An African wave worth watching; 2nd warmest June on record
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
Reader Comments
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It's just an 'area of interest.'
If it manages to squeeze up through the Antilles, pass Puerto Rico, and make it to the Florida Straits, we may see some action in the CONUS. Then again, it could meet its demise along the way. But not looking like it's getting into the Caribbean at this juncture. Everyone predicts the shear will decrease in a couple of days. Will see.
ATTENTION...NATIONAL HURRICANE CENTER
1558 UTC FRI JUL 17 2009
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
ATLANTIC OBJECTIVE AIDS FOR
DISTURBANCE INVEST (AL972009) 20090717 1200 UTC
...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090717 1200 090718 0000 090718 1200 090719 0000
LAT LON LAT LON LAT LON LAT LON
BAMS 12.0N 34.7W 12.8N 38.5W 13.2N 42.5W 13.6N 46.4W
BAMD 12.0N 34.7W 12.3N 37.5W 12.2N 40.4W 12.0N 43.2W
BAMM 12.0N 34.7W 12.4N 38.3W 12.6N 41.8W 12.6N 45.1W
SHIP 20KTS 24KTS 28KTS 34KTS
DSHP 20KTS 24KTS 28KTS 34KTS
...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090719 1200 090720 1200 090721 1200 090722 1200
LAT LON LAT LON LAT LON LAT LON
BAMS 13.8N 50.3W 15.2N 58.2W 18.4N 65.9W 21.6N 72.5W
BAMD 11.8N 45.9W 12.1N 51.3W 13.9N 57.2W 16.2N 64.0W
BAMM 12.5N 48.3W 13.5N 54.6W 16.3N 60.9W 20.0N 67.2W
SHIP 40KTS 51KTS 59KTS 66KTS
DSHP 40KTS 51KTS 59KTS 66KTS
...INITIAL CONDITIONS...
LATCUR = 12.0N LONCUR = 34.7W DIRCUR = 275DEG SPDCUR = 14KT
LATM12 = 11.9N LONM12 = 31.6W DIRM12 = 274DEG SPDM12 = 16KT
LATM24 = 11.5N LONM24 = 28.0W
WNDCUR = 20KT RMAXWD = 0NM WNDM12 = 20KT
CENPRS = 1012MB OUTPRS = 1014MB OUTRAD = 100NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
$$
NNNN
Always wanted aa link to that. plase? TIA
It will be at least 18z, if not 00z.
Guy1: Do you know who to make Jeff Masters blog go crazy?
Guy2: No, how?
Guy1: Watch this.....
Thus, Invest 97 was born.
What about it reminds you of Andrew? It could be reminiscent of lots of different Cape Verde systems...
LOL
Well a continued west to west-northwest track over the next several days seems quite likely, as the subtropical ridge to the north holds strong up to at least 250 mb, and models don't significantly weaken this ridge in the coming days.
What is unnerving to me is the undisturbed oceanic heat content in the western Caribbean that has not been cooled by any tropical cyclones thus far this year. Last night, the NOGAPS and GFS were developing anticyclonic flow in that area about a week from now.
I'm just joking... I'm waiting for someone to say that. It could remind me of Andrew later though - we'll see.
Drak, long way out, but do you see possible threat to the CONUS?
May I ask why? I was not around for Andrew nor was I watching hurricanes at that time...I would love some insight.
nevermind.. i didn't see the other post yet...about you joking.
LOL
Some slow development of the system is possible. Shear is a comfortable 4knots over the system and is expected to be at least marginal for development. The main problem will be dry air. These type of systems like to ramp up though once they hit some higher sea surface temperatures similar to what we saw in 2007 as far as intensification. I expect a west or WNW track to continue bring the wave in the general direction of the Lesser Antilles.
If it is meant to be something, it will write its own chapter, every storm is different
Funny thing is it will hopefully keep the lid on the "its going to be a fish" posts lol
Too early to say. If it manages to ramp up near the Lesser Antilles our focus will shift back to shear. It will become very tedious to forecast shear in the Bahamas.
Well said.
Yes, but primary the SE US at the moment. There will be a weakness at the GOM according to the GFS.
This ain't no fish that I can see.
nice visible floater on...95L/97L/preTD2/preAna...
It's what I've been saying for a week now, high is too strong and the pattern does not favor a recurvature.
Can you post that link to the ECMWF with all the graphics? I'm not at my home computer right now.
Tropical Update
Interesting. I've been waiting for that run....
This is a mega-combo.
This provides graphics to all models and ECMWF.
Link
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