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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well, I tried to be funny by posting a picture of Shaq wearing swim goggles, and I claimed he was testing the SST's, and I got a ban instead :PP
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341. JRRP
Member Since: August 16, 2007 Posts: 0 Comments: 5799
Quoting TampaSpin:


Floodman a surprise to many will be coming with FRED. That high is building in fast to the NW of FRED! Watch as you know what will happen.


Given the current scenario? The ridge builds back in at the rate forecast and Fred pulls it together just in time to make the coast as a strong TD or weak to moderate TS (depends on whether or not he pasuses a little before making the track change to the WSW due to the building ridge...he'll need luck and enough moisture to pull it off...I don't disagree with you, TS but the deck needs to be just right to draw the cards he needs (to use a different metaphor)
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338. 789
Quoting ElConando:
Now it looks like Fred is giving us the finger :P.
roflmao
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Quoting Floodman:


It's very difficult to remove bad mojo, once it's on one...that's why I use new BuzzKill with carbon tetrachloride!

Sorry guys, looking to lighten the mood a bit...LOL
I for one do enjoy your humor...Everyone else, remember, be calm, stay alert and be prepared!
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well...if Glenn Beck says it...and Rush confirms it...it must be more true than the gospel...
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Quoting TampaSpin:


Floodman a surprise to many will be coming with FRED. That high is building in fast to the NW of FRED! Watch as you know what will happen.


What about dry air?
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Quoting BurnedAfterPosting:


Bill Gates lol
I saw some of your earlier posts. This El Nino is weak compared to the others I have seen. Whether or not it strengthens who knows(I myself Doubt it).As far as Fred goes it may get to T.S. status, but it would have to stall over the Bahama,s to reach hurricane force. And that is only if the shear holds off long enough. I believe Patrap mention this already. Hell would have froze over but global warming melted all the ice? VERY FUNNY!
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Shear appears to be starting to relax to Fred's West as you can see storms building on the WEst side.....JUST MY OPINON!
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332. Relix
So, StormW, do you agree 98L should go north of the islands? Thanks for any response =D
Member Since: August 3, 2006 Posts: 0 Comments: 2722
Quoting TampaSpin:


Floodman a surprise to many will be coming with FRED. That high is building in fast to the NW of FRED! Watch as you know what will happen.


LOL you sound like a more trustworthy version of stormtop, no offense :).
Member Since: September 6, 2009 Posts: 2 Comments: 3719
Very loosely related question:

Why is it that the West Pacific typhoon discussions are very different than the ones issued for the East Pacific / North Atlantic? (Aside from the fact that they're issued by a different agency)

They seem to talk much more about outflow: poleward, equator-ward, radial, etc ... as opposed shear, dry air, SSTs, etc.

Are the ocean basis that much different in terms of cyclone formation, intensification, movement? Or do they apply different reasoning to forecast the same behavior?
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Quoting Floodman:


Mosy likely not with the trof pulling out and the ridge building back in


Floodman a surprise to many will be coming with FRED. That high is building in fast to the NW of FRED! Watch as you know what will happen.
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good afternoon all, blog seems a bit feisty today :O

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Now it looks like Fred is giving us the finger :P.
Member Since: September 6, 2009 Posts: 2 Comments: 3719
I expect xFred to move WSW shortly around the building high to its NW!
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Quoting ElConando:


i'm not good with movement prediction but your just hypothetically speaking that any great intensification would happen if it were to stall but that it is not going to happen in this case?


Mosy likely not with the trof pulling out and the ridge building back in
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Quoting Patrap:
RUSH now confirming Glenn Becks Florida Story..details to follow tonight


When HANNITY COMES ON!!! yeah...
Member Since: September 6, 2009 Posts: 2 Comments: 3719
RUSH now confirming Glenn Becks Florida Story..details to follow tonight.

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Quoting Floodman:


It's very difficult to remove bad mojo, once it's on one...that's why I use new BuzzKill with carbon tetrachloride!

Sorry guys, looking to lighten the mood a bit...LOL


Good luck!
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Quoting TampaSpin:
Thanks StormW.....i guess to say as some are saying its nothing to a Tropical Storm....i should not have used Rapid Intense. My bad!


yup that is what I meant, sorry I probably came across too caustic as well

my bad on my part.
Quoting Patrap:


I never hang with Gangs..bad mojo can rub off on one


It's very difficult to remove bad mojo, once it's on one...that's why I use new BuzzKill with carbon tetrachloride!

Sorry guys, looking to lighten the mood a bit...LOL
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Thanks StormW.....i guess to say as some are saying its nothing to a Tropical Storm....i should not have used Rapid Intense. My bad!
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Sw winds across the Se US.

..or Shields Up.

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Quoting TheCaneWhisperer:


As is expected of a weak system battling the diurnal cycle and dry air. Fact is, he's still there and the circulation is VERY well defined. Each morning the breath is deeper and deeper, now, it's catching the attention of the NHC. Tomorrow morning the breath will be deeper yet, slowly getting better organized, IMO.


lol I like that description, guess we will see

I wouldnt be shocked if Quasi-Fred became a TS again.


Also watcher yea that is something I kept in the back of my mind when so many said FISH and it wouldnt get past 40W, then it was 50W, then it was 60W lol
Haf ex Fred just taken a southern dip?
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zoom at 80 percent


07L/DIS/FRED
MARK
25.9N/66.6W
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Its kind of sad when someone voices different opinion that doesn't run with overall blog,that everyone starts jumping all over that person.We are weather enthusiasts here,and at times we have differing opinions,I myself don't think exFred is going to do anything,but thats just my opinion.
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There are NO storms in the Atlantic Basin
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310. JRRP
the convection is increasing near the center
Member Since: August 16, 2007 Posts: 0 Comments: 5799
Quoting ElConando:


There is a good amount of dry and sinking air around 07L, which makes it not a good environment for convection to occur. I am not saying it may not intensify, just that it will be slow.


Won't he pick up some moisture from that left over front that moved off Florida?
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Quoting BurnedAfterPosting:


yes I am aware that they are still running the models, that doesnt change the fact that the circulation at this time is weaker than it was last night.


As is expected of a weak system battling the diurnal cycle and dry air. Fact is, he's still there and the circulation is VERY well defined. Each morning the breath is deeper and deeper, now, it's catching the attention of the NHC. Tomorrow morning the breath will be deeper yet, slowly getting better organized, IMO.
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Quoting StormW:
Alright gang, let's keep it civil. Tampaspin is calling what he see's. Just like I do.

The deal with ex-Fred...yes, there is dry air ahead for at least another 24 hours. Upper level winds WILL become more favorable. This could allow for it to regain a closed LLC.

As far as the dry air, this may get taken care of once over the Gulfstream, 29-30C. However, I wouldn't look for any rapid intensification, unless the wave can develop another closed LLC and take care of the dry air pretty quick. Some intensification I do buy, but for anything substantial, he would have to stall near the Bahamas / FL east coast.


i'm not good with movement prediction but your just hypothetically speaking that any great intensification would happen if it were to stall but that it is not going to happen in this case?
Member Since: September 6, 2009 Posts: 2 Comments: 3719
Quoting watcher123:
"Fred has no chance of getting past 40w..."

Paraphrase of the pros a week ago...
lol
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Quoting divdog:
Kinda floating on that island by yourself. You also show it skirting the keys on your map. Good luck with that forecast.


Been there before and survived before! Thanks!
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Quoting StormW:
Alright gang, let's keep it civil. Tampaspin is calling what he see's. Just like I do.

The deal with ex-Fred...yes, there is dry air ahead for at least another 24 hours. Upper level winds WILL become more favorable. This could allow for it to regain a closed LLC.

As far as the dry air, this may get taken care of once over the Gulfstream, 29-30C. However, I wouldn't look for any rapid intensification, unless the wave can develop another closed LLC and take care of the dry air pretty quick. Some intensification I do buy, but for anything substantial, he would have to stall near the Bahamas / FL east coast.


I never hang with Gangs..bad mojo can rub off on one
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Quoting StormW:
Alright gang, let's keep it civil. Tampaspin is calling what he see's. Just like I do.

The deal with ex-Fred...yes, there is dry air ahead for at least another 24 hours. Upper level winds WILL become more favorable. This could allow for it to regain a closed LLC.

As far as the dry air, this may get taken care of once over the Gulfstream, 29-30C. However, I wouldn't look for any rapid intensification, unless the wave can develop another closed LLC and take care of the dry air pretty quick. Some intensification I do buy, but for anything substantial, he would have to stall near the Bahamas / FL east coast.


Sounds reasonable StormW, is there a chance it could stall or were you just throwing it out there?
Quoting StormW:
Alright gang, let's keep it civil. Tampaspin is calling what he see's. Just like I do.

The deal with ex-Fred...yes, there is dry air ahead for at least another 24 hours. Upper level winds WILL become more favorable. This could allow for it to regain a closed LLC.

As far as the dry air, this may get taken care of once over the Gulfstream, 29-30C. However, I wouldn't look for any rapid intensification, unless the wave can develop another closed LLC and take care of the dry air pretty quick. Some intensification I do buy, but for anything substantial, he would have to stall near the Bahamas / FL east coast.


Oh no, you said that word STALL. Don't you know all storms headed towards Central FL have to STALL first...:)
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Quoting TampaSpin:


BAP look at this LOOP.....you can see how the trough is disapating and being replaced by High Pressure. Fred could move more WSW soon under that is forming to its West. Ya, once the shear relaxes and it it will in my opinion, it could go from xFred to a TS in 48hrs....that is not over-hyping.


that isn't "rapid intensification!!" as you put lol

again I am not debating that Quasi Fred cant come back to TS status or that it would hit Florida, but the way you stated it was overhyping
Quoting surfsidesindy:
Okay now, don't blast me, but as a non-professional I don't understand why FredEx would not get better organized and strengthen IF the sheer drops AND he hits the warm SSTs in the Bahamas and the Gulf Stream. What would prohibit that from happening?


It has the chance to do that, people are just saying the fred is not in the best shape, he has a long way to go before he can start intensifing into a TD or TS and a hurricane is not looking likely with his ragid shape.
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297. JRRP
13.5
39.8
Link
Member Since: August 16, 2007 Posts: 0 Comments: 5799
Quoting ElConando:


LOL xD are you serious???
Quoting surfsidesindy:
Okay now, don't blast me, but as a non-professional I don't understand why FredEx would not get better organized and strengthen IF the sheer drops AND he hits the warm SSTs in the Bahamas and the Gulf Stream. What would prohibit that from happening?


There is a good amount of dry and sinking air around 07L, which makes it not a good environment for convection to occur. I am not saying it may not intensify, just that it will be slow.
Member Since: September 6, 2009 Posts: 2 Comments: 3719
ExFred to become the FREDEX express.
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Quoting surfsidesindy:
Okay now, don't blast me, but as a non-professional I don't understand why FredEx would not get better organized and strengthen IF the sheer drops AND he hits the warm SSTs in the Bahamas and the Gulf Stream. What would prohibit that from happening?


Bill Gates lol
Okay now, don't blast me, but as a non-professional I don't understand why FredEx would not get better organized and strengthen IF the sheer drops AND he hits the warm SSTs in the Bahamas and the Gulf Stream. What would prohibit that from happening?
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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.