turtlehurricane Posted September 2, 2011 Share Posted September 2, 2011 Lee looks a bit sub-tropical to me. Very powerful cyclone regardless, solid area of gale force winds just off the coast of Louisiana, and gusts over 30 mph are already being reported across the southern delta. Surprisingly there's already 2.5 ft of surge at New Orleans, water is being funneled into Lake Pontchartrain from the Gulf. Link to comment Share on other sites More sharing options...
phil882 Posted September 2, 2011 Share Posted September 2, 2011 It looks like this system is going to come inland far before the NHC current projections. The llc is beginning to become better defined near the area of convection that has formed near the Louisiana coastline. This is more or less in line with what the GFS has been projecting in most of its last few runs, and its done better with the track of Lee so far in comparison to the ECWMF. Quite a bit of a contrast compared to the last few storms when the ECWMF was dominating genesis events. Link to comment Share on other sites More sharing options...
dan88 Posted September 3, 2011 Share Posted September 3, 2011 1000mb drop, Center a good deal north of the NHC location, 28 deg 15 min N (28.25N) vs the 8pm advisory of 27.8N. It also is .3 degrees East of the 8pm advisory. 000 URNT12 KNHC 030028 VORTEX DATA MESSAGE AL132011 A. 02/23:57:00Z B. 28 deg 15 min N 091 deg 19 min W C. 850 mb 1430 m D. 31 kt E. 066 deg 14 nm F. 143 deg 39 kt G. 054 deg 51 nm H. 1000 mb I. 14 C / 1526 m J. 20 C / 1522 m K. 9 C / NA L. NA M. NA N. 1345 / 8 O. 0.02 / 7 nm P. AF306 0413A LEE OB 02 MAX FL WIND 39 KT NE QUAD 23:40:20Z Link to comment Share on other sites More sharing options...
dan11295 Posted September 3, 2011 Share Posted September 3, 2011 Does that that mean Lee will landfall and move out sooner? Or still get hung up like the current forecast Link to comment Share on other sites More sharing options...
brad1551 Posted September 3, 2011 Share Posted September 3, 2011 No way 960mb. No way that is a cat 3. To much shear from the west. When the dry air moves out, the storm will weaken back to TD and just dump rain and lots of it. Now I wonder how Lee could play out with Kata. That's interesting. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 Question for the mets, but what would 20 inches of rain do to New Orleans? Since New Orleans is a "bowl", 20" could have disastrous effects. However, part of the Corps of Engineers flood protection system is several huge pumps to keep water pumped out of New Orleans into Lake Ponchartrain. They had to repair/replace several of those pumps after Katrina, but the Corps says it's ready. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 My personal opinion is that NHC is moving Lee too slowly- their speed is slower than almost all the guidance- closer to the UK and Euro, but the Euro ensembles are faster than the Op- my guess is that this will be 12-24 hours faster especially later in the period. I truly hope you are right. I have to work in this mess this weekend, and if it came on ashore and picked up speed and got the heck out of here like so many storms do after landfall, I would certainly prefer that. But I went through TS Allison in June of 01, and it sat on Baton Rouge for 3 days. It was terrible. And Lee sounds like it could be another storm like that, unfortunately. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 One good thing about Lee is that it sounds like the tornado risk is going to be extremely low. No warnings or even watches yet and no slight risk though there is a "see text" over the Louisiana Marshlands which IMO is just a CYA type of thing in case one spins up at some point. Not so fast. There was a tornado warning issued this afternoon for east of New Orleans, somewhere about 2 or 3 pm. It was a radar catch, and I never heard confirmation of a twister on ground. I haven't heard any radio since I left work, however, so that might have been the only one so far. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 From looking at the hourly rainfall rates and total rainfall compared to NAM/GFS 12z 12 hr forecasts, I am wondering if the forecasted rainfall is somewhat overdone as a result of the dry air intrusion from the ULL. Not to say there wont be a lot of rain but I think with the potential of slightly faster system movement combined with precip rates being kept down (mostly around 0.1/0.2"/hr atm) excessive rainfall may be able to be avoided. I live in Baton Rouge, which is about 100 miles from the Gulf. I was at work - mostly outside - today. We had our first few raindrops around 8 or 9 this morning. It increased only slightly, and we had only light showers most of the day. But I think that is because we're just beginning to get the first outer bands. I was in TS Allison 10 years ago, and it *sat* on Baton Rouge for 3 days, and rained profusely. My house had 8" of rain from a flash flood one morning, up and down in 2 hours time. I wouldn't be a bit surprised if Lee is another Allison. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 Lee looks a bit sub-tropical to me. Very powerful cyclone regardless, solid area of gale force winds just off the coast of Louisiana, and gusts over 30 mph are already being reported across the southern delta. Surprisingly there's already 2.5 ft of surge at New Orleans, water is being funneled into Lake Pontchartrain from the Gulf. I forgot the exact figures now, or even exactly where I got it from. But one source I read today said that they were getting some of their info from oil rigs in the Gulf, in addition to the recon flights. They were having gusts reported from the rigs of - I believe - 60 mph. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 No way 960mb. No way that is a cat 3. To much shear from the west. When the dry air moves out, the storm will weaken back to TD and just dump rain and lots of it. Now I wonder how Lee could play out with Kata. That's interesting. My best friend is a NWS Met Tech. He says models he is running show Lee gradual lowest pressure could be 989 mb. "Strong TS": he says. I am looking for something like TS Allison from 2001, which was pretty bad rainfall wise. Link to comment Share on other sites More sharing options...
andyhb Posted September 3, 2011 Share Posted September 3, 2011 Not so fast. There was a tornado watch issued this afternoon for east of New Orleans, somewhere about 2 or 3 pm. It was a radar catch, and I never heard confirmation of a twister on ground. I haven't heard any radio since I left work, however, so that might have been the only one so far. You mean a warning. Link to comment Share on other sites More sharing options...
Sonny WX Posted September 3, 2011 Share Posted September 3, 2011 You mean a warning. Yes. As a matter of fact, I just caught that on re-reading, and I edited it. It is correct now. Good catch though. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 3, 2011 Share Posted September 3, 2011 The dumpage is now in full swing in SE LA. Waves of convection and heavy rain moving NW off the Gulf, with radar already showing some 4+" totals S of KHUM and near New Orleans. With expanding cold tops NE of the center and the diurnal convective max coming, going to be a long night. BTW, currently a TOR in effect near Houma as well. Will be interesting to see how things evolve from here. NHC alluded to another potential stall as shown in the models after some northward drift in the next 12-24 hours. Even if the system moves inland, with the large circulation feeding juice in off the Gulf, the somewhat subtropical nature of the system, and the fact that S LA is effectively a big swamp, there's not going to be much if any weakening until the big trough really comes down and gets it and moves it off to the NE. Another thing to watch for is the very heavy rain NW of the center once it starts interacting with the trough and a strong deformation axis develops NW of the LLC in an area of strong divergence in the right entrance region of the ULJ associated with the trough. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 3, 2011 Share Posted September 3, 2011 The good news is that this is occurring during the weekend. I could imagine this being much worse if we had to deal with a morning commute tomorrow in New Orleans. Absolutely. Looks like the recon flight just went through the center again and they are going to fix it a bit SW of their last fix. Looks like 28N, 91.9W. Obviously it's reforming and meandering around a bit. You can see little vorticity maxima in the rainshield on the radar out of KLIX. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 3, 2011 Share Posted September 3, 2011 Recon now finding peak FL winds near 50 kt well N of the center. 00Z GFS has slown down and shifted SE with the track, now looks very much like the 12Z ECMWF. Shows a swath of 6-10" of QPF from New Orleans right up I-59 to Meridian, Tuscaloosa and Huntsville. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 3, 2011 Share Posted September 3, 2011 Pretty obvious from recon data that (not surprisingly) it is a broad center with several smaller scale vortices that they are fixing on. Link to comment Share on other sites More sharing options...
dan88 Posted September 3, 2011 Share Posted September 3, 2011 Up to 58kt at flight level (850mb) 000 URNT12 KNHC 030543 VORTEX DATA MESSAGE AL132011 A. 03/05:17:50Z B. 28 deg 40 min N 092 deg 06 min W C. 850 mb 1403 m D. 40 kt E. 334 deg 14 nm F. 062 deg 45 kt G. 331 deg 31 nm H. 999 mb I. 17 C / 1524 m J. 20 C / 1523 m K. 11 C / NA L. NA M. NA N. 134 / 8 O. 0.02 / 2 nm P. AF306 0413A LEE OB 13 MAX OUTBOUND AND MAX FL WIND 58 KT N QUAD 05:34:00Z MAX FL TEMP 21 C 143 / 8 NM FROM FL CNTR ; Link to comment Share on other sites More sharing options...
dan88 Posted September 3, 2011 Share Posted September 3, 2011 SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...28.5N 91.8W ABOUT 170 MI...275 KM WSW OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 95 MI...155 KM SSW OF MORGAN CITY LOUISIANA MAXIMUM SUSTAINED WINDS...50 MPH...80 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 5 MPH...7 KM/H MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES Link to comment Share on other sites More sharing options...
Amped Posted September 3, 2011 Share Posted September 3, 2011 Almost onshore, 996MB at salt point. Link to comment Share on other sites More sharing options...
Wild Weather Monger Posted September 3, 2011 Share Posted September 3, 2011 Now that the COC is at the coast, it'll be interesting to see if Lee manages to stall out today at or just onshore. With much of the "coast" being 90 degree marsh, and tropical systems tendency to tighten up an inner core near a coast line, Lee may still make a run at minimum cane status. Link to comment Share on other sites More sharing options...
dan11295 Posted September 3, 2011 Share Posted September 3, 2011 Very heavy rain moving into NO now, fortunately there is a dry slot to the SW which should work in after a couple of hours it appears. On a side note, appears LIX radar estimates are a tad underdone, MSY picked up 1.23" last hour. Link to comment Share on other sites More sharing options...
phlwx Posted September 3, 2011 Share Posted September 3, 2011 I forgot the exact figures now, or even exactly where I got it from. But one source I read today said that they were getting some of their info from oil rigs in the Gulf, in addition to the recon flights. They were having gusts reported from the rigs of - I believe - 60 mph. The oil rigs are a good bit above the ocean surface so their wind readings will be a bit enhanced to begin with. Link to comment Share on other sites More sharing options...
phlwx Posted September 3, 2011 Share Posted September 3, 2011 Lee now sporting 60 mph winds and very close to marshfall. Link to comment Share on other sites More sharing options...
mike2010 Posted September 3, 2011 Share Posted September 3, 2011 PRELIMINARY LOCAL STORM REPORT NATIONAL WEATHER SERVICE NEW ORLEANS LA 653 AM CDT SAT SEP 03 2011 0627 AM FLOOD HARAHAN 29.94N 90.20W 09/03/2011 JEFFERSON LA PUBLIC 1.50-1.74 INCHES OF RAIN IN LESS THAN 1 HOUR AT THE END OF DICKORY AVE NEAR THE RIVER. 0649 AM 09/03/2011 COASTAL FLOOD 14 E NEW ORLEANS 29.97N 89.85W ST. BERNARD LA EMERGENCY MNGR 1 FOOT OF WATER IN STREETS OF VENETIAN ISLES SUBDIVISION NEAR CHEF PASS. HIGHWAY 90 WAS REPORTED PASSIBLE BUT WATER RISING NEAR CHEF PASS BRIDGE. Link to comment Share on other sites More sharing options...
Srain Posted September 3, 2011 Share Posted September 3, 2011 First morning visible image shows the exposed center just SE of Vermillion Bay... Link to comment Share on other sites More sharing options...
needbiggerboat Posted September 3, 2011 Share Posted September 3, 2011 Looks like the NAM wants to take Lee back out into the Gulf Link to comment Share on other sites More sharing options...
mike2010 Posted September 3, 2011 Share Posted September 3, 2011 12Z NAM continues the oddness. Even though it's not a tropical model, it does well with them 24 to 48 hours out. Has it on land tonight...and then back into the gulf again tomorrow. And close to a 100 mile offshore by tomorrow night. Continuing the easterly flow and slowly building tides even higher around LA and MI. It makes you wonder, since New Orleans is in a 'bowl' and this storm will just sit for days (if NAM is right) the undercutting of wave action along with the super saturated grounds from heavy rains. How significant the flooding could really be. Could it be so saturated that the water undercuts the levees ? It just seems odd how confident all the news reports are that their now super confident that New Orleans will be fine now. Even if the pumps are working flawlessy, the water is still being thrown out into the area of the tide that is still rising and pushing back. Which only increases the amount of water being pushed up against the levees. (since onshore flow continues for days longer)EDIT: at 42 hours it now developers a secondary low near Alabama. (2-headed monster ? ) Link to comment Share on other sites More sharing options...
Cheeznado Posted September 3, 2011 Share Posted September 3, 2011 Two runs in a row of the NAM have rotated Lee back down pretty far into the GOM- this seems extreme and it is the NAM but this does show Lee may have a few tricks up its sleeve and this scrape by the coast now may not be the real landfall which may wait another day or two? This still a hard to forecast system.... Link to comment Share on other sites More sharing options...
usedtobe Posted September 3, 2011 Share Posted September 3, 2011 The dumpage is now in full swing in SE LA. Waves of convection and heavy rain moving NW off the Gulf, with radar already showing some 4+" totals S of KHUM and near New Orleans. With expanding cold tops NE of the center and the diurnal convective max coming, going to be a long night. BTW, currently a TOR in effect near Houma as well. Will be interesting to see how things evolve from here. NHC alluded to another potential stall as shown in the models after some northward drift in the next 12-24 hours. Even if the system moves inland, with the large circulation feeding juice in off the Gulf, the somewhat subtropical nature of the system, and the fact that S LA is effectively a big swamp, there's not going to be much if any weakening until the big trough really comes down and gets it and moves it off to the NE. Another thing to watch for is the very heavy rain NW of the center once it starts interacting with the trough and a strong deformation axis develops NW of the LLC in an area of strong divergence in the right entrance region of the ULJ associated with the trough. In terms of precipitation. Lee will be an interesting storm as the typical transition is for precip to shift to the northern and northwestern side of the storm as they transition and interact with the jet. However, right now the system is quite sheared and most tropical systems that hold onto a distinct 500h low as they cross the appalachians produce a maximum along the east slopes of the appalachians due to the eastern flow to the northeast of the circulation center. Such a max seems to be even more enhanced at night. Camille and Danny (1985 version) were both good examples especially the former. http://www.hpc.ncep.noaa.gov/research/mcs_web_test_test_files/Page2007.htm The flaring up at night of tropical systems is pretty common with non-sheared storms. Elena was a great example of a tropical storm that weakened inland but flared up both night in an unsheared environment. http://www.hpc.ncep.noaa.gov/research/mcs_web_test_test_files/Page2549.htm Shearing complicates things as does the interaction with a jet streak making it less clear when the precip max would occur once the system moves northward away from the gulf coast. P.S. the 12Z nam looks to be on crack moving the low west and then east and still having it off the coast at 42 hrs or so. good luck with that. Link to comment Share on other sites More sharing options...
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