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 SavannahStorm:


I concur. Georgia shall be hereby deemed Hurricane Proof and all models shall discard any solutions possibly showing a Georgia landfall.


Well I don't know of any major hurricanes, but Hurricane David of 1979 hit Georgia for a second landfall as a minimal hurricane.
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Another closed Low at 10N 45W

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2486. Wariac
JRRP do you see any of those waves coming near PR?
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Anybody got the latest image from the 00GFS run?
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Quoting extreme236:


Highly doubt its showing a Cat 5...major cane maybe but not that strong.


can i get a link please?
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2483. Drakoen
Quoting frostynugs:
guys, I run a website and I can tell you that you do not need to be blaming wunderground. google ads is the culprit here. these sites are paid for with banner ads. to get those banner ads, you partner with an ad agency like google ads and they supply your banner ads and in turn give you cash. once in a while these guys will screw up and accept an ad from a malicious client, and suddenly, without you knowing anything about it, you are getting infected ads on your website. there's no way to know if they're there until someone has been infected. so, blame google ads for this one. wunderground had no way of knowing they would feed them bad ads.


Wunderground is an associate and is hosting these ads.
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Quoting Stormchaser2007:
Either those are downdrafts indicating convection dying due to SAL....

OR Marco sized bands.

look like outflow boundaries, not bands.
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Quoting philliesrock:
138 has the hurricane farther south than 18z.


Why are you at 138?

Im only on 120 using NCEP.

Do you use Accuweather pro or something?
Member Since: June 9, 2007 Posts: 4 Comments: 15950
Massive burst over 99L's center. This better be a TD when i wake up. Gnight all.
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2477. ackee
when do u guys think 99L will be ANA I would not be suprise if its stay as 99L the ways has been thus far
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2475. Drakoen
We'll see if the trend continues. Yeserday at this time it looked like death.
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99l....getting healthier...right JLPR??and going so...."west-ie"
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Quoting Acemmett90:

im going with macro bands


Marco for those who missed him


Member Since: June 9, 2007 Posts: 4 Comments: 15950
too funny I was wonder what marco bands were .....macro bands!
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138 has the hurricane farther south than 18z.
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Quoting Stormchaser2007:
Either those are downdrafts indicating convection dying due to SAL....

OR Marco sized bands.



Probably gonna stay small for a while until it can clear out more SAL and expand.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
guys, I run a website and I can tell you that you do not need to be blaming wunderground. google ads is the culprit here. these sites are paid for with banner ads. to get those banner ads, you partner with an ad agency like google ads and they supply your banner ads and in turn give you cash. once in a while these guys will screw up and accept an ad from a malicious client, and suddenly, without you knowing anything about it, you are getting infected ads on your website. there's no way to know if they're there until someone has been infected. so, blame google ads for this one. wunderground had no way of knowing they would feed them bad ads.
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2468. Drakoen
Quoting SavannahStorm:


I agree, that's the only explanation. I haven't clicked any links on this page and I'm getting pinged constantly by these two links, which claim to be adware. WU has got issues.


That would make it a phishing link
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Quoting StSimonsIslandGAGuy:
We

The models are getting smarter, they know a major landfall in Georgia is not allowed :)


I concur. Georgia shall be hereby deemed Hurricane Proof and all models shall discard any solutions possibly showing a Georgia landfall.
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2462. JRRP
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Either those are downdrafts indicating convection dying due to SAL....

OR Marco sized bands.

Member Since: June 9, 2007 Posts: 4 Comments: 15950
Sad but, i just won't open any links for a while that anyone puts up....Sorry....i have a very good virus protection.....but this is crazy.
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The wave after 99l is pointed to be a hurricane... where do you find these models? but look inside of central Africa...is like a train of waves coming one behind other.
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Quoting CycloneOz:
Hey JFV, if you wanna break "this voodoo" cutting down all these CV waves, you might want to consider some good karma!

On your birthday cake today, instead of 16 candles, replace them with the solid number candles you can buy at the store.

Buy 3 zeroes, blow them out...good karma! (You may get your truest wish! :)


I like the way you think...
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Quoting Drakoen:



Wunderground supports ads that have viruses.


I agree, that's the only explanation. I haven't clicked any links on this page and I'm getting pinged constantly by these two links, which claim to be adware. WU has got issues.
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Caveat Emptor "may the buyer beware"

I think that we all know that the internet has problems, that's why we use the virus programs etc. In this day & age its just too easy to look for someone to blame, to make them responsible.

We all came onto the blog knowing its an open internet site, and that the virus problem can exist here also. Admin is not to blame for the problems on our computers, about all they can do is scan what comes in. I don't think that will work, because the virus gets picked up when you open up an outside link.

Bottom Line, we all are responsible for our computers, so lets not make this a big issue.
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Quoting Drakoen:
Aside from the virus issue 99L is firing some decent convection.


We said it would make a come back.....it had way to much low level organization.
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SavannahStorm.

A little risky no?

Member Since: June 9, 2007 Posts: 4 Comments: 15950
GFS has a little something going into SE TX Friday. Dunno what it is just that it turned blue. Lol
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2446. Drakoen
Quoting weatherboykris:



I wasn't blaming drak...I was saying drak shouldn't blame WU...that's all.


Well I am.
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2444. Drakoen
Quoting SavannahStorm:
I'm going to copy and paste the attack info from my filter log so we know where they are coming from. These are the two I am constantly getting. Whatever you do, do not try to follow these links, as they are probably the source of the attack. I am only posting these so you know what links to watch out for.:

Security Error: Content at http://googleads.g.doubleclick.net/ may not load data from http://ads.technoratimedia.com/ads/get.cfm?urlChecker=http://&zoneIdentifier=DFA400577B659FC7&am p;showFr ameID=717B0991E62A476DB4CEEB01A44F904A.

and

Security Error: Content at http://googleads.g.doubleclick.net/ may not load data from http://cdn4.specificclick.net/img/?ag=1&pb=6154&pg=887650680644719194&us=cy89iorvHItQ7C& amp;rnd=711565.



Wunderground supports ads that have viruses.
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Quoting Acemmett90:

modles say cat4 or cat5 to eather but not includeing new york city, SFL , NOLA and THE CAOLINAS


Highly doubt its showing a Cat 5...major cane maybe but not that strong.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
So this virus is located everywhere? Sorry for going off-topic, I'd just rather not have an expensive computer repair bill.
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Quoting Wariac:
why is it people always blame the victim and not the attacker. drak did nothing wrong. Wrong is for someone to come here and intentionally infect people with a virus.



I wasn't blaming drak...I was saying drak shouldn't blame WU...that's all.
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New African wave is a hurricane at 114...99L still holding on, a weak low NE of the islands.
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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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