am19psu Posted February 22, 2011 Share Posted February 22, 2011 Wow-- 82 kt? Wtf? What do you think is causing it to read so high? Locations right in the path of the center (Mardie, Onslow) have barely had sustained gales, so I have skepticism Re: 82 kt. That having been said, that MW image is pretty decent. Well, I think if it was over the open ocean, it could be valid. Even now, ADT is T4.3/72 kts and it has a low bias in CDO environments with microwave eyes. I think the constant frictional dissipation caused by the land is causing the deviation from gradient winds that these intensity estimation algorithms assume. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 22, 2011 Author Share Posted February 22, 2011 Well, I think if it was over the open ocean, it could be valid. Even now, ADT is T4.3/72 kts and it has a low bias in CDO environments with microwave eyes. I think the constant frictional dissipation caused by the land is causing the deviation from gradient winds that these intensity estimation algorithms assume. Interestingly, the new JTWC warning has it at just under hurricane strength (60 kt (1-min)), and the discussion hints that satellite estimates are higher: ANIMATED INFRARED SATELLITE IMAGERY AND A RADAR LOOP FROM LEARMONTH SHOW IMPROVED DEEP CONVECTIVE BANDING WRAPPING AROUND A LOW LEVEL CIRCULATION CENTER. OBSERVATIONS FROM ONSLOW AIRPORT LOCATED 20 NM TO THE EAST ARE INDICATING UP TO 49 KNOT NORTHERLY GUSTS AND A MINIMUM SURFACE LEVEL PRESSURE OF 979 MB. THE INITIAL POSITION WAS BASED ON THE RADAR LOOP AND OBSERVATIONS FROM ONSLOW AIRPORT WITH GOOD CONFIDENCE. THE INITIAL INTENSITY WAS LOWER THAN THE PGTW AND APRF DVORAK ESTIMATES OF 65 KNOTS DUE TO THE OBSERVATIONS. Latest infrared and radar shots show the center straddling the coast. Onslow Airport had 44 kt (10-min) gusting to 56 recently-- several hours after the center passed: Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 22, 2011 Author Share Posted February 22, 2011 Onslow Airport-- which is on the backside of the "eyewall" feature (see radar shot, above)-- just had 53 kt gusting as high as 68. Given that this station most certainly didn't sample the highest, marine-exposure winds, these data strongly suggest Carlos is a 65-kt hurricane on our 1-min-based scale. I'll bet the JTWC would have gone with the Dvorak's 65 kt had they seen these data prior to issuing the most-recent warning. Link to comment Share on other sites More sharing options...
k*** Posted February 22, 2011 Share Posted February 22, 2011 This is like their Fay. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 22, 2011 Author Share Posted February 22, 2011 This is like their Fay. Quiet, troll. Lemme nerd out in peace. Link to comment Share on other sites More sharing options...
k*** Posted February 22, 2011 Share Posted February 22, 2011 Quiet, troll. Lemme nerd out in peace. I'm not really trolling, just making an observation. I actually like today's incarnation of carlos the best. Link to comment Share on other sites More sharing options...
Ed Lizard Posted February 22, 2011 Share Posted February 22, 2011 Looks like shear from the East has decreased somewhat. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 22, 2011 Author Share Posted February 22, 2011 Onslow Airport just had 57 kt (10-min) gusting to 72. By the American 1-min standard, Carlos is mostly certainly a hurricane now, and given that it's highly unlikely this inland location sampled the absolute highest winds in the system, I think this is a bona-fide Cat 3 on the Aussie scale. Let's see if they upgrade it. Link to comment Share on other sites More sharing options...
k*** Posted February 23, 2011 Share Posted February 23, 2011 Today is the 11th anniversary of the landfall of Cyclone Eline in Mozambique. Very neat storm. Started off near Java, crossed the Indian Ocean, switched names, and made dual strikes on Madagascar and Mozambique, rapidly intensifying each time prior to landfall. http://en.wikipedia.org/wiki/Cyclone_Leon-Eline Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 23, 2011 Author Share Posted February 23, 2011 So Carlos crossed the North West Cape, and despite the surface obs which suggested an upgrade, it never got one from either agency. The JTWC kept it at 60 kt (1-min)-- so no 'cane-- and the BoM kept it at 60 kt (10-min)-- so no Cat 3. The obs from Learmonth-- over which the center passed-- have been a bit blah: lowest pressure 980.8 mb, highest wind 40 kt (10-min) gusting to 54. Blah. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 23, 2011 Author Share Posted February 23, 2011 Today is the 11th anniversary of the landfall of Cyclone Eline in Mozambique. Very neat storm. Started off near Java, crossed the Indian Ocean, switched names, and made dual strikes on Madagascar and Mozambique, rapidly intensifying each time prior to landfall. http://en.wikipedia.org/wiki/Cyclone_Leon-Eline Yeah, cool cyclone. The Mozambique landfall (~115 kt) was much sexier than the Madagascar landfall (~90 kt). Here's that portion of Leon-Eline's track-- as depicted in Jorge's cool mapping/analysis tool: Link to comment Share on other sites More sharing options...
am19psu Posted February 23, 2011 Share Posted February 23, 2011 Looking ahead, I'm pretty bearish on March starting with a bang. There might a TC or two just because the monsoon is there, but the large scale pattern is going to be generally unfavorable. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 23, 2011 Author Share Posted February 23, 2011 Looking ahead, I'm pretty bearish on March starting with a bang. There might a TC or two just because the monsoon is there, but the large scale pattern is going to be generally unfavorable. Oh. OK. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 23, 2011 Author Share Posted February 23, 2011 This is like their Fay. Actually, this did turn out to be very Fay-like. Agreed. It mingled with land for days and was constantly on the verge of becoming a 'cane-- and got oh so close-- but never quite made it. (It probably will later today in the open ocean, but who cares now?) Total c*cktease system. I'm annoyed with myself for following it so closely. Link to comment Share on other sites More sharing options...
wxmx Posted February 24, 2011 Share Posted February 24, 2011 Today is the 11th anniversary of the landfall of Cyclone Eline in Mozambique. Very neat storm. Started off near Java, crossed the Indian Ocean, switched names, and made dual strikes on Madagascar and Mozambique, rapidly intensifying each time prior to landfall. http://en.wikipedia....lone_Leon-Eline Hmmm...the maps @wikipedia use SS for 10min winds... I think SS is for 1-min sustained winds only... looking at the official data from Reunion (which is now fixed in the tracker), and using one of the suggested conversion factors (1.14), it was a low end Cat 3 LF in Madagascar. Link to comment Share on other sites More sharing options...
k*** Posted February 24, 2011 Share Posted February 24, 2011 Hmmm...the maps @wikipedia use SS for 10min winds... I think SS is for 1-min sustained winds only... looking at the official data from Reunion (which is now fixed in the tracker), and using one of the suggested conversion factors (1.14), it was a low end Cat 3 LF in Madagascar. wikipedia hints that it was up to 120 kts at madagascar LF...with no citation Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 Hmmm...the maps @wikipedia use SS for 10min winds... I think SS is for 1-min sustained winds only... looking at the official data from Reunion (which is now fixed in the tracker), and using one of the suggested conversion factors (1.14), it was a low end Cat 3 LF in Madagascar. SS is strictly based on 1-min. So if someone is assigning SS values based on a 10-min wind in Wikipedia, they are incorrect. On a related note... Check out the map I posted above-- from your tracker gadget. This morning, the data were a blend of La Reunion and JTWC, and it showed a Cat-2 landfall. Now that the database has switched over and is only La Reunion, the landfall intensity has adjusted up to Cat 3. Link to comment Share on other sites More sharing options...
am19psu Posted February 24, 2011 Share Posted February 24, 2011 Can you have an annular tropical storm? Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 Getting on my high horse, wind speed internationally should be standardised ( along the lines of the metric system... virtually no yanks and poms, indoctrinated as they are to miles an hour, have any idea what a knot is anyway... and apart from trained sailors who has any idea of what the Beaufort scale is?). As such should the measurement of storms should be universal. Personally I'd run with the Aussie system (and attitude). After all I've been through, either on the edge or directly, that Queensland has had to offer in the past 20 years (also a hurricane in Miami in 1986?... help me out guys... the news story of the day was people stirpping containers washed up on the beach). Tropical low: "that's stuffed the weekend's fishing." Cat one: Hmmm, better get some beer and batteries. Cat two: Make sure gas bottles are filled and we should probably take the stuff off the deck. Cat three: Stuff off deck. Freeze some old bottles to keep the fridge going. Might be an idea to tape a few windows after we clean up the yard and stuff everything into the shed. Cat Four: Sh**, this is not good. Do we have enough food? Furniture and mattresses rammed against taped glass. Shed bursting. Roof Lifting. Cat five: F**k. Hold on this is going to be one hell of a ride (for those who have never faced the prospect of an Aussie cat 5 or equivalent... trust me it is terrifying no matter how many extreme weather events you have faced). So what's wrong with that system? Any other ideas? After all, when it's barrelling down your throat at up to 300kph or more, who really gives a toss at how it's rated.... it's the lower stuff that counts. We definitely prefer our system and will stick with it. Re: knots... As I understand it, that actually is the international standard unit of measurement for wind that all agencies-- including the BoM-- use for their technical discussiion and data records. (The BoM uses km/hr primarily for communicating with the public.) And that's what we use in these discussions here-- knots. The only difference is that the USA uses a 1-minute average-- but we have our reasons, and it's not going to change anytime soon. Re: intensity scales... I like the Aussie scale, but I personally prefer the USA scale because it's more detailed. Your scale-- and others around the world-- use five levels to describe all tropical cyclones, including tropical storms-- so each scale level covers a wider range of intensities. Our scale only covers hurricane-force systems, and so each scale level covers a narrower range and is more descriptive. For example, the Aussie Cat 3 in particular leaves me bewildered: it can be anything from a strong Cat 1 to a low-end Cat 3 on our scale. That's a rather wide range, in my opinion-- as a Cat 3 on our scale is waaaaaaay more serious than a strong Cat 1. But it's OK for us to use different systems. It makes the world interesting. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 P.S. No hurricanes hit Miami in the 1980s, and only one hurricane-- a very weak Cat 1 in 1987-- hit any part of the Florida Peninsula during that decade. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 Cat five: F**k. Hold on this is going to be one hell of a ride (for those who have never faced the prospect of an Aussie cat 5 or equivalent... trust me it is terrifying no matter how many extreme weather events you have faced). P.S. An Aussie Cat 5 starts in the middle of the American Cat 4-- so an American Cat 5 is even more potent and scarier. The last Cat 5 (on our scale) to hit the USA was Andrew 1992, which completely obliterated Miami's S suburbs. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 It would have been the 87 one ( i was young and drunk)... was it named? Floyd. It was barely a Cat 1 on our scale, and it hit the opposite coast (the W coast), so Miami wouldn't have gotten too much action from it. Five years later, one of the strongest hurricanes ever to hit the USA did hit the S suburbs of Miami (see above). Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 Time to change Josh. I disagree (and I love the US... spent time doing yacht deliveries down your east coast... got smashed in 52 footer off Hatteras). Your system, as you have with your odd imperial system which doesn't even stack up with the UK, is one of the only odd ones left. That you stick with knots is admirable, but again, why stick with an archaic system... the rest of the world could adapt to km immediately. As for rating a system... why confuse people... simple categories.... better response and attention. PS: Carlos did tuck in. I agree that it's weird the USA has stuck with its own measurement system-- but when it comes to tropical cyclones, all technical discussions all over the world (including in Australia) are in knots, so we're all on the same page. And, again, we prefer our intensity scale, so you'll have to live with it. And what on earth is confusing about it? The American public understands it just fine. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 The American public think Central America is Kansas..... that is what is wrong with it. Love the US... but it one of the most geographically inward and insular countries in the world... kids in Venezuela could identify more Aussie states than somebody from California Why don't we keep the discussion focused on tropical cyclones? Thanks. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 No it wasn't Andrew. Floyd rings a dark bell. Re Your somewhat weird pride re ratings. At 250-300kph it's irrelevant. Staggered warnings are more appropriate. Hurricane status is instigated around 120kph on the SS scale.... whereas a cat one sticks with gusts (technically) no less than 125kph).So where is the difference, apart from widening the categories across four (the highest being quite irrelevant... we know we are going to get hammered) as opposed to five? We prefer our system and you prefer yours. Why is it "weird pride" that we prefer ours? Not sure I follow. It seems from your comments that you're not very familiar with your own scale. Please read the first post of this thread, which has a discussion and chart comparing the two scales. It will help you understand how they stack up. Link to comment Share on other sites More sharing options...
phil882 Posted February 24, 2011 Share Posted February 24, 2011 Time to change Josh. I disagree (and I love the US... spent time doing yacht deliveries down your east coast... got smashed in 52 footer off Hatteras). Your system, as you have with your odd imperial system which doesn't even stack up with the UK, is one of the only odd ones left. That you stick with knots is admirable, but again, why stick with an archaic system... the rest of the world could adapt to km immediately. As for rating a system... why confuse people... simple categories.... better response and attention. PS: Carlos did tuck in. Metric units as a whole are the international standard for meteorological variables... in research literature... you will likely see m/s being used as opposed to knots. The conversion of metric units into other measurements is really not that big of a deal. In the United States we are more use to seeing empirical units. There was a big push back in the 70's to convert to metric in the US as it just makes more sense and is easier to convert from one scale of measure into the other. However, since a large portion of the population has for so long focused on using empirical units, the conversion just confused people that weren't familiar with metric (it wasn't really effectively taught back in schools, but is much more prevalent now). Knots is primarily a construct used by shipping and the general public in the United States is mainly familiar with miles per hour. Its fairly simple to convert from one unit to the other, and I feel like a country should have the right to adjust units it to inform the public in the best way possible so that they understand the wind threat. Now a far more valid arguing point is whether it is more useful to use wind gusts as opposed to average wind speed for making category designations. In fact, I think the Aussies might have a good idea in using gusts as a category designation, since typically short but powerful gusts can cause a lot more damage than a sustained wind. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 Re Scales (correct me if I am wrong) US 119-153kph = cat one v Aus 0-125kph US 154-177kph =cat two v Aus 125-164kph US 178-209kph = cat three v Aus 165-224kph US 210- 249kph = cat four v Aus 225-279kph US 249 + =cat five= Aus cat 5 280kph plus The scales are neatly compared in Post 1 of this thread-- please look at that. One thing I should point out is that we do not rate systems by peak gusts-- we do it by 1-min sustained. Anyhoo, if you're interested in comparing the two scales, refer to that post-- no point in retyping what is already there. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted February 24, 2011 Author Share Posted February 24, 2011 Looking at your p1 Saffir Simpson comparison I am way wrong. But strewth.... 260kph -310kph for a category four is US ludicrous (how many storms have clocked even 290kph).What is the point of category five above 310kph. it's a massive gap. No thanks our system is far better as it breaks severity into both believable and understandable effects. I know after 20 years what to expect from 1,2,3,4,5. In the Us both one and five are irrelevant... that makes the Australian system worthy of consideration.Like driving a Corvette.... brilliant in a straight line. Whatever, dude. Link to comment Share on other sites More sharing options...
am19psu Posted February 24, 2011 Share Posted February 24, 2011 If we're talking about the unit of measurement, knots is still the international standard for mariners and that's why the WMO mandates all RSMCs use knots in their technical discussion. The public advisories should be in whichever unit the issuing country finds most convenient for their audience. If you want to get scientific about it, the unit should really be mps, but no one (as far as I know) uses mps in a colloquial sense. If we're talking about scales, I'll take the S-S scale because the amount of mechanical energy produced goes by the square of wind speed. For structural failure, a finer resolution at the top end of the scale is more useful for emergency managers and engineers. For civilian users, again it should be based on whatever motivates the general public and I don't think it's really worthwhile to compare. The Aussie Scale works for Aussies, the S-S scale works in the Atlantic. The Japanese do just fine without a scale at all. Link to comment Share on other sites More sharing options...
am19psu Posted February 24, 2011 Share Posted February 24, 2011 Hey Psu, How many buildings in the US are built to SS Cat 5 (above 310kph)? Off the top of my head, the National Hurricane Center HQ in Miami. I'm sure there are others built to that requirement for essential personnel in the event of a hurricane strike. Link to comment Share on other sites More sharing options...
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