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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297. zingocat
6:30 PM GMT on August 24, 2007
I thought Florida had some of the best building codes in the country for hurricane forces. In NC things changed for codes after Fran and Floyd. I don't know how good, time will tell. But I don't think any house could not get damage on a 4 or 5 Cat. Jamaica has concrete houses, they must know something. Very few concrete houses in NC.
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296. bswigg
6:28 PM GMT on August 24, 2007
hey zingo...not too many blue tarps down here... you will see a few from Wilma, but that is like maybe 1 in 1000 roofs or so...not like it was last year at this time...This is from Miami up to Boynton beach area...
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295. Tazmanian
6:32 PM GMT on August 24, 2007
do you think i have what it takes to be a Featured Bloger i am asking you!



went me no by saying yes or no and i add your name

the ones that said yes are

texascanecaster1
NRAamy
TheStormWillSurvive
CosmicEvents
tornadofan
dean2007
HobeSoundShudders
ricderr
zingocat
groundswell
leftovers
MisterPerfect
MichaelSTL
KoritheMan
philliesrock
anvilhead
ryang
yankeerebel
mobilebayal
CrackerMI
Tropicnerd13
Twinkster
seafarer459
Weather456
Hurricaneblast
JustSouthofEquator
sammo
StormW
lowerbamagirl
Baybuddy
Gatorxgrrrl
SBKaren
CaptnDan142
Raysfan70
SETXHchaser
ajcamsmom
pslfl2
mobilebayrat
weatherboykris
tornadodude
1900hurricane
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BtnTx
bswigg
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mgreen91
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PascagoulaGal
russm1
salter



the ones that said no are

getalife
GoofOff
weatherblog
HurricaneMyles
BahaHurican
catfuraplenty

61 out of 6 said yes




ok all here is what you all are voteing for


note this is a yes or no vote olny
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294. Skyepony (Mod)
6:25 PM GMT on August 24, 2007
zingocat~ still have blue tarps around here, but they aren't the originals. They magically shred after a year & people put up new ones.

hunter~ Hurricane David..near sunset. It was clear in the middle with the east eye wall lit up fire red at the top. Ran across the street to check on some horses. Surreal.
Member Since: August 10, 2005 Posts: 161 Comments: 37355
293. skibrian95
6:28 PM GMT on August 24, 2007
zingocat...

don't count on the new roofs...most are still shingle, not nearly as good as tile, and frankly, the workmanship...if florida building standards plus a general rush to get people dry again has anything to say...will be shoddy in many of the fixes :(
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290. zingocat
6:25 PM GMT on August 24, 2007
Glad to hear the tarps are gone. If Florida has a storm maybe new roofs will do better.

Thinking about going to Gulfport, heard there is still a lot of rebuilding going on down there. Church's there are organized to rebuild from Katrina.
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287. Rlennon
6:24 PM GMT on August 24, 2007
LisenerVT


Link

Might have been this storm.
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286. boobless
6:00 PM GMT on August 24, 2007
First and last GW post for me:
I'm sure you've heard variations of the following opinion before. Here or somewhere else. But a good one imo: It is probably too late/impossible to return earth to "normal". If GW is due to some other process we can't/don't see/prove (insert your theory here)then the final doomsdays of extremely high afternoon temps are inevitable anyway. Closed loop system here on earth. Too many fish in the tank.

On a lighter note,cow flatulence has been blamed for a portion of this controversy. This is unfair to cows, but if true we need to thin the herd. If you asked a cow for a root cause I'm sure they would blame it on too many people. Anybody have any data correlating world population w/GW? My kitchen is too hot and crowded at Christmas when all of us get together. Time to thin the herd? Just as long as me and mine make it through the first cut ]

CO2 production from GW discussions (present company excepted) across the globe this very minute would choke a smaller planet.
Things are warmer then they were. I believe this. All I can suggest is that the Met community learn the new rules for heat distribution and tweak the models as required.

So, let's sling some heat around! Bring on the waves,blobs,swirls and storms that affect sparsely populated areas only.
Moo
285. skibrian95
6:20 PM GMT on August 24, 2007
zingocat...i will say not really...i can't remember the last time i saw one. they were around for quite a while. a lot of the reason is simply trying to bring in enough labor to cope with the 4 hurricanes that crossed florida that year (5 including the panhandle??). when you have a booming home building market, normal repairs as homes age, and then several storms...work did get backed up for a long time.

i just played a rugby tournament in Ft. Meyers last month and went by the hardest hit areas where charley came ashore. the trees still testify to his presence...but i don't remember seeing blue tarps as i passed the areas around punta gorda (landfall).

i think most people have their roofs fixed now.

i know my church and others did a lot to get teams out to help anyone that could not afford reconstruction...even a year out. so yes...it was quite a problem for some time.
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283. gthsii
6:18 PM GMT on August 24, 2007
water expands as it warms

it also expands as it freezes...H20 is one strange molecule
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282. austxanne
6:14 PM GMT on August 24, 2007
ainfla...I didn't take it that way....my posts sound so formal. i didn't get that you were sort of making a joke when you wrote that. sorry.

weatherhunter, i was in the eye of Carla....long time ago...very weird going outside and standing looking up..strange after all the noise you have until then...
its like when you're in a hard rain and drive under an overpass..
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281. Weather456
6:20 PM GMT on August 24, 2007
Tropical Disturbance Summary

Broad area of scattered clouds and showers over the area from 90W to 75W

north of 20N associated with an upper level low nover the East Gulf of

Mexico and a tropical wave near 88W-89W. This disturbed area will continue

west during the next 12-24 hrs merging with a broad area of low pressure

of the Bay of Campeche in 24 hrs. Wind shear is currently 5-10 knots over

the area and expected to remain so while it moves over the Bay.

Convection is over the Gulf of Drien and Gulf of Panama where a passing

tropical wave is enhancing lift along the EPAC monsoon trough. Two models,

the CMC and NOAGAPS develops this area into a weak to moderate tropical

cyclone in 24-48 hrs. By 60 hrs, the disturbance is moving ashore

Nicaragua and beyond 90 hrs, emerging into the Bay of Campeche. Current

wind shear ranges from 15 to 30 knots and expected to drop to 5-10 knots

in 24-48 hrs.

A tropical wave is analysed 1200 UTC near 48W south of 15N moving west

near 15 knots but recent visible imagery indicate that it maybe further

west at 1515 UTC. Visible imagery also indicate a swirl of clouds neat

9.65N/47.35W. Little convection is currently associated with this wave.

Wind shear is currently 5-10 knots near the the wave but sharply increase

as one goes north. This pattern is expected to continue for the next 24-48

hrs.

Lasttly, a tropical wave is near 21W south of 19N moving west near 10-12

knots. Modeate tos trong convection to the east of the wave between the

axis and the African Coast.

by W456


Member Since: July 24, 2005 Posts: 407 Comments: 19076
280. zingocat
6:17 PM GMT on August 24, 2007
I have heard there are still blue canvas on roofs in Florida because of 2004. Is that true skibrian95?
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279. listenerVT
6:13 PM GMT on August 24, 2007
As a very young child I experienced a storm that must have hit Rhode Island. All I know is that I was told to stay on the big bed in my parents' room, and that I mustn't go near the windows. I remember fierce wind, and things banging around, and that my mother was kind of freaked. It stopped and I went to look out the window, but my mother caught me and said it was coming again and I had to get back onto the bed. I must have been a pre-schooler, but can't remember more than that. Wish I knew (and Mom died some years ago). I was born in 1955. Did anything interesting hit Rhode Island in the latter half of the 50's? Interesting that I had a really hard time staying on the bed, because I wanted so much to look out that window! (Even then.)
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278. Skyepony (Mod)
6:13 PM GMT on August 24, 2007
I thought that surface low off the coast was looking weaker. Back up to 1015mb from 1013 this morning (according to NHC). I've got 1015.5mb & ↓ here in Melbourne.
Member Since: August 10, 2005 Posts: 161 Comments: 37355
277. skibrian95
6:15 PM GMT on August 24, 2007
i've been through 4 hurricanes total...but only that sickening charley came directly over my house. 3 that season crossed metro orlando. apparently, hurricane strength winds from a tropical storm had not hit orlando since 1964 (if I remember the reporting at the time). Then 2004 we saw 3.
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276. extreme236
6:15 PM GMT on August 24, 2007
Posted By: nash28 at 6:14 PM GMT on August 24, 2007.

We are right on par with a season slightly above average.


yep, but due to la nina, im thinking the late season part of this hurricane season will be a bit more active than usual
Member Since: August 2, 2007 Posts: 19 Comments: 19234
274. icepilot
12:10 PM CST on August 24, 2007
Jesus, study physics before you make comments about the physics of a process

- water expands when heated duh - But I don't think it will be enough to raise sea levels significatly

water contracts when cooled until the ice crystals form at which time it expands as air is trapped in the crystal matrix.

First year sea ice HAS salt in it (trapped in the ice crystals. If it lives throught a summer melt the salt is flushed out.

Seawater (+/- 32 PPM salts) freezes at 28 deg F or -2 C. The normal temp of a col of open water in the arctic starts at around -1.5C and INCREASES with depth till a thermocline is reached and it again decreases (it can get colder than -2C at depth due to the increased pressure)

Wind blowing acrossed open water creates wind driven currents - which brings warmer water up from slightly beneath the surface and it causes mixing of the surface layers both which slows the freezing process.'

Is "Gobal Warming" happening -the concensus is yes. (at one time, the concensus was the world was flat and the Sun revolved around the Earth) Does it matter Why? Only if we intend to do someting about it. (if we can) Will GW effect the population of the world? Yes if it continues as curently measured. The last question is "In what time frame will the effects take place and how 'Bad' will it get"......

I'm off til the next Tropical event happens - there is still several months of the season left - and the above type stuff belongs in Randy's blog anyway
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273. Tazmanian
6:13 PM GMT on August 24, 2007
come to my blog and vote
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271. nash28
6:14 PM GMT on August 24, 2007
We are right on par with a season slightly above average.

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270. extreme236
6:13 PM GMT on August 24, 2007
hurricane bill is a good example of how a ULL can develop and how any non tropical low pressures can develop
Member Since: August 2, 2007 Posts: 19 Comments: 19234
269. zingocat
6:12 PM GMT on August 24, 2007
Must not live near the coast of NC. Weatherhunter need to live east of Raleigh if you want hurricane. If you want ice or snow live west of Raleigh. They tell me I was in the eye of Hazel, but I was a baby.
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268. skibrian95
6:11 PM GMT on August 24, 2007
- In 1997 HURRICANE BILL developed from a non-tropical upper level low above Puerto Rico. Though infrequent a ULL can work its way down to the surface and become tropical.

there i have it...an ULL is rare to form into something tropical.

here is something that I must study up on as I don't fully understand the dynamics of this sort of system. i am still but a padawan learner...
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267. listenerVT
6:12 PM GMT on August 24, 2007
extreme236 ~

Well looking back since 2000, the F named storm has formed in late august and early september. (excluding 2005 as it was so abnormal). Also, Felix in 2001 formed on september seventh


Thanks! Seems like we're about par, then.
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266. skibrian95
6:09 PM GMT on August 24, 2007
weatherhunter...
i have all kinds of stories...but i'm not a journalist. i probably can't tell you much better than the scenes you have probably seen on TV with past guys like Mr. cantore trying to be at the center of landfall. pictures do a lot better than what I can write! i will say this...pictures, being 2D, really can't do full justice. it's a lot different with the wind howling AROUND your whole house rather than howling through the TV IN your house.
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265. zingocat
6:08 PM GMT on August 24, 2007
I was in the eye of Floyd or Fran, forgot which. One broke up at landfill, eye kinda blurred. F word storms, never good.

And yes, I am just lurking a few minutes.
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264. Skyepony (Mod)
6:04 PM GMT on August 24, 2007
Indialanticgirl~ 50% chance of rain for the afternoon, weekend looks like maybe more. Moisture is up but the air is sinking, inland has a better chance than us. I've seen a few incidence of sprinkles here since midnight. Stopped for now, looks gloomy. Beach sounds nice today, any breeze over there?
Member Since: August 10, 2005 Posts: 161 Comments: 37355
263. Inyo
6:05 PM GMT on August 24, 2007
Is that true about cirrus clouds? If so, that is good news
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262. Rlennon
6:08 PM GMT on August 24, 2007
Yes, hurricane opal.
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261. skibrian95
6:08 PM GMT on August 24, 2007
i saved a .jpg of the wunderground echo at the moment that the power went out...wish i could post it for you! but i don't have it on a sever and i don't think i can upload it.
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260. moonlightcowboy
6:05 PM GMT on August 24, 2007
The image “http://upload.wikimedia.org/wikipedia/commons/6/64/Hurricane_Bill_%281997%29.JPG” cannot be displayed, because it contains errors.
- In 1997 HURRICANE BILL developed from a non-tropical upper level low above Puerto Rico. Though infrequent a ULL can work its way down to the surface and become tropical.

HURRICANE BILL and how it formed from a ULL.
Bill developed from a large upper-level low that separated from the mid-oceanic trough northeast of Puerto Rico. On 7 July, satellite images indicate that cloudiness and showers associated with the upper- level low began to increase and although surface pressures were quite high north of Puerto Rico there was a small perturbation of the wind field and a trough at the surface. A low pressure center formed from the trough just east of the Bahamas and moved toward the west-northwest. The upper-level low moved southwestward into the Caribbean Sea resulting in a decrease in the wind shear over the surface low.

The first indications that a tropical depression might be forming was a 24-hour pressure drop of near 3 mb in the eastern Bahamas as the area of low pressure approached. Convection then gradually became organized and it is estimated that a tropical depression formed near 0600 UTC 11 July. By then, the tropical cyclone was already moving northeastward ahead of a cold front located over the eastern United States. The system reached tropical storm status by 1200 UTC on the same day.

Bill continued moving toward the northeast about 20 to 25 knots and reached cool waters. An eye was depicted on high resolution visible images at 1300 UTC 12 July, suggesting that Bill reached hurricane strength in spite of the cool waters. A special Dvorak classification from the Tropical Analysis and Forecast Branch (TAFB) indicated that Bill reached its peak intensity of 65 knots at 1500 UTC 12 July. The minimum pressure estimated at that time was 986 mb. Thereafter, Bill became absorbed by a frontal system and was no longer identifiable by 0600 UTC 13 July. Bill was never forecast to become a hurricane.
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259. weatherhunter
6:07 PM GMT on August 24, 2007
For Real? Like what was it like? I Live in North Carolina so I really don't know what its like to be hit by a hurricane
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258. skibrian95
6:06 PM GMT on August 24, 2007
weather hunter.

i was in the eye of charley at night
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257. skibrian95
6:05 PM GMT on August 24, 2007
LLJ

that must be it...that flow from the south must be stronger...and is in one direction...as strong as it looks, that would dissipate the low rotation.

I guess that's the answer. earlier in the day, it wasn't showing as much as the storms had not begun to fire.
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256. weatherhunter
6:04 PM GMT on August 24, 2007
Hey I know I don't really post here alot but I do read it Has anybody here ever been in like the eye of a hurricane?
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255. AinFLA
5:56 PM GMT on August 24, 2007
austxanne, it was a rhetorical question. No harm or dispersions meant.
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254. groundswell
6:01 PM GMT on August 24, 2007
skibrian-yes, the low probably isn't the cause, but every little bit helps and if there is any development at all, the pulse will be reflected in wave heights immeadiately due to the land proximity.
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253. skibrian95
6:02 PM GMT on August 24, 2007
indialantic--

MLB has forecast 50% chance storms for the next 3-4 days. lots of moisture now will fire off the dirunal storms that we are used to.

speaking of that moisture...there is a problem with those radar echos...there is definite rotation over the gulf stream...but a definite flow from the south coming in...though I don't see why as it is against the grain of the Low rotation...maybe it is a sign that the low is weakening?
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251. extreme236
6:02 PM GMT on August 24, 2007
Nice chart STL. It shows that everyone who says this season is a bust is wrong. As, we are already above average
Member Since: August 2, 2007 Posts: 19 Comments: 19234
249. Indialanticgirl
5:57 PM GMT on August 24, 2007
it may be raining in Melbourne but over on the beachside it is still painfully HOT AND SUNNY
Skyepony, will it rain all weekend, storms????
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247. listenerVT
5:55 PM GMT on August 24, 2007
MichaelSTL...(and all)...
I see what you mean about the number of storms.
Yet, in that context, what is the significance of unusual storms, such as the huge cyclone that slammed into Oman this year (first one in 4 or 5 decades there, I believe)?
Are we seeing primarily a shift to fewer, larger storms with tracks heretofore infrequent or unheard of?
How does anyone prepare for catastrophic unknowns?
Will we need a worldwide relief fund dedicated to victims of unpredictable storms?
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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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