Tropical Storm Lee lingers off Louisiana coast
Tropical Storm Lee continues to bring heavy rain, moderately strong wind gusts, and tornado risk to the Gulf Coast states east of Texas. Lee is 55 miles south of Lafayette, Louisiana, and is drifting almost due north at 4 mph. Lee's central pressure dropped to 988 mb since this morning, but has maximum sustained wind speeds that have decreased to 50mph. The National Hurricane Center has extended the tropical storm warning eastward to Destin, Florida. Since this morning, New Orleans Lakefront Airport has received about another inch of rain for a storm total of 6.87 inches. Rainfall estimates from radar suggest some locations, especially close to the coast, might have already seen up to 8 inches of rain from Tropical Storm Lee. Although the New Orleans area is in a dry slot of the storm, more rain can be expected through the night in the form of isolated storms with heavy downpours. Louisiana's Jefferson Parish officials ordered a mandatory evacuation for three towns earlier today: Lafitte, Crown Point, and Barataria. Heavy rain and tidal surge pushed the water of Bayou Barataria into the surrounding low-lying areas, and officials warned that if residents didn't leave, they might become stranded for a couple of days.
Figure 1. Infrared satellite of Tropical Storm Lee captured around 6pm EDT. Source: NOAA.
Forecast for Tropical Storm Lee
Lee's forecast hasn't changed much since this morning. Dry air is being pulled in from the west, which is giving the storm a very subtropical appearance, and is mitigating intensification. Earlier today, two centers of circulation were visible in satellite and confirmed by Hurricane Hunters. The centers were rotating around each other in full Fujiwara fashion, and although they were scientifically interesting, it meant that there was no clear center of circulation, and probably helped to weaken storm. The National Hurricane Center expects that Lee will come ashore in Louisiana later this evening and linger over the region until Monday, when it will finally be pushed north by a mid-latitude wave.
Lee's tornado threat
A tornado watch is in effect for southern Louisiana and portions of Mississippi, Alabama, and the western Florida Panhandle until 10pm CDT. The forecast is for small and short-lived tornadoes, but the threat for tornado damage is still there. A PhD student at Georgia Tech (and my former group member), James Belanger, runs a skillful model to predict the number of tornadoes that a tropical cyclone could produce. The model uses variables such as the size of the storm, the maximum wind speed, and moisture. For the 2008 hurricane season, the model accurately predicted the number of tornadoes that would be spawned from a quite a few tropical cyclones, including Hurricane Dolly, Tropical Storm Edouard, Tropical Storm Fay, and Hurricane Ike. Given today's forecast track and intensity, Belanger's model is forecasting 30-40 tornadoes could be spawned from Tropical Storm Lee, mainly in the Southeast states east of and including Louisiana.
Interestingly, although the nose of dry air that's being pulled in from drought-stricken Texas (visible in the satellite image above) is acting to keep the storm weak, it's also playing a role in the number of tornadoes that could be spawned from Lee. The dry air is a crucial component for the storm to develop discrete, isolated thunderstorm cells (versus a large shield of heavy rain). The discrete cells, just like during severe weather season, are the storms that are most capable of producing a tornado.
Angela
Reader Comments
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no trust me thats a eye starting too pop out
Watching radar, will head downstairs if it gets bad. Lull of storm right now.
Yeah, I know it's an eye.
Texas :-) I'm Texcasting everything until after the TropicalCyclone proves that it's going elsewhere through a sustained increase in distance away from Texas... or the Drought breaks, whichever comes first
- - - - - - - - - - - - - - - - - - - - - - - - - -
6amGMT's TS.Lee has been reevaluated&altered to Hurricane status for H.Katia's_12pmGMT_ATCF
20.9n57.8w has also been re-evaluated&altered
21.1n58.0w, 21.6n58.8w are now the most recent positions
Starting 3Sept_12pmGMT and ending 4Sept_12pmGMT
The 4 eastern line-segments represent HurricaneKatia's path
and the westernmost line-segment is the straightline projection.
Using straightline projection of the travel-speed&heading derived from the
ATCF coordinates spanning the 6hours between 6amGMT then 12pmGMT :
H.Katia's travel-speed was 10.3mph(16.6k/h) on a heading of 303.9degrees*(NW)
H.Katia was headed toward passage over Beaufort,SouthCarolina ~6days from now
Copy&paste 19.4n55.5w, 19.4n55.5w-19.9n56.2w, 19.9n56.2w-20.4n57.0w, 20.4n57.0w-21.1n58.0w, 21.1n58.0w-21.6n58.8w, bft, 21.1n58.0w-32.322n80.454w into the GreatCircleMapper for more info
The previous mapping (for 4Sept_6amGMT)
* 303.75degrees is midway between WNW and NW
CAPE HATTERAS 34 X X( X) X( X) X( X) X( X) 2( 2) 11(13)
CAPE HATTERAS 50 X X( X) X( X) X( X) X( X) X( X) 3( 3)
CAPE HATTERAS 64 X X( X) X( X) X( X) X( X) X( X) 1( 1)
MOREHEAD CITY 34 X X( X) X( X) X( X) X( X) 1( 1) 11(12)
MOREHEAD CITY 50 X X( X) X( X) X( X) X( X) X( X) 3( 3)
WILMINGTON NC 34 X X( X) X( X) X( X) X( X) 1( 1) 8( 9)
11Am Wind Advisory
CAPE HATTERAS 34 X X( X) X( X) X( X) X( X) 3( 3) 17(20)
CAPE HATTERAS 50 X X( X) X( X) X( X) X( X) X( X) 5( 5)
CAPE HATTERAS 64 X X( X) X( X) X( X) X( X) X( X) 1( 1)
MOREHEAD CITY 34 X X( X) X( X) X( X) X( X) 2( 2) 14(16)
MOREHEAD CITY 50 X X( X) X( X) X( X) X( X) X( X) 5( 5)
MOREHEAD CITY 64 X X( X) X( X) X( X) X( X) X( X) 2( 2)
WILMINGTON NC 34 X X( X) X( X) X( X) X( X) 1( 1) 12(13)
WILMINGTON NC 50 X X( X) X( X) X( X) X( X) X( X) 4( 4)
WILMINGTON NC 64 X X( X) X( X) X( X) X( X) X( X) 1( 1)
wwwwhhhaaatttt??
I'm thinking we will have a lot more of those to come... As "Lee" gets closewr to us here in Mobile the Tor-Con will be going up.... Its Pouring right now and would not surprise me to have a warning coming soon ....
Taco :o)
Katia, the perfect example of ... a FISH. I knew it would be so since the begining... but I was told it was too early to be too confident. Katia won't affect any land mass, so NEXT please!
Once again, Katia is only marine concern.
Friend of mine lives in Navarre. She got home from work at 2am and said there was a tornado in Navarre during early morning hrs.
A timely reminder IMO that it's not enough to look at the models, which represent mere possibilities. There must be some skill in analysis of data, real time imagery and the varied model output in order to develop a reasonable forecast. IMO this is why NHC forecasts generally, though not always, outperform individual and even ensemble models.
Starting is the right word here.. We've gone from Uniform Central Dense Overcast scene to an EMBEDDED CENTER~ Arc of convection within central overcast cloud region.. know your scene types.. now with pictures.. Start around page 27..but I expect the regulars to have already read the whole thing;)
TWAVE AT 40W COULD BE THE NEXT INVEST. HOPEFULLY THE NE ISLANDS WILL GET SOME DECENT RAIN FROM IT.
Model error for Lee in nm.
Model Name 0hr 24hr 48hr 72hr
GFNI 0 70.5 75.4 -
GFDI 0 62.5 63.3 63.6
GFDL 18.0 42.9 62.7 77.9
GFDN 7.9 52.1 55.8 -
CMC 24.3 56.8 73.9 108.4
EGRR 24.7 52.6 90.8 -
AVNO 28.2 43.3 51.4 48.6
BAMD - 65.8 73.5 84.8
BAMM - 59.5 97.4 155.6
BAMS - 81.0 154.5 248.4
AEMN 26.9 61.2 97.8 118.2
HWRF 21.4 70.3 85.1 138.3
LBAR 0 66.2 97.3 85.5
LGEM 0 58.7 62.8 126.0
NAM 28.0 71.0 41.8 48.5
Viewing: 1551 - 1587
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