Where's spring? 2nd most extreme March jet stream pattern on record extends winter

By: Dr. Jeff Masters , 3:15 PM GMT on March 20, 2013

Share this Blog
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

()
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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 518 - 468

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

Quoting MAweatherboy1:
Wow, already one named storm on the season!



NHC is definitely trying to inflate the seasonal totals with this one.

I was getting a little worried for when the first invest/storm would be named. We had an invest in February last year.
Member Since: Posts: Comments:
Quoting MAweatherboy1:
Wow, already one named storm on the season!



NHC is definitely trying to inflate the seasonal totals with this one.


PADDING the numbers...
Tsk tsk tsk
Member Since: Posts: Comments:
Quoting MAweatherboy1:
Wow, already one named storm on the season!



NHC is definitely trying to inflate the seasonal totals with this one.

It's a test.
Member Since: Posts: Comments:
Wow, already one named storm on the season!



NHC is definitely trying to inflate the seasonal totals with this one.
Member Since: Posts: Comments:
Quoting Grothar:


Wow. You must have some good high schools. :)

Yeah, they're not bad :-)
Member Since: Posts: Comments:
513. Skyepony (Mod)
NOAA has Wmodemo on a floater.. scripted as 79L. Test on..

Member Since: August 10, 2005 Posts: 227 Comments: 39467
Quoting AussieStorm:
Happy Harmony Day all. Around 45% of Australians are born overseas or have a parent who was born overseas. We speak over 260 languages.


Wow. You must have some good high schools. :)
Member Since: Posts: Comments:
Quoting Grothar:


I often dreamed I was the "Invisible Man". I was never quite sure what I looked like though.


Like the 'Unknown Comic'! LOL

Cold here for start of spring too. No snow at lower elevations, but lots of sleet. Lots of snow on the mountains though. Actually have a small garden at the new place, and need to get out and to try and plant some things soon to see if can grow anything! Have a few things in pots from patio of old place I may plant in ground. They should do better at the lower elevation an milder climate near the coast. Did lose a few things last winter that couldn't take it. But have a red currant, a raspberry, some strawberries and something else can't remember LOL! The best the last 2 years was the strawberry plants, though not a lot, was impressed (and SO much tastier than store bought!). But I've never had much a green thumb, but am trying!
Member Since: Posts: Comments:
Winter Storm Warning
URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA
330 PM PDT WED MAR 20 2013

...A VIGOROUS FRONTAL SYSTEM WILL BRING HEAVY SNOW TO THE
OLYMPICS TODAY AND TO THE CASCADES THROUGH TONIGHT. SNOW WILL
CONTINUE BUT GRADUALLY DECREASE THURSDAY AND THURSDAY NIGHT.

WAZ518-519-211200-
/O.CON.KSEW.WS.W.0006.000000T0000Z-130321T1200Z/
WEST SLOPES NORTHERN CASCADES AND PASSES-
WEST SLOPES CENTRAL CASCADES AND PASSES-
330 PM PDT WED MAR 20 2013

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT
THURSDAY...

* SOME AFFECTED LOCATIONS...MOUNT BAKER...STEVENS PASS...
SNOQUALMIE PASS...WHITE PASS...AND PARADISE AT MOUNT RAINIER.

* TIMING...SNOW...HEAVY AT TIMES...THROUGH TONIGHT. SNOWFALL WILL
CONTINUE ON THURSDAY BUT WARNING AMOUNTS ARE NOT EXPECTED.

* SNOW ACCUMULATIONS...ANOTHER 1 TO 2 FEET OF SNOW IS LIKELY
THROUGH TONIGHT. HEAVIEST AMOUNTS WILL FALL ALONG WEST FACING
SLOPES OF THE VOLCANOES. PASSES MAY GET CLOSE TO 1 FOOT OF
ADDITIONAL SNOW BY THURSDAY MORNING.

* MAIN IMPACT...HAZARDOUS WINTER DRIVING CONDITIONS...WITH SLOW
TRAVEL AND DELAYS POSSIBLE.

* SNOW LEVEL...2500 FEET FALLING TO 1000 FEET EARLY THURSDAY MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING INDICATES THAT 12 INCHES OF SNOW IS
EXPECTED IN A 12 HOUR PERIOD OR 18 INCHES IN A 24 HOUR PERIOD.

&&

$$

WEATHER.GOV/SEATTLE
MERCER
Member Since: Posts: Comments:
On this day 37 years ago, a violent tornado struck parts of Oakland county, Michigan. This tornado was several miles from where I live. It was rated an F4, killed 1, injured 55, and did hundreds of millions of dollars in damage in today's dollars. This was the last violent tornado to strike SE MI to this date. On average, SE MI gets a violent tornado every 5 years or so, it has been 37 years since the last F4. The last F5 in SE MI occurred all the way back on June 8th, 1953, it has been a while since one of those in my area.
Member Since: Posts: Comments:
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Geesh! Winter Storm Watch in effect from Thursday afternoon through
Friday morning...

The National Weather Service in Memphis has issued a Winter Storm
Watch... which is in effect from Thursday afternoon through Friday
morning.

* Snow/sleet/ice accumulations... significant snowfall accumulations
of up to 3 inches or more are possible.

* Timing... from 1 PM CDT Thursday afternoon until 7 am CDT Friday
morning.

* Impacts... snow and sleet accumulations may impact travel
across portions of northeast Arkansas and the Missouri
bootheel. Continue to monitor the latest forecasts.
Member Since: Posts: Comments:
Quoting GeorgiaStormz:
more snow




What's with the funky circles in Mississippi and Tennessee and the ellipse in Alabama?
Member Since: Posts: Comments:
more snow


Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting trHUrrIXC5MMX:


was that a forecast??? or you added it all up?

forecast for next 48hrs

Member Since: Posts: Comments:
Quoting Astrometeor:


10 inches from what? 5 ft or 7 ft?

7ft
Member Since: Posts: Comments:
502. VR46L
Quoting Astrometeor:
The moisture that Florida has seeketh is cometh.

Oh joy for the natives, rejoice!

...


I am surprised how quiet they are being about it , I guess they fear Jinxing it !
Member Since: March 1, 2012 Posts: 0 Comments: 6998
Quoting AussieStorm:
Happy Harmony Day all. Around 45% of Australians are born overseas or have a parent who was born overseas. We speak over 260 languages.


oh great.. I don't have to worry about speaking in English if I go there..lol
Member Since: April 23, 2011 Posts: 104 Comments: 14873
ga:

STALLED FRONT OVER THE GULF OF MEXICO WILL BEGIN SHIFTING
NORTHWARD ON FRIDAY AS LOW PRESSURE MOVES OUT OF EAST TX. THERE
ARE STILL DIFFERENCES BETWEEN THE MODELS ON EXACTLY WHERE THE WARM
FRONT SETS UP INTO SATURDAY. THE GFS IS FURTHER SOUTH WITH THE
BOUNDARY THAN THE NAM. THE GFS ALSO WIPES THE WEDGE OUT ACROSS NE
GA FAIRLY QUICKLY AS COMPARED TO THE OTHER LONGER RANGE MODELS.

FOR NOW...WILL GO PERSISTENCE UNTIL MODELS COME INTO BETTER
CONSENSUS.


will see about svr wx
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting AussieStorm:
yeah but 5-7feet is 60 to 84 inches. That's 10inches taller than me.


was that a forecast??? or you added it all up?
Member Since: April 23, 2011 Posts: 104 Comments: 14873
Quoting AussieStorm:
yeah but 5-7feet is 60 to 84 inches. That's 10inches taller than me.


10 inches from what? 5 ft or 7 ft?
Member Since: Posts: Comments:
Happy Harmony Day all. Around 45% of Australians are born overseas or have a parent who was born overseas. We speak over 260 languages.
Member Since: Posts: Comments:
Chance for sprinkles and flurries this evening. The clouds have darkened and lightened repeatedly over the course of several hours, yet nothing has fallen.

Member Since: Posts: Comments:
Quoting trHUrrIXC5MMX:


well let me tell ya that one tine for Mount Baker (Wash State) besides some crazy snowfall mounts, this one caught my attention... 44-51"

extreme!
yeah but 5-7feet is 60 to 84 inches. That's 10inches taller than me.
Member Since: Posts: Comments:
The moisture that Florida has seeketh is cometh.

Oh joy for the natives, rejoice!

...
Member Since: Posts: Comments:
Quoting AussieStorm
it look worse than a EF2



shear wasnt extreme
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Member Since: July 15, 2006 Posts: 178 Comments: 56141
little snow for new haven,conn
Member Since: Posts: Comments:
Quoting AussieStorm:
WOW!!!!!



@WeatherNut27 WxNut
Who would like a forecast like this? 5-7 feet of snow in the next 48hrs! Snow down to 1000'.

Link


well let me tell ya that one tine for Mount Baker (Wash State) besides some crazy snowfall mounts, this one caught my attention... 44-51"

extreme!
Member Since: April 23, 2011 Posts: 104 Comments: 14873


Member Since: February 11, 2012 Posts: 0 Comments: 9760
S AL

Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting TropicalAnalystwx13:

EF2.

it look worse than a EF2.
Member Since: Posts: Comments:
large EHI area






not particularly violent though
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting RTSplayer:


Really? I never dreamed I was Batman.


I often dreamed I was the "Invisible Man". I was never quite sure what I looked like though.
Member Since: Posts: Comments:
WOW!!!!!



@WeatherNut27 WxNut
Who would like a forecast like this? 5-7 feet of snow in the next 48hrs! Snow down to 1000'.

Link
Member Since: Posts: Comments:
Who wants my lake effect snow?? I'm sick of it.

You can take my cold temps too.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

EF2.


13miles
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Have You Ever Seen The Rain
Member Since: February 29, 2012 Posts: 0 Comments: 6260
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting AussieStorm:

That was that bad looking hook from the other day right. What was it rated at?

EF2.
Member Since: Posts: Comments:
HAVING SAID ALL THE ABOVE...I THINK IT IS PRUDENT AT THIS TIME TO
INTRODUCE SOME CHANCE OF SEVERE STORMS INTO THE HWO. IF THE GFS
WERE TO VERIFY...WE COULD END UP WITH SOMETHING FAIRLY

SIGNIFICANT. IF THE ECMWF ENDS UP VERIFYING...WE CAN WIPE OUR BROW
AND SAY "PHEW"
AND REMOVE THE SEVERE THREAT. BUT OTHER FACTORS TO
CONSIDER INCLUDE THE FACT THAT MANY PEOPLE AROUND THE STATE WILL
EITHER BE RETURNING FROM OR GETTING AN EARLY JUMP ON SPRING
BREAK...AND MAY BE LESS WEATHER AWARE THAN USUAL
. ADD TO THAT THE
FACT THAT THIS WILL ALSO BE PALM SUNDAY WEEKEND FOR MANY FOLKS. IT
IS BEST TO GET THE WORD OUT NOW FOR A POTENTIAL SEVERE WEATHER THREAT.
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting AussieStorm:

As I said Max, they want to become a regular news channel that does weather in the side.


I guess so.
Member Since: April 23, 2011 Posts: 104 Comments: 14873
ON THE 12Z GFS...THE SURFACE LOW MOVES FROM NORTHEAST TEXAS
(SATURDAY AFTERNOON) INTO CENTRAL KENTUCKY (SUNDAY MORNING). A
SIGNIFICANT WARM SECTOR SURGES INTO ALABAMA DURING THAT TIME...AND
INSTABILITY INCREASES (ESPECIALLY SOUTH OF I-20)...WITH SBCAPES
PEAKING AROUND 2800 J/KG IN OUR SOUTHERN COUNTIES SATURDAY
AFTERNOON. WHILE BULK SHEAR AND HELICITY VALUES ARE NOT IN HIGHEST
PERCENTILES OF WHAT WE HAVE EVER SEEN...THEY LOOK SUFFICIENT
ENOUGH TO BRING SOME ORGANIZATION TO ANY CELLS THAT WERE TO DEVELOP.


ON THE 12Z ECMWF...THE SURFACE LOW IS INITIALLY WEAKER THAN THE
GFS. IT ALSO KEEPS IT FARTHER SOUTH (INITIALLY) THAN THE GFS AS
WELL...WITH A 06Z SUNDAY POSITION BETWEEN JAN AND MOB. FROM THERE
THE SURFACE LOW SPLITS IN TWO...WITH ONE CENTER HEADING TOWARD
NASHVILLE AND THE OTHER FOR THE OUTER BANKS OF NC. THE MOIST WARM
SECTOR NEVER MAKES IT FAR INLAND...AND CENTRAL ALABAMA STAYS
RELATIVELY STABLE. THIS RESULTS IN A MUCH LOWER SEVERE THREAT FOR
OUR AREA. I WILL SAY THAT THIS 12Z SOLUTION IS TRENDED A BIT MORE
NORTH THAN THE PREVIOUS FEW RUNS OF THE ECMWF.

THE 00Z GEM WAS MORE SIMILAR TO THE 12Z GFS (BUT DELAYED BY ABOUT
18 HOUR)...ALTHOUGH THE 12Z GEM LOOKS CLOSER TO THE 12Z ECMWF. THE
12Z NAM LENDS SOME SUPPORT TO THE 12Z GFS...BEFORE IT GETS TO THE
END OF ITS RUN TIME.
Member Since: February 11, 2012 Posts: 0 Comments: 9760
alabama

THIS WILL BE A TOP-DOWN MOISTENING PROCESS...WHICH MANY TIMES
THIS TIME OF YEAR (AND WITH THIS TYPE OF TEMP/DEW POINT PROFILE)
RESULTS IN A MIX OF RAIN AND SLEET (WITH SLEET MOST LIKELY DURING
THE ONSET OF THE PRECIPITATION)
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting GeorgiaStormz:

That was that bad looking hook from the other day right. What was it rated at?
Member Since: Posts: Comments:
Quoting trHUrrIXC5MMX:


even information about the Pope they have in there...what the heck?

As I said Max, they want to become a regular news channel that does weather in the side.
Member Since: Posts: Comments:
more flurries!!!

THERMAL PROFILES AND TOP DOWN METHOD INDICATES A MIX OF
RAIN WITH SLEET IN WEST CENTRAL GA AND A SNOW/SLEET MIX FARTHER
NORTH. LITTLE TO NO ACCUMULATIONS ARE EXPECTED WITH ONLY A DUSTING
AT BEST AS MODELS ARE EVEN MORE QPF LIMITED.
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Member Since: February 11, 2012 Posts: 0 Comments: 9760
12z JMA




Member Since: August 19, 2006 Posts: 13 Comments: 16225
Really hate seeing pictures like this coming out of Colorado in March...

1348-acre Galena Fire, just west of Fort Collins.


Yeesh, that was close...


Click here for more photos of the Galena Fire

The good news is no homes were lost and they have the fire 100% contained. Plus we've got precip in the short range forecast...



Still... blech.
Member Since: March 26, 2006 Posts: 44 Comments: 1520
Quoting AussieStorm:

Well it is 09:45 here. That's morning for me.


I was up today at 6:30 AM... as part of my extreme work schedule...
Member Since: April 23, 2011 Posts: 104 Comments: 14873

Viewing: 518 - 468

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron