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

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

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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

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1297. latitude25
1:01 PM GMT on August 26, 2007
"Posted By: boobless at 2:26 AM GMT on August 26, 2007.

And Lat25,
Just to keep things friendly, I shoulda known you would want to start withe the last item on list. lol"

I have no idea what that means.
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1295. MissBennet
12:55 PM GMT on August 26, 2007
Posted By: groundman at 8:27 PM GMT on August 25, 2007.

Posted By: MissBennet at 7:59 PM GMT on August 25, 2007.
P.S. and this is the last I'll say on the subject. The only reason I know this stuff, is becuase my husband is an environmental lawyer, sueing the Oil, coal, and chemical companies for causing global warming, that caused Katrina and other intense hurricanes. .........................

I'm sorry but WHERE are people getting the money for legal suits like this?? From a movie?? ......

.....I don't mean to jump on you MissBennet and I know your husband just does what he is told, I would defend mine too even though he can be annoying. LOL

No offence taken Ground. As to your, his boss made millions (and I do mean lots of millions) on asbestos litigation in his youth, so he's footing the bill from that windfall for this litigation.
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1294. bbreaker
12:26 PM GMT on August 26, 2007
With the polor ice cap shrinking and a rise in temps all over the place. It reminds me of a movie i have seen a few times. Could there be some truth in that "movie" ???
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1293. Weather456
12:22 PM GMT on August 26, 2007
And the Atlantic title is still held by this non tropical low (or extratopical low)

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1292. Weather456
12:16 PM GMT on August 26, 2007
A naked swirl ESE of Barbados, put it in animation

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1291. extreme236
12:17 PM GMT on August 26, 2007
well after reading the TWD, the nhc seems still impressed with the structure of the wave at 52W with the cyclonic turning at the sfc, although they are saying how convection is limited
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1290. Weather456
12:04 PM GMT on August 26, 2007
Happy Sunday to All!

This image was taken 1100 UTC today

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1289. IKE
7:02 AM CDT on August 26, 2007
Tropical weather outlook for planet earth....

"Tropical cyclone formation is not expected during the next 48 hours."

96 days left in the Atlantic season and it's over.
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1288. stoormfury
11:26 AM GMT on August 26, 2007
is the rotation at 8N 43W a pertabation in the ITCZ?
Member Since: August 22, 2006 Posts: 0 Comments: 2722
1287. NorthxCakalaky
9:59 AM GMT on August 26, 2007
Going to bed.Be back when I can.School starts Monday for me.I think we could get a invest off the African coast this coming week.Auguast 27 to the 2 of September.
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1286. NorthxCakalaky
9:48 AM GMT on August 26, 2007
The last 3 winters here we get less snow.(N.C)

Texas floods.

South-East goes in a extreme drought.

Mid-West floods.

Hurricanes are much stronger/more of them.

I believe in GW.
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1285. KRL
7:30 AM GMT on August 26, 2007
Posted By: tornadodude at 3:30 AM GMT on August 26, 2007.

couldnt say that better myself

Indeed a lot of people, especially politicians, are jumping on the GW bandwagon with an agenda, and I think they're all off base saying its humans causing GW, but the fact is the global climate is on a warming trend, whatever is really at the heart of it.
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1284. KRL
7:21 AM GMT on August 26, 2007
Let's be optimists, LOL, 2/3rds of the ice caps are still there.

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1283. msphar
6:21 AM GMT on August 26, 2007
You are so right about that. Checking out for the night. Thanks again.
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1281. msphar
5:49 AM GMT on August 26, 2007
Thanks LLJ, got it now. It will be a big help.
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1276. mississippiwx23
5:26 AM GMT on August 26, 2007
LLJ, look at the previous 3 analyses and there is no movement of that low, or in other words, its stationary. Is it REALLY going to move out off the coast?
Member Since: August 20, 2007 Posts: 3 Comments: 683
1274. msphar
5:19 AM GMT on August 26, 2007
um, that looks like a noaa chart, doesn't look like the basic source, do you understand the relationship between these two ? ie is there a more direct access to that chart ?
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1271. msphar
5:10 AM GMT on August 26, 2007
LLJ where do you get that chart ?
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1269. fire831rescue
5:02 AM GMT on August 26, 2007
I think this blob is dissipating for the evening, as well. Possible regeneration and strengthening is expected for tomorrow, as well as, throughout the rest of the 2007 season. Goodnight, Ya'll.
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1268. fire831rescue
4:56 AM GMT on August 26, 2007
With all this worry about blobs, I had to do something. People were starting to panic...
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1267. listenerVT
4:51 AM GMT on August 26, 2007


Well, this little blob, which emerged late evening, is about to disperse for the night. Conditions indicate strong likelihood that this blog will reemerge tomorrow. Stay tuned for further postings.

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1266. hosweather
4:36 AM GMT on August 26, 2007
boobless at 4:34 AM GMT on August 26, 2007.
Hosweather, keeps it in the slower mid level moist flow at or near 15N now. The other drives it south to the rip-roaring ITCZ??

The ITCZ could be part of it. The CMC has the more southerly track and really slows down the westward movement of the system past 40W. This would keep the system in a moister environment for a longer time. I expect that the GFS has the system being slowly sheared to death after 40W but I don't see where the shear is coming from.
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1265. fire831rescue
4:52 AM GMT on August 26, 2007
Aw come on, boob. Don' leave now. There's possible waves out there...
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1264. boobless
4:47 AM GMT on August 26, 2007
Alright fire.
I'm done. The CAPS dit it.
I will turn off and in.
Thanks ]
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1262. mississippiwx23
4:39 AM GMT on August 26, 2007
I think it is interesting about the year that had a strong system go south with a strong SE high followed by mostly 'fish storms', however lets not forget where the GFS originally had Dean headed...Florida. WAY further north than what it really did, so we cant really trust any track this far into the future, let alone development. All we can really get an idea of is an increase in waves moving off the coast of Africa.
Member Since: August 20, 2007 Posts: 3 Comments: 683
1261. fire831rescue
4:35 AM GMT on August 26, 2007
Do I need to post my Blob Alert again...?
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1260. boobless
4:31 AM GMT on August 26, 2007
Hosweather, keeps it in the slower mid level moist flow at or near 15N now. The other drives it south to the rip-roaring ITCZ??
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1259. hosweather
4:03 AM GMT on August 26, 2007

All the models performed well on Dean in the short term. GFS was truly outstanding in identifying Dean when he was still way out over Africa. Contrast this with NOGAPS which was still denying Dean when he had his ritual naming.

All I was wondering was whether anyone with more experience than I have in interpreting models could identify what it is the models see interacting with the wave at about 40W that causes the models to diverge so sharply at that point.
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1258. listenerVT
4:20 AM GMT on August 26, 2007
Sweet dreams, Keeper! :~)
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1257. listenerVT
4:17 AM GMT on August 26, 2007
Thanks KoritheMan!

Was just off checking the loops and looking at the Western Hemisphere Global Satellite.
Said blob doesn't look too exciting yet.
At least the power didn't go out (here) during Dean, eh?
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1256. KoritheMan
4:11 AM GMT on August 26, 2007
listenerVT: There's a wave south of CV that has a low with it, or so some people have said. I have not looked at QuikSCAT, so I don't know, but it's something to watch. The wave about to come off should be watched too.
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4:06 AM GMT on August 26, 2007
like the tropics i too am going asleep later all
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1254. listenerVT
4:03 AM GMT on August 26, 2007
Haven't been online tonight, but not for lack of interest.
Power went out...with the sun out! How's that fair? Don't we even get a storm to go with it? LOL! When the electric came back on, the wireless didn't. Our call to Tech Support got outsourced to "Harry" in India, who had us unplug and replug all the same things we had already unplugged and replugged and it still didn't come up.
So we had to wait until our son came over and discovered that the router had reset itself. After he changed a 0.1 to 1.1, we were back up and running.
So I definitely prefer our In(house)source to the outsourcing.
Anyway, how are the blobs tonight?
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1253. TheCaneWhisperer
3:55 AM GMT on August 26, 2007
Posted By: hosweather at 1:31 AM GMT on August 26, 2007.

A comparison of the GFS and CMC models on the the CV low is very interesting. Both show similar development over the next 60 hours at which time the disturbance is at about 40W. At that time there is an interaction with something (I don't know what) that causes the two models to begin a 180 degree divergence. GFS has the low in steady decline from that point on whereas CMC shows rapid development. Anyone have any ideas about what it is that is causing the model divergence.

CMC always shows rapid development, lol. GFS had stellar short term performance with Dean, I would follow that until proven wrong. Both are global forcasting models, not hurricane specific, and require a more in depth look than glancing at a low on the MSLP. You need to examine all the features of the model to determine if it is accurate or not.
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1252. fire831rescue
3:59 AM GMT on August 26, 2007
All this talk about GW on here earlier... I though ya'll were talking about Bush... Then I realized hmmmm.... GW = Global Warming. That's a discussion I will stay out of 'cause I have my own opinions.
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3:56 AM GMT on August 26, 2007
got to wait see what happens over the seait appears they are being dragged into the itzc
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1250. fire831rescue
3:56 AM GMT on August 26, 2007
Is it a fleshy blob or is it weather related? The only blobs I want to hear about need to be weather related.
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3:55 AM GMT on August 26, 2007
blob alert
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1248. fire831rescue
3:53 AM GMT on August 26, 2007
On a serious note, what do ya'll think about that one area over Africa about to enter the Atlantic? Any chance for development. It appears it will exit above the ITCZ. Of course, I don't have my contacts in, so I could be seeing things.
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1247. boobless
3:50 AM GMT on August 26, 2007
Blobs not dead yet. It and me. ]QuikScat
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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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