Dr. Jeff Masters' WunderBlog

Where's spring? 2nd most extreme March jet stream pattern on record extends winter
Posted by: Dr. Jeff Masters, 3:15 PM GMT on March 20, 2013 +41
Punxatawney Phil got it way wrong. Pennsylvania's famous prognosticating rodent predicted just three more weeks of winter back on February 2. It's the first day of spring, but winter remains firmly entrenched over the eastern half of the U.S., where temperatures of 5 - 25°F below average have been the rule all week. The culprit is the jet stream, which has taken on an unusually contorted shape that is allowing cold air to spill down over the Eastern U.S. and Western Europe, but bringing near-record warmth to portions of Greenland. One measure of how contorted the jet stream has become is by measuring the difference in pressure between the Icelandic Low and the Azores High. There are two indices used to do this--one called the Arctic Oscillation (AO), which treats the flow over the entire Northern Hemisphere, and another called the North Atlantic Oscillation (NAO), which is more focused on the North Atlantic. The two are closely related about 90% of the time. When these indices are strongly negative, the pressure difference between the Icelandic Low and the Azores High is low. This results in a weaker jet stream, allowing it to take large, meandering loops, letting cold air to spill far to the south from the Arctic into the mid-latitudes. The AO index hit -5.2 today (March 20). This is the second most extreme March value of the index since record keeping began in 1948; only an AO value of -6.3 in March 1970 was more extreme. We've had some wildly variable jet stream patterns in recent years in the Northern Hemisphere. Just last year, we had the opposite extreme in March, when our ridiculous "Summer in March" heat wave brought a week of temperatures in the 80s to the Midwest U.S. The first day of spring today in Chicago, IL is expected to have a high temperature of just 25°F--a 60 degree difference from last year's high of 85°F on March 20!


Figure 1. The jet stream is taking a large dip to the south over the Eastern U.S., allowing cold air to spill southwards and bring winter-like conditions.

Unusual winter jet stream patterns tied to Arctic sea ice loss
Unusual jet stream contortions in winter have become increasingly common in recent years, according to a March 2013 paper by Tang et al., "Cold winter extremes in northern continents linked to Arctic sea ice loss". They found a mathematical relationship between wintertime Arctic sea ice loss and the increase in unusual jet stream patterns capable of bringing cold, snowy weather to the Eastern U.S., Western Europe, and East Asia, typical of what one sees during a strongly negative Arctic Oscillation. They theorized that sea ice loss in the Arctic promotes more evaporation, resulting in earlier snowfall in Siberia and other Arctic lands. The earlier snow insulates the soil, allowing the land to cool more rapidly. This results in a southwards shift of the jet stream and builds higher atmospheric pressures farther to the south, which increases the odds of cold spells and blocking high pressure systems that can cause extended periods of unusually cold and snowy weather in the mid-latitudes.

Related posts
From Heat Wave to Snowstorms, March Goes to Extremes by Andrew Freedman of Climate Central
Extreme jet stream causing record warmth in the east, record cold in the west (January 2013)
Arctic sea ice loss tied to unusual jet stream patterns (April 2012)
Our extreme weather: Arctic changes to blame? (December 2011)
Florida shivers; Hot Arctic-Cold Continents pattern is back (December 2010)
Jet stream moved northwards 270 miles in 22 years; climate change to blame? (June 2008)

I'll have a new post on Thursday.

Jeff Masters
HappyWinds-day (YouKnowWho)
As Winnie-the-Pooh would say, 'Bother.' And yes, this was taken on a rather blustery Tuesday, and winter ain't over in these parts!
HappyWinds-day
Gusty Winds (novembergale)
High winds create huge waves behind ice dunes on Lake Erie this last day of winter.
Gusty Winds
After the blizzard (springsun)
Extreme severe winterconditions in the northeast of Germany, Kap Arkona. Source: wetterzentrale
After the blizzard
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601. trunkmonkey 9:57 AM GMT on March 21, 2013    
Quoting trunkmonkey:


I'm blaming H.A.A.R.P. on global warming, and all the supporters on Climate Change, Global Warming, etc, are agents of the Government deflecting the real climate changer which is H.A.A.R.P.
Many who believe this is caused by Carbon or man made have been programmed someway by the Government.
Grant monies also have made their way to greedy college professors to have a lavious lifestyle, or an abundance of low paid assistants to further the Government theories.
Then, there are minions! these are the ones who don't have a life and spend their days combing the internet getting the false information the above individuals have posted as fact.



sounds crazy eh!

Member Since: August 18, 2007 Posts: 0 Comments: 467
602. AussieStorm 10:05 AM GMT on March 21, 2013    
Quoting indianrivguy:


Chamber of Commerce stuff... they promoted the area as "Greenland" to promote development and encourage settlement... the first land boom lie? Call it green and they will come :)

Good evening mate!

Evening mate!
I found these 2 lots of information about Greenland and it's name.

The name Greenland (Grønland) has its roots in this colonization and is widely attributed to Erik the Red (the Inuit call it Kalaallit Nunaat, "Our Land"), and there has been speculation on its meaning. Some have argued that the coasts in question were literally green at the time due to the medieval climate optimum, in as much as the Viking settlers practised some form of an agrarian economy. Others have suspected that the name was in part a promotional effort to lure people into settling there by making it sound more attractive. The condition of Greenland in the 10th century may have been more hospitable than today.


The population of Greenland in the 12th Century was 10,000 - and these would have had to feed themselves. And that refers to Viking settlers. According to http://www.greenland-guide.gl/leif2000/history.ht m the Inuit only appeared on the coasts around 1350 - around the time of the abandonment of the Western coast settlements. This indicates (to me, at least) that the climate was changing and the Viking way of life wes becoming unsupportable, while the Inuit way was able to succeed. The Inuit would have been further north during the climatic warming, and returning south as the conditions worsened.
Member Since: September 30, 2007 Posts: 5 Comments: 13361
603. aislinnpaps 10:21 AM GMT on March 21, 2013    
Morning, everyone. Evening, Aussie. A chillier morning again, though high's expected around 70 later on.

Breakfast's on the sideboard: Steak and eggs, oatmeal with brown sugar, yogurt, fresh fruit and orange juice. Enjoy!
Member Since: August 22, 2009 Posts: 0 Comments: 2438
604. Tropicsweatherpr 10:21 AM GMT on March 21, 2013    
Good morning to all,evening Aussie.

Moisture increases today and peaks tommorow as a trough moves close to PR.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
432 AM AST THU MAR 21 2013

.SYNOPSIS...MID TO UPPER LEVEL RIDGE ACROSS THE LOCAL AREA
WILL CONTINUE TO SLOWLY ERODE AS UPPER TROUGH MOVES TOWARDS
THE WESTERN ATLANTIC. AN INCREASE IN SHOWER ACTIVITY IS EXPECTED AS THE
AFOREMENTIONED TROUGH AND ASSOCIATED SURFACE FRONT APPROACH THE
LOCAL AREA. HIGH PRESSURE WILL BUILD ACROSS THE AREA EARLY NEXT
WEEK.

&&

.DISCUSSION...CLOUDINESS WITH SHOWERS HAVE BEEN MOVING ACROSS THE
SOUTHERN HALF OF PUERTO RICO OVERNIGHT. SHOWERS WILL CONTINUE THIS
MORNING AFFECTING THE LOCAL AREA FROM TIME TO TIME...AS PATCHES OF
LOW LEVEL MOISTURE MOVES ACROSS THE AREA. LATEST SATELITE IMAGES
AS WELL LATEST TPW PRODUCT FROM CIMMS ARE SHOWING AN INCREASE IN
MOISTURE ACROSS THE REGION. THIS WILL RESULT IN WETTER
CONDITIONS...WITH THE BETTER CHANCES FOR SHOWERS EXPECTED FRIDAY.
UPPER LEVEL TROUGH WILL MOVES ACROSS THE WESTERN ATLANTIC TONIGHT
AND FRIDAY. THIS SYSTEM IN COMBINATION WITH DAYTIME HEATING AND
LOCAL EFFECTS WILL AID IN THE DEVELOPMENT OF SHOWERS AND POSSIBLE
THUNDERSTORMS FRIDAY AFTERNOON. A DRIER TREND IS THEN EXPECTED
LATE IN THE WEEKEND...AS A HIGH PRESSURE BUILDS ACROSS THE REGION.
IN THE LONG TERM...NO SIGNIFICANT WEATHER EVENTS ARE FORECAST TO
AFFECT TH REGION.

&&

.AVIATION...MAINLY VFR CONDITIONS EXPECTED ACROSS THE LOCAL FLYING
AREA THROUGH 21/16Z. PASSING -SHRA REMAIN POSSIBLE OVER THE SOUTHERN
PORTIONS OF PR AND USVI THROUGH 21/14Z...THEN AFTERNOON CONVECTION
WILL DEVELOP OVER THE NORTH AND NORTHWEST SECTIONS OF PR BTWN 21/16Z
AND 21/20Z. MOUNTAIN OBSCURATIONS ARE LIKELY OVER THE INTERIOR
SECTIONS OF PR. A LIGHT SOUTHEAST WIND FLOW WILL CONTINUE BLW 10
KFT.

&&

.MARINE...TRANQUIL MARINE CONDITIONS ARE EXPECTEDE TO CONTINUE
TODAY. SEAS OF 4 FEET OR LESS AND WINDS OF 16 KNOTS OR LESS ARE
EXPECTED ACROSS THE LOCAL COASTAL WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 74 83 75 / 10 0 60 40
STT 84 75 78 75 / 10 30 30 40
Member Since: April 29, 2009 Posts: 64 Comments: 8253
605. AussieStorm 10:24 AM GMT on March 21, 2013    
Storm system moving through eastern Victoria.




Loop
Member Since: September 30, 2007 Posts: 5 Comments: 13361
606. MAweatherboy1 10:39 AM GMT on March 21, 2013    
Good morning. Saturday is the day to watch this week/weekend regarding severe weather, SPC has a large area outlined in a slight risk:



Only 15% probabilities now due to model differences, but their discussion hinted at these probabilities going up once details become more clear. Damaging wind will be the biggest threat with isolated tornadoes also possible.

You can read their full discussion here.
Member Since: February 11, 2012 Posts: 67 Comments: 6379
607. barbamz 10:40 AM GMT on March 21, 2013    
Good morning everybody. Two articles to read, if you like, with your morning coffee. Have a nice day!

Natural Climate Swings Contribute More to Increased Monsoon Rainfall Than Global Warming

Mar. 20, 2013. Natural swings in the climate have significantly intensified Northern Hemisphere monsoon rainfall, showing that these swings must be taken into account for climate predictions in the coming decades, a new study finds.

...Current theory predicts that the Northern Hemisphere summer monsoon circulation should weaken under anthropogenic global warming.

Wang and his colleagues, however, found that over the past 30 years, the summer monsoon circulation, as well as the Hadley and Walker circulations, have all substantially intensified. This intensification has resulted in significantly greater global summer monsoon rainfall in the Northern Hemisphere than predicted from greenhouse-gas-induced warming alone: namely a 9.5% increase, compared to the anthropogenic predicted contribution of 2.6% per degree of global warming.


Most of the recent intensification is attributable to a cooling of the eastern Pacific that began in 1998. ...

Read the whole article



Significant Contribution of Greenland's Peripheral Glaciers to Sea-Level Rise

Mar. 18, 2013. Glaciers at the edge of Greenland which are not connected to its huge ice sheet, or can be clearly separated from it, are contributing to sea-level rise much more than previously thought. Scientists from the University of Zurich together with colleagues from Denmark have found that, though these peripheral glaciers make up just 5-7 % of total ice coverage on the land mass, they account for up to 20% of the rise in sea level created by the region's melting.

Read the whole article


This is the Elephant Foot Glacier from space. (Credit: Landsat ETM; image editing: Tobias Bolch (University of Zurich))
Member Since: October 25, 2008 Posts: 24 Comments: 1614
608. LargoFl 10:47 AM GMT on March 21, 2013    
Member Since: August 6, 2011 Posts: 0 Comments: 22426
609. hurricanes2018 10:52 AM GMT on March 21, 2013    
its snowing at my house this morning at 7am
Member Since: March 12, 2013 Posts: 1 Comments: 856
610. AussieStorm 10:56 AM GMT on March 21, 2013    
HOLY COW. Major tornado has struck far southern NSW.

Major damage at Barooga (northwest of Yarrawonga south east of here) Reports of tornado damage with houses obliterated,people trapped in the cars from fallen trees, reports of a caravan in a tree with persons stuck inside, power lines down every where.

NSW Police Albury/South Western NSW (Sturt HWY) Live Audio Feed

Video of the Tornado.

Uploaded with ImageShack.us
Member Since: September 30, 2007 Posts: 5 Comments: 13361
611. aislinnpaps 11:24 AM GMT on March 21, 2013    
Glad it wasn't near you, Aussie!

Everyone have a great Thursday. Aussie, have a great Friday!
Member Since: August 22, 2009 Posts: 0 Comments: 2438
612. WunderAlertBot (Admin) 11:37 AM GMT on March 21, 2013    
JeffMasters has created a new entry.
613. AussieStorm 11:38 AM GMT on March 21, 2013    
Quoting aislinnpaps:
Glad it wasn't near you, Aussie!

Everyone have a great Thursday. Aussie, have a great Friday!

This storm system is heading my way tomorrow. Let's hope it's lost a lot of energy by the time it get's here. Of course I'll keep everyone informed.

1st reports coming in now.

Tornados tear through Victorian towns
Several tornados have ripped through parts of Victoria's north-east, destroying buildings and injuring several people.
The State Emergency Service (SES) says at least two tornados moved between Cobram and Yarrawonga about 8:00pm (AEDT) this evening.

Lachlan Quick from the SES says there have been a number of injuries.

He says Rutherglen was one of the most badly affected towns and a number of buildings have been affected.

"I know there are quite a lot of holiday homes that are unoccupied and that may have assisted us with fewer injuries," he said.

"But certainly at his stage it's very busy up there and we are issuing further volunteer units up there at the moment."
2013 ABC

................................................. .............................................
The latest update from NSW SES State Headquarters states:

NSW SES Update from southern NSW.

In Barooga up to 80% of the Golf Hotel roof has been dislodged. Trees on several vehicles along Golf Course road. Reports of homes damaged. The Post Office roof has been dislodged. Cobram-Barooga Golf Resort %u2013 extensive roof damage.

At Mulwala township near Corowa a caravan park has had several vans blown over. At Kissins Reserve camp site %u2013 multiple caravans blown over. NSW SES and Fire and Rescue on scene.

More updates as they come to hand. If you are driving in the Riverina area or NE Vic be aware trees may be down on roads.
Member Since: September 30, 2007 Posts: 5 Comments: 13361
614. Naga5000 11:40 AM GMT on March 21, 2013    
Quoting trunkmonkey:


I'm blaming H.A.A.R.P. on global warming, and all the supporters on Climate Change, Global Warming, etc, are agents of the Government deflecting the real climate changer which is H.A.A.R.P.
Many who believe this is caused by Carbon or man made have been programmed someway by the Government.
Grant monies also have made their way to greedy college professors to have a lavious lifestyle, or an abundance of low paid assistants to further the Government theories.
Then, there are minions! these are the ones who don't have a life and spend their days combing the internet getting the false information the above individuals have posted as fact.



Seriously? Grant money and greedy college professors? This whole rant comes off as little more than anti-intellectualism and a lack of knowledge about science. I actually don't feel like arguing with you; I honestly just feel sorry for you.
Member Since: June 1, 2010 Posts: 1 Comments: 458
615. dartboard16134 3:40 PM GMT on March 22, 2013    
you are so rite..these crazy money hungry people playing god till mother earth bites them in the as*,dont they know when they mess with nature it ALLWAYS go wrong
Member Since: March 26, 2003 Posts: 0 Comments: 2
616. dartboard16134 3:43 PM GMT on March 22, 2013    
Quoting AGWcreationists:
I believe CO2 is a greenhouse gas, one only needs to look at Venus. However, I am not sure that the human-caused increase concentrations in our atmosphere are signficant enough to cause the warming we have seen. Given that the Arctic has warmed in the past, IMO it is the result of the increase in solar cycles we have seen over the last 150 years or so, with ups and downs.

I do think ocean acidification reprents a potential serious problem. However, CO2 was much, much higher in geologic history and life did not end. Life will change in response to these environmental changes. It will not end, but it may change in ways detrimental to humanity.
ITS NOT HUMANS ITS HAARP AND THE GOVERNMENT LOOK IT UP
Member Since: March 26, 2003 Posts: 0 Comments: 2
617. mfount 4:09 PM GMT on March 28, 2013    
It is now March 28 and it is warming up a bit. Anyway, has the high pressure in Greenland weakened a little and what is its future/ Also, can someone send me a link to a map where I can monitor the North Atlantic myself, both the surface and an applicable altitude?
Member Since: February 6, 2003 Posts: 1 Comments: 10
618. CFCs 8:27 PM GMT on May 03, 2013    
I came here late so please forgive me if I repeat any questions people asked already.

If the current AO index -5.2 is linked to Arctic sea ice loss, then what the AO -6.3 in March 1970 is linked to? Too much ice? There was more than 80% more ice at that time, right?

Also why this unusual winter jet stream pattern has to happen at 80% ice loss and didn't happen at 40% or 79.99% loss?
Member Since: May 2, 2013 Posts: 0 Comments: 0

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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.

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