Disturbance 98L probably no threat to land

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

Share this Blog
2
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1592 - 1542

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33Blog Index

Quoting reedzone:


Me as another blogger? I've never been banned to be another blogger, nice try guys ;)
Nah, we weren't thinkin' that... I was trying to remember which of our bloggers was associated with the crownweather.com website...
Member Since: Posts: Comments:
Agreed Baha - had a lot of damage from Katrina as a Cat 1, but prior to landfall they were saying it was barely going to be a TS.

Do you realize that we really only had about 36 hours notice with Andrew? In today's world we gripe about the 3 day. Once Andrew started moving it just zipped on in.
Member Since: Posts: Comments:
Quoting InTheCone:


No, it is not Reedzone, he does occasionally blog here as Crownwx(I thnk that is the handle he uses)

Good catch there on the upper steering, Senior Chief!


Me as another blogger? I've never been banned to be another blogger, nice try guys ;)
Member Since: July 1, 2008 Posts: 13 Comments: 7396
DISTURBANCE INVEST (AL982009) 20090919 1200 UTC

...INITIAL CONDITIONS...
LATCUR = 13.3N LONCUR = 41.8W DIRCUR = 280DEG SPDCUR = 6KT
LATM12 = 13.0N LONM12 = 40.5W DIRM12 = 285DEG SPDM12 = 6KT
LATM24 = 12.9N LONM24 = 39.2W
WNDCUR = 25KT RMAXWD = 45NM WNDM12 = 25KT
CENPRS = 1008MB OUTPRS = 1012MB OUTRAD = 300NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM


SHIPS Text
Member Since: Posts: Comments:
Quoting zoomiami:
Both Andrew & Katrina did the little dance that Fred is doing. Not that I believe that Fred will develop into a major hurricane - more to the point they meandered across the Atlantic, got written off several times, and then got their act together closer to land. Andrew was further out than Katrina, but Katrina didn't even begin to be much more than a depression until about 90 miles off the coast. It then came ashore and headed more south due to the high building in.

Moral of this story - need to keep an eye on this, as that 90 miles of water closest to Florida has lots of food for Fred.
Katrina was the one that actually became a TS over the Central Bahamas. She was a shock to just about everybody from here to the FL coast.... AT least w/ Andrew we had a couple of days to prepare...
Member Since: Posts: Comments:
Quoting BahaHurican:
Technically all the other comments are still right. Unless and until there is a genuine regeneration of Fred, Fred DID die out in the CAtl.... it's like the person is dead, but u have a well-preserved body of the former person sitting in the same old chair in your den..... a mere remnant of the person....

I have to agree with those who have said this has been an interesting season...


I think we should save this -- great imagery!
Member Since: Posts: Comments:
Quoting StormW:


nice outflow going on.
Member Since: Posts: Comments:
Both Andrew & Katrina did the little dance that Fred is doing. Not that I believe that Fred will develop into a major hurricane - more to the point they meandered across the Atlantic, got written off several times, and then got their act together closer to land. Andrew was further out than Katrina, but Katrina didn't even begin to be much more than a depression until about 90 miles off the coast. It then came ashore and headed more south due to the high building in.

Moral of this story - need to keep an eye on this, as that 90 miles of water closest to Florida has lots of food for Fred.
Member Since: Posts: Comments:
1582. DDR
Quoting BahaHurican:
DDR, I think I chatted w/ pottery briefly on, say, Wednesday? Haven't seen him much the last little while....

Thanks Baha,im out everyone have a good day
Member Since: Posts: Comments:
Quoting yonzabam:


Fred was expected to be dissipated by an apparently irresistible combination of wind shear, dry air and marginal ssts.



well by some, but I did not expected Fred to completely dissipated even when it was a major.
Member Since: Posts: Comments:
What are the models reflecting on Fred this morning?
Member Since: Posts: Comments:
Quoting IKE:
Should be interesting watching what happens with drop-dead Fred today. System looks as good as it's looked in days.

Will check back in a bit on Freddie boy.....


with quiksat and this sat view it looks like there convection around the center for once..... when I read quiksat i figured 25.5 & 70 .....
Member Since: Posts: Comments:
Quoting Dakster:
As long as Fred doesn't become Andrew's little brother...
Quoting Dakster:
As long as Fred doesn't become Andrew's little brother...



Or Wilma's spouse.
Member Since: Posts: Comments:
Technically all the other comments are still right. Unless and until there is a genuine regeneration of Fred, Fred DID die out in the CAtl.... it's like the person is dead, but u have a well-preserved body of the former person sitting in the same old chair in your den..... a mere remnant of the person....

I have to agree with those who have said this has been an interesting season...
Member Since: Posts: Comments:
Well the furthest west I expected Fred to come was 65W and even thought it could of threatened Bermuda.

Now look at this interesting rule that one should of picked up.

"A storm will do a left turning or stair step motion if there is a quick succession of troughs in the upper westerlies."

This was forecast to happen when Fred was a major and it did occur, but still the forecast was for Fred to go out to sea.

This should of been seen coming. Listen to the rules. lol
Member Since: Posts: Comments:
Quoting IKE:
Should be interesting watching what happens with drop-dead Fred today. System looks as good as it's looked in days.

Will check back in a bit on Freddie boy.....

Member Since: Posts: Comments:
Quoting nrtiwlnvragn:


No problem. Is the 417mb version that much more detailed in the graphics?


The track charts are the same, it was the tables I had trouble reading, unlike the tracking charts, they were set up two to a page and too small for my bad eyes. They blurred past 100%, now they don't. Thanks again.
Member Since: Posts: Comments:
Quoting BahaHurican:
This is what they should be posting to indicate FredEx's position instead of that innocuous brown line:



That system just keeps going and going....


exactly what I was thinking!
Member Since: Posts: Comments:
DDR, I think I chatted w/ pottery briefly on, say, Wednesday? Haven't seen him much the last little while....
Member Since: Posts: Comments:
Quoting Weather456:
This is irony to the highest level.

Fred was once expected to head out to sea.


Fred was expected to be dissipated by an apparently irresistible combination of wind shear, dry air and marginal ssts.

Member Since: Posts: Comments:
Quoting StormW:


Yea...it's Rob from crownwx. Pretty sharp.



He is, we had a nice discussion back in late July on 98L. We both agreed it would become an invest but not so much a tropical one.

Member Since: Posts: Comments:
Quoting Weather456:
This is irony to the highest level.

Fred was once expected to head out to sea.


yeah lol, fred at first wasn't expected to go farther than 35 west, now its at 70
Member Since: Posts: Comments:
Quoting Weather456:
This is irony to the highest level.

Fred was once expected to head out to sea.
I was trying to explain that to my mum last night... lol

Someone commented earlier about how if things were better Fred "might have been" a major.... guess it's been so long since Fred's "youthful prodigy" days that pple have forgotten he was a major only a couple hundred miles from the CVs.... lol

What makes me laugh is how ppl were saying that Fred was never going to leave Africa... lol.... think he was offended and decided to become a world traveler instead.... ;o)
Member Since: Posts: Comments:
Quoting Weather456:
This is irony to the highest level.

Fred was once expected to head out to sea.


Just goes to show why there is so much interest and fascination with tropical weather, sometimes it just does the craziest things!

You have done an excellent job keeping up with this crazy season, I have really enjoyed all of your input this year!
Member Since: Posts: Comments:
1562. IKE
Should be interesting watching what happens with drop-dead Fred today. System looks as good as it's looked in days.

Will check back in a bit on Freddie boy.....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
1561. DDR
Quoting Weather456:


No, can I have a link. Thanks

Also i saw ur question. Is it a possibility that Trinidad formed from Venezuela. Looking at a map one would think that i came from from there.

Thanks a link to his blog i dont have,i havent seen him in a while
Member Since: Posts: Comments:
This is irony to the highest level.

Fred was once expected to head out to sea.
Member Since: Posts: Comments:
Quoting Weather456:


Yes we do have a blogger associated with crownwx but the user is "crownwx"
Thanks, 456. I knew it was somebody.... lol... the aged head is showing...

That blogger usually has sensible things to say, anyway.
Member Since: Posts: Comments:
Quoting DDR:
Good morning all
Beautiful morning in Trinidad,sun is shining for now.
456 Have you seen Pottery on the blog lately?


No, can I have a link. Thanks

Also i saw ur question. Is it a possibility that Trinidad formed from Venezuela. Looking at a map one would think that i came from from there.
Member Since: Posts: Comments:
Quoting BahaHurican:
This is our boy reedzone, isn't it? or some other blogger? I associate crownwx w/ a blogger....


No, it is not Reedzone, he does occasionally blog here as Crownwx(I thnk that is the handle he uses)

Good catch there on the upper steering, Senior Chief!
Member Since: Posts: Comments:
Quoting StormW:


Weakness...of course the steering has changed, though not greatly, 3 times in the past 3 runs.

PSU e-WALL STEERING FORECAST

Tanks... btw im putting up my shutters today because a nekkid swirl might be visiting on Monday night... hopefully he has no clothes on
Member Since: Posts: Comments:
Quoting CybrTeddy:
Recon leaves at 1500Z, what time is that EDT? Sorry, I should know this by now.


11am
Member Since: Posts: Comments:
1552. DDR
Good morning all
Beautiful morning in Trinidad,sun is shining for now.

456 Have you seen Pottery on the blog lately?
Member Since: Posts: Comments:
Quoting BahaHurican:
This is our boy reedzone, isn't it? or some other blogger? I associate crownwx w/ a blogger....


Yes we do have a blogger associated with crownwx but the user is "crownwx"
Member Since: Posts: Comments:
Recon leaves at 1500Z, what time is that EDT? Sorry, I should know this by now.
Member Since: Posts: Comments:
1549. Dakster
As long as Fred doesn't become Andrew's little brother...
Member Since: Posts: Comments:
Quoting indianrivguy:
Good morning Senior Chief, 456, Ameister!

nrtiwlnvragn: thank you very much for the link to the 1851 to current hurricane tracks pdf yesterday. I downloaded and saved the 417mb version.


morning
Member Since: Posts: Comments:
Quoting InTheCone:
Interesting write up on Ole' Freddy Boy at... Crown Weather
This is our boy reedzone, isn't it? or some other blogger? I associate crownwx w/ a blogger....
Member Since: Posts: Comments:
Quoting CaicosRetiredSailor:
One week ago today:TROPICAL DEPRESSION FRED ADVISORY NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009
500 PM AST SAT SEP 12 2009

...
THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON FRED.


Possible during the next day or two there will be advisory number 22.
Member Since: Posts: Comments:
Quoting indianrivguy:
Good morning Senior Chief, 456, Ameister!

nrtiwlnvragn: thank you very much for the link to the 1851 to current hurricane tracks pdf yesterday. I downloaded and saved the 417mb version.


No problem. Is the 417mb version that much more detailed in the graphics?
Member Since: Posts: Comments:

Viewing: 1592 - 1542

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33Blog Index

Top of Page

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.

Local Weather

Mostly Cloudy
66 °F
Mostly Cloudy