The climate is changing: the Arctic Dipole emerges

By: Dr. Jeff Masters , 3:53 PM GMT on December 11, 2009

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The dramatic loss of Arctic sea ice in recent years has created a fundamental new change in the atmospheric circulation in the Northern Hemisphere that has sped up sea ice loss and is affecting fall and winter weather across most of the Northern Hemisphere, according to several recent studies. Arctic sea ice loss peaks in September and October, exposing a large area of open water that heats the air above it. This extra heat has helped drive September - November air temperatures in the Arctic to 1°C (1.8°F) or more above average over about half of the depth of the lower atmosphere (Figure 1). This deep layer of warm air has grown less dense and expanded, pushing the top of the troposphere (the lower atmosphere) higher. The result has been a decrease in the pressure gradient (the difference in pressure) between the North Pole and mid-latitudes. With not as much difference in pressure to try and equalize, the jet stream has slowed down in the Arctic, creating a major change in the atmospheric circulation for the Northern Hemisphere.


Figure 1. Cross section of Arctic temperature anomaly from 1000 mb (the surface) to 300 mb (roughly, the height of the top of the lower atmosphere or troposphere). Cross section is taken along the Date Line (180°W), from 60°N latitude (left side) to the North Pole (right side), for September - November for the 12-year period 1998 - 2009. Three year averages were done to reduce the amount of year-to-year noise associated with natural variation. Other cross sections along different lines of longitude show similar results, though typically with more warming aloft and less warming at the surface. Image credit: NOAA/ESRL.

A new atmospheric pattern emerges: the Arctic Dipole
In a 2008 article titled, Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system Zhang et al. show that the extreme loss of Arctic sea ice since 2001 has been accompanied by a radical shift of the Arctic atmospheric circulation patterns, into a new mode they call the Arctic Rapid change Pattern. The new atmospheric circulation pattern has also been recognized by other researchers, who refer to it as the Arctic Dipole (Richter-Menge et al., 2009). The old atmospheric patterns that controlled Arctic weather--the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO), which featured air flow that tended to circle the pole, now alternate with the new Arctic Dipole pattern. The Arctic Dipole pattern features anomalous high pressure on the North American side of the Arctic, and low pressure on the Eurasian side. This results in winds blowing more from south to north, increasing transport of heat into the central Arctic Ocean. The Arctic Dipole pattern occurred in all summer months of 2007 and helped support the record 2007 summer reduction in sea ice extent (Overland et al., 2008). Overland et al., 2010 also found that the Arctic Dipole pattern tended to create an increase in easterly winds in the lower half of the atmosphere of 40% in fall, between 2002 - 2008. Fall 2008 through spring 2009 featured the old AO pattern. The new Arctic Dipole pattern re-appeared in June - July 2009, but the old AO pattern dominated in August - September, resulting in greater sea ice extent than in 2007 and 2008. The Arctic Dipole pattern was active again in October, inactive in November, and reasserted itself this December. As a result, Arctic sea ice reached a new record minimum for a 10-day period in early November, increased above record lows during late November and early December, and appears poised again to reach a new record minimum later this December (Figure 2).


Figure 2. Sea ice extent in the Arctic for this year (blue line) compared to the record low year of 2007 (green line) and 1979 - 2000 average (gray line). One could make the ice loss looks less significant by using the full satellite data record from 1979 - 2008 for the average. Image credit: National Snow and Ice Data Center.

Arctic Dipole blamed for colder winters in East Asia
It turns out that the new Arctic circulation patterns help to intensify the Siberian High, a large semi-permanent region of surface high pressure prevalent in winter over Siberia. According to Honda et al. (2009), this results in increased flow of cold air out of the Arctic in early winter over eastern Russia, Japan, Korea, and eastern China, causing colder temperatures. By late winter, the pattern shifts, resulting in colder than average temperatures from East Asia to Europe.

Arctic Dipole blamed for drier winters in Northern Europe
Francis et al. (2009) found that during 1979 - 2006, years that had unusually low summertime Arctic sea had a 10 - 20% reduction in the temperature difference between the Equator and North Pole. This resulted in a weaker jet stream with slower winds that lasted a full six months, through fall and winter. The weaker jet caused a weaker Aleutian Low and Icelandic Low during the winter, resulting in a more negative North Atlantic Oscillation--a pattern that usually brings reduced winter precipitation over Alaska and Northern Europe and increased precipitation over Southern Europe. A more negative NAO also tends to bring cold winters to eastern North America and Europe. Though it was not mentioned in the article, reduced Arctic sea ice may also cause dry early winter conditions in the U.S. and the Caribbean (Figure 3). The authors noted that strong La Niña or El Niño events can have a much larger influence on the wintertime atmospheric circulation, which will overshadow the changes due to Arctic sea ice loss.


Figure 3. Difference in early winter precipitation (November - January) between five years that had low Arctic sea ice (2005, 2006, 2007, 2008, and 2009), and five years that had unusually high Arctic sea ice extent (1981, 1984, 1986, 1989, 1993). Note that low sea ice may be responsible for dry conditions in early winter for the Caribbean and most of the U.S.

Commentary
Arctic sea ice loss appears to have created a new atmospheric circulation pattern that brings more warm air in the Arctic, creating a positive feedback loop that causes even more sea ice loss. This feedback loop increases the likelihood that an ice-free Arctic in the summer will indeed come by 2030, as many Arctic experts are predicting. It's worth noting that such an atmospheric circulation shift was not predicted by the climate models. Indeed, the loss of Arctic sea ice over the past three years exceeds what any of our models were predicting (Figure 4). While we can rightly criticize these models for their inaccuracy, we should realize that they are just as capable of making errors not in our favor as they are of making errors in our favor.


Figure 4. Arctic sea ice extent from observations (thick orange line) and 13 model forecasts used to formulate the 2007 IPCC report (light lines). The thick black line is the multi-model ensemble mean, with the standard deviation plotted as a dashed black line. Image has been updated to include the observed 2008 and 2009 measurements. None of the models predicted the record 2007 sea ice loss. Image credit: Arctic sea ice decline: Faster than forecast by Stroeve et al., 2007.

References
Francis, J.A., W. Chan, D.J. Leathers, J.R. Miller, and D.E. Veron, 2009, "Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent", Geophysical Research Letters, 36, L07503, doi:10.1029/2009GL037274.

Honda, M., J. Inoue, and S. Yamane, 2009. Influence of low Arctic sea - ice minima on anomalously cold Eurasian winters, Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.

Overland, J. E., M. Wang, and S. Salo, 2008: The recent Arctic warm period, Tellus, 60A, 589.597.

Overland, J. E., and M. Wang, 2010: Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice. Tellus, 62A, 1–9.

Richter-Menge, J., and J.E. Overland, Eds., 2009: Arctic Report Card 2009, http://www.arctic.noaa.gov/reportcard.

Simmonds, I., and K. Keay (2009), Extraordinary September Arctic sea ice reductions and their relationships with storm behavior over 1979.2008, Geophys. Res. Lett., 36, L19715, doi:10.1029/2009GL039810.

Wu, B., J. Wang, and J. E. Walsh, 2006: Dipole anomaly in the winter Arctic atmosphere and its association with sea ice motion. J. Climate, 19, 210-225.

Zhang, X., A. Sorteberg, J. Zhang, R. Gerdes, and J. C. Comiso (2008), Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system, Geophys. Res. Lett., 35, L22701, doi:10.1029/2008GL035607.

Jeff Masters

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Member Since: December 5, 2005 Posts: 0 Comments: 74
Quoting gordydunnot:
Bordonaro I don't know if I like this saying per Se, but its all good red, blond, brown, and black hair. Me myself brown hair and eyes only one who looks like mom, the rest look completely Irish. Its the person that counts anyway looks or not. I think the news has shown us that. I love hurricane season since I was a kid nothing trumps mother nature, but winter is very interesting maybe does more damage. Good night all.


I fell in love with weather at 7 yrs old. I grew up in the Northeast, so I enjoy all types of weather.

I now live in the southern end of Tornado Alley, in Arlington, TX. I have been here 29 yrs, so my favorite weather to follow is severe thunderstorms.

From March 1-June 1 each spring we have numerous severe thunderstorm warning and several tornado warnings for Dallas and Tarrant counties, the heart of our metro area.

I have seen 115MPH wind gusts, grapefruit sized hail, several funnel clouds which later became tornadoes. Whenever we have a surface Low nearby, we always seem to be in the "triple point". That is the warm sector, close to where the warm front, cold front and the surface Low meet.

You have SE surface winds, warm and very humid, SW wind shear and dry air being fed into a negatively tilted trough, with a cold front right behind the "dryline". The lift is enhanced and the wind shear causes explosive development of storms.

Every scenario is a new adventure! That will determine if the threat is strong straight line winds up to 80MPH, large hail and torrential rain or a large hail and tornado. Thankfully, it's usually the 1st two..

Member Since: August 25, 2009 Posts: 20 Comments: 6785
Latest Weather Observations for Darwin
12/12 16:00
Temp:26.0C(78.8F)
Wind: 32km/h(19.9mph)
Gusts: 43km/h (26.7mph)
Pressure: 1004.0 hPa
Rain since 09:00: 114.8mm (4.5')
RADAR loop
Member Since: Posts: Comments:
Bordonaro I don't know if I like this saying per Se, but its all good red, blond, brown, and black hair. Me myself brown hair and eyes only one who looks like mom, the rest look completely Irish. Its the person that counts anyway looks or not. I think the news has shown us that. I love hurricane season since I was a kid nothing trumps mother nature, but winter is very interesting maybe does more damage. Good night all.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
Good night all! Peace, love and happiness to all. Be blessed!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting gordydunnot:
And don't get me started on Motown. My whole point is that while today there are usually a couple of good bands there where to many to count then, even country was better then.


Here's some old, classic Motown music.
Martha Reeves and the Vandellas
Dancing in the Street


Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting Motttt:
late 70's'


PSST, hey you, 1970, see link below :0)!!!



Link
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting gordydunnot:
Bordonaro nice choose you got a lot of Blood Brothers with that choice. By the way congrats on the good looking grand kids lucky they don't look to much like grandpa. J/K


Thank God for that! My wife, my mom and my daughters all had blonde/red/brunette mixed hair. Starts blonde and as those years creep by the brunette and red hair creep in! My daughter has dirty bolde hair, my son in law has blonde hair also! My dad, grand dad and dreat grandfather and myself have black hair.

I grew up with all the music from the late 50's through the late 70's. I am a classic rock or christian rock lover. No heavy metal, no rap either!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
And don't get me started on Motown. My whole point is that while today there are usually a couple of good bands there where to many to count then, even country was better then.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
Atmoaggie Who and Pink Floyd what can I say, how about Sly and the family Stone.Oops Led Zeppelin God.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
Bordonaro nice choose you got a lot of Blood Brothers with that choice. By the way congrats on the good looking grand kids lucky they don't look to much like grandpa. J/K
Member Since: August 18, 2008 Posts: 0 Comments: 3113
(Just for Ike and Patrap)
Don't leave out Zeppelin!

Also partial to the Who, Jackson Brown, and Floyd, myself.
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Sorry Pcola just thought I was using an abbreviation. Chicklit there were to many good bands to many count. Some of my favorite Albums Worst of the Jefferson Airplane,( Dont you want somebody to love). Best of Simon and Garfunkel any song. On and On And On with the bands Beatles , Rolling Stones, Journey, help I must stop now not enough time.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
Local forecast I made for my area at 6:30PM EST tonight.

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Yep. When the temps from rural stations during the early 1900s are adjusted DOWNWARD they show the same trend as the runway ones.

Nothing to see here. All tidied up to fit the mold...
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Quoting Tazmanian:



ok
Quoting MrstormX:

There were three other Davids also:

Hurricane David


Typhoon David


And there was also Tropical Cyclone David but I couldn't find any pics.


Hurricane David was the first storm I went though. Very interesting, got my attention.
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Quoting Bordonaro:
Global climate change, rising sea levels, melting Arctic Ice Cap, Super Typhoons in the W PAC in November, a cyclone in India, in their December dry season, El Nino, record heat, wild fires, and drought in Australia, with a CAT 3 cyclone expected by Tuesday of next week, and it's only the beginning of their hurricane season, US Blizzards from coast to coast, tornadoes, floods, hurricane force wind gusts coast to coast, in the 1ST winter storm of the season, Canadian/US Lake Effect Snows up to 3-5 FT in 48 hrs, record highs in S FL!! Could these things be the sign of a changing climate.

Then I thought of this song, from the 1960's while I was growing up"

late 70's'
Member Since: September 10, 2001 Posts: 0 Comments: 213
Quoting stormygace:
210. that's where the Black Plague started in the 1300s. Might be the cure for the earth's fever. Wouldn't even need the AGW to stop using more than their "fair share" by over reproducing.

http://en.wikipedia.org/wiki/Bubonic_plague


Ironic you should mention that.
China seals off town amid plague outbreak
3rd death linked to infectious disease caused by Black Death bacteria


pneumonic plague

Nite all.
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Quoting pearlandaggie:
UHIE...so easy even a 6th grader can spot it... :)



I have to stop wasting my time reading the peer-reviewed literature. I can just go to YouTube and find the father/son research posts.

Peterson, T.C., Assessment of urban versus rural in situ surface temperatures in the contiguous United States: No difference found, Journal of Climate, 16, 2941-2959, 2003.

One of several studies making the same conclusions.





Member Since: Posts: Comments:
Global climate change, rising sea levels, melting Arctic Ice Cap, Super Typhoons in the W PAC in November, a cyclone in India, in their December dry season, El Nino, record heat, wild fires, and drought in Australia, with a CAT 3 cyclone expected by Tuesday of next week, and it's only the beginning of their hurricane season, US Blizzards from coast to coast, tornadoes, floods, hurricane force wind gusts coast to coast, in the 1ST winter storm of the season, Canadian/US Lake Effect Snows up to 3-5 FT in 48 hrs, record highs in S FL!! Could these things be the sign of a changing climate.

Then I thought of this song, from the 1960's while I was growing up"

Member Since: August 25, 2009 Posts: 20 Comments: 6785
417. I hear they have it pretty well contained. It's pnuemonic plague which can kill within hours and is airborne. I guess were lucky, though, that they have laws in place that allow them to quarantine entire areas without regard to human rights.
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Quoting MrstormX:

There were three other Davids also:

Hurricane David


Typhoon David


And there was also Tropical Cyclone David but I couldn't find any pics.

david 1979 a long time ago my first storm
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210. that's where the Black Plague started in the 1300s. Might be the cure for the earth's fever. Wouldn't even need the AGW to stop using more than their "fair share" by over reproducing.

http://en.wikipedia.org/wiki/Bubonic_plague
Member Since: Posts: Comments:
Member Since: July 17, 2009 Posts: 71 Comments: 27397
Quoting MrstormX:

There were three other Davids also:

Hurricane David


Typhoon David


And there was also Tropical Cyclone David but I couldn't find any pics.




ok
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Upon checking satellite imagery, it appears that the main convection of Cleo was hit in the past 24 hours by a package of the ITCZ. This caused Cleo to loop back counter-clockwise before the original convection disapated and the ITCZ system joined the circulation, causing a circulation flare-up in the northeast and an explosive convective flare-up in the southwest, while the former Cleo's main circulation remains in the southeast. The convection then destroyed itself as quickly as it formed, causing the "shock wave" effect, while the northeast circulation weakened. Now the entire system is reorganising around itself with no dominant COC. That's when a chain of chain of convection from Ward joined Cleo at the equator. Link

Similar behaviour has occured with ward, which rapidly organised itself from a wave to a strong tropical storm in less than 24 hours. More recently, an area of convection almost literally exploded, causing the storm to loop back on itself. After the convection started to weaken, a front-like feature to the northwest of the storm swung south, then back north toward a storm in Southern China, while the southwestern line of convection meets Cleo at the equator. Much of this progressed just in the last six hours. Link

The Australian system has organised itself in the past 24 hours, despite part of the system being on land. It was tracking in a generally WSW direction until something nudged it south in the past 12 hours, where at the coast it comes in contact with 32C warm water. Finally, there seems to be a tropical-looking wave organising near 10S, 172E, where water temperatures are near 29C and the system seems to be part of a front-like ICTZ pushing southeast toward the Humboldt. Link

Indian Ocean wind shear map


Australia wind shear map


SE Pacific wind shear map (165E to 135W)
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Quoting Tazmanian:
cool a storm will soon be name me David

There were three other Davids also:

Hurricane David


Typhoon David


And there was also Tropical Cyclone David but I couldn't find any pics.

Member Since: Posts: Comments:


AOI

AOI

AOI

AOI

Humor in Comments
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cool a storm will soon be name me David
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Quoting Orcasystems:


I love it when Ont gets snowed in :)


Except that not everybody gets snowed in. A friend of mine who lives a couple kilometres north of me says that their house has a door that opens inward so one can get out when they would otherwise be "snowed in". And don't forget that giant Victoria snowstorm that once brought 60 cm to the city!


Quoting HadesGodWyvern:
hmm. Cleo should be in the center of this radar with another disturbance at 5S 85E



Do you mean satellite? Cleo spans the whole region from 20S to the equator and from 65E to 80E. It has split into two circulations within the past 12 hours, with the southwest circulation looking like a shock wave (it was actually a large area of convection just a couple hours ago, and a looser convection has drifted north of 10S. The wave behind it might also interact both with the Australian system (when that storm affects the high pressure system west of Australia) and Cleo as well. Just 12 hours ago, Cleo was much more organised, with a clearly identifiable center and convection around it. Now it has completely expanded and split into two. Unusual behaviour was noted in the previous tropical cyclones, in the West Pacific, Nida (which exploded in size after weakening to a cat. 4 and creating a hole in the subtropical ridge) and TS 28W (which formed after combining the main convection of Nida and part of an ITCZ system from the equator, and then thowing out anotehr piece of circulation which twice formed and disappated near the Philippines, and is still located near the country). This may be having an effect, as I previously hypothesized, on global SSTs and storm tracks.
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409. HadesGodWyvern (Mod)
hmm. Cleo should be in the center of this radar with another disturbance at 5S 85E

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Quoting AstroHurricane001:


I live north of KOG, and currently there's about 18 cm of snow on the ground, after the snowsqualls. Toronto only got about 5 cm from the storm and less than 1 cm from the squalls. However, some places hit by the squalls have gotten close to a metre of snow, and yesterday the longest snowsquall from Lake Huron to Georgian Bay extended past the Bracebridge-Huntsville-Orillia area, past the Kawarthas and Petawawa, past Ottawa, past Montreal, past Quebec City, and into the Gulf of St. Lawrence!


I love it when Ont gets snowed in :)
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Quoting Chicklit:

You don't have a blog, Astro.
I recommend you start one as we need all the help we can get. Consider it public service!

Actually, he can access his settings etc through the MY QUICK MENU at the top of this page.

The programming must be set to identify a member as a blog only if they actually post something in their blog.

While astro might not be identified as a blog, he still can use the various menus to change various settings.



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Quoting gordydunnot:
Bordonaro I hope you don't think I was upset with your comment.I was just posting some old references to three dog night. I'll leave it to musical experts Moody Blues vs (3 dog night) was no slouch either. Rodney Dangerfield
If you're talkin' that era, my vote would have to be America.
img src="" alt="" />
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Quoting gordydunnot:
Pcola Clint's got to many to count. Well do you feel lucky Punk.We could probably start a blog on that alone. Lastly that's an interesting storm just east of India.

Had to read back and see why you were calling me a punk, only to found out you were actually referencing a comment PensacolaDoug made. :)
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Quoting HadesGodWyvern:
The convection south of Ward is what could be "David" or 07R Cleo is closer to Madagascar now


Cleo is now extremely large in size and disorganized, as I previously mentioned. It even extends to the equator, where it comes into contact with Ward's spiral band. Is David the name of the next S. Indian Ocean storm that could from?


Quoting Chicklit:

You don't have a blog, Astro.
I recommend you start one as we need all the help we can get. Consider it public service!


I am planning on starting blog entries soon, mostly talking about the signs of climate change, Southern Ontario weather, and interesting weather phenomena or patterns worldwide. However, do not expect a regularly reliable blog in terms of timing, as I am often rather busy.


Quoting HadesGodWyvern:
Date/Time(IST)
Position (lat. 0N/long. 0E)
Sustained maximum surface wind speed (kmph)

12-12-2009/0230
9.5/84.5
75-85 gusting to 95

12-12-2009/0830
10.0/84.0
65-75 gusting to 95

12-12-2009/1430
10.5/83.5
65-75 gusting to 95

12-12-2009/2030
10.5/83.0
65-75 gusting to 105

13-12-2009/0230
11.0/82.5
65-75 gusting to 105

13-12-2009/0830
11.5/81.5
65-75 gusting to 105

13-12-2009/2030
11.5/80.5
55-65 gusting to 95

14-12-2009/0830
11.5/78.5
45-55 gusting to 65

---
this format will look poor however I just noticed the intensity looks very oddish


Is that for the middle of the Atlantic Ocean, or a tropical storm?
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403. HadesGodWyvern (Mod)
Date/Time(IST)
Position (lat. 0N/long. 0E)
Sustained maximum surface wind speed (kmph)

12-12-2009/0230
9.5/84.5
75-85 gusting to 95

12-12-2009/0830
10.0/84.0
65-75 gusting to 95

12-12-2009/1430
10.5/83.5
65-75 gusting to 95

12-12-2009/2030
10.5/83.0
65-75 gusting to 105

13-12-2009/0230
11.0/82.5
65-75 gusting to 105

13-12-2009/0830
11.5/81.5
65-75 gusting to 105

13-12-2009/2030
11.5/80.5
55-65 gusting to 95

14-12-2009/0830
11.5/78.5
45-55 gusting to 65

---
this format will look poor however I just noticed the intensity looks very oddish
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Quoting AstroHurricane001:


When I click on Ignore user, it just goes straight to my own blog. In the control panel on the right-hand side, there is no ignore box or list that I can modify. Must be a problem with IE.

You don't have a blog, Astro.
I recommend you start one as we need all the help we can get. Consider it public service!
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401. HadesGodWyvern (Mod)
The convection south of Ward is what could be "David" or 07R Cleo is closer to Madagascar now
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Pcola Clint's got to many to count. Well do you feel lucky Punk.We could probably start a blog on that alone. Lastly that's an interesting storm just east of India.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
399. HadesGodWyvern (Mod)
Information from Tropical Cyclone Technical Bulletin From TCWC Darwin

Forecast and intensity
=======================
12 HRS: 12.8S 129.8E - 35 knots (CAT 1)
24 HRS: 12.6S 128.7E - 45 knots (CAT 1)
48 HRS: 13.0S 127.5E - 65 knots (CAT 3)
72 HRS: 14.4S 126.0E - 55 knots (CAT 2)

Additional Information
======================
Tropical low 01U has improved significantly in organisation during the past 12 hours with spiral banding features and a CDO developing overnight. The low has tracked steadily towards the southwest across the Van Diemen Gulf and at 00Z was located by radar on the coast close to Darwin. A brief period of gales was observed at Darwin Airport between 2200 and 2300 UTC, associated with a band of deep convection south of the low. The low was assessed at Dvorak DT=3.0 at 00Z based on a curved band wrap of 0.8, but Doppler radar and surface observations indicate gales in southern quadrant only. Final T-no kept to 2.5 due to land influence. The low is forecast to move WSW into the Timor Sea, and is expected to develop into a tropical cyclone tonight and intensify further under favourable environmental conditions during Sunday. The cyclone is expected turn south or southwest closer to the north Kimberley coast during Monday or Tuesday under the influence of the mid-level ridge over eastern Australia.
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Quoting Bordonaro:


In the latest satellite pics I saw of Ward looks like a borderline CAT 2 storm, I sure hope the Indian Bureau of Meteorology is correct on the current intensity forecast, or Sri Lanka is in for a huge, late season surprise!!


Huge in terms of size, if not intensity. Storm stretches 10 degrees from Myanmar to Sri Lanka.

The gigantic, unravelling disorganised system in the South Indian Ocean is Tropical Cyclone Cleo. The area of convection following it is the wave I was talking about earlier. In the far eastern side of the image, you can see the Australian wave beginning to form, and it also shows that spiral bands or fronts from Ward extend to Hong Kond and also comes into contact with Cleo.
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Quoting HadesGodWyvern:
India Meteorological Department
Tropical Cyclone Advisory Number ELEVEN
CYCLONIC STORM WARD (BOB05-2009)
5:30 AM IST December 12 2009
==========================================

Subject: Cyclonic storm over the southwest and adjoining southeast Bay of Bengal:

Cyclone alert for Tamil Nadu and Puducherry coast: Yellow Message

At 0:00 AM UTC, Cyclonic Storm Ward over southwest and adjoining southeast Bay of Bengal moved northwards and lays centered near 9.5N 84.5E, about 350 km northeast of Batticaloa (Sri Lanka), 500 km southeast of Nagapattinam and 600 km southeast of Chennai. The system is likely to move in a northwesterly direction towards Tamil Nadu coast.

However, satellite derived steering wind in upper troposphere suggests the possibility of northerly/ northeasterly movement of the system. Considering all the above, the system is under watch.

75 km/h (40 knots) according to 2100 UTC intensity table


In the latest satellite pics I saw of Ward looks like a borderline CAT 1 or maybe 2 storm, I sure hope the Indian Bureau of Meteorology is correct on the current intensity forecast, or Sri Lanka is in for a huge, late season surprise!!

Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting HIEXPRESS:
"Zhang et al. show that the extreme loss of Arctic sea ice since 2001 has been accompanied by a radical shift of the Arctic atmospheric circulation patterns"...

Here, the onset of colder weather is accompanied by ducks flying south. Do the ducks cause winter?


The strange thing is, in the past few weeks here in S. Ontario, it seems that the ducks/geese fly south during milder weather and back north whenever a storm passes leaving strong winds and cold air!
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Quoting Orcasystems:


I think he was talking about the old three letter indicator pharmaceuticals.


Yea well, I was pretty tame in that respect. I'm usually the sober one at the party laughing at all the others. :)
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394. HadesGodWyvern (Mod)
Mauritius Meteorological Services
Tropical Cyclone Advisory Number TWENTY-FIVE
DEPRESSION TROPICALE, FORMER CLEO (06-20092010)
4:00 AM Réunion December 12 2009
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At 0:00 AM UTC, Tropical Depression, Former Cleo (999 hPa) located at 14.5S 65.1E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The cyclone is reported as moving west-southwest at 9 knots.

RMSC Dvorak Intensity: T2.5/2.5

Near Gale-force Winds
=====================
15 NM from the center extending up to 60 NM in the southern semi-circle

Forecast and Intensity
========================
12 HRS: 14.7S 63.9E - 30 knots (DEPRESSION Tropicale
24 HRS: 15.0S 62.9E - 30 knots (DEPRESSION Tropicale
48 HRS: 16.4S 61.5E - 30 knots (DEPRESSION Tropicale
72 HRS: 19.7S 60.2E - 25 knots (se Dissipant)

Additional Information
======================
System has slightly re intensified as deep convective activity has strengthened near the center. 1644z ASCAT swath confirms that system has reached tropical depression status again with strongest winds mainly located in the southern semi-circle. This convective activity exists in relationship with the expected weakening vertical wind shear. Last Numerical Weather Prediction model suggest a slower track than previous ones. Despite this slow down movement, intensity forecast has also not significantly changed. Re intensification linked to the weakening wind shear should be limited due to low level dry air that is wrapping around low level circulation center.


---
strengthen back to tropical depression stage
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393. HadesGodWyvern (Mod)
India Meteorological Department
Tropical Cyclone Advisory Number ELEVEN
CYCLONIC STORM WARD (BOB05-2009)
5:30 AM IST December 12 2009
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Subject: Cyclonic storm over the southwest and adjoining southeast Bay of Bengal:

Cyclone alert for Tamil Nadu and Puducherry coast: Yellow Message

At 0:00 AM UTC, Cyclonic Storm Ward over southwest and adjoining southeast Bay of Bengal moved northwards and lays centered near 9.5N 84.5E, about 350 km northeast of Batticaloa (Sri Lanka), 500 km southeast of Nagapattinam and 600 km southeast of Chennai. The system is likely to move in a northwesterly direction towards Tamil Nadu coast.

However, satellite derived steering wind in upper troposphere suggests the possibility of northerly/ northeasterly movement of the system. Considering all the above, the system is under watch.

75 km/h (40 knots) according to 2100 UTC intensity table
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Quoting Orcasystems:
Has anyone seen KOG tonight :)
Hmm 3 feet of snow... in Ontario so far today.... happy dance happy dance :)


Snow squalls continue across Southern Ontario with 50-80 cm of snow possible for the hardest hit areas. Southwesterly winds increase in strength today with gusts up to 90km/h.


I live north of KOG, and currently there's about 18 cm of snow on the ground, after the snowsqualls. Toronto only got about 5 cm from the storm and less than 1 cm from the squalls. However, some places hit by the squalls have gotten close to a metre of snow, and yesterday the longest snowsquall from Lake Huron to Georgian Bay extended past the Bracebridge-Huntsville-Orillia area, past the Kawarthas and Petawawa, past Ottawa, past Montreal, past Quebec City, and into the Gulf of St. Lawrence!
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391. HadesGodWyvern (Mod)
Fiji Meteorological Services
Tropical Disturbance Summary
TROPICAL DEPRESSION 01F //
TROPICAL DISTURBANCE 02F
9:00 AM FST December 12 2009
=====================================

At 21:00 PM UTC, Tropical Depression 01 (1000 hPa) located at 11.5S 171.5E is reported as slowly moving southeast. Position FAIR based on multispectral infrared/visible animation imagery and peripheral observations. Sea surface temperature is 30C. Organization has improved significantly with increase in convection in the last 24 HRS. System lies to the east under a approaching 250 HPA trough in a moderately sheared environment. Outflow mainly to the north and east with dry air entrainment to the south. A surface ridge to the south depicts a southeast surge and a monsoon northwest surge to the north. TD01F is steered by a northwest deep layer mean winds. Most global models are developing the system and moving it southeast into an area of increasing shear.

POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 24 TO 48 HOURS IS MODERATE .

System #2
-----------

At 21:00 PM UTC, Tropical Disturbance 02 (1002 hPa) located at 12.0S 175.0E is reported as slowly moving. Position POOR based on multispectral infrared/visible imagery and peripheral observations. TD02F is embedded along a surface trough in a moderately sheared environment. Sea surface temperature is 30C. Most global models do not deepen the system.

POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 24 TO 48 HOURS IS LOW.
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Quoting Orcasystems:


I think he was talking about the old three letter indicator pharmaceuticals.


Correct for $1,000.00! May I have psychedelics for 1200.00 please?
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting gordydunnot:
Bordonaro I hope you don't think I was upset with your comment.I was just posting some old references to three dog night. I'll leave it to musical experts Moody Blues vs (3 dog night) was no slouch either. Rodney Dangerfield


Ok, wasn't sure if I made someone angry!
Member Since: August 25, 2009 Posts: 20 Comments: 6785

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