles from areas of higher density (pressure) to areas of lower pressure. The last is known as the NRF, which is essentially the force directed towards the center of a rotating mass.As a hurricane develops, these forces work with each other and eventually, when the storm reaches a certain intensity, an excess of NRF creates a secondary wind maximum approximately 40-60km from the center of the hurricane. This secondary wind maximum is always believed to be because the HBL cannot properly maintain a balance of angular momentum (or the acceleration of particles/mass in a circulation motion), or in other words, the HBL cannot keep the particles separated in such a way that the pressure and buildup of particles remain uniform. This, combined with a positive NRF, creates convergence. This convergence creates an up welling which then leads to a secondary maximum. This secondary maximum, in turn, creates more PGF (the force of a particle over a given area. The higher the PGF, due to more particles in a smaller area, the higher the winds). Eventually, this leads to enough of a convergence that a secondary eyewall is formed and two wind maxima are thus created. As many know, during this time, the overall windspeed of the maximum sustained winds decrease due to the maximum winds being spread out over a larger area and thus the wind speed lowers (or.. The PGF is distributed over a larger area and therefore while the mass remains the same, because force equals mass times acceleration, acceleration is lower and therfore the force or net wind speed decreases). Eventually, the PGF, combined with angular momentum, will coerce the outer eyewall to contract, thus ending the ERC. At this time, the winds will increase as will the overall size of the wind field of the storm, while allowing the hurricane to likewise strengthen.But the question that's plagues me today is why has Irma skipped this weakening phase of the ERC and likewise why has she been constantly cycling through them and having them take place in a rapid fashion? What I propose is this. Irma has been in essentially a perfect, or lab like environment, for her lifespan. This is what is allowing her to explosively deepen and shatter records. What I likewise propose is this. Irma is showing us that hurricanes create ERC of their own accord. In other words, an ERC has nothing to do with outside influences and is strictly because of the mechanism of the hurricane itself (and the strengthening mechanisms within). Likewise, because ERC are part of the hurricanes overall structure, in theory, it should not hurt the hurricane, but rather, help it. Left to its own devices, this is what Irma is doing. It's part of a necessary strengthening cycle for well developed hurricanes. The HBL, I propose, creates the issue for ERC as within this layer, there is friction. This friction slows the contraction of the secondary eyewall and forces the storm to balance itself out to preserve itself, while it deals with the friction and the effects of it. Because Irma is in a lab like environment, the friction of the ocean is essentially non existant as it is over flat and incredibly warm water. Likewise, there is no sheer or dry air to interfere with the Core and venting mechanisms of Irma. As such, these ERC can begin and complete without any interference and then, once the outer wind maxima are mature, the PGF and angular momentum can allow the outer wind maxima to contract, replacing the old eyewall and thus completing the ERC, in time for it to build and start once again. Therefore, she can bypass any weakening state that the friction within the HBL would cause, as, essentially, there isn't any to speak of. This, of course, is strictly a theory Link to comment Share on other sites More sharing options...
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