Little change to 90L; new African tropical wave is worth watching

By: Dr. Jeff Masters , 8:53 PM GMT on July 30, 2010

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Invest 90L is a tropical wave in the eastern Atlantic near 10N 33W with a very limited amount of heavy thunderstorm activity but a decent amount of spin. It does not have a well-defined surface circulation, and has shown little change in organization today. CIMMS wind-shear analyses show a low amount of wind shear (5 - 10 knots) over 90L, and sea surface temperatures are a record warm 29°C. The wave currently is in a moist environment and is not being affected by the dry Saharan Air Layer (SAL) to its northwest. The disturbance has moved far enough away from the Equator to leverage the Earth's spin to help it develop. The Saharan Air Layer with its dust and dry air lurks just to the north of 90L, but the SHIPS model predicts 90L will remain far enough from the dry air over the next five days so that it will not interfere with development.


Figure 1. Afternoon visible satellite image from 2pm EDT 7/30/10 of the relatively tiny 90L, and the large new tropical wave that moved off the coast of Africa yesterday.

Forecast for 90L
One factor inhibiting development of 90L this week will be the Madden-Julian Oscillation (MJO.) The MJO currently favors downward motion over the tropical Atlantic, which will act to decrease the chances of tropical storm formation. The Madden-Julian oscillation is a pattern of enhanced rainfall that travels along the Equator from west to east. The pattern has a wet phase with large-scale rising air and enhanced thunderstorm activity, followed by a dry phase with large-scale sinking air and suppressed thunderstorm activity. Each cycle lasts approximately 30 - 60 days. When the Madden-Julian oscillation is in its wet phase over a hurricane-prone region, the chances for tropical storm activity are greatly increased.

Perhaps the main factor interfering with 90L's development will be the presence of the large tropical wave to the east of 90L that moved off the coast of Africa yesterday. This new wave is large enough and close enough to 90L that it will probably begin to dominate regional weather patterns this weekend, stealing away 90L's inflow of low-level moist air. The new wave may also act to bring sinking air over 90L that will tend to suppress 90L's thunderstorm activity. It may turn out that the new wave will also steal some of 90L's spin, and end up being a threat to develop itself later on this weekend.

The latest 8am EDT (12Z) model runs for 90L show very little in the way of development of the storm. The predominant track forecast takes 90L into or just north of the northern Lesser Antilles Islands about 6 - 8 days from now. Looking at climatology based on research done by Dr. Bob Hart at Florida State University,, 90L has a 19% chance of developing into a tropical cyclone by 2pm Sunday. NHC is putting these odds at 20%. Dr. Hart also has an experimental product showing that historically, about 30% of all tropical cyclones that develop at 90L's current position eventually hit land as a hurricane. Of course, 90L is not yet a tropical cyclone, and I think that the large tropical wave off the coast of Africa will kill 90L this weekend.

Tropical wave in the eastern Caribbean
A tropical wave in the eastern Caribbean, south of the Dominican Republic, is moving west at 15 - 20 mph with no signs of development. The wave is under a high 20 knots of wind shear, due to strong upper-level westerly winds from an upper level low centered north of Puerto Rico. This shear is expected to remain remain high through Saturday. By Sunday, when the wave will be approaching Nicaragua, the wave will be far enough away from the upper level low that shear should fall to the moderate range, 10 - 20 knots. Some development is possible on Sunday, but the wave will have only about a 1-day window to develop before its westerly motion brings it inland over Nicaragua on Monday. NHC is giving this wave a 10% chance of developing into a tropical depression by 2pm Sunday.

Extreme cold records for 2010
In my post yesterday, I reported that fourteen countries had set their all-time hottest temperature record this year. I neglected to mention that one country has also set its coldest temperature in recorded history mark in 2010. Guinea had its coldest temperature in its history on January 9, 2010, when the mercury hit 1.4°C (34.5°F) at Mali-ville in the Labe region. Of the 229 countries with extreme coldest temperature records, 14 of these records have occurred in the past ten years (6% of all countries). There have been five times as many (74) extreme hottest temperature records in the past ten years (33% of all countries.) My source for extreme weather records is Chris Burt, author of Extreme Weather.

New study finds huge drop in the plants that form the base of the oceanic food chain
A study published this week in the journal Nature documents that microscopic marine phytoplankton, which form the basis of the marine food chain, have declined by 40% globally since 1950. Joe Romm at climateprogress.org discusses the implications, using this headline:

Scientists may have found the most devastating impact yet of human-caused global warming — a 40% decline in phytoplankton since 1950 linked to the rise in ocean sea surface temperatures. If confirmed, it may represent the single most important finding of the year in climate science.

I plan to discuss this paper next week.

Next update
I'll have an update this weekend, probably by 8pm EDT Saturday.

Jeff Masters

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This entire area looks just interesting to me.

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1190. KEEPEROFTHEGATE (Mod)
Quoting CybrTeddy:


Well then if August doesn't see a system, this season will probably be 7-8 storms. It would be only the 2nd season that I know of that the WPAC, Atlantic, and EPAC where all inactive.
we are having problems getting systems going i don't know what it is but there are issues that were unforseen by even the experts this coming week will be the first of the droppin numbers game iam sure
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Good morning Casters....
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Quoting Hhunter:
peak of hurricane season is aug and sept. oct can be active. the track race will start soon. you may be suprised yet still

It's gonna surprise a lot of us the heat is enormous I mean 100 degrees + in Florida I believe we may be tracking storms into Nov. and even a straggler or two in Dec.
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Quoting GTcooliebai:

Well if your telling me this yr. will have less storms than last yr. I think you and all the other forecasting agency are out of their mind and flawed because how can you go with a hyperactive season to a below normal one, it just doesn't make sense in this day in age?


I didn't say that. I said if August (which is unlikely to say the least) has no storms that this season will be 7-8 named. I highly doubt that will happen, as 2009 with high shear, lower SSTs, lower TCHP pulled out 4. We should be able to pull out 4, we'd be a 6 going into September
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Hi Storm Petrol, are you over your drought in the Caymans?
Member Since: July 11, 2006 Posts: 14 Comments: 11384
Ok folks, I have to go change the brakes on the "Boss'" car. I don't know why she needs them, she should just drive a little slower. Storm, I will read your updates upon my return. And of course, I look forward to them. Hope all have a good morning.
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Bouy in Caribbean (15.054 N 67.472 W)

3hrs ago

Wind Direction (WDIR): ENE ( 70 deg true )
Wind Speed (WSPD): 13.6 kts
Wind Gust (GST): 17.5 kts
Wave Height (WVHT): 5.2 ft
Dominant Wave Period (DPD): 7 sec
Average Period (APD): 4.7 sec
Atmospheric Pressure (PRES): 29.81 in
Pressure Tendency (PTDY): -0.02 in ( Falling )

Now
Wind Direction (WDIR): ESE ( 110 deg true )
Wind Speed (WSPD): 15.5 kts
Wind Gust (GST): 19.4 kts
Wave Height (WVHT): 5.6 ft
Dominant Wave Period (DPD): 7 sec
Average Period (APD): 5.1 sec
Atmospheric Pressure (PRES): 29.85 in
Pressure Tendency (PTDY): 0.03 in ( Rising )

Bouy

Winds were up to 25kts at a point when closer to the wave. Winds have shifted from ene to ese as the wave passed below.
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Quoting CybrTeddy:


Well then if August doesn't see a system, this season will probably be 7-8 storms. It would be only the 2nd season that I know of that the WPAC, Atlantic, and EPAC where all inactive.

Well if your telling me this yr. will have less storms than last yr. I think you and all the other forecasting agency are out of their mind and flawed because how can you go with a hyperactive season to a below normal one, it just doesn't make sense in this day in age?
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Quoting CybrTeddy:
Huh, I didn't notice they upped the odds on the Caribbean AOI to 20%. No convection whatsoever with it.
I think it has a definitive circulation though, thats probably why I was wondering about that myself, good morning to everyone btw.
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1180. aquak9
g'morning WU-Bloggers worldwide!

Keeper, gambler, ike, Seenya-Cheef and everyone.

SaintHurrifan now that was funny. That was a good laugh. I needed that cause otherwise things was lookin' mighty scary!
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do all these stats about ACE really matter the season will wake up when it feels like waking up 2nd week in August right up to the end of the season there should be plenty of storms to track. + it's a La Nina yr. and when was the last time we saw normal to below normal activity in a La Nina yr.
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Quoting KEEPEROFTHEGATE:
no not yet but come the end of august and we are still waitin well its not rocket science


Well then if August doesn't see a system, this season will probably be 7-8 storms. It would be only the 2nd season that I know of that the WPAC, Atlantic, and EPAC where all inactive.
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Hi StormW. Funny the arguments people have on here, isn't it. As if this were a movie and everything should start happening as you sit in your seat in front of the computer.
Member Since: July 11, 2006 Posts: 14 Comments: 11384
1175. KEEPEROFTHEGATE (Mod)
Quoting msgambler:
Morning Keeper....So your saying the season is a bust....hehehe
no not yet but come the end of august and we are still waitin well its not rocket science
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Sorry, it was a "low pressure center" not a "center of circulation."
Member Since: July 11, 2006 Posts: 14 Comments: 11384
Quoting StormW:
Good morning all; IKE, KOTG, Chicklit...


Morning Chief, looking forward to your input.
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1172. Hhunter
Quoting KoritheMan:


Therein lies the problem. We still don't fully understand the weather yet. And until we do, preseason forecasts are useless.

As far as the season being a bust goes, I'm not in that crowd at all. I didn't mean to make it seem like I was. I still fully anticipate an active season, probably something along the lines of 1998 or 1999, number wise.
peak of hurricane season is aug and sept. oct can be active. the track race will start soon. you may be suprised yet still
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NHC has not taken the floater off 90L.


They say this about the eastern Atlantic in the 8 a.m. Discussion:
...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 16N19W 11N21W 6N22W MOVING WESTWARD 10 TO 15 KT. SCATTERED STRONG SHOWERS AND THUNDERSTORMS ARE FROM 5N TO 7N BETWEEN 22W AND 24W...AND FROM 9N TO 12N BETWEEN 22W AND 30W.

THE 1010 MB LOW PRESSURE CENTER THAT WAS NEAR 10N34W SIX HOURS AGO HAS DISSIPATED. A SURFACE TROUGH REMAINS ALONG 34W/35W FROM 7N TO 13N. ANY OF THE PRECIPITATION THAT JUST IS RELATED TO THIS TROPICAL WAVE UNDOUBTEDLY IS MIXED WITH THE ITCZ SCATTERED STRONG SHOWERS AND THUNDERSTORMS THAT ARE FROM 2N TO 10N BETWEEN
32W AND 43W.

Member Since: July 11, 2006 Posts: 14 Comments: 11384
Quoting KEEPEROFTHEGATE:
so far the 2010 Hurricane Season is below normal on ACE points by 447 points we need 569 points just to achieved a normal season so far we have 122 points


Mostly do the very inactive WPAC typhoon season. Atlantic is about average where we are suppose to be coming into August with 2 named storms.
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Good morning Ike.I postd this twice yesterday with no response, albiet it was during romper room hrs lol.i think they were to young to know who Paul Bryant was. But Coach Bryant would say potential means you have not done it yet or maybe you never will.That pretty much sums up the 2010 hurricane season so far.I can see it now if it does not radically change "storm w when is the season going to pick up its nov 29 and we have only had x amount of storms.Well the mjo is picking up look tomorrow is nov 30 we still got plenty of time look at the mass of convection over alaska moving south."miami 009 hey levi these downcasters really get me what are they looking at?Not sure 09 they can't see the model run on Christmas day for a blizzard hitting Miami.Now Ike this was meant to be a little funny hope thier good sports and dont take it seriously.But to a lot of the older and wiser people thats how comical they sound sometimes.And thats Coach Paul Bear Bryant lol .Ike have a great day.
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Quoting KEEPEROFTHEGATE:
so far the 2010 Hurricane Season is below normal on ACE points by 447 points we need 569 points just to achieved a normal season so far we have 122 points
Morning Keeper....So your saying the season is a bust....hehehe
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Models are having a tough time that area out in the EATL because there is no real defined COC. Only the CMC developed Bonnie.
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1166. KEEPEROFTHEGATE (Mod)
morning storm
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1163. KEEPEROFTHEGATE (Mod)
so far the 2010 Hurricane Season is below normal on ACE points by 447 points we need 569 points just to achieved a normal season so far we have 122 points
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Quoting Chicklit:
The models run when there is a center of circulation and invest named. This is the earliest time in the life of a tropical storm. The models extrapolate data and make projections.
Because a COC from which they initialize dissipates does not mean they're "wrong." At the earliest stages it is always speculation, a "What If" scenario.


Agreed. However, many people put trust into these models way too early. Invests are areas that could develop. Everyone thinks that it will develop when models are in consensus, which is totally reasonable. However, it's just an area of interest.
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Morning Storm
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1160. KEEPEROFTHEGATE (Mod)
2010 Tropical Cyclone Activity
Updated Jul 27 , 2010

BASIN CURRENT YEAR TO DATE
Northern Hemisphere 82
Western Pacific 14
Southern Hemisphere 196 [2009-2010]



BASIN NORMAL YEARLY ACE** NORMAL YEAR TO DATE
Northern Hemisphere 569 122
Western North Pacific 310 70
Southern Hemisphere 204 --
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The models run when there is a center of circulation and invest named. This is the earliest time in the life of a tropical storm. The models extrapolate data and make projections.
Because a COC from which they initialize models dissipates does not mean they're "wrong."
At the earliest stages it is always speculation, a "What If" scenario.
It's the nature of the game.
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1157. DESteve
Quoting StormW:


Yeah.


LOL I knew you were over there somewhere good morning !!!
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Quoting CybrTeddy:


I like seeing fish storms, out to sea and not hurting nobody. Storms like Bill, Fred, ect. That way we can observe a Hurricane's beauty on satellite without having to worry about who's under it.


As much as I agree, there are hidden aspects to fish storms.

1. They do cause swells that are felt on beaches thousands of miles away. I've heard of plenty of times where fish storms have taken lives due to rip currents and swells. However, if people don't abide by the warnings, it's their fault.

2. There are ships, mainly cargo, etc. that are out on the water where these storms are running by and easily enough a ship can capsize and take life.

I'm not downcasting, but fish storms, as well as the storms that impact land can both be dangerous in their own ways.
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1154. KEEPEROFTHEGATE (Mod)


2010 Northern Hemisphere Tropical Cyclones
Maximum Wind Speed & ACE per storm (ATCF operational intensity estimates)

North Atlantic
Alex (85 ACE = 7.3725)
TD02 (30 ACE = 0.0)
Bonnie (whirl) (35 ACE = 0.49)
Western North Pacific
01W (30 ACE = 0.0)
Omais (50 ACE = 2.0075)
Conson (75 ACE = 8.3225)
Chanthu (75 ACE = 3.5775)
Northern Indian Ocean & Arabian Sea
Laila (65 ACE = 4.46)
Bandu (55 ACE = 2.39)
Phet (125 ACE = 14.16)
Eastern Pacific
Agatha (40 ACE = 0.2825)
Blas (55 ACE = 2.715)
Celia (140 ACE = 25.4875 )
Darby (105 ACE = 10.3925)




--------------------------------------------------------------------------------

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As for the models, there are no models designed specifically for tropical cyclogenesis. The hurricane specific models were designed for cyclones (TD and up). That is not to say they can't be used on invest areas, but one needs to understand the limitations of the models. NHC for the past few years has been requesting other versions of the GFDL and HWRF to test for cyclogenesis (removal of the spun up or bogus vortex), but it appears their requests have fallen on deaf ears. Cyclogenesis and intensity are the least understood areas of tropical cyclone research and are now getting more of the attention in research, as shown by the millions that will be spent this summer on the PREDICT program.
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Quoting TankHead93:
One can clearly see the effect of the battle between now ex-90L and the newer wave behind it. The 850mb vorticity of ex-90L is now being transferred over to the new wave, the new wave is winning the battle and will take over, over the next couple of days. Click on the link and follow what I stated by clicking on past vorticity maps. (left hand side of link page) Link
What are some thoughts on this?
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90L will like Bonnie and Schwarzenegger will be back in about 3 days....

Sometimes Trolls take pics of other people and post them in fake profiles..

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1149. KEEPEROFTHEGATE (Mod)
TODAY is the last day of july in 15 days if things don't pick up a major adjustment of seasonel numbers will have to be done at the moment it looks like a downward turn is likly


good morning wunder bloggers
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Quoting DESteve:
Not like we dont go thru this same discussion every year.. just wait.. things are changing.. and as StormW has indicated looky at the MJO and how that is coming around.. just wondering what kind of pattern we will have 1 week on 1 week off, 2 weeks on 2 weeks off.., or 12 weeks on 1 off.. (LOL)


yup, 2009 had a explosion of activity and that was a 9 named season. figures that if 2009 can pull of 4 in august why cant 2010?
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Quoting SQUAWK:


Ike is not a "downcaster." He is an optimist. He is usually hoping for good weather and a good outcome. Unlike the ones that wish for a disaster. Those are the ones I would classify as "downcasters."


I like seeing fish storms, out to sea and not hurting nobody. Storms like Bill, Fred, ect. That way we can observe a Hurricane's beauty on satellite without having to worry about who's under it.
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1146. DESteve
Not like we dont go thru this same discussion every year.. just wait.. things are changing.. and as StormW has indicated looky at the MJO and how that is coming around.. just wondering what kind of pattern we will have 1 week on 1 week off, 2 weeks on 2 weeks off.., or 12 weeks on 1 off.. (LOL)
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but anyway whats next oh yes right behind ex-90L yes I see pre-91L doing great
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Good morning
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1143. KEEPEROFTHEGATE (Mod)

NMFC Norfolk Tropical Feed
No Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico
By Maritime.CDO@navy.mil (NMFC CDO) from Naval Maritime Forecast Center Norfolk Virginia. Published on .

As of Sat 31 Jul 2010 12:15:01Z

2010 Storms
All Active Year


Atlantic
NONE
East Pacific
97E.INVEST
Central Pacific
92C.INVEST
West Pacific
94W.INVEST
95W.INVEST
Indian Ocean
NONE
Southern Hemisphere
NONE
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1142. SQUAWK
Quoting reedzone:


Not saying you're a downcaster, but you do tend to post more when storms are dying.. Though this has been de-actvated, and it deserved to be because the circulation ripped apart do to the interaction of the one wave leaving and the other joining in. 91 should be coming soon with this mess and I still think we have potential for some development down the road.. yeah I know.. call me a wishcaster :P I just don't see how nothing can evolve out of this when it gets to "the area".


Ike is not a "downcaster." He is an optimist. He is usually hoping for good weather and a good outcome. Unlike the ones that wish for a disaster. Those are the ones I would classify as "downcasters."
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1141. IKE
Quoting clwstmchasr:
Doesn't it seem like since about mid-June we keep thinking that in about 10-14 days things are going to really explode? I was convinced that we were going to have an early July Cape Verde storm. Now here were are one day from Aug 1st and the feeling is that we're a week to 10 days away from the tropics exploding.


You're exactly correct.

My motto the rest of 2010...I'll believe it when I see it.
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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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