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

By: Dr. Jeff Masters , 3:55 PM GMT on August 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: 2589 - 2539

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

Well this means nothing...but this is probably a Category 3 hurricane.

Member Since: Posts: Comments:
Quoting sammywammybamy:


Welcome To Florida

The Sun/Hurricane State

Where We get hit by Hurricanes Alot

Youve just went from the Pot to the Frying Pan

=)


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.
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Just putting this out there...

IF 99L can continue to fire convection till the 2am TWO they might go RED.

Chances are they wont but it would have deep convection and a closed surface low.



I agree. Which means I'm gonna end up staying up for this 2am TWO for a third night...
Member Since: Posts: Comments:
Quoting extreme236:


Couldn't help but laugh at the "7 days" thing since I just watched The Ring...sorry for that off topicness lol


LOL

I see how you could relate that.
Member Since: Posts: Comments:
Just putting this out there...

IF 99L can continue to fire convection till the 2am TWO they might go RED.

Chances are they wont but it would have deep convection and a closed surface low.



African wave seems to be doing well.
Member Since: Posts: Comments:
Quoting Alockwr21:
NC/SC is definitely over due for a cane.


Yea.. Isabel was the last time that has really happened where they had a bad one. And I was in that one, not a fun experience for us Virgina people. Now I'm a Floridian.
Member Since: Posts: Comments:
2579. HadesGodWyvern (Mod)
Japan Meteorological Agency

Tropical Disturbance Summary (0000z 11AUG)
=========================================

At 9:00 AM JST, Tropical Depression, Former Morakot (996 hPa) located at 32.0N 120.0E has 10 minute sustained winds of 25 knots with gusts of 40 knots. The depression is reported as moving north-northeast of 10 knots
Member Since: Posts: Comments:
2577. JRRP
south CV...
Member Since: Posts: Comments:
324 hours out: Category 2/3 Hurricane.
Member Since: Posts: Comments:
2574. 7544
Quoting Drakoen:
Major Hurricane bearing down on the Lesser Antilles on the GFS run


well does go back to fla this run
Member Since: Posts: Comments:

Do I spy a low-level circulation there?
Member Since: Posts: Comments:
Quoting Vortex95:
BTW to all i personally use ad-adware to get rid of spyware and such as well as McAfee siteadvisor which blocks a site which has known to be malicious. ad-adware is a free service that has the ability to get rid of most spyware.

TIP: Once infected with spy-ware disconnect from the internet before trying to rid of the virus, spyware, adware, malware, etc.

In other news 99l is lookin good.

Malwarebytes is better but it will not work with this since it an AD...
I think we should be watching the yellow circle. it is starting to blow-up again.
Member Since: Posts: Comments:
Quoting Stormchaser2007:


Thats the key but,

Yeah.


Couldn't help but laugh at the "7 days" thing since I just watched The Ring...sorry for that off topicness lol
Member Since: Posts: Comments:
NC/SC is definitely over due for a cane.
Member Since: Posts: Comments:
Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting sammywammybamy:
99L
MODELS



and the SHIPS has it as an afternoon breeze in 5 days...
Member Since: Posts: Comments:
Quoting presslord:


I don't know what your problem is...but...that's WAY too rational...


'Course cause its gonna hit the Carolina's! ;)
You didn't get slammed with the Virus did you Press?
Member Since: Posts: Comments:
2564. JLPR
well it looks like all the waves are having a good night

and im off ...university tomorrow
I hate getting up early lol xD
Member Since: Posts: Comments:
2563. Drakoen
Major Hurricane bearing down on the Lesser Antilles on the GFS run
Member Since: October 28, 2006 Posts: 57 Comments: 30830
2561. ackee
does anyone realize that the GFS has change the track of posssible Bill or ANA on every single runs
Member Since: Posts: Comments:
180 Hours.

About a Category 2.
Member Since: Posts: Comments:
Quoting hunkerdown:
am I in the wrong place ? I have already shuttered up, just lying in wait...


level headed rationality will not be tolerated...
Member Since: August 13, 2007 Posts: 0 Comments: 10492
Quoting Vortex95:
What exactly is goin on here with these viruses? how are you guys getting them?

I think is an Ad.... if your press(ALT,CTRL,DEL) and go to the (Processes) tab you can tell that (or a: iexplorer.exe ) if you like Microsoft,
or B: firefox.exe ) if you like Fire fox is running at you can end it. it should stop the attack. or in my opinion (AD. it like it take a picture of you computer but is just a browser open and making you think is already in you computer

Member Since: Posts: Comments:
Models are going West as i knew they would....

Member Since: September 2, 2007 Posts: 179 Comments: 20448
Quoting CybrTeddy:


So in about 7 day's the GFS thinks we're looking down the barrel of a Category 1/2 Hurricane?


Thats the key but,

Yeah.
Member Since: Posts: Comments:
Quoting presslord:


I don't know what your problem is...but...that's WAY too rational...

Rational thoughts are not allowed on this blog tonight. (and yes, I violated my own rule earlier)
Member Since: Posts: Comments:
Quoting philliesrock:

Link

It's a pay site but it's worth it.


Thanks.
Member Since: Posts: Comments:
Actually, WU's TOS specifically says they have no liability in such cases. That's pretty standard on most sites. We accept the site as-is, with no warranties at all (See TOS section 8).

http://www.wunderground.com/members/tos.asp
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Hurricane Bill 150 hours.

Probably strong Cat 1.


So in about 7 day's the GFS thinks we're looking down the barrel of a Category 1/2 Hurricane?
Member Since: Posts: Comments:
Quoting TampaSpin:
LOL everyone is calling the wave coming off Africa Bill........it could be ANA......LOL


Hm thats true.

Another gender confused disturbance.

**Rembers Alma-Arthur**
Member Since: Posts: Comments:
Quoting presslord:


I don't know what your problem is...but...that's WAY too rational...
am I in the wrong place ? I have already shuttered up, just lying in wait...
Member Since: Posts: Comments:
There is outstanding cloud organization on the second wave.
Member Since: Posts: Comments:
Quoting Twisterman555:


Sorry, my bad. :(
Quoting philliesrock:

NEVER MIND...I was looking at an old run. It hits Hispaniola and curves out to sea.


?? The output from the 00Z GFS is still spitting out right now. It's only at 150 hours, still east of the Windwards.
Member Since: Posts: Comments:
Quoting Stormchaser2007:


Where do you get the GFS from?

Link

It's a pay site but it's worth it.
Member Since: Posts: Comments:
Quoting superweatherman:

I am new at blogging but I have been reading this blog for 2 years. Any one that has this problem should buy a router and block the web page (antivirusbestscan5.com)...
It worked for me... Or buy a firewall software… but I don’t like using them since it may slow your computer…


If you've been able to track down the URL, I suggest notifying the major virus and anti-spyware websites that it sends out malware. I'm sure they would love to block it out via an upcoming update.
Member Since: Posts: Comments:
2541. Wariac
I'm not panicking...I'm just a curios lucker...I just asked since people keep mentioning the supposed "bill"
Member Since: Posts: Comments:
Quoting hunkerdown:
We don't even have present Ana yet, so there is no future Bill. Before you start panicking on long range models, which have been WAY off so far this season, lets wait for something to develop before we truly need to worry about where it MIGHT be heading. There will be plenty of time for tracking an actual storm when/if it forms.


I don't know what your problem is...but...that's WAY too rational...
Member Since: August 13, 2007 Posts: 0 Comments: 10492

Viewing: 2589 - 2539

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.

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron