One third of Arctic ice cap now missing; Midwestern floods; tropical update

By: Dr. Jeff Masters , 12:46 PM GMT on August 24, 2007

Share this Blog
4
+

Sea ice in the Arctic continues its record decline, thanks to unusually cloud-free conditions and above-average temperatures. For August 21, the National Snow and Ice Data Center estimated that fully one third of the Arctic ice cap was missing, compared to the average levels observed on that date from 1979-2000. Sea ice extent was 4.92 million square kilometers on August 21, and the 1979-2000 average for the date was about 7.3 million square kilometers. Arctic sea ice has fallen below the record low absolute minimum of 4.92 million square kilometers set in 2005 by about 8%, with another 3-5 weeks of the melting season still remaining. Reliable records of sea ice coverage go back to 1979.


Figure 1. Extent of the polar sea ice on August 21, compared to the average for the date from the 1979-2000 period (pink line). Image credit: National Snow and Ice Data Center.

With one third of the Arctic ice cap already gone, and another month of melting to go, we need to consider what effect this will have on weather, climate, and sea level rise. Well, we don't need to worry about sea level rise, since the polar sea ice is already in the ocean, and won't appreciably change sea level when it melts. However, the remarkable melting of the ice cap will likely lead to unusual weather patterns this fall and winter. The lack of sea ice will put much more heat and moisture into the polar atmosphere, affecting the path of the jet stream and the resultant storm tracks. Expect a much-delayed arrival of winter to the Northern Hemisphere again this year, which may lead to further accelerated melting of the ice cap in future years.

Last week, I remarked that the most recent images from the North Pole webcam show plenty of melt water and rainy conditions near the Pole. It turns out that was misleading, since the webcam is on a ship that was headed towards the pole, but had not reached it. There have been rainy conditions at the Pole this summer, and there is some open water there, but this is not uncommon in summer. Shifting ice frequently opens up leads (cracks) with open sea water at the Pole. It was one of these open leads that British swimmer Lewis Gordon Pugh swam in for 18 minutes this July to draw attention to global climate change.


Figure 2. Total rainfall from August 10-22 as estimated by NASA's TRMM satellite.

Midwest flooding
To get an idea of the magnitude of the flooding that has hit the Midwestern U.S. during the past ten days, take a look at the total amount of rain from August 10-22 (Figure 2). We can blame Tropical Storm Erin for the rain in Texas and Oklahoma (up to 11 inches), and for the nine flooding deaths that occurred in those states. However, the unbelievable rain amounts in excess of 20 inches in Minnesota and Wisconsin were primarily due to a frontal system--with the help of some copious moisture pumped northwards by the counter-clockwise circulation around Erin while it spun over Oklahoma.

Tropical update
There are no threat areas in the Atlantic to discuss. Two of our four reliable forecast models, the NOGAPS and ECMWF, are predicting that a tropical depression could form off the coast of Nicaragua on Sunday. The models forecast that this system would move inland over Nicaragua and Honduras by Monday.

I'll have an update on Saturday morning.
Jeff Masters

After Hurricane Dean (sprinter)
Bulldozer trying to clear sand and debris from Norman Manley Highway(Airport Road)
After Hurricane Dean
Findlay Ohio flood (prairieview)
The flood is over, now the cleanup
Findlay Ohio flood

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: 1197 - 1147

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 | 27Blog Index

1197. KEEPEROFTHEGATE (Mod)
1:19 AM GMT on August 26, 2007
so has a blob alert been issued yet
Member Since: Posts: Comments:
1196. latitude25
1:07 AM GMT on August 26, 2007
"Posted By: boobless at 12:37 AM GMT on August 26, 2007.

Statement on Tropical Cyclones and Climate Change from the
WMO International Workshop on Tropical Cyclones-November 2006
A good "talking points" summary if you wish to limit your GW discussion to tropical cyclones.
Link has surely been up here before. If so, sorry, here it is again."

Talk about wishcasting.

The low res models show substantially weaker simulated models and the high res only show some increase in intensity. Where the relationship to SST's have been examined the relationship dependence is much weaker.

So they deduce from that their models are flawed/broken and they go on to predict an increase in cyclone intensity.

Someone wanted their funding on that one.
Member Since: Posts: Comments:
1195. extreme236
1:09 AM GMT on August 26, 2007
the sfc analysis shows the low pressure about to come off africa at 20N. Although, I dont think it is associated with the wave about to come off.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1194. boobless
1:07 AM GMT on August 26, 2007
come on baby...don't get too far from 15N.
Member Since: Posts: Comments:
1193. extreme236
1:05 AM GMT on August 26, 2007
well at the rate both of those african waves are moving, I dont think they would disrupt each other much, unless one got much stronger than the other, then one of them would be disrupted
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1192. hosweather
1:00 AM GMT on August 26, 2007
That is a big surface low south of the Cape Verdes. I don't see anything likely to disrupt its development other than the next wave coming off W Afr. Looks really good to go.
Member Since: Posts: Comments:
1191. extreme236
12:57 AM GMT on August 26, 2007
List of when the named storm beginning with "F" developed since 2000:

2000: September 10th
2001: September 7th
2002: September 5th
2003: August 25th
2004: August 25th
2005 (outlier): July 21st
2006: September 3rd
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1190. extreme236
12:53 AM GMT on August 26, 2007
And I was looking up when the "F" named storm has developed since 2000, and it has developed in either late august or early september, so were right around where we have been for several years, with the exception of 2005, which was wacko
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1188. presslord
12:51 AM GMT on August 26, 2007
I realize this is purely anectodal...but....Hugo didn't come thru here til late Sept....so don't tell me it's over til it's over....
Member Since: Posts: Comments:
1187. extreme236
12:52 AM GMT on August 26, 2007
Oh, I never said she was complacent. I was just why people were jumping on her
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1186. hosweather
12:48 AM GMT on August 26, 2007
extreme236

Anyway, not what I would call complacency.
Member Since: Posts: Comments:
1185. extreme236
12:49 AM GMT on August 26, 2007
Posted By: KoritheMan at 12:44 AM GMT on August 26, 2007.

Thanks, extreme.


Your welcome :)
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1184. extreme236
12:47 AM GMT on August 26, 2007
Amystery was jumped on because she said things without really backing them up. She said that if we dont get any storms by a certain time it will be below average season, which isnt true. She also seemed to think she knew for sure what was going to happen.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1183. hosweather
12:42 AM GMT on August 26, 2007
stormlvr

I don't see a lot of complacency. When Amystery suggested not too much activity going forward, he was jumped on pretty good.
Member Since: Posts: Comments:
1182. cirrocumulus
12:39 AM GMT on August 26, 2007
stormlvr and extreme 236: I think that ridge is going to allow a storm to go near Florida and then on into the south. Also, go to weather.com and notice that parts of Arkansas have had no rain in 30 days. A little bit odd? Something's up sooner than later.
Member Since: Posts: Comments:
1181. KoritheMan
12:40 AM GMT on August 26, 2007
Thanks, extreme.
Member Since: Posts: Comments:
1180. extreme236
12:36 AM GMT on August 26, 2007
Posted By: KoritheMan at 12:35 AM GMT on August 26, 2007.

extreme236, where can I get an animated loop for that African wave? I can't seem to find one. I saw the CV wave via the tropical page on here, but I haven't seen a loop. Can you help?


Link

try this link. click on circled area you want to view the satillites on and then once you click on one of the circles you get a bunch of boxes of specific areas. click on the box that says west africa and you will get a bunch of images such as infrared. then you click the various java animations or whatever other loops it lets you open
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1179. boobless
12:15 AM GMT on August 26, 2007
Statement on Tropical Cyclones and Climate Change from the
WMO International Workshop on Tropical Cyclones-November 2006
A good "talking points" summary if you wish to limit your GW discussion to tropical cyclones.
Link has surely been up here before. If so, sorry, here it is again.

Link
Member Since: Posts: Comments:
1178. extreme236
12:35 AM GMT on August 26, 2007
Posted By: KoritheMan at 12:31 AM GMT on August 26, 2007.

extreme, you left for a few hours and are asking if anything new is happening? Isn't that kind of, eh...pointless? No offense, but it's just odd to me.


Yeah its kind of odd. But, you know how things can be in the tropics, they can change all the time. Blobs can pop up in a matter of hours lol. And we all know how fun blob watching is lol
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1177. hosweather
12:24 AM GMT on August 26, 2007
The low that people have been talking about developing is the one just SW of the Cape Verdes. You can see it on my last posted link.

The only low I see in the central Atlantic is an extra-tropical storm above 40N. The ridge is forecast to build back in below this low.
Member Since: Posts: Comments:
1176. KoritheMan
12:34 AM GMT on August 26, 2007
extreme236, where can I get an animated loop for that African wave? I can't seem to find one. I saw the CV wave via the tropical page on here, but I haven't seen a loop. Can you help?
Member Since: Posts: Comments:
1175. KoritheMan
12:32 AM GMT on August 26, 2007
stormlvr, well said!
Member Since: Posts: Comments:
1174. extreme236
12:31 AM GMT on August 26, 2007
Posted By: ryang at 12:30 AM GMT on August 26, 2007.

Hey Extreme!

Nothing new tropical wise.


Ok. I was just looking over the page to see what everyone was talking about when I was gone. So, a few models develop that CV wave?
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1173. stormlvr
12:29 AM GMT on August 26, 2007
Hello folks. Love the banter on this blog. I am concerned that I sense a certain level of complacency about the season so far. As a long time weather fanatic and one who was lucky enough to be a met for some time, please allow me to throw in my 2 cents. The season so far has been forecast rather accurately by several long term forecasters. I will use the CSU forecast as I prefer the detailed discussion they offer. CSU forecast a slightly above August with 3 storms, 2 hurricanes, 1 intense an above September with 5 storms and a very active October and November with 5 storms. They need 1 hurricane to verify August with 6 full days left. The reason for the slower start was the moderate levels of Saharan dust in June/July reducing SST's and increasing stability and inducing higher pressures over the Eastern Atlantic which has a residual effect for 1 to 2 months. They felt activity would increase in September since Eastern Atlantic SST's would reach their warmest point and upper atmospheric conditions would remain favorable. Then the developing La Nina would be the kicker for a very active Oct/Nov. The only reservation I have about the CSU forecast is the residual effects of the Saharan dust in the Eastern Atlantic which may have an impact further into the season and reduce the total number of storms by 1 or 2. Of more concern to me is the overall steering pattern across the Atlantic for storms that develop. The Atlantic ridge will undergo changes due to the gradual change of seasons but remain relatively strong. The central Atlantic trof will likely be weaker than normal with another trof developing over or near the East Coast between the Continental and Atlantic ridge. The depth and orientation of the weakness near the East Coast will largely determine how severe the impact will be on the US Coast. Of course, every season will have its share of fish storms and we can hope for the best. This season it appears there is a good chance for storms that form to come pretty far west before going fishing. So for those of you who want a storm, be careful what you wish for. For those of you who have become complacent, beware.
Member Since: Posts: Comments:
1171. ryang
8:29 PM AST on August 25, 2007
Hey Extreme!

Nothing new tropical wise.
Member Since: Posts: Comments:
1170. extreme236
12:24 AM GMT on August 26, 2007
Ok, Im back everyone. Anything new happening?
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1169. KoritheMan
12:16 AM GMT on August 26, 2007
How can one call it inactive before the fact. i.e. it ain't over til is over. No facts to prove it at the moment. Can't prove a negative.

Or, the correlary, how can one call it ACTIVE before the fact also. Not really any more facts to prove that either, til it's over.


Well, you can prove an active season will likely (not will, but will LIKELY) take place by looking at the overall weather pattern both now and in the future. Also, years that have had similar conditions in the Atlantic were also quite active, like this one, and I'm sure people wrote that season off since a tropical cyclone didn't occur until relatively close to September after the first one formed. La Niņa was present in 1999 as well, and this year has behaved similarly thus far, and has generally the same conditions as 1999 did. That's one fact you can use to say this season has a good chance to be active.

On the other hand, this year reminds me of 1993, because of the dates in which the storms up to the E storm formed. Not to say this will be like 1993, but it sure reminds me of it so far as far as formation dates go.

If we were to get an anomalous warming of the equatorial East Pacific this year (it would have to be a rapid warming), and had a neutral ENSO phase with a warm-bias or an El Niņo, I would say this season will be inactive. However, there are no signs currently pointing to an El Niņo this year, although there may be one in 2008, according to some models, but they are just models, and are not gospel.

At any rate, we have already had one big storm this year -- Dean, and it is the 9th most intense Atlantic hurricane on record. So this season is by no means a bust, nor is it over. There are likely going to be many more storms once the upward MJO pulse kicks in, and MJO won't make or break the season either, just help supress and/or ramp up activity.

It only takes one storm to make the season busy for the community affected. Tell the people affected by Dean it's been quiet -- they'd tell everyone real quick like it hasn't been.
Member Since: Posts: Comments:
1168. BahaHurican
7:56 PM EDT on August 25, 2007
That particular low in the central ATL that people have been looking at / talking about all day is interesting in that it is forecast to remain more or less in the same place until at least next week Wed. Looks like it is jammed in between some highs and can't get out.

If we do get some development from the wave that's likely to come offshore tomorrow or Monday, wouldn't the presense of that low likely influence the new system to move north rather than west?
Member Since: Posts: Comments:
1167. AinFLA
12:14 AM GMT on August 26, 2007
Posted By: KoritheMan at 11:46 PM GMT on August 25, 2007.
If you are going to call it inactive, fine, but use facts. Unlike some people here, I'll listen to them.



K'Man, agree with most of what you say but somehow the last bit of logic is flawed But by whom, I not sure.

How can one call it inactive before the fact. i.e. it ain't over til is over. No facts to prove it at the moment. Can't prove a negative.

Or, the correlary, how can one call it ACTIVE before the fact also. Not really any more facts to prove that either, til it's over.

And please, don't anybody on this blog point to any BS computer models. Because I'll blow you off in 2 seconds.

You are right on one thing, most, NOT ALL, are idiots. Most don't avail themselves of the basic information they have on hand and couldn't tell you which way the wind is blowing if it was spitting rain and dust in their face.

1165. KoritheMan
12:00 AM GMT on August 26, 2007
hosweather: I actually like that graph. Pretty neat. Thanks.
Member Since: Posts: Comments:
1164. hosweather
11:43 PM GMT on August 25, 2007
Not too current but otherwise a great look at how the surface winds are blowing in the Atlantic.
Member Since: Posts: Comments:
1163. Weather456
11:54 PM GMT on August 25, 2007
Weather 101

Cold Core Lows (Upper Level Lows)

In comparison to its enviroment, this low is most intense and coldest in the upper troposphere. It is therefore weaker at lower levels and can be hard to find below 500 mb. Subisdence is confined to the center and low level lifting is found on the Eastern ppheriphy of the circulation. A line of cold low may comparise the tropical upper trospheric trough or TUTT for short.

W456

I'll list some characteristics of subtropical cyclones later.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
1162. KoritheMan
11:42 PM GMT on August 25, 2007
Amystery, are you referring to me when you said KM, or kmanislander? I wouldn't think either of us call anyone names. It's true though, most here are idiots -- no actual data to back up what they say. Why should I provide what happened in the past to users like you, when you are going to ignore it and think you right, and that you are someone who is given the power of God to stop and form tropical cyclones at your will.

I'll gladly back up what I say with facts, but only if you will listen to it. I am not a person to waste my breath on people who won't listen, so don't expect me to provide every piece of data like STL does UNLESS you will listen.

And yes, it is true that the ones who say it'll be active get praise, and I guess that isn't fair. But all signs point to that. Dean just dissipated two days ago. Give it a freaking chance, my word. I will agree with LLJ that we don't know till the season is over.

If you are going to call it inactive, fine, but use facts. Unlike some people here, I'll listen to them.
Member Since: Posts: Comments:
1159. aspectre
11:18 PM GMT on August 25, 2007
"But there is a huge gap between the SAL around the African coast and the one in the E-Pacific."

I think...
...two tropical waves started off the coast of Africa; one soon labeled Invest90L, which would become Dean. The tropical wave following Invest90L was suppressed by a dust storm coming off of Africa.
Remnants of that dust storm have been chasing after Dean ever since, though it was never fast enough to catch up before Dean's collapse.
Member Since: Posts: Comments:
1156. taistelutipu
11:21 PM GMT on August 25, 2007
Thank you very much, MichaelSTL, for your detailed explanation.
The lower graphic in the post about the "false" SAL west of Mexico is quite impressive - such a great difference in SSTs on a relatively small area. La nina coming?

While I'm at it my thanks go to all of you experts, StormJunkie, Weather456, H2PV, IKE, texascanecaster, etc (can't remember all the names yet). I really appreciate your readiness to explain these complexe phenomena to laymen like me. This is one of the reasons why this site is so addictive.

I can go to sleep now with a good conscience since I've learnt something new today. ;-)
Member Since: Posts: Comments:
1155. boobless
11:23 PM GMT on August 25, 2007
Posted By: presslord at 11:20 PM GMT on August 25, 2007.
to do whatever it is they have been conspiring to do...


Don't forget GW-as in G Dubya...
Member Since: Posts: Comments:
1154. hosweather
11:15 PM GMT on August 25, 2007
Temp at 41026 is 81.1 degrees, the warmest it has been for days????
Member Since: Posts: Comments:
1152. presslord
11:17 PM GMT on August 25, 2007
Aha!!! Cape Verde (CV)....Colombia/Venezuela (CV)...clearly evidence of the NHC conspiracy to...well....to do whatever it is they have been conspiring to do...
Member Since: Posts: Comments:
1151. KEEPEROFTHEGATE (Mod)
11:08 PM GMT on August 25, 2007
tropics will remain at a depress rate of systems till that distubance at 41/51 which is pumping cold air downward over the mid atlantic all the way from the coast of greenland that is a strong northerly flow over the mid atlantic and from the looks of sat doesnt look to be movin any time soon
Member Since: Posts: Comments:
1150. Rick54
6:08 PM CDT on August 25, 2007
here da full bottom line of global warming:...

Or the deserts will expand, maybe crops will begin to fail in the Midwest (good chance we will never see an ethanol economy anyway) and our population will revert to a size equal to the carrying capacity of the Earth to support us.

The whole notion that technology can fix this mess is a joke. Sooner or later our economy and population are going to have to reverse if for no other reason the Earth and everything in it is finite. Just look at the pics taken from the moon.
Member Since: Posts: Comments:
1149. hosweather
11:08 PM GMT on August 25, 2007
texascanecaster1

You're probably mostly right but I don't know about meteorologists and weather forecasters getting rich. Maybe they'll be tarred and feathered instead.
Member Since: Posts: Comments:
1147. Rick54
5:55 PM CDT on August 25, 2007
Bottom line, the current Arctic ice loss trend is very troubling.

Even more troubling to my mind is the potential for change in the world's weather systems due to changes in albedo in the arctic.
Member Since: Posts: Comments:

Viewing: 1197 - 1147

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 | 27Blog Index

Top of Page

About JeffMasters

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
53 °F
Overcast