Four invests in the Atlantic; fair weather in Arctic to drive rapid sea ice loss

By: Dr. Jeff Masters , 3:38 PM GMT on August 12, 2011

Share this Blog
28
+

It's a busy day in the tropical Atlantic, with the National Hurricane Center tracking four areas of interest (Invests.) None of these systems is a danger to any land areas over the next three days. The disturbance of most concern is the one farthest from land, a tropical wave that emerged from the coast of Africa two days ago. This wave, (Invest 93L), is located about 500 miles southwest of the Cape Verde Islands, and is moving westward at 15 - 20 mph. Recent visible satellite loops show that 93L has lost some of its heavy thunderstorms since yesterday, and the system is poorly organized, though there is a good deal of spin to the system. There is dry air to its north that is interfering with development. The SHIPS model and University of Wisconsin CIMSS wind shear analysis are showing high wind shear in excess 20 knots affecting 93L, which has undoubtedly contributed to the storm's loss of organization. Sea surface temperatures are 27.5°C, which is one degree above the 26.5°C threshold usually needed to support a tropical storm.


Figure 1. Morning satellite photo of the four Invests in the Atlantic today.

Forecast for 93L
High wind shear above 20 knots is predicted along 93L's path through Saturday afternoon, followed by a drop to the moderate range, 10 - 20 knots, for the succeeding four days. This should allow the storm to organize over the weekend. The latest 00Z and 06Z model runs of the four best models for predicting tropical storm formation (GFS, ECMWF, NOGAPS, and UKMET), have only one model, the GFS, that is indicating significant development of 93L. This model brings 93L near the northern Lesser Antilles Islands by Wednesday. NHC gave 93L a 40% chance of developing into a tropical depression by Sunday morning in their 8am outlook. Given 93L's recent struggles, I'd put these odds at 30%.

92L
An African wave midway between the northern Lesser Antilles Islands and the coast of Africa, near 18°N 45°W, is moving west-northwest at 20 mph. This system, (Invest 92L), is being given a 40% chance of development by NHC. Recent visible satellite loops show a modest amount of heavy thunderstorm activity, but no signs of a surface circulation. A Windsat pass from 8:04 am EDT this morning also showed no surface circulation, and noted top winds of around 35 mph. Water vapor satellite loops show that a large area of dry air surrounds 92L, and this dry air is causing problems for the storm. The SHIPS model and University of Wisconsin CIMSS wind shear analysis are showing moderate wind shear of 10 - 20 knots affecting 92L. Sea surface temperatures are 27 - 27.5°C, which is a degree above the 26.5°C threshold usually needed to support a tropical storm.

Forecast for 92L
Moderate wind shear of 10 - 20 knots is predicted along 92L's path over the coming five days, which should allow the storm to organize if it can handle the dry air surrounding it. The latest 00Z and 06Z model runs of the four best models for predicting tropical storm formation (GFS, ECMWF, NOGAPS, and UKMET) show weak development or no development of 92L, and NHC gave 92L a 40% chance of developing into a tropical depression by Sunday morning in their 8am outlook. A steady west-northwest motion for 92L is predicted by all of the models, which should make the storm miss the Lesser Antilles by a comfortable margin. However, Bermuda may be at risk from 92L next week.

94L
A broad low pressure system about 700 miles northeast of the northern Lesser Antilles Islands has developed a small amount of heavy thunderstorm activity, and may be a threat to become a tropical depression early next week. This system, (Invest 94L), is currently headed west-southwest at 10 mph, but is expected to turn northwest later today. Recent visible satellite loops show some spin to the cloud pattern at middle levels of the atmosphere, but no signs of a surface circulation. This system is also battling dry air, which is keeping the its heavy thunderstorms relatively meager. The SHIPS model is showing moderate wind shear of 10 - 20 knots affecting 94L. Sea surface temperatures are 28°C.

Forecast for 94L
Moderate wind shear of 10 - 20 knots is predicted along 94L's path over the coming five days, which should allow slow development, if it can handle the dry air surrounding it. None of our reliable models for predicting tropical storm formation (GFS, ECMWF, NOGAPS, and UKMET) show no development of 94L, and NHC gave 94L just a 20% chance of developing into a tropical depression by Sunday morning in their 8am outlook. Bermuda is the only land area that needs to be concerned with 94L.

95L
The final invest out there is an area of disturbed weather along on old frontal boundary several hundred miles off the coast of North Carolina. This sytem, Invest 95L, is headed northeastwards out to sea, and is not a threat to any land areas.



Figure 2. Arctic sea ice extent on August 11, 2011, was the 2nd lowest on record for the date. The Northeast Passage and Northwest Passage (southern route) were both ice-free. Image credit: UIUC Cryosphere Today.

Arctic sea ice poised to undergo record decline in mid-August
A strong high pressure system with a central pressure of 1035 mb has developed over the Arctic north of Alaska, and will bring clear skies and warm southerly winds to northeast Siberia and the Arctic during the coming week, accelerating Arctic sea ice loss. Widespread areas of northeastern Siberia are expected to see air temperatures 4 - 12°C (7 - 22°F) above average during the coming week, and the clockwise flow of air around the high pressure system centered north of Alaska will pump this warm air into the Arctic. Arctic sea ice extent, currently slightly higher than the record low values set in 2007, should fall to to its lowest extent for the date by the third week of August as the clear skies and warm southerly winds melt ice and push it away from the coast of Siberia. This weather pattern, known as the Arctic Dipole, was also responsible for the record sea ice loss in 2007, but was stronger that year. The weather conditions that led to the 2007 record were quite extreme--one 2008 study led by Jennifer Kay of the National Center for Atmospheric Research showed that 2007's combination of high pressure and sunny skies in the Arctic occur, on average, only once every 10 - 20 years. The 2011 summer weather pattern in the Arctic has not been nearly as extreme as in 2007, but the total sea ice volume has declined significantly since 2007, leading to much loss of old, thick, multi-year ice, making it easier to set a new low extent record with less extreme weather conditions. The GFS model is predicting that the Arctic Dipole will weaken by 8 - 15 days from now, with cloudier weather and weaker high pressure over the Arctic. This should slow down the rate of Arctic sea ice loss to very near the record low values observed in 2007. It remains to be seen if 2011 Arctic sea ice extent will surpass the all-time low set in September 2007; it will be close, and will depend on the weather conditions of late August and early September, which are not predictable at this time. It is already possible to sail completely around the North Pole in ice-free waters through the Northeast Passage and Northwest Passage, according to sea ice maps maintained by the UIUC Cryosphere Today website. This marks the fourth consecutive year--and the fourth time in recorded history--both of these Arctic shipping routes have melted free. Mariners have been attempting to sail these passages since 1497. This year, the Northeast Passage along the north coast of Russia melted free several weeks earlier than its previous record early opening.

Next post
I'll have a new post by 1pm Saturday.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 711 - 661

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37Blog Index

Quoting Patrap:
Im betting on 99L reaching the GOMEX,

,,,just saying


pre 99l needs to be closely watched
Member Since: August 13, 2007 Posts: 0 Comments: 10492
Quoting Stormchaser2007:
Really cooling down now.



Aw, earlier this year people were saying we were gonna start heading towards an El Nino at the end of the year. Having a La Nina is gonna make getting snow a little trickier here in central GA. :(
Member Since: Posts: Comments:
Quoting weatherh98:


Ya'll franklin hasnt formed yet and we are talking about k and l storms.... I understand that the atlantic is active and that franklin and a few other storms may and probably will form but I don't like being wrong so the only way right now to be right is to say that what ever we speculate about now won't happen the way we think it will it will at least be out of order and i find it highly likely that we will not see all of the waves form that are out there now and are about to roll off the coast... my two cents
I mean that is real what you are saying but i feel that we are getting closer to the peak of the season but we will have franklin,gert, harvey,and irene. Trust me we will see jose and katia right after those 4 develop and 2005 will be caught up too somewat. But the writings are on the wall for these 4 storms. so by the beginning of next week we will see all 4 named storms in the atl.
Member Since: July 25, 2010 Posts: 0 Comments: 2751
Quoting Stormchaser2007:
Really cooling down now.



Looks like we might even dip back into a La Nina before the season is out. It'll be interesting to see if we can hold La Nina/Neutral into the 2012 season. Still, we'll have 6 months over the winter to analyse that, so we'll leave it for now...
Member Since: Posts: Comments:
Quoting NICycloneChaser:


I think K and L could still come from anywhere, and nobody can be sure when, but the other three invests all have a pretty good chance of becoming storms.


I can agree with thatand i do think k and l will form soon i just dont wanna look to far out
Member Since: Posts: Comments:
dos anyone no if 92L have a close low ?
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
Quoting weatherh98:


Ya'll franklin hasnt formed yet and we are talking about k and l storms.... I understand that the atlantic is active and that franklin and a few other storms may and probably will form but I don't like being wrong so the only way right now to be right is to say that what ever we speculate about now won't happen the way we think it will it will at least be out of order and i find it highly likely that we will not see all of the waves form that are out there now and are about to roll off the coast... my two cents


I think K and L could still come from anywhere, and nobody can be sure when, but the other three invests all have a pretty good chance of becoming storms.
Member Since: Posts: Comments:
Quoting NICycloneChaser:
You know, I'm really starting to think that we could get a named storm from all four of these invests. That could put us on 9 by early/mid next week. If that happened, we would be on par with 2005. Jose formed on August 22nd in 2005, so we would have another week or so after that to get another one. I think this season is going to really challenge last year's 19.


It's looking possible. However, we never know when lulls will come (which they often do. We've not had a proper one yet). Last year only really got properly going in terms of numbers in late August.

It may just hit the wall like 2007 did with October or a better example is 1936: 15th storm by September 9th. Then only one more storm the rest of the year.

Still, does look favourable odds for a big year in terms of numbers right now. We'll see about the impact.
Member Since: Posts: Comments:
Really cooling down now.

Member Since: Posts: Comments:
Quoting SouthDadeFish:
I was thinking the same. Very active thus far. Although in 2005 we already had a cat 4 and a cat 5 by this time.


Yeah, intensity wise we are well behind 2005. 92L or 93L might yet have something to say about that.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
94L is beginning to get its act together; looks a bit like "95L" did in its early stages. We can see how it has that tail-like feature forming in a similar fashion to Bret did, and deep convection is firing right over its COC. Maybe an orange circle at 8PM?

To be honest I could see them going 40-50% at 8pm...
Member Since: Posts: Comments:
Quoting MississippiWx:
18z NAM still likes 94L:



its takes 94L too FL i see
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
Don't worry everyone, the hurricanes are coming. There isn't any doubt about that.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
94L is beginning to get its act together; looks a bit like "95L" did in its early stages. We can see how it has that tail-like feature forming in a similar fashion to Bret did, and deep convection is firing right over its COC. Maybe an orange circle at 8PM?




maybe am giveing 94L a 50 too 60% ch at 8pm



what do you see with 92 and 93L and when you think 93L will get it act togeter and get in the game with the rest?
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
Quoting bigwes6844:
we may pass 2005 in a few because did u see the african train coming off Africa. Its looking like jose and katia may come real soon after these 4


Ya'll franklin hasnt formed yet and we are talking about k and l storms.... I understand that the atlantic is active and that franklin and a few other storms may and probably will form but I don't like being wrong so the only way right now to be right is to say that what ever we speculate about now won't happen the way we think it will it will at least be out of order and i find it highly likely that we will not see all of the waves form that are out there now and are about to roll off the coast... my two cents
Member Since: Posts: Comments:
If JFV could understand this, he'd like it.


Member Since: Posts: Comments:
18z NAM still likes 94L:

Member Since: Posts: Comments:
X
Member Since: July 15, 2006 Posts: 178 Comments: 56089
we may see other TD or to by late tonight or sat
Member Since: May 21, 2006 Posts: 5091 Comments: 115454

TD6
Member Since: Posts: Comments:
94L is beginning to get its act together; looks a bit like "95L" did in its early stages. We can see how it has that tail-like feature forming in a similar fashion to Bret did, and deep convection is firing right over its COC. Maybe an orange circle at 8PM?

Member Since: July 6, 2010 Posts: 113 Comments: 32832
Quoting NICycloneChaser:
You know, I'm really starting to think that we could get a named storm from all four of these invests. That could put us on 9 by early/mid next week. If that happened, we would be on par with 2005. Jose formed on August 22nd in 2005, so we would have another week or so after that to get another one. I think this season is going to really challenge last year's 19.
I was thinking the same. Very active thus far. Although in 2005 we already had a cat 4 and a cat 5 by this time.
Member Since: Posts: Comments:
Good evening guys. I see we now have TD6, which may become Franklin.
Member Since: Posts: Comments:
Quoting P451:


It's not just that but so far we've had nothing but crappy systems that struggled to organize. Half of which that track to no man's land.


Seems to me, this being a learning blog, the Emily type storms, are the ones worth watching. Why did storm X die? Why didn't storm y develop more? After they reach hurricane status, pretty much all's left, is intensity and track.
Member Since: Posts: Comments:
Indeed, 2002's six is the record with six straight storms not reaching hurricane status.

1942 did have six straight tropical storms, but that was mid season.
Member Since: Posts: Comments:
Quoting NICycloneChaser:
You know, I'm really starting to think that we could get a named storm from all four of these invests. That could put us on 9 by early/mid next week. If that happened, we would be on par with 2005. Jose formed on August 22nd in 2005, so we would have another week or so after that to get another one. I think this season is going to really challenge last year's 19.
we may pass 2005 in a few because did u see the african train coming off Africa. Its looking like jose and katia may come real soon after these 4
Member Since: July 25, 2010 Posts: 0 Comments: 2751
when do you guys think 93L will be geting its act togeter
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
Last season we had 7 named storms that only made it to Tropical Storm status.

This year, so far, we'll have 6 if TD6 becomes Franklin and dissipates after it's expected peak of 45 MPH.
Member Since: Posts: Comments:
Quoting NICycloneChaser:
You know, I'm really starting to think that we could get a named storm from all four of these invests. That could put us on 9 by early/mid next week. If that happened, we would be on par with 2005. Jose formed on August 22nd in 2005, so we would have another week or so after that to get another one. I think this season is going to really challenge last year's 19.
...and people declared this season a bust after Emily (finally) went poof.

Concerning Emily, a part of her lives on, unfortunately.
Member Since: Posts: Comments:
Quoting SouthDadeFish:
Fun fact I've discovered: Going back through the archives I could only find one other year since 1960 that the first six storms failed to reach hurricane status. That year was 2002. It doesn't look like TD 6/Franklin will become a hurricane. Pretty unique situation.


I remember that one. Pretty boring until Isidore and Lili.

Seems pretty similar to this year so far.
Member Since: Posts: Comments:
Quoting angiest:


Arguments worthy of when Ivan reformed and trek'd across the Gulf.


I'm not arguing either way. Or at least not stubbornly. I think it would get a new name if it were to be named, and I stated my reasons why. I am well aware I could be wrong and no one knows for sure. It's the NHC's decision. But the fact that they stopped calling it the remnants of Emily makes me learn ever so slightly to the "new name" side. It's possible it could pull an Ivan though.
Member Since: Posts: Comments:
You know, I'm really starting to think that we could get a named storm from all four of these invests. That could put us on 9 by early/mid next week. If that happened, we would be on par with 2005. Jose formed on August 22nd in 2005, so we would have another week or so after that to get another one. I think this season is going to really challenge last year's 19.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Howa 'bout 90L x2?

Member Since: Posts: Comments:
Quoting HurricaneSwirl:


I don't think so. The TWO doesn't call it "the Remnants of Emily" or "an area of low pressure associated with the Remnants of Emily". I think the "real" remnants of Emily got sucked out to the NE. 94L is a part of Emily that split and went south, but I don't think the NHC recognizes it as the remnants of Emily, so it would likely get a new name.


Arguments worthy of when Ivan reformed and trek'd across the Gulf.
Member Since: Posts: Comments:
Yep Mississippiwx,
if 94L can pull a 95L then were on our way to TS Gert
Member Since: Posts: Comments:
Quoting HurricaneSwirl:


I don't think so. The TWO doesn't call it "the Remnants of Emily" or "an area of low pressure associated with the Remnants of Emily". I think the "real" remnants of Emily got sucked out to the NE. 94L is a part of Emily that split and went south, but I don't think the NHC recognizes it as the remnants of Emily, so it would likely get a new name.
No more Emily! Please!
Member Since: Posts: Comments:
Huh, what happened? The 50 knot and the TS force wind probabilities went down by a color since they put out the advisory.
Member Since: Posts: Comments:
Fun fact I've discovered: Going back through the archives I could only find one other year since 1960 that the first six storms failed to reach hurricane status. That year was 2002. It doesn't look like TD 6/Franklin will become a hurricane. Pretty unique situation.
Member Since: Posts: Comments:
Quoting Patrap:
Break one


Im outta Fresca's !!!!



I'll second that motion. It's Friday, tropics are coming alive, it's happy hour, it's 73F with wicked low humidity, and the Pats won last night. Life just doesn't get any better.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting serialteg:


isnt 94 the emily remnants?

94L originated as a piece of energy associated with Emily that split off, so it isn't actually Emily.
Member Since: Posts: Comments:
850mb vort with 94L has become pretty elongated north to south. The northern piece will probably break off and fade away while the more circular southern end will stay dominate. It remains to be seen if it can stick together...but like Teddy said, 94L is much better looking now on satellite. We'll see if the 850 vort can consolidate better.



Member Since: Posts: Comments:
Quoting HurricaneGeek:
It appears Franklin won't become a hurricane. That means we most likely will start the season 0-6 for hurricanes. What's the record? It's very interesting especially since the E PAC is 5-0.


2002 managed six as well.

I suspect that's it: some of the little tropical storms we see today wouldn't have been named a few years ago.
Member Since: Posts: Comments:
Im betting on 99L reaching the GOMEX,

,,,just saying
Member Since: Posts: Comments:
Quoting tropicfreak:


Wow LOL they may have to end up designating two tropical systems today. Would it be named Emily if it develops?


I don't think so. The TWO doesn't call it "the Remnants of Emily" or "an area of low pressure associated with the Remnants of Emily". I think the "real" remnants of Emily got sucked out to the NE. 94L is a part of Emily that split and went south, but I don't think the NHC recognizes it as the remnants of Emily, so it would likely get a new name.
Member Since: Posts: Comments:

Viewing: 711 - 661

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
36 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron