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

By: Dr. Jeff Masters , 3:55 PM GMT en Agosto 10, 2009

Share this Blog
4
+

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.

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: 2639 - 2589

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 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

I am no expert but I do believe the experts at the NHC may need a little help in a couple days. I may raise you one Tampa there could be 3-4 systems in the next few days the way things are popping tonight those highs to the north look to be getting stronger getting better environment all the time.
Member Since: Posts: Comments:
Quoting Stormchaser2007:

Many thing going for it.

7 knots of shear.

Little SAL

Lower latitude

Model support



May I add, persistence model support. Heck that GFS model looks like a Georges and a Isabel all combined into one!
Member Since: Posts: Comments:
Quoting stormdude77:
Hey, Stormchaser...how's it going...long time no see


Good, thanks!

Nice to see you Ryan!

Hope things are going well with you.
Member Since: Posts: Comments:
The Caribbean Blob is firing now..along with 99L...DMax is going to doing wonders for both...

Member Since: Septiembre 2, 2007 Posts: 178 Comments: 20439
Hey, Stormchaser...how's it going...long time no see
Member Since: Posts: Comments:
Quoting Acemmett90:

if 99L possibly doe become a cane over night is has to have a pin hole eye right


I dont even know what to say...
Member Since: Posts: Comments:
2631. KEEPEROFTHEGATE (Mod)
looks like all ok coming in going out on my end

bell.net

privacy scan ok
fraud scan ok
virus scan ok
spyware scan ok

Time Elapsed 3:30:56

SYSTEM UPGRADE

wifi security
hot spots
active shield

installation complete

Time Elasped 01:22:29
Member Since: Posts: Comments:
Quoting FloridaTigers:
Gee, I'll be so shocked if this new wave fizzles.

Many thing going for it.

7 knots of shear.

Little SAL

Lower latitude

Model support

Member Since: Posts: Comments:
-80C

We'll see how long it lasts.
Member Since: Posts: Comments:
Gee, I'll be so shocked if this new wave fizzles.
Member Since: Posts: Comments:
Holy Smokes! Wave two is organized into amazing cloud patterns. It's meant to be Bill.
Member Since: Posts: Comments:
Quoting leftovers:
same stuff we use to get free about 5 yrs ago


Its absolutely not.

Do you even have it?
Member Since: Posts: Comments:
Quoting Progster:


The inverted trof over the NE gulf and Central Fla at the 120 GFS is more intriguing. As a model developer once said to me..."beyond day-7: Hopeless"

The virus:

H1W0 (hurricane's 1 WU zero)


Well thats 5 days out.. so :)
Member Since: Posts: Comments:
Still going with the TCVN



Member Since: Posts: Comments:
Quoting TampaSpin:


BAMM is not used for that....its used to forecast tracking along with BAMS and BAMD


Ya learn something everyday! Thanks.
Member Since: Posts: Comments:
The only Hurricane I was in was 1996 during Hurricane Fran. I lived and still live in Raleigh at the time. NOBODY thought it was coming that far inland..at the last minute it decided to take a more northerly track. Pretty scary as 10 year old!
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Strong TS Bill

120 hours



The inverted trof over the NE gulf and Central Fla at the 120 GFS is more intriguing. As a model developer once said to me..."beyond day-7: Hopeless"

The virus:

H1W0 (hurricane's 1 WU zero)
Member Since: Posts: Comments:
Quoting leftovers:
still got it wrong yesterday


??
Member Since: Posts: Comments:
So have we decided that the virus is defiantly coming from banner ads an not posted links.I would think Admin. would post something to the affect but may need legal ck. first, Also 99l looks to have a lighter vapor image dead center of the vapor image. I have had at least twice were I clicked on ads here that would not go away or allow me to leave site. So I unplugged laptop and removed battery and started over.I guess I been lucky.
Member Since: Posts: Comments:
Quoting Alockwr21:
Wonder if the BAMM and NOGAPS will jump on board with the others.


BAMM is not used for that....its used to forecast tracking along with BAMS and BAMD
Member Since: Septiembre 2, 2007 Posts: 178 Comments: 20439
Quoting cchsweatherman:
Well, have a good night everyone. Sorry for overstaying my welcome on here like you all have made it seem. Just trying to bring rational thinking and honesty to a blog that seems to have become lax with such. I never intend to bring drama here like many on here think. Good luck with the computer problem Drak and Happy Birthday to WeatherStudent.


No need for a double post.
Member Since: Posts: Comments:
Or the free version of avast.

www.avast.com
Member Since: Posts: Comments:
Quoting CybrTeddy:
I think this is what the TWO might say:

An area of low pressure associated with a Tropical wave has become better organized over night. This system has a medium chance 30-50% of becoming a Tropical Cyclone in the next 48 hours.

A Strong Tropical Wave has emerged off the African coast line. Conditions are favorable for development and there is a medium chance, 30-50% of this becoming a Tropical Cyclone in the next 48 hours.

A tropical wave associated with an small area of low pressure near the Windward Islands have diminished. There is a low chance, less than 20% of this system becoming a Tropical cyclone in the next 48 hours.

Not so sure about the middle one.


I agree with number 3...number 2 I'm not certain of, and number 1 I'm more along the lines of "Shower and thunderstorm activity has increased in association with the broad area of low pressure west of the Cape Verde Islands. Environmental conditions appear favorable for development, and a tropical depression could form today or tomorrow as it moves westward at 10 to 15 MPH"

Just a guess...
Member Since: Posts: Comments:
Still a fish for the US. (Breaths a sigh of relief)...for this run at least!
Member Since: Posts: Comments:
Now


GFS 6 hours.

Member Since: Posts: Comments:
Well, have a good night everyone. Sorry for overstaying my welcome on here like you all have made it seem. Just trying to bring rational thinking and honesty to a blog that seems to have become lax with such. I never intend to bring drama here like many on here think. Good luck with the computer problem Drak and Happy Birthday to WeatherStudent.
Member Since: Posts: Comments:
Use the full suite of McAfee to block viruses.
Member Since: Posts: Comments:
Quoting sammywammybamy:


When's The Most Reasonable time you think itll become a Td..

This Question is Open For Anyone..


Sammy we could easily have 2-3 named storms by this time next week....time will tell.....i think 99L will be named first........Wow are Caribbean blob is REALLY like the night lite.....it is really blowing up!
Member Since: Septiembre 2, 2007 Posts: 178 Comments: 20439
Wonder if the BAMM and NOGAPS will jump on board with the others.
Member Since: Posts: Comments:
I think this is what the TWO might say:

An area of low pressure associated with a Tropical wave has become better organized over night. This system has a medium chance 30-50% of becoming a Tropical Cyclone in the next 48 hours.

A Strong Tropical Wave is emerging off the African coast line. Conditions are favorable for development and there is a medium chance, 30-50% of this becoming a Tropical Cyclone in the next 48 hours.

A tropical wave associated with an small area of low pressure near the Windward Islands have diminished. There is a low chance, less than 20% of this system becoming a Tropical cyclone in the next 48 hours.

Not so sure about the middle one.
Member Since: Posts: Comments:
Quoting BA:


you could get accuweather pro for that cost


I do.

But Accuweather Pro is $25 a month.

Worth it
Member Since: Posts: Comments:
.
Member Since: Posts: Comments:
All is status quo with the "Africane".

It seems to be consolidating to where the GFS shows it.
Member Since: Posts: Comments:
2596. BA
Quoting Stormchaser2007:


Thanks.
Quoting Stormchaser2007:


Thanks.


you could get accuweather pro for that cost
Member Since: Posts: Comments:
Quoting CybrTeddy:
324 hours out: Category 2/3 Hurricane.


I think a Bermuda High is going to be building almost exactly where that killa L is on the model map.

If something does develop that close to the CONUS on 8/24/2009...expect it to be "Son of Andrew" S. FL bound.
Member Since: Posts: Comments:
2594. 7544
what a big diffence in 99l shape in only 3 hours go to shaow you waht a system with a closed low can spin up fast and not even in dmax yet . this can really blow up in the next 6 hours stay tuned dont knock it yet
Member Since: Posts: Comments:
2592. Skyepony (Mod)
Quoting jeffs713:

Do I spy a low-level circulation there?


The high res is very impressive..
Member Since: Posts: Comments:
Quoting CybrTeddy:


I know, the year I moved to Florida I got slammed by Charley, Frances, Ivan and Jeanne after just having to endure Isabel. Then follow that up by Katrina, Rita, and Wilma.
where in Florida are you, it is very important
Member Since: Posts: Comments:
Well this means nothing...but this is probably a Category 3 hurricane.

Member Since: Posts: Comments:

Viewing: 2639 - 2589

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 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog 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

Clear
75 ° F
Despejado