An African wave worth watching; 2nd warmest June on record

By: Dr. Jeff Masters , 1:51 PM GMT on July 17, 2009

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There's finally a African tropical wave worth mentioning, in what has been a very inactive June/July period for African waves with a potential to develop. A tropical wave near 12N 36W, about 1200 miles west of the coast of Africa, is triggering some modest heavy thunderstorm activity over the open ocean as the storm moves west at 10 - 15 mph. NHC designated this wave 97 L at noon today. Wind shear is a modest 15 knots over the disturbance, which is low enough to allow some slow development over the next few days. As long as the disturbance stays south of Puerto Rico's latitude (18°N), wind shear should remain low enough to allow development. However, there is a substantial amount of African dust and dry air surrounding the system on its west and north sides. This dry air will retard development, and may be able to completely disrupt the disturbance at some point over the next 3 - 4 days. None of the computer models develop the disturbance. The National Hurricane Center is giving this system a low (less than 30% chance) of developing into a tropical depression in the next 48 hours.


Figure 1. The first African wave of 2009 worth watching.

Second warmest June on record
The globe recorded its second warmest June on record, 0.02°C short of the record set in 2005, according to the National Climatic Data Center. The period January - June was the fifth warmest such period on record. Global temperature records go back to 1880. The most notable warmer-than-average temperatures were recorded across parts of Africa and most of Eurasia, where temperatures were 3°C (5°F) or more above average. The global ocean Sea Surface Temperature (SST) for June 2009 was the warmest on record, 0.59°C (1.06°F) above the 20th century average. This broke the previous June record set in 2005. The record June SSTs were due in part to the development of El Niño conditions in the Eastern Pacific. If El Niño conditions continue to strengthen during the coming months, we will probably set one or more global warmest-month-on-record marks later this year. The last time Earth experienced a second warmest month on record was in October 2008.


Figure 1. Departure of temperature from average for June 2009. Image credit: National Climatic Data Center.

June sea ice extent in the Arctic 4th lowest on record
June 2009 Northern Hemisphere sea ice extent was the 4th lowest since 1979, according to the National Snow and Ice Data Center. The record June low was set in 2006. This summer's melt is lagging behind the melting in the summer of 2007, which set the record for the lowest amount of summer sea ice in the Arctic. Forecasts of summer Arctic sea ice melt made in early June by two teams of German scientists put the odds of a new record sea ice minimum this year between 7% and 28%. With the amount of sunlight in the Arctic now on the wane, it appears unlikely that we will set a new record sea ice minimum in 2009. This year will probably have the 2nd or 3rd least sea ice extent on record come September, when the melting season ends. The ice-free seas that nearly surround Greenland now have contributed to temperatures of 2 - 3°C above average over the island over the past ten days. With clear skies and above-average temperatures likely over most of the island for at least the next week, we can expect near-record July melting over portions of the Greenland Ice Sheet this month.

Northwest Passage likely to open for the third consecutive year
The fabled Northwest Passage is more than half clear now, and has a good chance of melting free for the third consecutive year--and third time in recorded history. The first recorded attempt to find and sail the Northwest Passage was in 1497, and ended in failure. The thick ice choking the waterways thwarted all attempts at passage for the next four centuries. Finally, in 1905, Roald Amundsen completed the first successful navigation of the Northwest Passage. It took his ship two-and-a-half years to navigate through narrow passages of open water, and his ship spent two cold, dark winters locked in the ice during the feat.

We can be sure the Northwest Passage was never open from 1900 on, as we have detailed ice edge records from ships (Walsh and Chapman, 2001). It is very unlikely the Passage was open between 1497 and 1900, since this spanned a cold period in the northern latitudes known as "The Little Ice Age". Ships periodically attempted the Passage and were foiled during this time. The Northwest passage may have been open at some period during the Medieval Warm Period, between 1000 and 1300 AD.


Figure 3. Ice extent as measured by an AMSR-E microwave satellite sensor on July 15, 2009. Most of the famed Northwest Passage (red lines) has melted out. Image credit: University of Bremen.

References
Walsh, J.E and W.L.Chapman, 2001, "Twentieth-century sea ice variations from observational data", Annals of Glaciology, 33, Number 1, January 2001 , pp. 444-448.

I'll have an update on the African tropical wave at least once this weekend if the system doesn't fall apart.

Jeff Masters

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Quoting Drakoen:
You are SO funny Patrap how DO you do it!?!?!?!?


It's called beer.
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Quoting Patrap:
So this is 96L ..?



Have to wait a few days to see if anything significant detaches from front I suppose..
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You are SO funny Patrap how DO you do it!?!?!?!?
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'RIP' calls shortly ;-)
Its just a cycle folks.
Pat I think I need a song for that.
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Don't know any schoolmarms here in new england.
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So this is 96L ..?

"snicker,grin,..snark"

Member Since: July 3, 2005 Posts: 426 Comments: 128667
Quoting IKE:
It looks about 10 times better then the wave that is around 55W looked when it was at 35-40W.



That is true, and lets not forget then 97L was the FIRST wave that looked promising when it came off the African Coastline 2-3 days ago.
Member Since: July 1, 2008 Posts: 13 Comments: 7396
Quoting Drakoen:
97L infiltrating some dry air easily seen on rainbow imagery.


yep
got some good rotation goin though
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Dis here be da Golf of Mexico's Eyes R Looped ,cher

Member Since: July 3, 2005 Posts: 426 Comments: 128667
Quoting StSimonsIslandGAGuy:
Is this a weather blog or a New England schoolmarm grammar blog?


Yes.
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805. StSimonsIslandGAGuy 1:25 PM PDT on July 17, 2009
Is this a weather blog or a New England schoolmarm grammar blog?


oh, snap!

;)
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Taz...on your contest, am I the only one who voted for California? Thank you.
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On a different note, and prior to "Ralph", the talk earlier this week was about the cold front moving down across the northern gulf and the possibility of some pretty heavy rain (and maybe a frontal remnant left over in the Northern Gulf to fester) or the dreaded "Gulf Low" that some of the models were forecasting....Looks like the front is going to stall over the Northern Gulf area tommorow and the models have backed off of the "Gulf Low".....Here is the 3:00 PM from Tallahassee NWS:

SHORT TERM...TONIGHT THROUGH MONDAY...
THIS EVENING..EXPECT CONVECTION TO CONTINUE PAST SUNSET AS SQUALL/OUTFLOW/SEA BREEZE CELL MERGERS. SOME STRONG WILL BE STRONG
WITH GUSTY WINDS...AND WOULD NOT BE SURPRISED TO SEE AN ISOLD SEVERE
STORM. WILL GO WITH 40-50 PCT NW-SE POP GRADIENT.

TONIGHT... THE FRONT WILL APPROACH OUR NRN ZONES. OVERNIGHT THERE REMAINS POTENTIAL FOR ANOTHER MCS TO DEVELOP UPSTREAM IN THE
MID-SOUTH AS THE SYNOPTIC SCALE TROUGH OVER THE EAST COAST INTENSIFIES. WILL GO WITH 20-40 PCT N-SE POP GRADIENT.

SATURDAY...BY AFTERNOON FRONT CREEPS INTO OUR NWRN ZONES. A DECENT POP GRADIENT IS FORECAST WITH 20 NW TO 70 PCT SE. THE FRONT SHOULD
CONTINUE TO MAKE SLOW SEWD PROGRESS DURING THE OVERNIGHT HOURS. THIS WILL ALLOW TEMPS TO DROP INTO THE MID 60S ACROSS THE NRN ZONES BY
SUN MORNING.

SUNDAY...THE FORECAST IS A BIT UNCERTAIN SIMPLY BECAUSE OF THE UNCERTAINTY INVOLVED WITH HOW FAR TO THE SE THE FRONT WILL
ULTIMATELY GET. BELIEVE IT WILL BECOME QSTNRY ACROSS FL ZONES. IT LOOKS AS IF DEW POINTS WILL DROP INTO THE UPPER 50S IN AFTERNOON
ACROSS OUR NWRN ZONES WITH LOWER TO MID 60S EVEN INTO NW FL. A RARE BREAK FROM THE HUMIDITY OF SUMMER TO BE SURE. ALSO MODELS BEGIN TO DIVERGE THIS DAY. GFS WITH STRONG SURFACE WAVE DEVELOPING ALONG STALLED FRONT BY EVE WHICH THEN RIDES EWD ALONG WAVE WITH
DEVELOPMENT OF POSSIBLE CONVECTIVE FEEDBACK PROBLEMS...ECMWF WITH WEAKER LOW AND NAM WITHOUT LOW. THIS REFLECTED IN NOTICEABLY HIGHER POPS THAN IN NAM. WILL GO WITH 0-40 PCT NW-SE POP GRADIENT.

Looks like some rain through Sunday but it might be worth looking at in a few days if there is any signifcant remnant lying around..


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97L is Tropical Wave Ralph,correct?


Atlantic Ocean View (Updated ~3 hours)
Member Since: July 3, 2005 Posts: 426 Comments: 128667
97L infiltrating some dry air easily seen on rainbow imagery.
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Quoting GeoffreyWPB:
Man...what a storm going on here in Lake Worth, Fl.!


Yea!
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Man...what a storm going on here in Lake Worth, Fl.!
Member Since: September 10, 2007 Posts: 0 Comments: 11275
LRO Sees Apollo Landing Sites
07.17.09


NASA's Lunar Reconnaissance Orbiter, or LRO, has returned its first imagery of the Apollo moon landing sites. The pictures show the Apollo missions' lunar module descent stages sitting on the moon's surface, as long shadows from a low sun angle make the modules' locations evident.

The Lunar Reconnaissance Orbiter Camera, or LROC, was able to image five of the six Apollo sites, with the remaining Apollo 12 site expected to be photographed in the coming weeks.

The satellite reached lunar orbit June 23 and captured the Apollo sites between July 11 and 15. Though it had been expected that LRO would be able to resolve the remnants of the Apollo mission, these first images came before the spacecraft reached its final mapping orbit. Future LROC images from these sites will have two to three times greater resolution.
Member Since: July 3, 2005 Posts: 426 Comments: 128667
799. IKE
It looks about 10 times better then the wave that is around 55W looked when it was at 35-40W.

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Quoting CaneWarning:


You should "apologies" for that. Sorry couldn't resist. :)


I guess a grammar and syntax class wouldn't hurt either.
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Quoting Drakoen:


Maybe a lesson on how to spell and type would be in order first.




now that was funny
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Quoting Drakoen:


Maybe a lesson on how to spell and type would be in order first.


You should "apologies" for that. Sorry couldn't resist. :)
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Quoting WeatherStudent:


i'm sorry, i didn't know. i apologies. would anyoen else liek to take a stab at my questiont then?


Maybe a lesson on how to spell and type would be in order first.
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Quoting WeatherStudent:


i'm sorry, i didn't know. i apologies. would anyoen else liek to take a stab at my questiont then?


The answer is yes.
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guys whats see what 97L dos 1st
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After analyzing Invest 97L, it does seem to have some good low-level structure coming together with clear cyclonic circulation and inflow becoming established from the south and east. In watching water vapor imagery, the disturbance could be drawing in some dry air from the north and west, which combined with diurnal minimum, has lead to a marked decrease in convection. Like many others have stated, it will be very interesting to see what happens during diurnal maximum.

But I do want to say that given the fact that we still don't have a true system out there, its really hard to determine its future. So, for right now, I'm just going to sit back and watch this disturbance.
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Quoting cg2916:
Someone please tell me what DMIN and DMAX are, without using those big giant words, please.


It's been posted several times.
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Yeah it doesn't have much convection...but that doesn't matter so much right now.
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Drak,

What will happen during DMAX? Will dry air eat this up? will it continue west or recurve? Will shear help or inhibit?, are you liking the HWRF model or not? I'm not freaking out but should I be worried here in FL?
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Someone please tell me what DMIN and DMAX are, without using those big giant words, please.
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sj and as you just pointed out higher sst's lay ahead for the system albeit one to two days away, and they gradually get warmer and warmer, it will be interesting to see if it can maintain itself to take advantage of the warmer waters.
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763. Cotillion 7:57 PM GMT on July 17, 2009

LOL. very well done!
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Can't help say it looks pretty anemic right now lol
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97L?

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No need to answer him then drak...That is if you are not in the mood.

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Quoting Seflhurricane:
anyone know the water temperatures around our invest


Almost 81 degrees at the surface, which is all that really matters with the way this thing is moving.
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It's an invest? Can someone fill me in, my power just came back.
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Quoting WeatherStudent:
drak, on the visable staellite imagery this afternoon, it appears to be establishing three distinctive feeder bands to sustain itself, one to i's east, the other one to it's south, and last one to it's west. thoughts my friend?


Don't start with the 20 questions. I'm not in the mood.
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yes agreed sh, patience is needed time will tell..
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Quoting OSUWXGUY:


Thanks! Some good solid info here... That's right the HWRF is supposed to become THE model eventually while the GFDL is put out to pasture. I'm sure there's a boatload of research being funded for it.


GFDN (Navy version of GFDL) will continue to be improved.
Member Since: September 23, 2005 Posts: 14 Comments: 11215
Quoting willdunc79:
I agree that we shoul wait until Dmax and see what thi invest does but I say that the dry air will totally kill off this invest but hey let's wait and see.

What is DMAX?
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anyone know the water temperatures around our invest
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Quoting smartguy1:
one thing that i have noticed while observing these waves is that none has seemed to persist past 40w since coming off the coast, this one seems to be following that trend not saying it is no doubt the structure looks good but the convection has died out at the moment


True sg1, but this is the absolute worst time of day for it as well. Will have to see if it rebuilds convection when night falls.
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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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