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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3239. WAHA
Quoting BenBIogger:


Right now he's in school.

How do you know?
Morning everyone!!

FINALLY 99L is a TD. Going catch up on posts.
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Just now got online today. Anyone mentioned that a couple models develop the 50W wave and the CMC takes it into the Gulf?
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3223. Acemmett90 1:37 PM GMT on August 11, 2009
Quoting mobilegirl81:
Looks like the models are trying to tell us something.

the are not telling us they are telling weatherstudent to get the heck off the east coast


that's just too dang funny...is weatherstudent JFV?? i haven't seen his scared frantic self in a while...
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3235. jscs
Quoting BobinTampa:
Tropics are the lead story on Ch. 28's website here in Tampa. And we NEVER get hit (thanks Deflector Shields).

Think they'd be getting antsy down Miami way. I'm sure WeatherStudent is running through the streets screaming like a little girl right now.



People are ready for a good story. Seems to me it's far too early to even say these storms will get named. Quiet year equals loud voices when anything forms.
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I must admit... Weather456 does make some nice graphics to understand whats going on.

Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting heliluv2trac:
where is weatherstudent somewhere probably asking everyone is it coming here


Today's his birthday. His present of significant tropical activity arrived same day.

Gotta love that Karma!
Member Since: August 26, 2006 Posts: 10 Comments: 3696
3232. WAHA
Quoting Acemmett90:

the are not telling us they are telling weatherstudent to get the heck off the east coast

Oh, and how is he offensive?
Weather student is saying "Follow my nose!"
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Quoting heliluv2trac:
where is weatherstudent somewhere probably asking everyone is it coming here


Right now he's in school.
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Quoting caribbeansurvivor1:
Good Morning JRRP, ready to the College? What is expected to TD 1 and the "Bill" wave? I think we will have Anna at 12 or so....What u think pal?


TD 2* TD 1 was in May.
Member Since: July 8, 2005 Posts: 259 Comments: 24044
Quoting WPBHurricane05:


LOL...I can hear him in West Palm Beach...50 miles away!


Same here lol
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where is weatherstudent somewhere probably asking everyone is it coming here
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Models will change a lot between now and when something actually reaches land.
Member Since: September 12, 2007 Posts: 0 Comments: 725
Quoting BobinTampa:
Tropics are the lead story on Ch. 28's website here in Tampa. And we NEVER get hit (thanks Deflector Shields).

Think they'd be getting antsy down Miami way. I'm sure WeatherStudent is running through the streets screaming like a little girl right now.



LOL...I can hear him in West Palm Beach...50 miles away!
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Quoting BobinTampa:
Tropics are the lead story on Ch. 28's website here in Tampa. And we NEVER get hit (thanks Deflector Shields).

Think they'd be getting antsy down Miami way. I'm sure WeatherStudent is running through the streets screaming like a little girl right now.



lol
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Good Morning JRRP, ready to the College? What is expected to TD 1 and the "Bill" wave? I think we will have Anna at 12 or so....What u think pal?
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Tucan sam?
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Tropics are the lead story on Ch. 28's website here in Tampa. And we NEVER get hit (thanks Deflector Shields).

Think they'd be getting antsy down Miami way. I'm sure WeatherStudent is running through the streets screaming like a little girl right now.

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3219. KEEPEROFTHEGATE (Mod)
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Looks like the models are trying to tell us something.
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Quoting CybrTeddy:


Do you think TD 2 will even become named?


I do. But at the moment im not following any models due to the lack of consistency and data. Im going to wait until tomorrow until I make a full intensity forecast and track. If the models look the same then Ill wait again.
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Quoting RescueAFR:
Some folks blogged earlier that is was a suprise South Fla media hadn't mentioned the activity in the Atlantic...Sure enough SunSentinel.com..just posted to the front page the track of TD2..see it didnt take long!!
Stay well...


They're talking about it in Tampa for sure.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
3214. 7544
Quoting fmbill:



Good morning, all. I'm curious...per the 00z GFS, it appears the wave at 50w will come to the Florida east coast; followed by Ana crossing the southern tip of Florida; followed by "Bill" brushing the Florida east coast.

Anyone else seeing this?


thanks so its back to fla again
Member Since: May 6, 2007 Posts: 0 Comments: 6812
GFDL is pretty disturbing. It clearly develops 3 separate systems. The first is TD02 the next is the 'Bill' wave and the third is the 50W wave which it has cutting through south Florida and making it into the Gulf.

Tracks are marked by red lines and circles are points of genesis

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Blog Update
Reflector site for those at work, which includes Weather456, daily update.


TD2

AOI
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting Stormchaser2007:


Look at shear and SAL then come back to me lol


Do you think TD 2 will even become named?
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3210. JRRP
GFDL still showing Bill to the west
Link
Member Since: August 16, 2007 Posts: 0 Comments: 5847
That does not look good.
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The tropical outlook has caused me to go into deep-breathing mode.

wow...
Member Since: August 26, 2006 Posts: 10 Comments: 3696
3192. TheCaneWhisperer 1:27 PM GMT on August 11, 2009
Quoting Funkadelic:
Im surprised the news here in south florida wont talk about what models ae developing behind 99L.


That plays out, it would be chaos. The insurance industry is crippled right now thanks to Gov. Christ


with the economy the way it is...a storm is the last thing anybody needs....i can just see the media and insurance companies scaring the bejeebies out of everyone...not to mention all the empty forclosed homes down south...not good at all...
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3206. Seastep
Quoting extreme236:
Well I didn't expect to see a special advisory issued to upgrade this to a depression. Interesting. Good morning all.


It looked awesome at 5-6am. Perfectly round convection. That with an observed fully closed low. Really not a tough call at that point.

You can still see a hint of in the first frame at SSD, but not on the floater. Look at the CATL loop.
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Some folks blogged earlier that is was a suprise South Fla media hadn't mentioned the activity in the Atlantic...Sure enough SunSentinel.com..just posted to the front page the track of TD2..see it didnt take long!!
Stay well...
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Quoting ineedwind:


I think 50w and 60w are dead. Looked way more promising yesterday. For TD2, NHC just looks at the data and makes their judgment based on hard facts (not wrong at all). Just saying they're not taking into account that it is basically surrounded by dry air/SAL.


Great point, but it has been that way for a few days, if it meets the requirements of a closed low per quikscat and Dvorak it can be classified despite what future it holds.
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3203. WAHA
Quoting Autistic2:
Two yellow and a TD.
Yet the 0-0-0 rolls on!
But how long? Untill latter today?
Will the SAL slow this down?
Is this the end of the Perfecta?
The plot thickens with the mystery guest named SAL.

LATTER?! YOU FAIL!
Quoting CybrTeddy:
TD2 is forecasted to go up to 60-65 MPH at the end of the forecast period so beyond that it wouldn't surprise me to see TD2 become a Hurricane.


Look at shear and SAL then come back to me lol
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Quoting TheCaneWhisperer:


That plays out, it would be chaos. The insurance industry is crippled right now thanks to Gov. Christ


You can say that again.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
3200. ackee
where does the CMC and umket takes wave behind TD#2 any link thanks in advance
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Quoting mobilegirl81:
Bill would develop low enough to be a gulf storm.


Hummm...2 storms within days appart!
Member Since: September 2, 2007 Posts: 178 Comments: 20439
Quoting keywestbrat:
Hi indianrivguy,
I was just thinking the other day I hadn't seen you this season. How you doing?


well enough thank you. Been lurking, not much to comment upon until today. I hope things are well with you! Economy being what it us, I was forced to move and now live in a mobile home.. the newest models have me VERY nervous. My ability to prepare has been severly hampered by finances.. I'm sure I'm not the only one faced with these circumstances, but I must say.. I have been watching this season with dread in my heart.
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Quoting mobilegirl81:
Looks like TD2 could pull a Frances/Jeane track.


A Jeane track might be kind of hard to pull off considering its current location:

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lol....let's see who eats who!
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TD2 is forecasted to go up to 60-65 MPH at the end of the forecast period so beyond that it wouldn't surprise me to see TD2 become a Hurricane.
Member Since: July 8, 2005 Posts: 259 Comments: 24044
Two yellow and a TD.
Yet the 0-0-0 rolls on!
But how long? Untill latter today?
Will the SAL slow this down?
Is this the end of the Perfecta?
The plot thickens with the mystery guest named SAL.
Member Since: Posts: Comments:
Quoting Funkadelic:
Im surprised the news here in south florida wont talk about what models ae developing behind 99L.


That plays out, it would be chaos. The insurance industry is crippled right now thanks to Gov. Christ
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Bill would develop low enough to be a gulf storm.
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Quoting Acemmett90:

good hows that bill wave doing


See posts 3145 and 3027
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Looks like TD2 could pull a Frances/Jeane track.
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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.