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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hi guys seem that we have two systems on the two
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Tropical Update ont he Weathe Channel "We will monitor this wave" They Suck.
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Quoting cchsvweatherman:
Well, I've spent the last while conducting a more thorough analysis. My conclusions are as follows:

As Doctor Masters stated, the conditions for 99L favor development. However, this storm is likely to take a track rarely seen due to some unusual conditions in the Atlantic Ocean at this time.

The dark blue arrows on my graphic indicate the northerly Antarctic winds, which are violent winds sweeping across Antarctica at the present time. These winds will likely push 99L in a northerly direction. Coupled with the westerly flow from Africa, I believe this storm will head to the Northeastern coast of the United States, where it will combine with several Atlantic Waterspouts and a strong Northeasterly wind along the way to form a very powerful Nor'easter. All those with interests in this area should begin considering steps to prepare for this Nor'easter.

As the graphic indicates, the green winds of the ITCZ will likely not be powerful enough to counteract these Antarctic winds and nudge the storm back to Africa. El Nino's cross winds will almost certainly help to advance the Nor'easter condition, possibly resulting in one of the most powerful Nor'easters ever seen.

Again, as my graphic clearly indicates, and based on data obtained from my V1-ViperDvorak radar system, conditions are extremely favorable for 99L to be come a Nor'easter. All those on the northern Atlantic coast should begin preparations.



I thought this was the real cchs at first...then I realized there was no way cchs could be that crazy.
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Quoting Greyelf:


WS, you really should consider a name change to "Wheresitgonnago".


ROTFLMAO!
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Kman...you called it on the Barbados system!
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Until I see more of a pronounced system near the islands, I'm not concerned. All systems have yet to materialize this year, and I'm tired of jumping on the band wagon
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Well,I for one started making immediate preparations up here for the pending super Nor'easter headed our way,anyway here would be utterly reckless to not heed these warnings after seeing those detailed graphics
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Quoting BurnedAfterPosting:


Hanna d-min is during the evening hours just before sunset and d-max is during the hours just before sunrise


Thanks Burned. I need to have this embedded in my brain.
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Run the NASA GOES loop with a minimum of 11 frames. You can see a small low level circulation that goes under the eastern portion of the convection.
Member Since: October 28, 2006 Posts: 57 Comments: 30833
Quoting WeatherStudent:
guys, that's notw eatherman, that's a troll who stole his avatar.
Please dont start this early
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Quoting cchsvweatherman:
Well, I've spent the last while conducting a more thorough analysis. My conclusions are as follows:

As Doctor Masters stated, the conditions for 99L favor development. However, this storm is likely to take a track rarely seen due to some unusual conditions in the Atlantic Ocean at this time.

The dark
blue arrows on my graphic indicate the northerly Antarctic winds, which are violent winds sweeping across Antarctica at the present time. These winds will likely push 99L in a northerly direction. Coupled with the westerly flow from Africa, I believe this storm will head to the Northeastern coast of the United States, where it will combine with several Atlantic Waterspouts and a strong Northeasterly wind along the way to form a very powerful Nor'easter. All those with interests in this area should begin considering steps to prepare for this Nor'easter.

As the graphic indicates, the green winds of the ITCZ will likely not be powerful enough to counteract these Antarctic winds and nudge the storm back to Africa. El Nino's cross winds will almost certainly help to advance the Nor'easter condition, possibly resulting in one of the most powerful Nor'easters ever seen.

Again, as my graphic clearly indicates, and based on data obtained from my V1-ViperDvorak radar system, conditions are extremely favorable for 99L to be come a Nor'easter. All those on the northern Atlantic coast should begin preparations.



I have a pic on the fridge like this when my daughter was 2 !
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Quoting kmanislander:


Current steering would favour a track due W into Central America but that system is a very slow mover so we will have to see if if develops further before worrying about track.

There is a big high over the GOM now that would keep it due W but I have not looked at forecast steering 4 days out. Maybe someone else has that handy.


As long as the disturbance stays shallow... it should definitely have that W component to it... now if it gains depth then we could be looking at some N component to start materializing with this one, but that's only if its strengthens rapidly with all the high octane in the Carib.
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Quoting cchsvweatherman:
Well, I've spent the last while conducting a more thorough analysis. My conclusions are as follows:

As Doctor Masters stated, the conditions for 99L favor development. However, this storm is likely to take a track rarely seen due to some unusual conditions in the Atlantic Ocean at this time.

The dark blue arrows on my graphic indicate the northerly Antarctic winds, which are violent winds sweeping across Antarctica at the present time. These winds will likely push 99L in a northerly direction. Coupled with the westerly flow from Africa, I believe this storm will head to the Northeastern coast of the United States, where it will combine with several Atlantic Waterspouts and a strong Northeasterly wind along the way to form a very powerful Nor'easter. All those with interests in this area should begin considering steps to prepare for this Nor'easter.

As the graphic indicates, the green winds of the ITCZ will likely not be powerful enough to counteract these Antarctic winds and nudge the storm back to Africa. El Nino's cross winds will almost certainly help to advance the Nor'easter condition, possibly resulting in one of the most powerful Nor'easters ever seen.

Again, as my graphic clearly indicates, and based on data obtained from my V1-ViperDvorak radar system, conditions are extremely favorable for 99L to be come a Nor'easter. All those on the northern Atlantic coast should begin preparations.



Time to put down the alcohol and go to bed, your mind is playing tricks on you.
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Shear forecast in that area is not good. This could be a rapid developer as i have stated. Click the pic to get a 4 day loop.



look at these freaking SST's in the Central and Western Caribbean.....ouch.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
Everyone ignore the imposter cchsV
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Quoting kmanislander:


See my post #492


Seen & TY - will face this one first if/as it developes - am concerned that exisiting conditions in Caribbean are favourable for something to develope as system tracks further West
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Quoting WeatherStudent:
what got over him?
thx ignoring WS till he grows some chest hair
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Quoting cchsvweatherman:
Well, I've spent the last while conducting a more thorough analysis. My conclusions are as follows:


IMPOSTER!!!!

Your cchsVweatherman...
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Quoting WeatherStudent:


quick question, where would it go, kman??


WS, you really should consider a name change to "Wheresitgonnago".
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487. cchsvweatherman

Imposter back again.... c c h s v w...
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Quoting hurricanehanna:
**tapping microphone*** Is this thing on?


Hanna d-min is during the evening hours just before sunset and d-max is during the hours just before sunrise
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Quoting WeatherStudent:
guys, that's notw eatherman, that's a troll who stole his avatar.


It might actually be, cause last year his troll copy was talking about nor easters too
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Quoting kmanislander:


Current steering would favour a track due W into Central America but that system is a very slow mover so we will have to see if if develops further before worrying about track.

There is a big high over the GOM now that would keep it due W but I have not looked at forecast steering 4 days out. Maybe someone else has that handy.


Link
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Florida landfall this weekend?
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Quoting cchsvweatherman:
Well, I've spent the last while conducting a more thorough analysis. My conclusions are as follows:

As Doctor Masters stated, the conditions for 99L favor development. However, this storm is likely to take a track rarely seen due to some unusual conditions in the Atlantic Ocean at this time.

The dark blue arrows on my graphic indicate the northerly Antarctic winds, which are violent winds sweeping across Antarctica at the present time. These winds will likely push 99L in a northerly direction. Coupled with the westerly flow from Africa, I believe this storm will head to the Northeastern coast of the United States, where it will combine with several Atlantic Waterspouts and a strong Northeasterly wind along the way to form a very powerful Nor'easter. All those with interests in this area should begin considering steps to prepare for this Nor'easter.

As the graphic indicates, the green winds of the ITCZ will likely not be powerful enough to counteract these Antarctic winds and nudge the storm back to Africa. El Nino's cross winds will almost certainly help to advance the Nor'easter condition, possibly resulting in one of the most powerful Nor'easters ever seen.

Again, as my graphic clearly indicates, and based on data obtained from my V1-ViperDvorak radar system, conditions are extremely favorable for 99L to be come a Nor'easter. All those on the northern Atlantic coast should begin preparations.



LOL...LMAO
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Quoting extreme236:
487. I think Ive just been dumbfounded


Me too and that rarely happens
Member Since: October 28, 2006 Posts: 57 Comments: 30833
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Quoting cchsvweatherman:

you should be banned for that

that is a cchs imposter obviously trying to tarnish his image
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Quoting SSideBrac:

Any prognosis for direction etc with specific regard to Cayman Islands? I know it is early days but in my mind, this poses more of an "immediate" (in terms of proximity) potential threat to Caribbean than 99L - will not hold u to anything u may say LOL


See my post #492
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2008 Sept 2 Graphical Atlantic TWO








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Thanks Waha
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487. I think Ive just been dumbfounded
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Quoting DaytonaBeachWatcher:

really they were making me LMAO
people were being rude and the recipient was saying "Good evening sir." lol
i was rollin


As was I! LOL... It's all good. Young and the restless has taken a backseat lately.
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Quoting WeatherStudent:


congrats on hitting the nail int he coffin, big K, it never fails my friend. you certainly ahve got a very good eye when it comes to tropical meteorology. quick question, where would it go, kman??


Current steering would favour a track due W into Central America but that system is a very slow mover so we will have to see if if develops further before worrying about track.

There is a big high over the GOM now that would keep it due W but I have not looked at forecast steering 4 days out. Maybe someone else has that handy.
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490. 7544
good catch on tampa spins part nice call
Member Since: May 6, 2007 Posts: 0 Comments: 6874
**tapping microphone*** Is this thing on?
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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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