DopplerWx Posted August 21, 2011 Share Posted August 21, 2011 Like many have said the exact strength isn't that important 144hrs out, the track is. And the track shows a sig. threat to the e coast of florida up to nc. Link to comment Share on other sites More sharing options...
GaWx Posted August 21, 2011 Share Posted August 21, 2011 I don't think any hard rules can be determined from such a small sample set-- i.e., the handful of majors that hit GA/SC/NC in the last century or more. I'm the first to say that a cyclone with a W component in its movement is more likely to be healthy, but that is not written in stone, and I should point out that one of the strongest landfalls in the region-- Hazel 1954, which had an intensity around ~938 mb/115 kt-- was moving just E of due N. I'm not saying the Euro doesn't overdo it with the pressures, and I'm definitely not saying Charleston's getting a Cat 4-- just that I don't think we can take a deterministic view of intensity based on heading. Good point. Actually, I think we are pretty much in agreement as these are just guidelines I like to use as opposed to hard rules. As I just mentioned, SST's are above normal and norms are a bit warmer near the coastline now vs. in mid to late Sep. when Hugo and Gracie hit. So, there'd be an extra boost from SST's. So, cat. 4 is certainly not impossible. However, I'm still going with a cat. 4 at CHS as being very unlikely. Cat 3 would be very believable. The two in 1893 as well as the one in 1885 were cat. 3's moving either N (one case) or even NNE (two cases). Regarding Hazel, good point. That's why these are guidelines rather than hard rules. However, keep in mind that peak wind strength was near 30 N when it was still moving NNW as per the following: http://weather.unisy...HAZEL/track.dat I realize that you may not agree with this and I realize it was still incredibly strong at landfall. Then again, wasn't some of that strengthening supposedly due to an unusual amount of extratropical energy being added? That possibility doesn't really seem to be available with Irene. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted August 21, 2011 Share Posted August 21, 2011 Now this I can agree with. I guess I may have misunderstood your point earlier. No prob, buddy. I think we can all agree that the tropical doldrums are over. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted August 21, 2011 Share Posted August 21, 2011 Josh and Benchmark, I know. I misunderstood 40/70's earlier remark. No problem. Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted August 21, 2011 Share Posted August 21, 2011 What a difference since early this morning. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted August 21, 2011 Share Posted August 21, 2011 Good point. Actually, I think we are pretty much in agreement as these are just guidelines I like to use as opposed to hard rules. As I just mentioned, SST's are above normal and norms are a bit warmer near the coastline now vs. in mid to late Sep. when Hugo and Gracie hit. So, there'd be an extra boost from SST's. So, cat. 4 is certainly not impossible. However, I'm still going with a cat. 4 at CHS as being very unlikely. Cat 3 would be very believable. The two in 1893 as well as the one in 1885 were cat. 3's moving either N (one case) or even NNE (two cases). Regarding Gracie, good point. That's why these are guidelines rather than hard rules. However, keep in mind that peak wind strength was near 30 N when it was still moving NNW as per the following: http://weather.unisys.com/hurricane/atlantic/1954/HAZEL/track.dat I realize that you may not agree with this and I realize it was still incredibly strong at landfall. Then again, wasn't some of that strengthening supposedly due to an unusual amount of extratropical energy being added? That possibility doesn't really seem to be available with Irene. OK, we're totally on the same page. I completely agree that historical analogies are useful, as long as one doesn't view them as rigid rules for unfolding events, which you are not. Re: Hazel, those data are pre-reanalysis, so I wouldn't worry too much about them. A recent paper put out by the reanalysis folks puts Hazel's landfall intensity at 115 kt-- a low-end Cat 4. But, yes, my impression has always been that Hazel was already showing some signs of transition at landfall near the SC/NC border, and that this may have augmented the winds. Link to comment Share on other sites More sharing options...
DoctorMu Posted August 21, 2011 Share Posted August 21, 2011 It looks like the center is moving South-South west, I'm a little confused.. My hypothesis is that some of the apparent movement NW last night and into the morning was related to the interaction of this gigantic vortex with South America...plus the interaction of dry air entrained into the system, with primary convection north of the center. The storm may be continuing a WNW track hugging PR and Hispanola. Link to comment Share on other sites More sharing options...
Ian Posted August 21, 2011 Share Posted August 21, 2011 plz remember not to post something with no value just to post. if you can't figure out which way it's moving maybe read till you do... Link to comment Share on other sites More sharing options...
battlebrick Posted August 21, 2011 Share Posted August 21, 2011 http://www.wundergro...w=0&lightning=0 closed eyewall? here are some st.croix stations to watch out for: http://www.wunderground.com/US/VI/Saint_Croix.html Link to comment Share on other sites More sharing options...
Sickman Posted August 21, 2011 Share Posted August 21, 2011 It looks like the center is moving South-South west, I'm a little confused.. I have no idea what you're looking at, but it may be advisable to look/study a little more before saying stuff like this. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted August 21, 2011 Share Posted August 21, 2011 Josh and Benchmark, I know. I misunderstood 40/70's earlier remark. No problem. Cool-- seems like we're all on the same page. Link to comment Share on other sites More sharing options...
Mallow Posted August 21, 2011 Share Posted August 21, 2011 http://www.wundergro...w=0&lightning=0 closed eyewall? here are some st.croix stations to watch out for: http://www.wunderground.com/US/VI/Saint_Croix.html As odd as it may be for a storm this weak (though I don't believe it's unprecedented), it sure looks like some sort of pseudo-eye has formed based on radar. Link to comment Share on other sites More sharing options...
28storms Posted August 21, 2011 Share Posted August 21, 2011 Link to comment Share on other sites More sharing options...
DopplerWx Posted August 21, 2011 Share Posted August 21, 2011 http://www.wundergro...w=0&lightning=0 closed eyewall? here are some st.croix stations to watch out for: http://www.wundergro...aint_Croix.html center is about to pass over st croix, and the banding is looking better and better. diurnal max tonight should be fund to watch. Link to comment Share on other sites More sharing options...
Hurriplane Posted August 21, 2011 Share Posted August 21, 2011 I have no idea what you're looking at, but it may be advisable to look/study a little more before saying stuff like this. Nevermind, I found out where it's moving, keep getting ahead of myself. The 5pm advisory should be out at any moment, I only see what looks like a closed eyewall, or atleast near closing. More thunderstorms look to have formed near the center and you can clearly see the center on radar now. Link to comment Share on other sites More sharing options...
Southland Wx Posted August 21, 2011 Share Posted August 21, 2011 FYI, Euro ensemble mean is a hair further southwest than the Op Euro...most members take it about 100-150 miles off the N FL/GA coast and into SC. After 144 hours, the ensemble cluster diverges dramatically. 144 hour ensembles have 1-2 members in the NE Gulf and 1-2 near Cape Hatteras (out of several dozen members), with the rest focused on SC/GA. That spread at 168 hours widens to just south of Cape Cod to Mobile Bay with the cluster ranging from Savannah to Wilmington. Worth noting for those up the coast, the operational Euro appears to be on the northwest edge of the ensemble guidance. In other words, we have a long way to go for those up the coast and forecast confidence nosedives, probably more than usual beyond day 5-6. Link to comment Share on other sites More sharing options...
battlebrick Posted August 21, 2011 Share Posted August 21, 2011 they kept it at 45 kts, still florida landfall. Link to comment Share on other sites More sharing options...
David Reimer Posted August 21, 2011 Share Posted August 21, 2011 While it's very possible that this effect is due to Irene getting closer to the TJUA radar site, the storm has become impressive, at least visually, in the past hour. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted August 21, 2011 Share Posted August 21, 2011 They were characteristically conservative with the track, shifting it only a little to the right for this package. Of course, they want to see if the model shift is a real trend or just the usual windshield wiping. Makes sense. Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted August 21, 2011 Share Posted August 21, 2011 <A href="http://www.nhc.noaa.gov/index.shtml?">Home Public Adv Fcst/Adv Discussion Wind Probs Maps/Charts Archive US Watch/Warning 000WTNT34 KNHC 212044TCPAT4BULLETINTROPICAL STORM IRENE ADVISORY NUMBER 5NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011500 PM AST SUN AUG 21 2011...CENTER OF IRENE NEAR ST. CROIX...SUMMARY OF 500 PM AST...2100 UTC...INFORMATION----------------------------------------------LOCATION...17.7N 64.4WABOUT 25 MI...40 KM E OF ST. CROIXABOUT 120 MI...195 KM ESE OF SAN JUAN PUERTO RICOMAXIMUM SUSTAINED WINDS...50 MPH...85 KM/HPRESENT MOVEMENT...WNW OR 285 DEGREES AT 17 MPH...28 KM/HMINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES Link to comment Share on other sites More sharing options...
Hurriplane Posted August 21, 2011 Share Posted August 21, 2011 Pressure dropped to 999 and movement has slowed. Link to comment Share on other sites More sharing options...
David Reimer Posted August 21, 2011 Share Posted August 21, 2011 Pressure dropped to 999 and movement has slowed. Pressure dropped to 999 MB with the 2 PM advisory in accordance with the final pass by recon. Link to comment Share on other sites More sharing options...
Chinook Posted August 21, 2011 Share Posted August 21, 2011 I don't know why you continue to say that a cat 4 is nearly impossible. Hugo hit Charleston as a cat 4 in late sept when the SST's are a little less than now, which is at peak. Also, as others have said, there is no trough to weaken it. So, even though it may not reach cat 4, it won't be for any reasons you've stated. This is the closest I've seen to a Hugo redux since Hugo. Not exact, mind you, but in the sense that the only steering is by the high. Hugo was in a rather weird steering situation as it went from the Puerto Rico area to the US- an upper low in the southeast US and a strong high out near Bermuda. At this time, Hugo was directly north of Hispaniola at 23.50N -69.30W Link to comment Share on other sites More sharing options...
wxsmwhrms Posted August 21, 2011 Share Posted August 21, 2011 They were characteristically conservative with the track, shifting it only a little to the right for this package. Of course, they want to see if the model shift is a real trend or just the usual windshield wiping. Makes sense. Absolutely. Of more interest to me is that they now have the forecast track in the shorter term going across PR, just skimming the northern part of Hispaniola, and going north of Cuba. If that track holds for the next couple of advsiories, would expect an increase in the forecast intensity. Link to comment Share on other sites More sharing options...
peribonca Posted August 21, 2011 Share Posted August 21, 2011 Gusts to 50mph in Christiansted Excited to be in my first eye! Link to comment Share on other sites More sharing options...
Typhoon Tip Posted August 21, 2011 Share Posted August 21, 2011 Anyone care to speculate on why the GFDL is such an outlier? For whatever reason, it has been playing catch up for Irene's whole history--showing a 1008 wave in the W Caribbean in yesterday's runs for instance. A bit perplexing for the model that usually is one of the best. The GFDL is a limited grid barotropic version of the GFS; because of that it is not likely as proficiently detecting subtle influences from the larger domain - trough lifting out and leaving behind a weakness/shear axis in the geopotential medium. TC's always move toward said weaknesses while also executing beta drift (right hand drag provided by corriolis) Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted August 21, 2011 Share Posted August 21, 2011 they kept it at 45 kts, still florida landfall. I wouldn't read too much into that.....they will keep shifting it N, but have to be careful to avoid jumping the gun. Link to comment Share on other sites More sharing options...
blazess556 Posted August 21, 2011 Share Posted August 21, 2011 Station just gusted to 60 knots http://www.ndbc.noaa.gov/station_page.php?station=chsv3 Link to comment Share on other sites More sharing options...
wxsmwhrms Posted August 21, 2011 Share Posted August 21, 2011 Hugo was in a rather weird steering situation as it went from the Puerto Rico area to the US- an upper low in the southeast US and a strong high out near Bermuda. At this time, Hugo was directly north of Hispaniola at 23.50N -69.30W Yes, I still remember thinking that Hugo was a fairly rare situation in that the steering flow was very well defined between a low to the SW and upper high to the east - it was very difficult for it to go anywhere other than toward SC. That will not be the case in this situation as the initial turn to the NW is being induced more be a weakness in the ridge,and then with heights building to the N it is not a clear cut situation where it will go from there. Thus the spread in the ECMWF ensemble discussed above. Link to comment Share on other sites More sharing options...
DopplerWx Posted August 21, 2011 Share Posted August 21, 2011 if the 00z models hold serve then we will see more of a shift on the nhc's track, but for now they are doing the smart thing. no need to jump the gun 5 days out. Link to comment Share on other sites More sharing options...
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