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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Seems 97L is fighting off some significant dry air in its path..... if it can mix out this dry air, and get into a more favorable environment, it has a shot.
It would seem to be at least a day or two away from any significant development.
I see the blog is about the same as always, only busier! LOL
Poor Drak used to be so quiet, and would hardly ever show any personality..... maybe our you prognosticator has finally turned found some of that obnoxious traits of teenage years? LOL
Look forward to participating in the blog this season..... been waiting..... and lurking!
The season must be on...!
AOI
AOI
SJ, yep..... just got done! Lots of nice thunder and lightening!
Wide view of 97L and dry air.....
I much prefer EUMETSAT's take on the dust (all magenta). Plus, the brownish-colors depict mid-level clouds building.
You know it Pat.... I save all my best art for the prime part of the season! LOL
Sorta yes. Bascially the purpose of verification is to follow up on how accurate the last model was, looking at postions of fronts highs and lows as well as wind speeds but you want to look at the 12hr forecasted panel. Intializiation is when you check the first panel of the new run and see how well it started off. By the time the model run comes in the 00hr panel is actually expired so looking at the obs for that same time frame tell you if the winds were on target, to strong or to light, directions are right and the pressures for highs and lows are accurate.
If you do these steps and the real data, obs are different then the models, then you need to make adjustments on all panels. If you do not do it then you are trusting something 72 hours out that could be off by hours or way off on intensity.
Thanks
Texas Drought- Help Me
Maybe I am wrong with this one Orca but isnt that just the front that moved across the east coast today? Do you really think it would go tropical?
Actually...yes it is..but can it go tropical... no idea. Its out of my league on that one... its just starting to look like it is trying to form something... just a gut thing.
Depends whether this front stalls.....
I think we are more likely a few more weeks from stalled out fronts..... the last few fronts are still moving through at a good clip!
Oh ok...I am pretty sure that is just the low that pushed through the east coast. the whole eastern half of Virginia was under tornado watches today with it. There were some strong storms on it. The southern edge of the front is lagging over the Gulf states and brought us some rain today.
LOL, it's early still. I'm learning to use the tools! ;P
Just for fun - got an analog year to compare? I know they are all different - not much need in comparison really - again, just fun.
Pat!I SEE A BLOB NEAR THE TIP OF THE YUCATAN PENINSULA!
Did Quikscat catch it?
At some point the Atlantic is going to vent? Will it force the issue here?
Looks like a sabre moving forward.
Had a 1/2" here today. Overdue. Nice. Garden looking like an emerald already.
This means that a tropical cyclone now centred within about
800 kilometres of Hong Kong may affect us.
At 10 a.m., Typhoon Molave was estimated to be about 400
kilometres east-southeast of Hong Kong (near 21.5 degrees
north 117.9 degrees east) and is forecast to move
west-northwest at about 22 kilometres per hour towards the
coast of Guangdong.
According to the present track, Molave will pass within 150
km of Hong Kong between midnight and daybreak tomorrow.
Local winds are expected to strengthen gradually during the
day today with squally showers commencing later in the
afternoon. The Observatory will consider the need to issue
Strong Wind Signal No. 3 this afternoon.
---
HKO has intensified it into a typhoon (65 knots) as well.
I wouldn't want to be anywhere near the bottom of the lookout when a typhoon hit... it would be like the bottom of Niagara falls.
theres one to the west of 97L also that i wouldnt take my off of just yet either
Not good at historical stuff..... lucky to find my car keys! LOL
Just looking at all the tools available, i don't see a TD developing out of any of these blobs unless they can stay in tack till they get to the Mid Caribbean.
Just reffering to the second yellow area west of 97L. It looks decent but under some shear. it will be a major rain event but not sure it will have time to form into anything.
97L has lost convection during the past few hours. this could have as a result of the southwest path it took during the afternoon , which brought it over cool water temp of 79 deg. The stucture of the system is still well organised as it continues to move west around the southern periphery of the high pressure. what i have noticed on latest sat pics, is the wave to the east of the system is fast approaching it and may amalgamate to one complex system. shear near the system and for many more days will be low. while there is only a pocket of dry air, and that is in the mid levels to the west of 97L, while 97L is still,over minimal sst it will be approaching the area around 50W where water temps are near 82 deg although 97L looks a bit ragged this evening i expect it o slowly develop tne next few days, on a path that will take it through the central winwdard islands
Both will get sheared apart eventually...
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