Disorganized Leslie headed towards Bermuda

By: Dr. Jeff Masters , 4:18 PM GMT on September 03, 2012

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Tropical Storm Leslie continues to struggle with moderately high wind shear of 15 - 20 knots, due to strong upper-level winds out of the northwest. The shear is keeping heavy thunderstorms confined to the southeast quadrant of the storm. These thunderstorms are as far removed from the center as we've so far with Leslie, as seen on satellite loops. According to the latest SHIPS model forecast, the shear is expected to stay moderately high through Tuesday night, then drop to the low category, 5 - 10 knots, by Wednesday night. At that time, Leslie will be over warm ocean waters of 29°C, and the reduction in shear and warm waters should allow Leslie to intensify into at least a Category 1 hurricane by Friday, as predicted by most of the intensity forecast models. Intensification to a stronger storm may be hampered by its slow motion, which will cause Leslie to churn up cool water from the depths that will slow intensification. Once Leslie begins moving more quickly on Saturday, this effect will diminish, and Leslie could be at Category 2 strength on Saturday, as predicted by the HWRF and LGEM models. Steering currents for Leslie are expected to be weak on Tuesday - Friday, as Leslie gets stuck between two upper level lows. The latest guidance from our top computer continues to show Leslie making a very close pass by Bermuda on Saturday, and that island can expect a 3-day period of rough weather Friday through Sunday. Leslie will stay stuck in a weak steering current environment until a strong trough of low pressure approaches the U.S. East Coast on Saturday. This trough should be strong enough to pull Leslie quickly to the north on Saturday and Sunday, and Leslie may be close enough to the coast that the storm will make landfall in Canada on Monday, September 10. None of the reliable models have shown that a direct hit on New England will occur, but we can't rule that possibility out yet. The most likely long-term fate of Leslie will be for it to miss land entirely and brush by the coasts of Nova Scotia and Newfoundland, but any forecast of what a tropical cyclone might do a full seven days in advance is pretty speculative. Regardless, Leslie will bring an extended period of high waves to Bermuda, the U.S. East Coast, and Nova Scotia and Newfoundland this week. These waves will be capable of causing significant beach erosion and dangerous rip currents.


Figure 1. Morning satellite image of Tropical Storm Leslie. The low-level circulation center is fully exposed to view, thanks to strong northwest winds creating 15 - 20 knots of wind shear.

Invest 99L in the Central Atlantic
A small extratropical low pressure system that got cut off from the jet stream and is now spinning away in the Central Atlantic, near 26°N 42°W, (Invest 99L), is headed west at 10 mph, and has developed a small amount of heavy thunderstorm activity. This storm is not a threat to any land areas, and in their 8 am EDT Tropical Weather Outlook on Monday, NHC gave 99L a 30% chance of developing into a tropical cyclone by Wednesday morning.

Jeff Masters

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Quoting AussieStorm:
This is what the front that's going to hit Sydney dumped on Perth...








That looks like sleet. (please send some to North America... I'm done with summer)
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1271. Patrap
Quoting CybrTeddy:
Hey pat, nice pictures. Defiantly could say that Isaac willl be one to remember for you guys for a long time. Hearing that damage estimates from Isaac are now estimated with insurance claims to be around 3 billion.


Isaac was very different,as having a East wind for 26 Hours was just plain wrong in my sperience.
Member Since: July 3, 2005 Posts: 420 Comments: 127549
Australia emerges from coldest winter nights in 30 years.

Those shivering through the winter nights this year can take comfort in knowing they were not alone – Australia has just emerged from its coldest overnight minimum temperatures on average across the country in 30 years.

What is perhaps just as significant is that this year also saw the third coldest over overnight minimums on record with Australia recording an average minimum of-0.91˚C.

Tasmania was the only state to have warmer than average minimum temperatures this year, with a minima average of 0.37˚C.

One region to keenly feel the cold was the Northern Territory, which shivered through its coldest minimum temperature average on record, while South Australia rugged up under its seventh coolest.

Elsewhere, Western Australia saw its lowest minimum temperatures since 1976 averaging -0.75˚C, while New South Wales averaged a minima of -0.51˚C through winter.

These bitterly cold temperatures are at least partly due to emerging El Niño conditions, which typically brings reduced rainfall. The lack of cloud cover leads to daytime heating rapidly escaping resulting in a dramatic drop in overnight minimum temperatures.

“Persistent high-pressure systems also resulted in above average day time maximums with the overall national average maximum temperature around 0.4C above the long term seasonal average,” says Felim Hanniffy, Meteorologist at The Weather Channel.
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SAB and TAFB as well as the ADT all show 13L at 2.5, or TS strength. Expect an upgrade to TS Michael at 11am.
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Interesting facts I came up with on the Hurricane Severity Index.


SS cat - Min HSI - Max HSI

TS - 2.36* - 11.55 (*used 35kts and 64kts)
1 - 7.69 - 22.65 (65 and 83kts)
2 - 11.84 - 30.24 (84 and 96kts)
3 - 14.45 - 39.19 (97 and 113kts)
4 - 18.44 - 44.65 (114 and 133kts)
5 - 23.90 - 50 (134 and 150kts Max is flawed)


The minimum on Cat 2 through 5 may need to be adjusted upward by 4 points, as it's inconceivable that such a storm would not score maximum in the 35kt's size range and at least half in the next range.

Still, the scale DOES reflect that notion that "weaker" SS scale storms can in fact be more destructive.

On this scale, the weakest possible category 4 (think Charley, but one-sided,) is actually weaker than the strongest possible category 1.

Meanwhile cat 5 Andrew definitely ranks weaker than the maximum severity category 3 storm, explaining very well why Katrina was so much worse than any of Andrew's landfalls. Again, Andrew's Florida landfall ranks somewhere between 29 and 33, on the bottom end of Category 5, and less than the top end of cat 3. This also makes sense because the two storms had similar central pressures at landfall.
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1265. LargoFl
...looks like Leslie absorbs isaac's moisture at the end of this run
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This is what the front that's going to hit Sydney dumped on Perth...







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1263. LargoFl
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Any Cape Verde systems in the horizon that we need to worry about?
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Quoting CybrTeddy:
Morning all, the ECMWF continues to want to bomb Leslie out into a very powerful major hurricane, the GFS is continuing to also show the development of Leslie into a major, same With the CMC and UKMET. The ECMWF/CMC duo also show that part of what appears energy associated with Isaac and a trough could develop into a system in the gulf. Active times continue.



And we got the 13 name storm this am
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Hey pat, nice pictures. Defiantly could say that Isaac willl be one to remember for you guys for a long time. Hearing that damage estimates from Isaac are now estimated with insurance claims to be around 3 billion.
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1258. LargoFl
..watch and see how it explodes in size
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Quoting Patrap:
Uptown NOLA Isaac Images, post Storm, Home damage, and other..



























The house got VERY lucky with the direction the tree fell!
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Quoting Patrap:


Got power back here Uptown round 4 pm Saturday I think it was.

Net and Phone with Cox Cable came back fully yesterday.

Statewide, Isaac power outages drop to 6 percent, PSC says
Published: Monday, September 03


That's quite a stretch, surprised it took that long
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1255. LargoFl
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Morning all, the ECMWF continues to want to bomb Leslie out into a very powerful major hurricane, the GFS is continuing to also show the development of Leslie into a major, same With the CMC and UKMET. The ECMWF/CMC duo also show that part of what appears energy associated with Isaac and a trough could develop into a system in the gulf. Active times continue.
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1253. Patrap
Uptown NOLA Isaac Images, post Storm, Home damage, and other..


























Member Since: July 3, 2005 Posts: 420 Comments: 127549
Hurricane Isaac once again unearths Alabama shipwreck




Visitors are once again flocking to the Alabama coast to view a 150-foot mystery ship that is uncovered every few years when a hurricane tears through the area.

Fox10TV.com reports Hurricane Isaac has uncovered the remains of the ship, which is thought to be an early 20th century vessel named The Rachael that ran aground, in Gulf Shores, Alabama.

The station reports that according to the Alabama Historical Commission, the ship is believed to have ran into rough waters while carrying timber in 1930. Archeologist Amanda Hill tells the station that according to interviews with witnesses, the ship was looted of its cargo and set on fire.

The ship was last seen after Hurricane Ike in 2008, though it had been seen many times prior. It was originally believed to date back to the Civil War, but those rumors were laid to rest after it was studied in 2008 and found to have many details that date closer to the early 20th century. The Rachael is believed to have been built in 1919.

Also in 2008, the Alabama Historical Commission considered digging up the remains and moving them to a museum. However, since the remains are on private property, the property owners would be forced to foot the bill for the excavation.

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Quoting Grothar:


I still eat scones. Picked up the habit years ago.

I love good scones, but it is rather difficult to find good (authentic) ones here. This may sound like blasphemy, but I actually like the ones at Starbucks (the petite vanilla ones, when warmed up). That said.. they are nothing compared to authentic ones.
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1250. LargoFl
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1249. Grothar
Quoting K8eCane:


i will definitely read your blog. you give good, accurate info. and its easy to get you to appear.


Thanks, Katie.
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1248. Patrap
Quoting Grothar:


It should be an interesting one today. How is the power situation there. I heard a lot of people don't have power yet.


Got power back here Uptown round 4 pm Saturday I think it was.

Net and Phone with Cox Cable came back fully yesterday.

Statewide, Isaac power outages drop to 6 percent, PSC says
Published: Monday, September 03
Member Since: July 3, 2005 Posts: 420 Comments: 127549
1247. LargoFl
oh man look whats coming....................
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Quoting Grothar:


We may need more than that if these models of other systems come to fruition. Leslie looks like she wants to be a large storm. If that big anti-cyclone moves over her, it should be something to watch.

Even the FIM8 shows a very large system.


That is a massive system... will create massive swells and beach erosion all up and down the eastern seaboard.
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1245. Grothar
Quoting Patrap:
Doc Masters should have a updated entry for us soon I feel.



It should be an interesting one today. How is the power situation there. I heard a lot of people don't have power yet.
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Quoting Grothar:


I still eat scones. Picked up the habit years ago.

I make my own.
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1243. LargoFl
Quoting K8eCane:


wow...like u really need more rain lol
I am just hoping this doesnt reach down into south east florida,they had alot of flooding down there.
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Quoting RitaEvac:
Haven't been on blog since last Wednesday



My Deepest Sympathies.....

I would give the whole rundown on what you missed, but I need to get back to school stuff :'(

Leslie:
Member Since: February 11, 2012 Posts: 0 Comments: 9720
1241. Patrap
Member Since: July 3, 2005 Posts: 420 Comments: 127549
1240. LargoFl
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1239. K8eCane
Quoting LargoFl:
Clean out your gutters..whew heavy rain coming.......


wow...like u really need more rain lol
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Quoting TropicalAnalystwx13:
Im starting to think that we're going to exhaust the original naming list.
I'll be able to reuse my 'Team Zeta!' t-shirt? :)

In other questions, for anyone...

I've been watching the storm system over Alabama - you know, trying to shift it more East by shear force of will and all that.

I noticed that many of the bursts of convection, storm cells, and rain originate at the same rough point before "expanding" (on radar at least, for lack of a better term) and moving SE then ESE. Right now that point is pretty stationary (on radar) northish of Tuscaloosa and westish of Birmingham.

Is there a term for that type of "convective birth point"? Really not sure what to call it and I'd like to read up on the process and forces involved.
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Quoting Grothar:


Looks like it's moving south, Geoff.


Yes sir. It's going to be a very interesting week.
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1236. Patrap
Note the swirl in the Mid Gulf at 25 N



Member Since: July 3, 2005 Posts: 420 Comments: 127549
Haven't been on blog since last Wednesday, have no insight on what Leslie has been doing other than it's supposed to sit and spin all week out there. Stopped hearing news outta LA, but caught some brief stories on news about crews draining water by deliberate breach somewhere.
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1234. LargoFl
Clean out your gutters..whew heavy rain coming.......
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Quoting Patrap:
Birmingham
NEXRAD Radar

Base Reflectivity 0.50 Elevation
Range 248 NMI



I'm sick and tired of Alabama getting all the Rain :P
Member Since: February 11, 2012 Posts: 0 Comments: 9720
1232. Patrap
Member Since: July 3, 2005 Posts: 420 Comments: 127549
1231. MahFL
Hmm, all those bands of clouds in the northern GOM sure look like bands of a tropical system.....
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1230. WxLogic
Quoting GeoffreyWPB:


Quite a train.
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1229. Grothar
Quoting fireflymom:
Making your words last night come true this morning Grothar.



And I thought you just read my jokes. :)
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1228. LargoFl
GFS at 111 hours, slower than Nam near Tampa bay........
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1227. WxLogic
As of 12Z... 500MB VORT from Isaac's remnants continue to move S/SE towards the GOM:

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1226. Grothar
Quoting GeoffreyWPB:


Looks like it's moving south, Geoff.
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1225. Grothar
Quoting AussieStorm:


Okay, I'll put the kettle on, you fix up the scones, I'll have 2.


I still eat scones. Picked up the habit years ago.
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1224. Patrap
Member Since: July 3, 2005 Posts: 420 Comments: 127549
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1222. Patrap
Braithwaite father and son rescue about 120 from Hurricane Isaac's floodwaters
Published: Sunday, September 02, 2012, 9:30 PM


On Tuesday night, Isaac's winds whipping and floodwaters high, a Braithwaite father and son kept watch over the minimal levee between eastern Plaquemines Parish and the Gulf of Mexico. As midnight hit, Jesse Shaffer Sr. and Jr. decided one would rest for an hour while the other sat on the levee, locally known as the "wall." Then they would switch, hour by hour, charting the water's rise. But at 12:10 a.m. Wednesday, relatives called to say the water already was rushing over the wall several miles south of their location.

On the northern end of Braithwaite, "it was coming up 6 inches every 10 minutes," Shaffer Jr. said.
Water quickly flowed into lawns and down streets in eastern Plaquemines Parish. Then, it seeped into first floors. Residents who had remained in their homes soon climbed stairs with possessions in tow. As the water rose further, many climbed again, to attics and roofs.
Eventually, they had climbed as high as they could. They flailed their arms and screamed.

With official emergency crews waiting for the winds to subside and the sun to rise, no one responded to their cry, except the Shaffers, who are credited with helping to save about 120 lives.
They rescued a 6-month-old baby and a 70-year-old man. They chopped through roof ventilation systems to gain entry. Some residents swam to them. The Schaffers discovered others fragilely bobbing in the currents, clutching debris that floated 10 to 15 feet above asphalt streets.

And whereas Wednesday morning everyone scrambled with all their might to exit, residents now desperately want to return. They want to survey the lake that once was home, and determine what remains of their material lives.
So as Hurricane Isaac moved on, the Shaffers have taken on a new community role: They are guiding residents back.
Many returning residents said this weekend that they will no longer rebuild within Plaquemines' walls. They said, instead, they will move a few miles north to St. Bernard Parish's protected enclave.

Cut off from the world

Eastern Plaquemines residents call their insubstantial 8- to 9-foot levee the "wall." It's supposed to protect eastern Plaquemines from Braithwaite to White Ditch, but it does not meet federal standards and leaves residents vulnerable when storms approach.
The wall is also what they call the mammoth new 26- to 32-foot federal levee system that cuts across the St. Bernard and eastern Plaquemines Parish line, protecting St. Bernard from waters to the south.
Eastern Plaquemines has just one parish border: To the south, east and west is Mother Nature, either the Mississippi River or the unbridled Gulf of Mexico.

When a massive storm is set to hit, the 20-foot-tall levee gate on Braithwaite's northern border shutters, removing easy entry for eastern Plaquemines residents to the walled-off world of safety. By the time the 8-foot parish wall alongside the Gulf began overtopping Wednesday morning, most residents who lived behind it and could flee had done so. Shaffer and son observed the caravan of cars racing into St. Bernard. Eastern Plaquemines had only about 2,000 inhabitants in 700 homes, and while most already had evacuated before the gate closed, the remaining hundreds crossed the border by riding along the levee itself as the actual road was blocked by that solid 20-foot gate.

"We had watched the cars coming through, and the surge coming over the levee kept getting stronger and stronger. And those cars had to drive through the surge coming over like a waterfall. It was crazy," the younger Shaffer said. "There was a lot of people that didn't make it. They didn't have cars there, so ..."
Helping people reach the wall
The spontaneous rescue effort began about 4 a.m. Wednesday with Jesse Shaffer Sr., 53, searching the east bank with his brother-in-law, Lanny Lafrance, 52. That was about seven hours before any other rescue team arrived.

"I had some friends calling me that were stuck. We had to get to them, and the Sheriff's Office was on the other side of the river ... and the water came up so quick," Shaffer Sr. said.
Before dawn, the men already had scooped up eight people, including two floating on a spare tire and a couple with a baby.

"This man here, Jesse, I called him and said my son and grandson were trapped, and he said 'I'm on my way,'" said Mary Williams, 66, who couldn't enter her home on Saturday because the water still was too high. "Him, he needs to go to the President. He needs to be a national hero."
At the break of dawn Wednesday, Shaffer Sr. rescued her son, Richard Clark, along with several others trapped on the second floor of his Braithwaite home. Clark said Shaffer's boat "was the first one we seen that morning." He said he had called the Coast Guard two hours earlier but officials had told him the winds were too strong to stage a rescue.
"We didn't know at the time if we would drown or not," Clark said.

With winds still gusting at near-hurricane force, Shaffer Sr. pulled up to Clark's second-floor window in his Carolina skiff.
Until the sun rose, Shaffer Sr. wouldn't let his 25-year-old son join him on the rescue mission. He was protective of his son.
At least in the light, you can find a tree to grab on to if the boat goes under, the father said.
Shaffer Sr., a former cabinet maker, current shrimp trawler and commissioned deputy sheriff, knew his community well enough to navigate it in pitch dark, in a boat, with 80 mph winds and fierce currents.
While he waited to join his father on the boat, Shaffer Jr. used his youthful instincts.
"I put it on Facebook. I said, 'Message me, text message me.' By the end of the day, I had 80 texts... addresses, locations of more individuals who had to be rescued," he said.

Shaffer Jr., a volunteer firefighter, emergency medical technician and nurse, vividly recalls his first rescue.
"We was heading south on Highway 39, past this house that was a trailer home and there was five people on there and they were screaming, they were just screaming like crazy," he said.
"They were so relieved to see us. They were spinning around. They were screaming the whole time. By the time we pulled to their roof, they had about that much, that much leeway before the entire house was engulfed with water," he said, holding his hands a few inches apart.

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.