EasternUSWX Posted August 28, 2012 Share Posted August 28, 2012 Tropical storm force winds beginning to overspread the lower delta. These winds are sustained in mph, extremely impressive wind field for a tropical storm at such a distance. These winds are occurring with the outermost spiral bands, which are relatively weak. Noticed that. Recon just took off and already is 50+ KT FL and surface right off the coast. Link to comment Share on other sites More sharing options...
Derecho! Posted August 28, 2012 Share Posted August 28, 2012 Seems like the gap in windspeeds between FL and SFMR is getting a bit smaller. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 28, 2012 Share Posted August 28, 2012 It might not look great, but its actually very comparable to what the HRRR is depicting in the near future. For example. Current Infrared: Lets compare that to the HRRR OLR valid for 7z: eerily similar right?... although this is suppose to be 5 hours in the future. If we go forward to the end of the most recent HRRR run you get something like this. So yes, not a great presentation right now, but it could be the beginning of substancial banding we need on satellite imagery to mix out of the rest of this possible dry air. Yeah I've been watching the HRRR actually since this morning. I do see that as well. Obviously the thing probably will gets its act together somewhat tonight, the upper level environment is getting better...I'm just a little unsure of how much. It's looked healthy at times today..only to kind of fall apart again and go back to the semi circle look. The models are all in agreement to strengthen it...just don't see a reason to really go much more than the NHC call right now. Dry air never wants to leave these things. If anything..a fascinating display of power struggle today. Link to comment Share on other sites More sharing options...
CUmet Posted August 28, 2012 Share Posted August 28, 2012 So yes, not a great presentation right now, but it could be the beginning of substantial banding we need on satellite imagery to mix out of the rest of this possible dry air. The convective blowup on the north side is the first time that's happened since the shear vector shifted easterly, and I think it's an important sign that the forcing for vertical motion is more axisymmetric now than it was before. I think we'll see significant intensification tonight and tomorrow. Link to comment Share on other sites More sharing options...
Ground Scouring Posted August 28, 2012 Share Posted August 28, 2012 There are indications that the boundary layer north and west of Isaac is rapidly moistening based upon surface and other data. I would not be shocked to see a rapid increase in intensity over the next several hours. Link to comment Share on other sites More sharing options...
Mitchel Volk Posted August 28, 2012 Share Posted August 28, 2012 I thinl that the NHC has a good handle on this storm. Link to comment Share on other sites More sharing options...
EasternUSWX Posted August 28, 2012 Share Posted August 28, 2012 Seems like the gap in windspeeds between FL and SFMR is getting a bit smaller. Recon has solid 60MPH from basically the coast downward. First time we seen that good of winds over the northern side in a while. Also like to note that the convection over Florida is falling apart as HRRR showed and should now let he shear from the northeast side drop off. Link to comment Share on other sites More sharing options...
LakeEffectKing Posted August 28, 2012 Share Posted August 28, 2012 12z GFS/EnKF came back a bit east, as PSU had suspected earlier based on the 12z GFS output. These outputs have been doing very well, and hopefully they can implement them into operational status (and more timely) in the near future.: http://www.hfip.org/products/ Link to comment Share on other sites More sharing options...
PatrickSumner Posted August 28, 2012 Share Posted August 28, 2012 Click link below if you want to take a look at the NAM-HIRES. I think it has a pretty good idea of what's going to happen with Isaac as well. http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=08%2F28%2F2012+00UTC&rname=UPPER+AIR+PARMS&pname=sim_reflectivity&pdesc=&model=NAM-HIRES&area=NAMER&cat=MODEL+GUIDANCE&fcast=Loop+All&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M Link to comment Share on other sites More sharing options...
Santa Clause Posted August 28, 2012 Share Posted August 28, 2012 Looks like models pulling it back east....great news for New Orleans. Link to comment Share on other sites More sharing options...
jburns Posted August 28, 2012 Share Posted August 28, 2012 WVUE FOX8 in New Orleans. "We are addicted to the internet where there are web sites that you can even know what is happening with the hurricane hunter flights as they happen almost. You can see every radar frame. People can get overwhelmed with information. The truth is for most people this will just be a glorified thunderstorm" Link to comment Share on other sites More sharing options...
thunderman Posted August 28, 2012 Share Posted August 28, 2012 The convective blowup on the north side is the first time that's happened since the shear vector shifted easterly, and I think it's an important sign that the forcing for vertical motion is more axisymmetric now than it was before. I think we'll see significant intensification tonight and tomorrow. Just for reference later: Link to comment Share on other sites More sharing options...
Bostonseminole Posted August 28, 2012 Share Posted August 28, 2012 Pressure down slightly.. 01:17:30Z 26.950N 86.633W 694.4 mb (~ 20.51 inHg) 3,050 meters (~ 10,007 feet) 981.1 mb (~ 28.97 inHg) - From 189° at 15 knots (From the S at ~ 17.2 mph) 16.3°C (~ 61.3°F) 12.0°C (~ 53.6°F) 15 knots (~ 17.2 mph) 22 knots* (~ 25.3 mph*) 1 mm/hr* (~ 0.04 in/hr*) 22.0 knots* (~ 25.3 mph*) 146.7%* 01:18:00Z 26.917N 86.633W 694.4 mb (~ 20.51 inHg) 3,042 meters (~ 9,980 feet) 980.6 mb (~ 28.96 inHg) - From 223° at 15 knots (From the SW at ~ 17.2 mph) 16.2°C (~ 61.2°F) 12.4°C (~ 54.3°F) 16 knots (~ 18.4 mph) Link to comment Share on other sites More sharing options...
Sn0waddict Posted August 28, 2012 Share Posted August 28, 2012 WVUE FOX8 in New Orleans. "We are addicted to the internet where there are web sites that you can even know what is happening with the hurricane hunter flights as they happen almost. You can see every radar frame. People can get overwhelmed with information. The truth is for most people this will just be a glorified thunderstorm" They ripped into the NHC too "They aren't that good at forcasting intensity, that's for sure" Link to comment Share on other sites More sharing options...
Ian Posted August 28, 2012 Share Posted August 28, 2012 Serious question: does the hrrr have known strengths in the tropics? It's usually a third rate model to kill time with when storm chasing. I find it very odd to see it so much tonight. Can only guess folks are having trouble making reaches otherwise. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 28, 2012 Share Posted August 28, 2012 I think in terms of how the satellite should look if this intensifies, we want that one convective blob to wrap around and convection to continue to increase and really expand the CDO northward. That may be tough in the short term with the environment just north of the center over the nrn Gulf a little more hostile. Perhaps towards dawn it tries a little more...I'm just not overly excited quite yet. The environment is slowly becoming better so perhaps near dawn and into tomorrow it tries to have a better CDO type appearance and organization. Link to comment Share on other sites More sharing options...
PSUBlizzicane2007 Posted August 28, 2012 Share Posted August 28, 2012 They ripped into the NHC too "They aren't that good at forcasting intensity, that's for sure" Someone should ask them to try and do a better job. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 28, 2012 Share Posted August 28, 2012 Serious question: does the hrrr have known strengths in the tropics? It's usually a third rate model to kill time with when storm chasing. I find it very odd to see it so much tonight. Can only guess folks are having trouble making reaches otherwise. I think for a meso model..it has a decent cumulus parameters in the tropics as compared to the NAM. I think Phil even said this tonight. However, JMHO..it may be a little overzealous. Link to comment Share on other sites More sharing options...
Weathergun Posted August 28, 2012 Share Posted August 28, 2012 Drier air over NE Gulf could get entrained into Isaac later tonight: Link to comment Share on other sites More sharing options...
CoastalWx Posted August 28, 2012 Share Posted August 28, 2012 Drier air over NE Gulf could get entrained into Isaac later tonight: Well that one area really isn't the issue. Link to comment Share on other sites More sharing options...
ALhurricane Posted August 28, 2012 Share Posted August 28, 2012 Serious question: does the hrrr have known strengths in the tropics? It's usually a third rate model to kill time with when storm chasing. I find it very odd to see it so much tonight. Can only guess folks are having trouble making reaches otherwise. In testing it has shown some promise with tropical cyclones. I don't have numbers in front of me, but I have sat in on the training sessions for it. That's not saying it is right on this one, but the results so far have raised my interest. Link to comment Share on other sites More sharing options...
BeauDodson Posted August 28, 2012 Share Posted August 28, 2012 WVUE FOX8 in New Orleans. "We are addicted to the internet where there are web sites that you can even know what is happening with the hurricane hunter flights as they happen almost. You can see every radar frame. People can get overwhelmed with information. The truth is for most people this will just be a glorified thunderstorm" I was just listening to him say that. I don't know how accurate these predictions are http://w1.weather.go...&threat=coastal But - if they are right then the main story (which many of us already know) will be the flooding. I am surprised how much people are obsessed with whether this thing ends up with winds of 70-80-90 mph. I can understand the concern about wind - but the bigger story will be the 10-20 inches of rain and flooding. I realize a lot of "us" are intrigued by storm structure and strengthening - will it/won't it - but from a meteorological point of view the concern is the surge and flooding - how long the fetch may be in from the southeast into areas that flood easily. Of course 10-20 inches of rain could overwhelm some areas. Seems with a broad wind field that the build up of storm surge - combined with high tide - could make for a decent story maker. I wonder how much of the general public focuses on storm intensity - specifically wind. I hate the NHC wind rating system. Does not tell the full story - not by far. People always want to know if it is a Cat 1 - 2 - 3 or what. It is almost like a light bulb goes on in their head if you give them the "right" number. Maybe that number is a 2 or maybe it is a 3 - depending on the person. You don't see many people being interviewed that ask the question - so what is the storm surge going to be and how much rain are we expected Some of the people I have seen interviewed are saying things like - ahhh it's only a tropical storm or a category 1 - not really worried. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 28, 2012 Share Posted August 28, 2012 I was just listening to him say that. I don't know how accurate these predictions are http://w1.weather.go...&threat=coastal But - if they are right then the main story (which many of us already know) will be the flooding. I am surprised how much people are obsessed with whether this thing ends up with winds of 70-80-90 mph. I can understand the concern about wind - but the bigger story will be the 10-20 inches of rain and flooding. True. Link to comment Share on other sites More sharing options...
Ian Posted August 28, 2012 Share Posted August 28, 2012 I think for a meso model..it has a decent cumulus parameters in the tropics as compared to the NAM. I think Phil even said this tonight. However, JMHO..it may be a little overzealous. Lots of jargon I'm more interested in results. The model is pretty iffy in most cases I've seen. Link to comment Share on other sites More sharing options...
dan88 Posted August 28, 2012 Share Posted August 28, 2012 Waiting on drop, but 979.4mb on extrap Link to comment Share on other sites More sharing options...
Derecho! Posted August 28, 2012 Share Posted August 28, 2012 Well that one area really isn't the issue. Yeah, if every area satellite WV was uniformly filled with moisture....it would be the Phillipine Sea or something. One reason we generally don't have multiple Cat 5s a year though. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted August 28, 2012 Share Posted August 28, 2012 Serious question: does the hrrr have known strengths in the tropics? It's usually a third rate model to kill time with when storm chasing. I find it very odd to see it so much tonight. Can only guess folks are having trouble making reaches otherwise. I haven't used it in this type of a tropical situation before, but I have to say that overall I have found the HRRR to be a quite useful tool for convective forecasting in the spring and summer for my own needs. I certainly would not refer to it as a third rate model personally. I mean, it isn't perfect by any stretch, but I think it does a pretty good job showing convective mode, strength, etc. Link to comment Share on other sites More sharing options...
jburns Posted August 28, 2012 Share Posted August 28, 2012 Where on earth are you getting that idea? WDSU met just said the same thing. Link to comment Share on other sites More sharing options...
chris87 Posted August 28, 2012 Share Posted August 28, 2012 I think for a meso model..it has a decent cumulus parameters in the tropics as compared to the NAM. I think Phil even said this tonight. However, JMHO..it may be a little overzealous. It has explicit convection so no cumulus parameterization. People like its pretty output and it's run every hour, hence it's popularity. Link to comment Share on other sites More sharing options...
A-L-E-K Posted August 28, 2012 Share Posted August 28, 2012 Lots of jargon I'm more interested in results. The model is pretty iffy in most cases I've seen. It did great with a couple derechos around here this summer but was pretty useless most of the time when vorticity/forcing was much weaker....this probably doesn't translate at all though so whatever. I still think a low end cat 2 is a decent guess...with something weaker much more likely than something stronger. Link to comment Share on other sites More sharing options...
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