Disturbance 98L probably no threat to land

By: Dr. Jeff Masters , 1:46 PM GMT on September 18, 2009

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A tropical disturbance (98L), is located midway between Africa and the Lesser Antilles Islands. This disturbance has a well-defined surface circulation, and has developed a modest amount of heavy thunderstorm activity overnight. This morning's QuikSCAT pass (Figure 1) shows a complete, circular wind pattern around the low pressure center of 98L, but top winds were only 25 mph. Wind shear is moderate, about 15 knots, and Sea Surface Temperatures are 28°C, which is about 2°C above the 26°C threshold needed to support a tropical cyclone. There is a large amount of dry air to the north and west of 98L, and this dry air is interfering with development.

The global computer models predict differing amounts of wind shear in the path of 98L as it moves west-northwest at 10 mph over the next three days. The ECMWF, GFS, and UKMET models do not develop 98L, while the NOGAPS, GFDL, and HWRF do. The models that do develop 98L predict that a strong trough of low pressure will turn 98L to the northwest and then north beginning on Monday, with the result that 98L misses the Lesser Antilles Islands by at least 500 miles. Given the moderate or higher wind shear in 98L's path, and dry air to the northwest, the system should develop only slowly. NHC is giving 98L a medium (30 - 50%) chance of developing into a tropical depression by Sunday. At this time, it does not appear that 98L will ever threaten any land areas.

The remains of Hurricane Fred are still spinning away, near 25N 66W, about 900 miles east of Florida. Wind shear is 20 knots, which is marginal for development, and there is very dry air surrounding ex-Fred on all sides. None of the computer models develop ex-Fred, and it will have a tough time regenerating with so much dry air and wind shear. The remains of Fred should move over Florida Monday night or Tuesday morning.


Figure 1. Morning QuickSCAT image of the Atlantic, showing the well-defined surface circulation of disturbance 98L. Image credit: NOAA/NESDIS.

One year anniversary of Hurricane Ike
I've been focusing this week on the 20th anniversary of Hurricane Hugo, but we also passed the one year anniversary of Hurricane Ike. Many areas along the Texas and Louisiana coast affected by Ike have fully recovered, but recovery efforts will still take many more years in other areas. In Galveston, which suffered $3.2 billion in damage, 75% of the businesses have reopened, and 95% of the population has returned. Boston.com has posted a very nice series of clickable images that show before and after scenes of some of the areas that have recovered from Hurricane Ike.

Ike washed away huge sections of beach and dunes that helped protect the Texas coast from more serious damage, and this week the state legislature approved $135 million in funds to help replace these critical natural protection systems. The restored beaches will probably last ten years, barring another strike by a hurricane of Ike's stature. Texas considers two-thirds of its 367-mile shoreline to be critically eroding, which it defines as a historical rate of more than 2 feet a year. Much of this erosion can be blamed on sea level rise. Global sea level rose seven inches over the past century, and is expected to rise at least that much over the coming century.


Figure 2. Villagers in Haiti plant one of their "Million Tree Campaign" trees. Image credit: Lambi Fund of Haiti.

Hurricane relief donations
There hasn't been a need for new hurricane-related disaster relief efforts this year, in stark contrast to 2008. However, the charities we rely on to provide disaster relief still require funds to operate in quiet years, and I encourage you to consider a donation at this time to one of my two favorite disaster relief charities. Portlight.org, which was very effective at helping out isolated, under-served communities in the wake of Hurricane Ike, is committed to raising $12,000 to purchase and outfit a mobile kitchen. This kitchen will be capable of feeding up to 2,000 people two hot meals per day in post-disaster situations. The Lambi Fund of Haiti has launched its "Million Tree Campaign", which aims to use local labor to plant a million trees over the next three years along severely deforested slopes in Haiti. Both of these charities wrote to me several times last year about the stunning generosity readers of this blog showed with their donations. Thanks!

Twenty years ago today
As Hurricane Hugo approached the U.S. Virgin Islands in the early morning hours of September 18, 1989, the storm slowed down to 10 mph. The slower speed allowed Hugo to punish the island of St. Croix with the worst beating of any location along the hurricane's destructive path. At 2am local time on September 18, 1989, Hurricane Hugo's eyewall struck St. Croix, bringing incredibly ferocious Category 4 winds, sustained at 140 mph. The hurricane's gusts were remarkably violent, and many residents witnessed tornado-like vorticies barreling across the island as the hurricane raged about them. A storm surge of 2 - 3 feet, topped by battering waves 20 - 23 feet high, assaulted the coast, adding to the destruction. Wunderground member Mike Steers wrote me to describe his experience on St. Croix: "Hugo was incredible. Many vortexes came in that night. The roar and intensity of the winds that night were incredible. When the eyewall came over, we were forced to take refuge in the bathroom as the rest of the house came apart. The pressure was so low outside the house that all of the water was sucked out of the toilet and an air draft was created through the toilet. Just when I thought it was as bad as it would get, the intensity of it all dialed up even higher. Dozens and dozens of times, my ears would violently pop due to rapid pressure changes. The next morning, of course, the devastation was unbelievable. In my front yard was a 18-foot boat with an outboard on it, that had been picked up from a marina two miles away. I had lost my house, and job, the Seaplane company I was a pilot for. After a couple months, I had to leave everything behind. In some respects, after 20 years, there an many aspects of the society that have yet to recover". Two people were killed on St. Croix, 80 injured, and 90% of the buildings were damaged or destroyed. Damage estimates for St. Croix were astronomical, over $1 billion, and the island's entire infrastructure was virtually wiped out. Six weeks after the hurricane, only 25% of the public roads had been cleared, and only 25% of the island had power.


Figure 3. GOES visible satellite image of Hurricane Hugo taken on September 18, 1989. Note the lack of cloud cover on the hurricane's southwest side, indicating that strong upper-level winds from the southwest were likely creating wind shear, weakening the storm. Image credit: Google Earth rendition of the NOAA HURSAT data base.

As Hugo departed St. Croix, strong upper-level winds from the southwest created wind shear that weakened the storm to a Category 3 hurricane with 130 mph winds. The upper level winds also caused Hugo to accelerate to 15 mph and turn more northwest. The eye passed over Puerto Rico's Vieques Island at 8am and over Fajardo on the extreme northeastern tip of Puerto Rico at 9am. On Culebra Island, an island twelve miles east of Fajardo, a gust to 170 mph was recorded by the ship Night Cap in the main harbor. The south-facing harbor received sustained southerly winds in excess of 120 mph for several hours as Hugo roared by to the south. The resulting wave "set-up" created a storm surge in excess of 13 feet in the supposedly hurricane-proof harbor. A large portion of the Caribbean's charter boat fleet, some 200 boats, was sheltering in Culebra's harbor, and 136 of these boats were badly damaged or sunk. Over 80% of the wooden structures on both Culebra and Vieques were destroyed.


Figure 4. Damage on St. Croix (two top photos), Culebra Island (bottom right), and Puerto Rico's Roosevelt Roads Navy Base (bottom left), after Hurricane Hugo. Image credit: NOAA Photo Library.

Along the northeastern coast of Puerto Rico, waves up to ten feet high riding on top of a 3 - 4 foot storm surge caused severe coastal flooding of low-lying areas. Hugo's winds tore into Puerto Rico's El Yunque rainforest, downing thousands of trees. The agricultural sector was devastated, with nearly all of the island's banana and coffee crops wiped out. Twelve deaths in Puerto Rico were attributed to Hugo, six of which occurred in the southern city of Guayama where some residents were electrocuted by downed power lines. Nearly 28,000 people were left homeless by the storm, and damage to the island exceeded $1 billion.

Storm chaser Michael Laca was at Luquillo Beach on the northeast shore of Puerto Rico, and has posted a remarkable 28-minute video on YouTube of Hurricane Hugo footage.

Jeff Masters

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Quoting StormChaser81:

Well if you where on this blog for awhile you would see why I said something. I think WS has a new friend.


You haven't answer the question...Who are you? The blog's owner? lol This is America freedom of speech.
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Quoting atmoaggie:
Now that is an ERC!
Link
Very cool.


Niiice!
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This might turn some heads!

Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting HIEXPRESS:
" The remains of Fred should move over Florida Monday night or Tuesday morning."

It will get torn apart by Mt. Dora.


Nope your wrong Space Mountain at Disney will tear it apart!
Member Since: September 2, 2007 Posts: 179 Comments: 20448
227. atmoaggie

Wow. Very cool.
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Undead Fred....

Sorry, it's Friday and I'm a little brain dead and loopy.
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Quoting atmoaggie:
Now that is an ERC!
Link
Very cool.


Definitely a nice one to fly in and see the inner decaying eye.
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233. 789
Quoting atmoaggie:
Now that is an ERC!
Link
Very cool.
very cool!
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" The remains of Fred should move over Florida Monday night or Tuesday morning."

It will get torn apart by Mt. Dora.
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previous position zoomed 80 percent

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Quoting TampaSpin:
Shear has eased some as the COC is almost starting to cover.....LOOK OUT folks.



Well you can see... the TSTM outflow disrupting the circulation a bit... shouldn't be uncommon during these type of scenarios as dry air at mid/upper levels should enhance evaporational cooling and increase the downdrafts speeds (more than to be expected) so it might be have like a Danny for a bit. Hehe...
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Quoting TampaSpin:
Do you all realize how fast Fred would intensify if Shear would drop to 10kts...we may not want to see that!


I was just reading about late season storms that form in the Bahamas area. It sounds like they particularly like to flare up when there is energy in the area left behind by systems that move off of Florida, like the conditions that we have right about...now.
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Now that is an ERC!
Link
Very cool.
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What i don't like is the possible combination of the MidLevel low trying to make it to the Surface and arriving into the GOM the same time Fred arrives.......this could get very interesting!
Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting proroller:
197. jeffs713 3:35 PM GMT on September 18, 2009

Quoting StormChaser81:


Im confused all your ever post is spanish now, why not save us the time going through your post and dont post that stuff.


Or just not post at all...
Or just post pertinent information in English...



Who guys are you to say what this guy needs to do....first If he wants to write in Spanish that is his business not yours JEFF713 and STORMCHASER81


Well if you where on this blog for awhile you would see why I said something. I think WS has a new friend.
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corrected position



07L/DIS/FRED
MARK
25.6N/66.6W
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Don't forget,

Fred is SUPPOSED to be dead now. No chance of ever reaching the US.
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Oh Fred.....Well, I guess I better be on the lookout here in JAX, FLA.

Thanks, StormW, for the update, as always.
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197. jeffs713 3:35 PM GMT on September 18, 2009

Quoting StormChaser81:


Im confused all your ever post is spanish now, why not save us the time going through your post and dont post that stuff.


Or just not post at all...
Or just post pertinent information in English...



Who guys are you to say what this guy needs to do....first If he wants to write in Spanish that is his business not yours JEFF713 and STORMCHASER81
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Shear has eased some as the COC is almost starting to cover.....LOOK OUT folks.

Member Since: September 2, 2007 Posts: 179 Comments: 20448
197. jeffs713 3:35 PM GMT on September 18, 2009

Quoting StormChaser81:


Im confused all your ever post is spanish now, why not save us the time going through your post and dont post that stuff.


Or just not post at all...
Or just post pertinent information in English...



Who guys are you to say what this guy needs to do....first If he wants to write in Spanish that is his business not yours JEFF713 and STORMCHASER81
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Quoting presslord:
Como se dice "buzzkill" en espanol?


"mata esperanzas" hehe... I hope.
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Little burst of convection, its trying but the shear is winning right now. but even with the shear the banding features have become more noticable in the last couple of frames.
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Quoting presslord:
Como se dice "buzzkill" en espanol?


EL JVFWS
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Quoting StormW:
Hot off the press!

TROPICAL WEATHER SYSNOPSIS / 98L / SEPTEMBER 18, 2009 ISSUED 11:30 A.M. EDT


Hi Storm

As I posted earlier, I think that if you run the vis loop you will see that the actual center of 98L is at 13.3 N where it was originally stated to be. I do not see anything near 12.6 that could be a center. Just my opinion FWIW.
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Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting presslord:
Como se dice "buzzkill" en espanol?


Usted lo dice " JFV/WS"

LOL
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Do you all realize how fast Fred would intensify if Shear would drop to 10kts...we may not want to see that!
Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting presslord:
Speakin' o' buzzkill...Where's JFVWS?


You've got to let it go! [that's the same advice I give my wife from time to time but she never seems to take it! LOL]
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I was trying to see if maybe WS would listen once and post stuff at least in english.
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Como se dice "buzzkill" en espanol?
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07L/DIS/FRED
MARK
25.5N/66.3W

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Quoting StormChaser81:


Im confused all your ever post is spanish now, why not save us the time going through your post and dont post that stuff.

Even better, use that other button under his posts.
Avoid the one you hit and you will not have to see his twice and many of us not at all. Try it; I can attest that you will like it.
Why would you quote a post you didn't like seeing once?
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Quoting jeffs713:

Or just not post at all...
Or just post pertinent information in English...


Exactly, lol.
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Quoting StormW:


Correct.


Thank you, sir...
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Quoting StormChaser81:


Im confused all your ever post is spanish now, why not save us the time going through your post and dont post that stuff.

Or just not post at all...
Or just post pertinent information in English...
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Quoting mikatnight:
#153
Sorry Jeffs, but you can't deny freedom of speech. From An American President:
"America isn't easy. America is advanced citizenship. You've gotta want it bad, 'cause it's gonna put up a fight. It's gonna say, "You want free speech? Let's see you acknowledge a man whose words make your blood boil, who's standing center stage and advocating at the top of his lungs that which you would spend a lifetime opposing at the top of yours." You want to claim this land as the land of the free? Then the symbol of your country cannot just be a flag. The symbol also has to be one of its citizens exercising his right to burn that flag in protest. Now show me that, defend that, celebrate that in your classrooms.

Then you can stand up and sing about the land of the free."


Now I really gotta go...

Oh, I wasn't trying to deny freedom of speech. I was trying to force the people who bash the government to do three things:
1. expand their viewpoint to see that we really do have it good.
2. appreciate the freedoms and rights that we do have.
3. if they still don't like it, DO something about it, and stop trying to just complain. Complaining does no good when there is not action attached.
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wow the doomcasters are alive, unfortunately
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Quoting WeatherStudent:


Aqui estoy, buenos dias.


Im confused all your ever post is spanish now, why not save us the time going through your post and dont post that stuff.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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