Normandy Posted August 27, 2011 Share Posted August 27, 2011 Agree on the core looking better, definitely seems like land helped tighten the core a bit. Impressive storm, seems like it is even larger than Ike in aerial coverage. Gonna be a long day for the East Coast. What are mets thoughts on this winding down over land? I remember Ike brought hurricane force winds WELL inland and took a while to spin down. Link to comment Share on other sites More sharing options...
LakeEffectKing Posted August 27, 2011 Share Posted August 27, 2011 I suspect that the nature of Irene and her well developed outer bands, which over the ocean, were just circulating around and essentially feeding themself, and not allowing a core to develop/tighten up. Now, the outer bands are dealing with land friction...which would allow winds to be directed more by the pressure gradient force (crossing the pressure field more) thus allowing bands to feed into a still vigorous wind circulation at the core, and thus a revuvination of the convection near and adjacent to the inner center of circ.....in essence, taking back some of the wind energy from the outer bands....maybe this is why some of the models showed a bit of deepening post NC interaction....just some random thought exercises.... Link to comment Share on other sites More sharing options...
CT Rain Posted August 27, 2011 Share Posted August 27, 2011 I suspect that the nature of Irene and her well developed outer bands, which over the ocean, were just circulating around and essentially feeding themself, and not allowing a core to develop/tighten up. Now, the outer bands are dealing with land friction...which would allow winds to be directed more by the pressure gradient force (crossing the pressure field more) thus allowing bands to feed into a still vigorous wind circulation at the core, and thus a revuvination of the convection near and adjacent to the inner center of circ.....in essence, taking back some of the wind energy from the outer bands....maybe this is why some of the models showed a bit of deepening post NC interaction....just some random thought exercises.... It seems to me the increased ageostrophic flow over land (and not much... we're talking part in Pamlico Sound and parts in swamps/tidal rivers/inlets) was just enough to tighten up the core. Increased convergence near the low helped fire vigorous convection. Link to comment Share on other sites More sharing options...
capecod04 Posted August 27, 2011 Share Posted August 27, 2011 I suspect that the nature of Irene and her well developed outer bands, which over the ocean, were just circulating around and essentially feeding themself, and not allowing a core to develop/tighten up. Now, the outer bands are dealing with land friction...which would allow winds to be directed more by the pressure gradient force (crossing the pressure field more) thus allowing bands to feed into a still vigorous wind circulation at the core, and thus a revuvination of the convection near and adjacent to the inner center of circ.....in essence, taking back some of the wind energy from the outer bands....maybe this is why some of the models showed a bit of deepening post NC interaction....just some random thought exercises.... She's also interacting with a low level jet over the mid Atlantic as well. She looks better now than she did 12 hours ago Link to comment Share on other sites More sharing options...
Sunny and Warm Posted August 27, 2011 Share Posted August 27, 2011 I suspect that the nature of Irene and her well developed outer bands, which over the ocean, were just circulating around and essentially feeding themself, and not allowing a core to develop/tighten up. Now, the outer bands are dealing with land friction...which would allow winds to be directed more by the pressure gradient force (crossing the pressure field more) thus allowing bands to feed into a still vigorous wind circulation at the core, and thus a revuvination of the convection near and adjacent to the inner center of circ.....in essence, taking back some of the wind energy from the outer bands....maybe this is why some of the models showed a bit of deepening post NC interaction....just some random thought exercises.... wouldn't that also then cause convection and rainfall rates in the outer bands to lessen as well? Link to comment Share on other sites More sharing options...
mempho Posted August 27, 2011 Share Posted August 27, 2011 This storm is going to be quite the case study. The one thing that bothers me is that people are not going to understand the nuances of all this and it appears that people are already making fun of this storm...to the point that Drudge has a link to some "scientist" who claims that this is a phony hurricane and is barely even a tropical storm. Link to comment Share on other sites More sharing options...
LakeEffectKing Posted August 27, 2011 Share Posted August 27, 2011 It seems to me the increased ageostrophic flow over land (and not much... we're talking part in Pamlico Sound and parts in swamps/tidal rivers/inlets) was just enough to tighten up the core. Increased convergence near the low helped fire vigorous convection. Yes, and we've seen this before with wide wind field TC's that initially interact with land (Katrina over Fl and to an extent as it made landfall east of NO, and I believe Ike did the same)....How many times have we heard "It looks better now than it did xx hours ago"....or " if it only had a few more hours..." So I'd argue, a well developed central core hurricane making land fall, will weaken....and a wide windfield/crappy inner core LF'ing hurricane either maintains itself, or the land interaction itself can re-ignite the core.....Let's see if we have any decent flare up once this gets to the coast (albeit with very marginal water temps)....good stuff! Link to comment Share on other sites More sharing options...
LakeEffectKing Posted August 27, 2011 Share Posted August 27, 2011 This storm is going to be quite the case study. The one thing that bothers me is that people are not going to understand the nuances of all this and it appears that people are already making fun of this storm...to the point that Drudge has a link to some "scientist" who claims that this is a phony hurricane and is barely even a tropical storm. Happens with nearly every storm as LF is occurring.... Link to comment Share on other sites More sharing options...
psuhoffman Posted August 27, 2011 Share Posted August 27, 2011 I suspect that the nature of Irene and her well developed outer bands, which over the ocean, were just circulating around and essentially feeding themself, and not allowing a core to develop/tighten up. Now, the outer bands are dealing with land friction...which would allow winds to be directed more by the pressure gradient force (crossing the pressure field more) thus allowing bands to feed into a still vigorous wind circulation at the core, and thus a revuvination of the convection near and adjacent to the inner center of circ.....in essence, taking back some of the wind energy from the outer bands....maybe this is why some of the models showed a bit of deepening post NC interaction....just some random thought exercises.... Many should only hope to give as much insight as you often provide with your "random thought exercises"... they are valued. Link to comment Share on other sites More sharing options...
Uncle Bobby Posted August 27, 2011 Share Posted August 27, 2011 I won't pretend that I came up with the notion myself, as it's been discussed on here a couple times, but I'd be interested to hear what the mets think about the presence of the right entrance region of the jet streak to Irene's immediate north. Here's the 15Z 300mb mesoanalysis. That seems like some significant divergence, but I've never looked for such a feature adjacent to any hurricane before, so I don't know if that is seen around 'canes often or not. Link to comment Share on other sites More sharing options...
Isopycnic Posted August 27, 2011 Share Posted August 27, 2011 Pretty cool feed going on here..lots of debris flying around (commentary is a bit annoying though ): http://www.ustream.tv/channel/live-severe-weather-webcam They drove over some powerlines and the feed died. OOps. Link to comment Share on other sites More sharing options...
mempho Posted August 27, 2011 Share Posted August 27, 2011 Happens with nearly every storm as LF is occurring.... [/b] I guess we can always point to the embarrassment of Katrina. From "no big deal" to "America's tsunami" within the first 24 hours after landfall. People should know not to make snap judgements based on the opinions of reporters who have no idea what they're even looking for. The only good one was Cantore that morning. He had seen the horror himself. Link to comment Share on other sites More sharing options...
NaoPos Posted August 27, 2011 Share Posted August 27, 2011 I won't pretend that I came up with the notion myself, as it's been discussed on here a couple times, but I'd be interested to hear what the mets think about the presence of the right entrance region of the jet streak to Irene's immediate north. Here's the 15Z 300mb mesoanalysis. That seems like some significant divergence, but I've never looked for such a feature adjacent to any hurricane before, so I don't know if that is seen around 'canes often or not. That notion was introduced earlier this week by Mt.Holly's very own met, Mike Gorse. here's a touch up of the disco and the effects of the jet: MUCH OF THE MODEL GUIDANCE STILL SHOWS THE DEVELOPMENT OF A STRONG 250 MB JET NORTH OF THE HURRICANE INTO SUNDAY, GENERALLY FROM THE EASTERN GREAT LAKES TO NORTHERN NEW ENGLAND. THIS UPPER-LEVEL JET EVEN HAS SOME ANTICYCLONIC CURVATURE TO IT AND GIVEN THE ORIENTATION OF THIS JET IT IS SUCH THAT IRENE IS WITHIN THE RIGHT ENTRANCE REGION AS SHE TRACKS NORTHWARD. THIS SCENARIO MAY TEND TO HELP WITH A POLEWARD UPPER-LEVEL OUTFLOW CHANNEL AND ASSIST IN THE INTENSITY OF THE SYSTEM AS A WHOLE. THEREFORE, DESPITE SOME INCREASING SHEAR AS THE HURRICANE GAINES LATITUDE ALONG WITH COOLER WATERS AND LAND INTERACTIONS, PERHAPS THIS IS WHY MUCH OF THE MODEL GUIDANCE NEARLY INSISTS THIS SYSTEM MAINTAINS A RATHER LOW CENTRAL PRESSURE ALL THE WAY INTO SOUTHERN NEW ENGLAND. IT BECOMES EVEN MORE OF AN INTENSITY FORECAST CHALLENGE AS TROPICAL CYCLONES GET THIS FAR NORTH AND INTERACT WITH BAROCLINIC ZONES AND LARGE SCALE SYNOPTIC FEATURES. THE PRESENCE OF THE SURFACE FRONT AND UPPER-LEVEL JET IS CONCERNING AS THIS MAY PLAY A SIGNIFICANT ROLE IN ENHANCING THE RAINFALL RATES. THE AMOUNT OF RAIN THAT LOOKS TO OCCUR WITH THIS SYSTEM MAY END UP BEING THE MAIN TOPIC OF DISCUSSION FOR MANY YEARS. AN EXAMINATION OF THE WIND FIELD AT 925 MB IS STILL CONCERNING WITH A LARGE AREA OF 60 TO NEARLY 85 KNOTS TRACKING ACROSS THE CWA THIS EVENING THROUGH SUNDAY MORNING. WHILE THE FRICTIONAL EFFECTS WILL TEND TO SLOW THE WIND DOWN SOME AND ALSO ALLOW FOR SOME DECOUPLING BETWEEN THE SURFACE AND ABOVE, THE PRESSURE GRADIENT COMBINED WITH ENHANCED MIXING WITHIN HEAVIER RAIN/CONVECTION SHOULD PRODUCE SIGNIFICANT/DAMAGING GUSTS. Link to comment Share on other sites More sharing options...
Chinook Posted August 27, 2011 Share Posted August 27, 2011 It's a bit interesting to see some storm reports pop up on my GRLevel3. I highlighted a couple for you. This seems to make the storm a bit more intense than THE ESTIMATED INTENSITY AT LANDFALL WAS 75 KT. Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted August 27, 2011 Share Posted August 27, 2011 tons of rain Link to comment Share on other sites More sharing options...
Eyewall2005 Posted August 27, 2011 Share Posted August 27, 2011 Convection trying to wrap around the center... Link to comment Share on other sites More sharing options...
salbers Posted August 27, 2011 Share Posted August 27, 2011 STMAS wind and pressure plot: Link to comment Share on other sites More sharing options...
wxsmwhrms Posted August 27, 2011 Share Posted August 27, 2011 I guess we can always point to the embarrassment of Katrina. From "no big deal" to "America's tsunami" within the first 24 hours after landfall. People should know not to make snap judgements based on the opinions of reporters who have no idea what they're even looking for. The only good one was Cantore that morning. He had seen the horror himself. I know this is slightly OT, but I still remember how mad I was when I heard the TV people in New Orleans on the morning of landfall acting like it was "no big deal" while I knew that on the coast of MS annihilation was occurring and dozens of people were likely dying. And I don't need to comment on what transpired for there... Link to comment Share on other sites More sharing options...
dan88 Posted August 27, 2011 Share Posted August 27, 2011 It's a bit interesting to see some storm reports pop up on my GRLevel3. I highlighted a couple for you. This seems to make the storm a bit more intense than THE ESTIMATED INTENSITY AT LANDFALL WAS 75 KT. The weakening offshore seemed to be more of a function of the structure not mixing down the winds as efficiently, rather than a weakening of the circulation strength itself. Even last night there were 108kt at 700mb, and dropsondes regularly showed winds at various heights of 100kt+. It would not be all that surprising that there was an increase in the surface winds with the improved structure being able to mix down those stronger winds aloft, rather than the deepening of the low. Link to comment Share on other sites More sharing options...
A-L-E-X Posted August 27, 2011 Share Posted August 27, 2011 She's also interacting with a low level jet over the mid Atlantic as well. She looks better now than she did 12 hours ago Yup... a report of a sustained 90 mph wind with gust to 110 mph from Cedar Island, NC, which is high end Cat 1. Link to comment Share on other sites More sharing options...
yoda Posted August 27, 2011 Share Posted August 27, 2011 Anyone else see a 947/948 on last recon pass? Link to comment Share on other sites More sharing options...
Dsnowx53 Posted August 27, 2011 Share Posted August 27, 2011 The weakening offshore seemed to be more of a function of the structure not mixing down the winds as efficiently, rather than a weakening of the circulation strength itself. Even last night there were 108kt at 700mb, and dropsondes regularly showed winds at various heights of 100kt+. It would not be all that surprising that there was an increase in the surface winds with the improved structure being able to mix down those stronger winds aloft, rather than the deepening of the low. If that general wind profile exists, and the storm becomes more baroclinic via jet streak interactions, perhaps some of those stronger winds could mix down to the surface... Link to comment Share on other sites More sharing options...
A-L-E-X Posted August 27, 2011 Share Posted August 27, 2011 Anyone else see a 947/948 on last recon pass? Yup, and the radar presentation is dramatically improving and much better than what it was at landfall. Link to comment Share on other sites More sharing options...
Joe4alb Posted August 27, 2011 Share Posted August 27, 2011 very impressive center of circulation now. http://www.wunderground.com/radar/radblast.asp?zoommode=pan&prevzoom=zoom&num=6&frame=0&delay=15&scale=0.587&noclutter=0&ID=MHX&type=N0R&showstorms=0&lat=0&lon=0&label=you&map.x=400&map.y=240&scale=0.587¢erx=316¢ery=311&showlabels=1&rainsnow=0&lightning=0&lerror=20&num_stns_min=2&num_stns_max=9999&avg_off=9999&smooth=0 http://radar.weather.gov/radar.php?product=N0R&rid=mhx&loop=yes Link to comment Share on other sites More sharing options...
pazzo83 Posted August 27, 2011 Share Posted August 27, 2011 It is moving over what is essentially swamp/Pamlico Sound right now, so it's not like the land there would weaken it much. Link to comment Share on other sites More sharing options...
HKY_WX Posted August 27, 2011 Share Posted August 27, 2011 Anyone else see a 947/948 on last recon pass? Is that confirmed? Link to comment Share on other sites More sharing options...
A-L-E-X Posted August 27, 2011 Share Posted August 27, 2011 Is that confirmed? Yup-- 947.1 mb Link to comment Share on other sites More sharing options...
HKY_WX Posted August 27, 2011 Share Posted August 27, 2011 Yup-- 947.1 mb wow, so odd to see that pressure w/ a cat 1. that is a high end cat 3 pressure. Link to comment Share on other sites More sharing options...
dan88 Posted August 27, 2011 Share Posted August 27, 2011 Is that confirmed? There was a 950mb drop in the bay with 6kt spash winds. This would appear to be the current center pressure. The 947.1mb was just the extrap, right along the bay coastline. Link to comment Share on other sites More sharing options...
A-L-E-X Posted August 27, 2011 Share Posted August 27, 2011 wow, so odd to see that pressure w/ a cat 1. that is a high end cat 3 pressure. I know lol, I wonder if anyone keeps records like what is the strongest Cat 1 to ever make landfall in terms of pressure? I'd bet that one would be the new record. BTW check this out http://www.wundergro...t201109_hd.html See the surface wind obs map on there? Is that an obs report of Cat 3 winds just south of Hatteras by the hurricane hunters? Link to comment Share on other sites More sharing options...
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