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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891. earthlydragonfly
4:19 AM GMT on July 31, 2010
Quoting JFLORIDA:
Usually the people who don't want to allow talk of GW or climate are those that really don't want reasonable discussion of climate to occur.

They want to maintain it as a political topic outside scientific discourse. Its always a conspiracy or someone else being "political" in an attempt to suppress reasonable discussion.


Ill step in here... (probably should shut up but )

I think everyone here cares about the subject! It is very important... However, we are in the start of hurricane season and right now that is what most want to talk about. But the GW discussions and debates almost have no chance of conclusion in this format. So the ongoing conversations (pointless to many because it is a forgone conclusion that it will not be resolved on this blog) are choking the ability for what most come here for this time of year, Hurricanes, tropical storms and chasing Blobs across the Tropics..... You want to have a great debate on this blog... wait till December. JMHO.
Member Since: July 1, 2005 Posts: 10 Comments: 1683
888. msgambler
4:18 AM GMT on July 31, 2010
Earthly, when does school start down in South FL
Member Since: February 27, 2010 Posts: 0 Comments: 1125
887. xcool
4:18 AM GMT on July 31, 2010
EricSFL



http://cimss.ssec.wisc.edu/tropic2/predict/overshooting_tops/


go here


lol
Member Since: September 26, 2009 Posts: 2 Comments: 15684
886. xcool
4:17 AM GMT on July 31, 2010
i see 24hr ban
Member Since: September 26, 2009 Posts: 2 Comments: 15684
885. EricSFL
4:17 AM GMT on July 31, 2010
How could "hot" towers be the term used for coldest cloudtops? lol
Member Since: May 26, 2010 Posts: 0 Comments: 804
884. floridaT
4:17 AM GMT on July 31, 2010
Quoting JFLORIDA:
So far there are five anti climate talk posts, just on this page and not one actually discussing climate. And really few discussing tropical weather.

The numbers dont lie.

I haven't seen this type of public suppression in a few years.
ya cant blame them they only watch fox news fair and ballenced is good enough for them if rush and glen say its a plot they believe it
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882. xcool
4:15 AM GMT on July 31, 2010



hot tower blue
Member Since: September 26, 2009 Posts: 2 Comments: 15684
881. ssmate
4:15 AM GMT on July 31, 2010
Quoting JFLORIDA:
Usually the people who don't want to allow talk of GW or climate are those that really don't want reasonable discussion of climate to occur.

They want to maintain it as a political topic outside scientific discourse. Its always a conspiracy or someone else being "political" in an attempt to suppress reasonable discussion.
and sometimes people get bored with it when it's discuseed ad nauseum day after day.
Member Since: July 17, 2008 Posts: 0 Comments: 347
880. floridaT
4:15 AM GMT on July 31, 2010
so just north of sabastion inlet?
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876. Bordonaro
4:13 AM GMT on July 31, 2010
Quoting earthlydragonfly:


it was a joke meaning its seem to be every night as of late

No problem, tonight was a weird night :o)!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
875. Bordonaro
4:12 AM GMT on July 31, 2010
Quoting btwntx08:

2010 the yr of trolls

Sad, but true, I already have about 11 folks on my ignore list!! And it's on July 29TH!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
874. earthlydragonfly
4:12 AM GMT on July 31, 2010
Quoting Bordonaro:

Page through about 150 blog entries! We had all sorts of insanity. Maybe someone needs to spike the blog with lithium, a mood stabilizer!!


it was a joke meaning its seem to be every night as of late
Member Since: July 1, 2005 Posts: 10 Comments: 1683
873. xcool
4:12 AM GMT on July 31, 2010
NOT GW TALK
Member Since: September 26, 2009 Posts: 2 Comments: 15684
872. floridaT
4:11 AM GMT on July 31, 2010
dewey what part of fl ya from?
Member Since: September 2, 2007 Posts: 0 Comments: 1093
870. msgambler
4:11 AM GMT on July 31, 2010
Quoting earthlydragonfly:


did somebody hear something???
Am I gonna have to put you in that same category as Orca?
Member Since: February 27, 2010 Posts: 0 Comments: 1125
868. Bordonaro
4:10 AM GMT on July 31, 2010
Quoting earthlydragonfly:


tonight???

Page through about 150 blog entries! We had all sorts of insanity. Maybe someone needs to spike the blog with lithium, a mood stabilizer!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
867. EricSFL
4:10 AM GMT on July 31, 2010
Quoting FLdewey:
Just watching Austin Powers... It's a MAN baby.


"Oh behave..."
Member Since: May 26, 2010 Posts: 0 Comments: 804
866. earthlydragonfly
4:10 AM GMT on July 31, 2010
Quoting msgambler:
See earthly is the one that is minus-ing me


did somebody hear something???
Member Since: July 1, 2005 Posts: 10 Comments: 1683
864. Bordonaro
4:09 AM GMT on July 31, 2010
Quoting TropicalAnalystwx13:


Its midnight madness I tell ya!

Who spiked the "Kool-Aide" tonight??? We're talking insanity on here tonight! Is it a new phase of the Moon???
Member Since: August 25, 2009 Posts: 20 Comments: 6785
863. msgambler
4:08 AM GMT on July 31, 2010
See earthly is the one that is minus-ing me
Member Since: February 27, 2010 Posts: 0 Comments: 1125
862. earthlydragonfly
4:08 AM GMT on July 31, 2010
Quoting Bordonaro:

Good evening or good morning :o). I believe this blog has officially gone off the "deep end" tonight!!


tonight???
Member Since: July 1, 2005 Posts: 10 Comments: 1683
861. msgambler
4:07 AM GMT on July 31, 2010
Quoting earthlydragonfly:


Minus (click)
LOL
Member Since: February 27, 2010 Posts: 0 Comments: 1125
860. xcool
4:07 AM GMT on July 31, 2010
floridaT LOL
Member Since: September 26, 2009 Posts: 2 Comments: 15684
859. TropicalAnalystwx13
4:06 AM GMT on July 31, 2010
Quoting Bordonaro:

Good evening or good morning :o). I believe this blog has officially gone off the "deep end" tonight!!


Its midnight madness I tell ya!
Member Since: July 6, 2010 Posts: 113 Comments: 32870
856. earthlydragonfly
4:06 AM GMT on July 31, 2010
Quoting KEEPEROFTHEGATE:
90L IS GOING ON TO 91L


tropical romance??
Member Since: July 1, 2005 Posts: 10 Comments: 1683
855. xcool
4:05 AM GMT on July 31, 2010



UPDATE


Member Since: September 26, 2009 Posts: 2 Comments: 15684
854. Bordonaro
4:05 AM GMT on July 31, 2010
Quoting earthlydragonfly:


evening

Good evening or good morning :o). I believe this blog has officially gone off the "deep end" tonight!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
853. floridaT
4:05 AM GMT on July 31, 2010
accually ms gambler i dont think so at all. ive heard some good comments and ive checked my filters only one on ignore and ya all aint him
Member Since: September 2, 2007 Posts: 0 Comments: 1093
852. earthlydragonfly
4:05 AM GMT on July 31, 2010
Quoting msgambler:
I try not to. That's one ugly mug to look at....LOL


Minus (click)
Member Since: July 1, 2005 Posts: 10 Comments: 1683
851. 954FtLCane
4:05 AM GMT on July 31, 2010
Quoting hunkerdown:

omg its drunk hour...any one watchin big brother?
Member Since: September 30, 2008 Posts: 0 Comments: 108
The Blog has a deadly case of Midnight Madness!!!!!!!!!!
Member Since: July 6, 2010 Posts: 113 Comments: 32870
Quoting deautschlandfutbol:
How's it peeps? Look like we got us a tropical soup out in the waters. How's errrybody tonight?


evening
Member Since: July 1, 2005 Posts: 10 Comments: 1683
Quoting earthlydragonfly:


can u see me?????? peeka booooo i see you
I try not to. That's one ugly mug to look at....LOL

At least when you look at me ya have a King to look at...LOL
Member Since: February 27, 2010 Posts: 0 Comments: 1125
90L IS GOING ON TO 91L
Member Since: Posts: Comments:
846. xcool



bye 90L.NEXT 91L
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting msgambler:
I am hidden cause everyone thinks I am a troll I guess and they are ignoring me.


can u see me?????? peeka booooo i see you
Member Since: July 1, 2005 Posts: 10 Comments: 1683
its midnight time to call it a night later wunder bloggers
Member Since: Posts: Comments:
How's it peeps? Look like we got us a tropical soup out in the waters. How's errrybody tonight?
Member Since: Posts: Comments:
842. xcool
ha
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting KEEPEROFTHEGATE:
no thats because some people minuses everyones posts
I know Keeper, I was venting....LOL
Member Since: February 27, 2010 Posts: 0 Comments: 1125

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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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