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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1292. will40
LOL ice
Member Since: September 19, 2005 Posts: 2 Comments: 4266
1289. will40
If the NHC at 2:00 am says it is still moving WNW they are seeing something that we arn't lol
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting StormW:
Good night all!


Nite buddy
Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting StormW:
Good night all!


Nght Storm. :)
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1285. will40
Quoting StormW:






well that explains it lol
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting TampaSpin:


Actually was thinking of changing it back....it was alot easier to pic out from the rest.....LOL

Actually I like Hippos
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Quoting will40:


it is hard to tell if it is that or the shear blowing the clouds south


I looked at a zoom on RGB zoomed in and it appears to be moving WSW....that does not surprise me as it tries to move under the High to its NW.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
Hmmm? The NAM (yeah, I KNOW) Takes Fredex to NC/SC border.

The GFS loses 98l? I think. Model not through yet.

But both of those models show a low in NW Caribbean going over the Yucatan into BOC.

Link
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1280. JRRP
Quoting JLPR:


yep big umm

xD
im actually expecting a red circle either at 2am or 8am

si todo continua como va podria ser q tenga circulo rojo a las 8am
pero no creo q lo sea a las 2am
aun que deberia tenerlo :P
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Quoting Seastep:
Tampa - Have to say, and I know I'm in the minority, but I like your old avatar.

Loved the ray's posture in context of the shield.


Actually was thinking of changing it back....it was alot easier to pic out from the rest.....LOL
Member Since: September 2, 2007 Posts: 179 Comments: 20448
1278. will40
Quoting StormW:


From earlier:

1126. StormW 9:17 PM EDT on September 18, 2009
I could be wrong on this...but I wouldn't be surprised to see a center reformation to the east on 98L. Has the classic "S" cloud pattern, along with the upper level anticyclone sitting over that big blow up of convection.



so it looks like the anticyclone is going on top of it now?
Member Since: September 19, 2005 Posts: 2 Comments: 4266
1275. Seastep
Tampa - Have to say, and I know I'm in the minority, but I like your old avatar.

Loved the ray's posture in context of the shield.
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1274. will40
Quoting TampaSpin:
xFred appears to be moving WSW now


it is hard to tell if it is that or the shear blowing the clouds south
Member Since: September 19, 2005 Posts: 2 Comments: 4266
1273. will40
Quoting JLPR:


yep big umm

xD
im actually expecting a red circle either at 2am or 8am



Yep those two areas of convection are getting very close to each other
Member Since: September 19, 2005 Posts: 2 Comments: 4266
xFred appears to be moving WSW now
Member Since: September 2, 2007 Posts: 179 Comments: 20448
1271. JLPR
Quoting JRRP:
mmm..


yep big umm

xD
im actually expecting a red circle either at 2am or 8am
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1270. will40
If Dr Masters list the GW in an update there should be no reason for a ban just for discussing it
Member Since: September 19, 2005 Posts: 2 Comments: 4266
1269. JRRP
mmm..
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1268. will40
Quoting thelmores:


Thel i think the person later admitted he posted a pic that got him baned.
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting Seastep:


To say folks are being banned based on that is just flat out false.

I know of no instance of "censorship" in that regard. Bans go both ways, depending on the content.

I actually give kudos to Doc for allowing free flow of information and opinion.


I have personally via email questioned Dr. Masters on GW, the Debate, and even at times his sources..... and EVERY single time I received a cordial reply from Dr. Masters...... which I consider amazing thinking about how much his time is in demand.

Bottom line, Dr. Masters IS NOT against free speech, in fact he encourages dissent as long as you have facts to back your position.

I refuse to believe ANYBODY has been banned for expressing a contrary position. I call BS on that!
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ROFLMAO.. move on, Orca! Now back to Fred. Will the possible (notice..no wish, down, etc casting) storm be named Fred?
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Quoting foggymyst:
Thanks for the compliment, Orca. Nope, no bs with that one, that's great for my ego. :)


Ahh you going to make me blush ... You keep forgetting how shy I am.
Member Since: October 1, 2007 Posts: 81 Comments: 26516
Thanks for the compliment, Orca. Nope, no bs with that one, that's great for my ego. :)
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1262. JRRP

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exFred, kinda looks like a booger a kid flung across the atlantic, maybe he lived in Cape Verde.
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1260. 789
Quoting Grothar:
Goodnight everyone! I really enjoy the good banter. This blog has been a very good diversion for me. Honestly, my wife is a sweetheart! She said I can watch Frasier reruns now, then I can go to bed. You all stay well and I shall return as usual when I can. Thanks for a very entertaining evening.
gnite
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1259. Gumluvr
Quoting Grothar:
Goodnight everyone! I really enjoy the good banter. This blog has been a very good diversion for me. Honestly, my wife is a sweetheart! She said I can watch Frasier reruns now, then I can go to bed. You all stay well and I shall return as usual when I can. Thanks for a very entertaining evening.


Goodnight....stand up for yourself and tell her you want to watch something else. LMAO I expect that won't get you far. We can be fairly mean when we want to. :)
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1258. will40
Quoting JLPR:
So the center of 98L is between the two areas of convection



umm... im expecting the center to jump eastward and align with the deep convection in the east side




If that happens it is really gonna blow
Member Since: September 19, 2005 Posts: 2 Comments: 4266
1257. Grothar
Goodnight everyone! I really enjoy the good banter. This blog has been a very good diversion for me. Honestly, my wife is a sweetheart! She said I can watch Frasier reruns now, then I can go to bed. You all stay well and I shall return as usual when I can. Thanks for a very entertaining evening.
Member Since: July 17, 2009 Posts: 71 Comments: 27208
1256. JLPR
So the center of 98L is between the two areas of convection



umm... im expecting the center to jump eastward and align with the deep convection in the east side

Member Since: Posts: Comments:
Member Since: October 1, 2007 Posts: 81 Comments: 26516
1253. Gumluvr
Quoting Orcasystems:


Some of the funniest people on this blog are women.. Surfmom, BeachFoxx, Zoo, Foggy and many others...


Yep!
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Oh wow, Fred-Ex or Ex-Fred looks pretty bad, maybe he was finally shot by a "Silver Bullet" and is dying, will be interesting to see him on the vis. satellite in the morning.
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Quoting Gumluvr:


I am laughing, too. My husband is gone to the races so I can laugh without him noticing. He is a TV nut and I am a weather blog nut. He does take high pressure to a whole new level when I spend my evenings lurking on this blog. I just enjoy it after a long day at work and cooking for the family. You guys can get pretty funny. I thank you all for the info and the laughs. :)


Some of the funniest people on this blog are women.. Surfmom, BeachFoxx, Zoo, Foggy and many others...
Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting Seastep:


I'm not convinced of AGW, just look at some preliminary work on my model validation blog pics, but have never been banned.

And, I have stated plenty on the subject, as have many others.

To say folks are being banned based on that is just flat out false.

I know of no instance of "censorship" in that regard. Bans go both ways, depending on the content.

I actually give kudos to Doc for allowing free flow of information and opinion.

If you're posting something blatantly false or grossly misleading, well, it should be scrubbed.

Sorry, felt the need to defend that. Doc has his views, but he does not censor opposing viewpoints.

My experience. I'd be with atmo in banning wu if it were so. But it's not.

If Doc wants to reference something in HIS blog post, he can. And, he doesn't ban for questioning it that I am aware of.

Shifting gears, I'll even oppose it. As I've said before, next 5-15 years will tell the story. Sat temps only. Don't even bring anything up to me before that, as temps have been higher with less CO2 and CO2 concentrations have been much higher than now in the past. Sat is the only objective, apples to apples, measure available.

Have had roughly 30 years of that and the first 2/3 were warm (take out 1997 and theory is toast, really, imo). The other 1/3 is flat, slight cooling. IMO, exactly why the language has change to northern latitudes and ice.

If we get 50/50 heating/cooling, the AGW CO2 argument is over. Really don't even need that ratio based on the increases in man-contributed CO2. If it is the cause, based on the annual increases, it shouldn't be anywhere near 50/50.

No argument on our contribution of CO2. If that is increasing at such "alarming" levels and is the cause, then there should be evidence of the same. And, sorry, anyone telling you that it is too urgent to wait 5-15 years is, well, [fill in the blank]. I could go through a litany of doomsday warnings from the past base on "urgency" that never reached fruition.

Analogous to tropical systems... patience. A decades long storm. We have a naked swirl. Is it possible that it will regenerate? Sure. But, based on the actual man-contributed CO2 %, highly unlikely that man-contributed CO2 is really a factor. That would be, imo, equivalent to going out to a storm and adding that % of red hot moisture/water to a system. Wouldn't really make a difference. I'll even be generous and add 10% to the storm. :)


You are right but I just happened to post my POV at the wrong time. Has nothing to do with the good DR.
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1249. JLPR


O_O
wow
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Quoting Seastep:


Hard to tell at night, but looks gone. And nobody can accuse me of being a poofer.

Have to wait and see. Didn't like the clear circulation all day, but the finishing visibles gave no suggestion of anything to worry about.

Even before that, TS at best, imo.


the circulation is still very much evident, its just being covered by convection right now
1246. Gumluvr
Quoting Orcasystems:


I will guarantee all of the married men were laughing... maybe not aloud..as their wives might be in the same room :)


I am laughing, too. My husband is gone to the races so I can laugh without him noticing. He is a TV nut and I am a weather blog nut. He does take high pressure to a whole new level when I spend my evenings lurking on this blog. I just enjoy it after a long day at work and cooking for the family. You guys can get pretty funny. I thank you all for the info and the laughs. :)
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1245. Grothar
Quoting Bordonaro:


That's for ME!!! I totally messed up on Danny & Erika!! I'm looking for crow recipes for us to share online!!!


Who was the one who posted the big guy eating the crow last night? Was it you, as well? Memory is slipping. It is either the hour or the age.
Member Since: July 17, 2009 Posts: 71 Comments: 27208
1244. Seastep
Quoting Grothar:


Hey Seastep, since I missed most of the blog tonight, what is the latest on 007L (Fred) doesn't look like much is left. Possible he has one final trick before brushing our beaches in SFL?


Hard to tell at night, but looks gone. And nobody can accuse me of being a poofer.

Have to wait and see. Didn't like the clear circulation all day, but the finishing visibles gave no suggestion of anything to worry about.

Even before that, TS at best, imo.
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1243. Grothar
Quoting iceman55:





OOOH! ice, why do you have to post those right before we retire. Have you no mercy?? I am beginning to hate those little lines.
Member Since: July 17, 2009 Posts: 71 Comments: 27208

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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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