Ian Posted August 30, 2012 Share Posted August 30, 2012 That storm might be the one of the day for rotation.. tho it petered out right after that new warning. It had 5-7 scans of a strong couplet though. The stuff that was reported in Gulfport was like a quick one to two scan blip. I think it was in pretty rural areas though. Closing in on 50 tornado warnings for Isaac -- Harrison and Jackson have had 10 and 8 respectively.. almost all day . If tomorrow is another sizable day on that end could end up with a pretty high number of tornadoes from the system. Link to comment Share on other sites More sharing options...
Srain Posted August 30, 2012 Share Posted August 30, 2012 Morning e-mail from Jeff: Isaac continues to bring flooding rainfall and storm surge to the LA and MS coast. Overnight strong SSW winds have surged the waters within Lake Pontchartrain northward away from New Orleans and into the northern shore of the lake. Severe storm surge flooding of 5-7 feet is currently in progress from the western side of the lake to the eastern side of the lake including the cities of Slidell, Mandeville, and LaPlace. Early this morning a levee was breached near a pump station in the City of Slidell and while the pump station continues to operate, it cannot keep out with the influx of water and portions of the city are now flooding with 3-5 feet of water…all locations in the city at an elevation below 9 ft will be subject to flooding. Overtopping also occurred late yesterday afternoon in St John the Baptist Parish and around LaPlace where at least 1000 residents are still being rescues from their rooftops. Initial water level readings on the west side of Lake Pontchartrain include that record high storm surge levels may have been produced and flooding west of New Orleans and on the north shore of the lake is equal if not greater than hurricane Katrina and hurricane Gustav. These high water levels are a function of the storm track, as Isaac passed to the south and then west of Lake Pontchartrain allowing a continuous feed of sea water on SE winds into the lake. Hurricane Katrina passed just east of the lake initially pushing sea water in from the east, then sloshing that surge southward on the west side of the eye against the New Orleans levees. Waters levels in portions of Plaquemines Parish are only 3-5 feet lower than Hurricane Katrina 13-14 vs 17-19. I cannot emphasize enough how poorly the Saffir Simpson scale it at relating storm impacts and the fact that this was only a Category 1 hurricane appears to have resulted in residents not heeding the evacuation orders. The focus during landfalling tropical cyclones must be on the impacts and NOT the category of the storm….the category only suggest wind damage impacts and has no relation on the storm surge or rainfall flood threat. Every hurricane is different, a slow moving large weak hurricane like Isaac can produce significant impacts as shown due to the far reaching effects and the continuous adverse conditions. Below are listed the storm surge values expected for the various portions of the affected coast as issued in an e-mail on Monday at 140pm. As you can see the values for Plaquemines Parish are highlighted in red (7-11ft), with the levees only 8ft tall it was highly likely that they would be overtopped. SE LA (from the mouth of the MS River west to near Houma): 6-9 ft SE LA (from the mouth of the MS River to the LA/MS state line): 7-11 ft SE LA (Lake Pontchartrain): 5-8 ft MS coast: 8-12 ft AL coast: 6-10 ft FL panhandle: 3-6 ft Storm surge values along the coast will subside today as onshore winds weaken however areas where levees have been overtopped will take days to drain. Isaac will continue to move inland and weaken however large feeder bands on the east side of the system will continue to produce flooding rainfall over MS and E LA. As the center moves NNW tonight into southern AR, the potential for core rainfall will increase. The threat will be shifting to fresh water flooding as Isaac moves north into AR , MO, and IL over the next 48 hours. While much of this region is suffering in severe drought, the very heavy rainfall of a tropical system in a short period of time can lead to flooding. Additional rainfall amounts of 6-15 inches will be possible along the track of Isaac. Link to comment Share on other sites More sharing options...
dan11295 Posted August 30, 2012 Share Posted August 30, 2012 Those bands in MS continue to show rotation, multile TOR active. Getting confirmed reports of TOG with these cells too. 0716 AM TORNADO PASCAGOULA 30.37N 88.55W 08/30/2012 JACKSON MS EMERGENCY MNGR JACKSON COUNTY EMERGENCY MANAGEMENT REPORTED A TORNADO SPOTTED ON MARKET STREET IN PASCAGOULA. Link to comment Share on other sites More sharing options...
Ian Posted August 30, 2012 Share Posted August 30, 2012 Those bands in MS continue to show rotation, multile TOR active. Getting confirmed reports of TOG with these cells too. 0716 AM TORNADO PASCAGOULA 30.37N 88.55W 08/30/2012 JACKSON MS EMERGENCY MNGR JACKSON COUNTY EMERGENCY MANAGEMENT REPORTED A TORNADO SPOTTED ON MARKET STREET IN PASCAGOULA. ~45 more tornado warnings since midnight... looks like a number seen. Closing in on 100 warnings now since Sunday. This afternoon might have some higher end potential as well. Should end up with pretty significant numbers confirmed I'd think. Link to comment Share on other sites More sharing options...
Stebo Posted August 30, 2012 Share Posted August 30, 2012 ~45 more tornado warnings since midnight... looks like a number seen. Closing in on 100 warnings now since Sunday. This afternoon might have some higher end potential as well. Should end up with pretty significant numbers confirmed I'd think. Tomorrow as well as this thing starts to lift Northward. Link to comment Share on other sites More sharing options...
Ian Posted August 30, 2012 Share Posted August 30, 2012 Tomorrow as well as this thing starts to lift Northward. yeah.. tho the 500 low starts to degrade moving forward so i'd think the numbers have already peaked or are doing so now. Link to comment Share on other sites More sharing options...
GaWx Posted August 30, 2012 Share Posted August 30, 2012 During the 6-10 day period, the 12Z Euro appears to take some sort of offshoot of Isaac/trof/front combo SEward to off the SE US coast and develop it as a homebrew kind of deal that then does some kind of Fujiwara effect thing offshore with Leslie fwiw. It eventually gets absorbed by Leslie as it then heads in the general direction of Nova Scotia. This is a really bizarre looking scenario. The 0Z Euro had done something similar. Link to comment Share on other sites More sharing options...
phil882 Posted September 4, 2012 Share Posted September 4, 2012 Surprised nobody has mentioned this yet, but both the ECWMF and GFS suggest that Isaac will emerge and re-develop out over the Gulf of Mexico in the next 48-72 hours. Talk about following in Ivan's footsteps. ECMWF: GFS: Link to comment Share on other sites More sharing options...
PSUBlizzicane2007 Posted September 4, 2012 Share Posted September 4, 2012 Ehhhh.... I'm going to disagree with you that this would be considered Isaac. While Ivan had a solid circulation the entire time one could follow, this does not. To me, this appears more to be energy that split off from Isaac's remnants and became an MCS. Link to comment Share on other sites More sharing options...
phil882 Posted September 4, 2012 Share Posted September 4, 2012 Ehhhh.... I'm going to disagree with you that this would be considered Isaac. While Ivan had a solid circulation the entire time one could follow, this does not. To me, this appears more to be energy that split off from Isaac's remnants and became an MCS. http://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8vor4/wg8vor4java.html This animation would argue that we have a traceable low-level vorticity maxima. It doesn't appear the circulation has remained closed though, but again you could say the same thing for TD#7 / Helene earlier this year. Link to comment Share on other sites More sharing options...
wxmx Posted September 4, 2012 Share Posted September 4, 2012 Isaac gave an indigestion to the states. It's getting out from where it got in . It will be interesting if it develops, whether it keeps the name or it gets a new one. My guess is it would be a new one, despite Helene's precedent. Link to comment Share on other sites More sharing options...
dan11295 Posted September 5, 2012 Share Posted September 5, 2012 NHC gives it a 10% in the 8 pm TWO. Given that they make no mention of Isaac in the outlook it is safe to say if it develops this will get a new name. Link to comment Share on other sites More sharing options...
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