Hawaii braces for Felicia; 99L near the Cape Verdes Islands may develop

By: Dr. Jeff Masters , 3:55 PM GMT on August 10, 2009

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A strong tropical wave (99L) is just south of the Cape Verdes Islands, 800 miles off the coast of Africa. This morning's QuikSCAT pass showed a nearly closed surface circulation, stretched out along one axis. The satellite saw winds of up to 45 mph in a band of heavy thunderstorms well south of the Cape Verdes Islands. The islands have seen winds of only 10 - 15 mph and some occasional rain showers thus far from the disturbance. Heavy thunderstorm activity associated with 99L died down this morning, but appears to be making a comeback late this morning. Wind shear is moderate, about 10 knots, and sea surface temperatures are moderately warm, about 27 - 28°C. There is a large area of dry air to 99L's north that is interfering with the storm's organization, though.


Figure 1. Current satellite image of disturbance 99L.

Wind shear is expected to be moderate, 5 - 15 knots, through Wednesday. SSTs will remain relatively constant at 27°C, but the dry, stable air of the Saharan AIr Layer (SAL) to 99L's north will be problem for it. NHC has given 99L a moderate (30 - 50% chance) of developing into a tropical depression by Wednesday morning, which is a reasonable forecast. Most of the models show some weak development, but none of them predict 99L will become a hurricane. It is too early to say if 99L will recurve north of the Lesser Antilles Islands or not, since it will be at least 5 days before the storm makes it that far. It is unusual, though, for storms forming this far north to make it all the way across the Atlantic to hit the Lesser Antilles Islands.

The GFS and ECMWF models are predicting the possible development of a new tropical wave coming off the coast of Africa late this week.

Felicia continues to weaken, but is a flash flooding threat to Hawaii
Tropical Storm Felicia has weakened steadily over the past 24 hours, thanks to cool sea surface temperatures and increasing shear. Recent satellite loops show that strong upper-level winds from the west have pushed the storm's heavy thunderstorm activity to the northeast side of the center, exposing the surface center as a swirl of low clouds. Felicia's relatively meager heavy thunderstorm activity is steadily moving away from the center of the storm.


Figure 2. History of hurricane activity over Hawaii since 1950. Hawaii islands have been hit by only 9 tropical cyclones of tropical depression or greater strength, with 4 others passing withing 75 miles of an island. Image credit: NOAA Coastal Services Center.

Sea surface temperatures (SSTs) under Felicia are 25°C, well below the 26°C threshold typically needed to sustain a hurricane. SSTs will slowly increase to 26°C by Tuesday. Wind shear has increased to a high 30 knots, and is expected to increase further to 40 knots by Tuesday. The high shear combined with the cool SSTs should continue to weaken Felicia today. I give a 30% chance that the shear will completely rip away Felicia's heavy thunderstorm activity by the time the storm reaches Hawaii, leaving only a swirl of low-level clouds that will not cause significant flooding problems. The wind speed probabilities forecast shows about a 25% chance Felicia will still be a weak tropical storm at 3 am Hawaiian time Tuesday morning, and a 15% chance the storm will have dissipated. If Felicia does hold together that long, it would be only the tenth tropical cyclone of tropical depression or higher strength to affect the islands since 1950 (Figure 2). Large swells from Felicia are already affecting the Big Island, and a high surf warning has been posted for east-facing shores of the Big Island and other Hawaiian islands. Felicia or its remnants may bring heavy rain, flash flooding, and mud slides to the islands beginning this afternoon, and a Flash Flood Watch has been posted for most of the islands.

Links to follow:
Long range radar from the Big Island
Wundermap for Hawaii

I'll have an update Tuesday morning.

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Quoting WPBHurricane05:
Oh dear Lord, Bozo the clown. Haven't seen him in YEARS! Thanks for the memories Storm W!


My sides are hurting LOL
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the broad area of low pressure in th CATL looks rather interesting to night.what i have noticed is that a LLC is trying to reform ner 13n 48w. there is significant convergence as can be seen with the low level clouds streaming to the new centre. there is also good divergence and it will be inteesting to see what pans out from this system
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I was working , I am the manager, I use the blog and links from the blog to keep updated on weather, as we have weekly emrgency meetings. we do have a great security system , but 2 of us were on wu when it crashed...i do not know if it is related but i was curious because others are having problems as well...
thank you for your answers...
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Quoting Acemmett90:
don't know and i don't recomend going to look on page 15



i just went back to page 15 and everything is fine
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Quoting zoomiami:
Thanks Thelmore


you are welcome.....

trust me, that Malwarebytes-Anti-Malware works really well to remove the virus going around in this blog.....

once again.....

http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html
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Oh dear Lord, Bozo the clown. Haven't seen him in YEARS! Thanks for the memories Storm W!
Member Since: July 31, 2006 Posts: 56 Comments: 8112
Quoting StormW:





LMAO
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1980. java162
Quoting FloridaTigers:
What happened on page 15? What virus? Someone please give me a summary


just go down the blog and watch the previous comments!!!!!!!!
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1979. IKE
I ran a complete scan. Everything okay on mine.

Everything isn't okay on 99L.....

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Quoting PcolaDan:


Ah, I see. Your actually saying to place the link in without actually linking it. That could work.
Right, for example, here is the newest GFS run:

http://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2009081018&field=Sea+Level+Pressure&hour=Animation

That is how we should share webpages on the blog while there is a virus threat.
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What happened on page 15? What virus? Someone please give me a summary
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Quoting Acemmett90:
first of all your at work you should be working
second of all a htion hotel should have a good firewall
third was there any anti virus software at all on the main computer


Fourth, what was on page 15 ??
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Thanks Thelmore
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Quoting FLWeatherFreak91:
No, I mean for people to copy and paste the link into the browser. No direct link. Weather websites are fairly obvious to identify, and being able to see what site you are navigating to would help.


Ah, I see. Your actually saying to place the link in without actually linking it. That could work.
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1968. Dakster
Quoting kmanislander:
1952. Dakster 8:51 PM EST on August 10, 2009

You are so likely to be banned for that


I modified it....

Eeryone was a little too serious so I wanted to lighten the mood a little.

At least I didn't post a pic of one in use!
Member Since: March 10, 2006 Posts: 0 Comments: 10804
Quoting HurricaneJoe:


Yes, it is. DMAX tonight may help it a bit.


Yup. Next wave looks impressive though.
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1965. java162
Quoting Dakster:


I thought trojans prevented viruses...



lmao
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Umm at the risk of being burned at the stake, I opened page 15 too, but like an idiot from my secured work station at Hilton Hotels. It crashed my browser as well, and all the pcs that we have are connected and everyone that one of the employees have brought up weather underground has some weird virus in it!!! I am on my laptop now and seem to be having no problems. I am running a scan now. How much trouble will I be in for crashing my workstations by viewing a weatherblog? is it even possible? could it be something else?
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When did the NHC put the yellow circle up near the island? Guess I am late seeing it?
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What the heck is all this virus talk? Who spread a virus?
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1952. Dakster 8:51 PM EST on August 10, 2009

You are so likely to be banned for that
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link location if you want to copy and paste.....

http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html
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1957. caneman
Death to all tropical blobs.
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Quoting PcolaDan:


NOT a good idea. Sorry, but it's way to easy to put a bogus URL in the text body then put another in the actual link. This gives a false sense of security.
No, I mean for people to copy and paste the link into the browser. No direct link. Weather websites are fairly obvious to identify, and being able to see what site you are navigating to would help.
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Quoting extreme236:


Well yeah but at least its starting to fire off some convection.


Yes, it is. DMAX tonight may help it a bit.
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Quoting HurricaneJoe:


It's gonna need to do a little more than that, though


Well yeah but at least its starting to fire off some convection.
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I suggest anybody who has virus troubles, particularly win-antivirus, to download, install, update, and run quick scan....

Malwarebytes-Anti-Malware

I do a lot of virus removal, and this "free" program removes most of these "scare-ware" virus's.





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Quoting extreme236:
Finally 99L showing some signs of life.


It's gonna need to do a little more than that, though
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Quoting FLWeatherFreak91:
For the sake of those on the blog prone to viruses, we should all mutually agree to post the actual URL instead of a link when sharing information. Seeing www.weather.gov instead of "LINK" is a sure fire way to lessen your chances of getting a virus. But for this to work we will need to keep posting this to remind everyone not to post links.


NOT a good idea. Sorry, but it's way to easy to put a bogus URL in the text body then put another in the actual link. This gives a false sense of security.

p.s. 2 good programs are Malwarebytes and Spybot search and destroy, google them (I won't link to them) :)
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Finally 99L showing some signs of life.
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Been gone since 2PM, and I see that 99L has fizzled for the day. Anything else going on?
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1942. IKE
Quoting kmanislander:
It will soon be prozac time for all bloggers who were relying on 99L to become the first TS of the season.

I feared this might happen LOL


99L looks terrible.
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Quoting StormW:


Zoloft is good.
or Lexapro
Member Since: August 15, 2008 Posts: 0 Comments: 2515
1940. java162
Quoting pottery:
good evening.
Invest 99 looks pretty dismal right now.
The one behind it may suffer the same fate, if 99 has not left a lot of moisture behind it. There is still plenty of dry air in the Trop. Atl. Unusual for this time of year? I think so.
If the wave can hold together until it gets to the Caribbean, it could possibly blow back up. Temps there are hot, and there has been plenty moist air around there/here.
We even had a tornado, filmed by a couple of people, yesterday, near here. I did not see it. Most unusual. No damage from that.



what island was the tornado?
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1939. Dakster
Quoting FLWeatherFreak91:
Well you can see for yourself. http://blip.tv/file/555356


I can prove MAC's get viruses. They make anti-virus tools for the MAC. They are complete with a pattern file.

I rest my case...
Member Since: March 10, 2006 Posts: 0 Comments: 10804

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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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