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Felicia not weakening; new African wave may develop

By: Dr. Jeff Masters, 3:12 PM GMT on August 08, 2009

Hurricane Felicia has not weakened today, and continues to hold its own in spite of cool sea surface temperatures beneath it. Recent satellite imagery shows that the tops of thunderstorms surrounding the eye have cooled slightly, indicating that the updrafts sustaining the eyewall are maintaining their strength. The appearance of the hurricane has improved some today, with the storm assuming a more symmetric appearance.


Figure 1. Current satellite image of Hurricane Felicia.

Sea surface temperatures (SSTs) under Felicia have now fallen to 24.7°C, well below the 26°C threshold typically needed to sustain a hurricane. SSTs will slowly increase to 26°C by the time the storm reaches Hawaii, though. Wind shear is expected to remain low to moderate, 5 - 15 knots, through Monday morning. By Monday night, shear will rise to 20 knots, and remain above 20 knots thereafter. The higher shear combined with the relatively cool SSTs should mean that Felicia will be rapidly weakening in its final 24 hours before reaching Hawaii. Several of the computer models continue to show that this shear will be high enough to tear Felicia apart before it reaches Hawaii, though it appears to me that Felicia's current strength and annular structure will help it resist the shear enough to allow the storm to hit Hawaii as a tropical depression with 35 mph winds. Regardless, Felicia will bring heavy rain Hawaii beginning on Monday morning, and these rains will have the capability of causing flash floods and mudslides. The Hurricane Hunters are scheduled to make their first low-level investigation of Felicia this afternoon (around 10 am Hawaiian time). The NOAA jet also flies into Felicia today, and will drop a series of dropsondes that will be used to gather data that will be fed into today's 12Z and 00Z computer model runs.

Typhoon Morakot hits Taiwan
Typhoon Morakot hit Taiwan yesterday, battering the island with Category 1 winds and heavy rain. The Taipei airport recorded sustained winds of 56 mph, gusting to 76 mph, at the peak of the storm. Morakot killed 6 on Taiwan and 10 in the Philippines, and is headed towards a final landfall on mainland China as a tropical storm later today. Storm chaser James Reynolds intercepted the storm and posted videos on typhoonfury.com and Youtube. Morakot is still visible today on Taiwan radar.


Figure 2. Visible satellite image of a spinning tropical wave leaving the coast of Africa. The image was taken at 8am EDT 8/8/09.

African tropical wave may develop
A strong tropical wave with a moderate amount of spin is moving off the coast of Africa this morning. The wave is under about 10 - 20 knots of wind shear and has sea surface temperatures beneath it of 27°C. These conditions are probably too marginal to allow development over the next two days. As the wave moves westward away from Africa over the next few days, wind shear should slowly decrease and the SSTs will warm, potentially allowing for some slow development. The UKMET, GFS, and NOGAPS models all indicate the possibility that this will become a tropical depression 3 - 5 days from now. The ECMWF model forecasts that strong easterly winds over the wave will create too much shear to allow development. The wave is well south of the Saharan Air Layer, so dry air and African dust should not interfere over the next 3 - 5 days. I give the wave a medium (30 - 50% chance) of developing into a tropical depression in the next seven days.

I'll have an update on Sunday.

Jeff Masters

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

2501. Drakoen
Quoting mobilegirl81:
The models have done this to previous systems(Frances, Jean, Ivan);Driving them out to sea.


Dean, Ike. Bertha was suppose to recurve out to sea before even getting to 40W. It is simply too early to make that assumption.
Quoting CybrTeddy:
99L is becoming better organized by the minute. They might have to go with Red alert at 2 PM. Closed low, organized convection, persistence, model support. TD 2 is possible by 5 PM.

Someone do a TCFA survey.
Quoting mobilegirl81:
The models have done this to previous systems(Frances, Jean, Ivan);Driving them out to sea.


The models had Ivan going out to sea with that monster high to it's north?
Now I think 99L may become a code red at 2pm or 8pm and a Td by 5pm or 11pm.
Quoting WeatherStudent:
for the love of god, one can clearly see that some of those models are already begining to turn it northwest, incrediably surreal.
No, it is not surreal. Go to the NHC's model page for a description of the BAMs and LBAR.
Quoting sammywammybamy:


Rapid Intesification????

It Seems..


No. Just good organization.
G'morning all. I see one of our wave actually got a number. Nice to know it is still way out.
Quoting extreme236:
Special SAB classification indicates 99L very close to TD status:

09/1330 UTC 14.2N 21.8W T1.5/1.5 99L -- Atlantic


Models will continuously show this pattern of recurvature. Not going to happen.
Ike is a good example. It had a rather high latitude and didn't recurve. It ended up in the gulf in fact.
Quoting jasoniscoolman10:
here is the tropical wave..lots of t.stormon the top of this wave but no in the middle of the wave yet..its going to need some t/storm in the middle soon.


That's not where the COC is located
2512. Drakoen
2513. Dakster
At the 2 TWO

A. Gone
B. Yellow
C. Orange
D. Red
E. TD
F. Red Alert

Based on what you all are saying I'll go with D. Red...
Quoting jasoniscoolman10:
here is the tropical wave..lots of t.stormon the top of this wave but no in the middle of the wave yet..its going to need some t/storm in the middle soon.


You're way off again...
i know that it's always hot in the gulf at this time of year - some of the hottest waters on earth - i wasn't sure if it was any hotter than USUAL for this time of the year.
Red at 2pm 5pm and 11pm ... Td At 2 am Tommorow..
2517. Relix
Poll: D

I need to say... this is in a higher lat that the islands so they will probably be safe (reminder: too early, too early, too early!) but coast interests should keep an eye on it. I don't trust the models with their latest run.
Oh my gosh, could this be it?!Ana is waking up now.
2519. Drakoen
The GFS is the only model that recurves this out to sea for now.
Quoting sammywammybamy:


Rapid Intesification????

It Seems..


Rapid organization it seems.

Quoting sammywammybamy:
Red at 2pm 5pm and 11pm ... Td At 2 am Tommorow..


They dont issue advisories at 2am. 5 am/pm and 11 am/pm are the advisory times unless a special one is issued.
A. And B. are out of the Question

Ill go With Red.
Mellow out already everyone.... the models have it going into the middle of no where... take a few Valium or maybe a Rum, and wait and see.


Quoting sammywammybamy:
Red at 2pm 5pm and 11pm ... Td At 2 am Tommorow..


Those arent the times of the TWOs. Those are from 2007 lol.

2009:
8am
2pm
8pm
2am

We may have red by 2pm.
Extreme , Basicly i am Saying "Red" Today

Td Tonight or Tommorow ...

Being Conservative..
2527. cg2916
Quoting Dakster:
At the 2 TWO

A. Gone
B. Yellow
C. Orange
D. Red
E. TD
F. Red Alert

Based on what you all are saying I'll go with D. Red...

C.
Quoting mobilegirl81:
The models have done this to previous systems(Frances, Jean, Ivan);Driving them out to sea.
That is because weather conditions can change at the drop of a hat, for any reason. Tropical systems CAN be fickle and models aren't always perfect. The models are computers run and designed by humans, need any more be said. Individual runs ned to be taken with a grain, consistency is more what you want to see.
Good morning all....99L is kicking up some dirt I see. A tropical depression sometime later tonight or early tomorrow is certainly possible. In fact, I am positive by tomorrow no later than 2PM we will have a Tropical Depression or Tropical Storm on our hands...Unless suddenly conditions turn for the worse.
I'll wait and see what Storm says. Is he up yet?
Quoting extreme236:
Ike is a good example. It had a rather high latitude and didn't recurve. It ended up in the gulf in fact.


What accoured with ike was very rare,to this day iam still not sure how it made it across at that latitude.
I'd worry more about the shear ahead of this storm dosent look good in another 15 degrees west.
Quoting extreme236:


They dont issue advisories 2am. 5 am/pm and 11 am/pm are the advisory times unless a special one is issued.

It's 8am, 2pm, 8pm, 2am and intermediate times are 5am, 11am, 5pm, 11pm


looks closed to me.
Quoting Orcasystems:
Mellow out already everyone.... the models have it going into the middle of no where... take a few Valium or maybe a Rum, and wait and see.


Or a valium and rum and come back when you wake up :)
waiting on the Dr's new blog.
Quoting Drakoen:


Dean, Ike. Bertha was suppose to recurve out to sea before even getting to 40W. It is simply too early to make that assumption.


I agree with you Drak that it is way to early to even knnow where this will go....

But I have to say ussally if a storm forms close to 12n then it does have a chace to hit S FL and even cross into the Gulf of Mexico.... But after saying that it is way to early to even say what it will do.... We have about 10 days to watch it and then have a better handle on this 1....

Taco :0)
Central convection continues to fire

2539. cg2916
Quoting sammywammybamy:
Extreme , Basicly i am Saying "Red" Today

Td Tonight or Tommorow ...

Being Conservative..

That's being liberal.
Quoting weatherwatcher12:

It's 8am, 2pm, 8pm, 2am and intermediate times are 5am, 11am, 5pm, 11pm


You got it backwards son. :)
Well, it's possible they could say something for the Cape Verde islands if it sticks around there.

Like in '06:

I repeat: 2006. (So don't get too excited.)

ZCZC MIATCPAT4 ALL
TTAA00 KNHC DDHHMM
BULLETIN
TROPICAL DEPRESSION FOUR INTERMEDIATE ADVISORY NUMBER 1A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042006
800 PM AST MON AUG 21 2006

...TROPICAL DEPRESSION MOVING A LITTLE FASTER TOWARD THE WEST OVER
THE FAR EASTERN ATLANTIC OCEAN...

A TROPICAL STORM WARNING IS IN EFFECT FOR THE CAPE VERDE ISLANDS. A
TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED WITHIN THE WARNING AREA WITHIN THE NEXT 24 HOURS.


So, they may do if they deem it necessary. (Which would cause an earlier update.)
2542. Drakoen
The fact that this thing is developing just south of the cv islands worries me because alot of famous nameed formed here and were retired by what they did.
Quoting CybrTeddy:


You got it backwards son. :)

Lol, oops I was thinking about the TWO's
Didn't Ike form during a positive NAO?
Quoting CaneAddict:
Good morning all....99L is kicking up some dirt I see. A tropical depression sometime later tonight or early tomorrow is certainly possible. In fact, I am positive by tomorrow no later than 2PM we will have a Tropical Depression or Tropical Storm on our hands...Unless suddenly conditions turn for the worse.



Havent Seen You in a While

Loop of 99l:

Link


looks embryonic
Quoting Dakster:
At the 2 TWO

A. Gone
B. Yellow
C. Orange
D. Red
E. TD
F. Red Alert

Based on what you all are saying I'll go with D. Red...


D
Quoting weatherwatcher12:

It's 8am, 2pm, 8pm, 2am and intermediate times are 5am, 11am, 5pm, 11pm
The TWOs are 8, 2, 8, 2. Once it is formed, TD or better, updated are 5, 11, 5, 11. Intermediate updated would then be at 8, 2, 8, 2 ONLY if there are watchs or warnings posted.
Going to have to agree with Drakoen right now with regards to this system more than likely not recurving out to sea. According to most computer models and the TPC thinking, we should start to see a pretty expansive ridge building across the Atlantic with the Azores and Bermuda Highs bridging together over the next 24 to 48 hours. This would prevent such recurvature as the GFS has been showing. It seems to me the GFS does this with nearly every system that comes off Africa at a higher altitude than 12N. In addition, the current steering pattern would favor a more westerly to slightly north of westerly motion over the next 24-48 hours. All this makes me favor this system not recurving out to sea, but I could always be wrong. Just giving my input.
2553. Drakoen
I have the center's highest latitude near 13.5N
Will have an update sometime later...bbl all. Have a good one.
Reminding me of Bertha a bit. Large system.

Quoting Dakster:
At the 2 TWO

A. Gone
B. Yellow
C. Orange
D. Red
E. TD
F. Red Alert

Based on what you all are saying I'll go with D. Red...

C or D


img
src="http://www.webdesign.org/img_articles/7300/1pokeball.gif" alt="" />
New Blog
NEW BLOG!
NEW BLOG
2561. Dakster
Anyone else catch that if you have ATT for internet, we may be in for a rough time if problems occur. Workers are preparing to strike starting tonight.

Can you imagine, a storm forms and half of the blog, can't blog because they have no internet!

Looks like D's have it so far, but we shall see soon. 99L has the classic comma shape going.
2562. Drakoen
new blog
Before I go...I'm going to lean towards drakoen as far as recurving not happening. Over the next few days ridging of the dominate high out there will become quite stretched out and if im looking at models correctly there will be a bridging of the two highs..this would tend to not allow and recurvature. As much as we would love to see a fish storm...I don't think this season will see to much of those. BBL.
Bertha formed north of the CV islands. This one is south with a strong fluxuating bermuda high to its north and west.
2565. JRRP
really looks like TD


No shear to speak of.
Famous names developed where this one is and went on to become retired names because of what they did, not just the strength.
Quoting hunkerdown:
The TWOs are 8, 2, 8, 2. Once it is formed, TD or better, updated are 5, 11, 5, 11. Intermediate updated would then be at 8, 2, 8, 2 ONLY if there are watchs or warnings posted.
Finally,theres something to pay attention in the atlantic 2009 season.The only problem in that part of the world the system is forming,satellite photos come out every six hours and its difficult to view the changes...