Saturday, February 22, 2014

The Absurdly Long Entry: Discussion of D.C. Area Snowfall; Atmospheric Oscillations; and Global Climate Change Plus Commentary

**This entry was posted February 22nd, 2014.**

A light blanket of snow covers the grassy area of Dupont Circle, Washington, D.C., 9:47AM February 18, 2014.

I had walked from my apartment Tuesday morning to the Bank of America ATM at Dupont Circle and took the Metro from there to work rather than from U Street / Cardozo. I took this picture and three more in this entry on that short walk.


This is the entry I intended to post a few days ago.

I wanted to note that Washington, D.C., "officially" is now above normal for snowfall this winter season.

The 0.3 inches that fell in the early hours of Tuesday morning (Feb. 18th) pushed the Reagan Washington National Airport climate station (KDCA) 2013 - 2014 seasonal snowfall total to 15.5 inches or 0.1 inch above the present (1981 - 2010) 30-year average (mean) of 15.4 inches.

However, this is kind of problematic given that the KDCA average is somewhat skewed by those rare big snowfall years. The Capital Weather Gang had an entry about later that day (link embedded): Officially snowy: D.C. snow edges above average, for only 4th time in 25 years.

The snow-dusted sidewalk in the 1900 block of New Hampshire Avenue, Washington, D.C., 9:36AM February 18, 2014.


As the title states, it notes that only four winters in the past 25 years have featured above normal snowfall -- and three have been blockbuster years. These four including the present are as follows:

2009-2010: 56.1 inches (Rank: 1st)

1995-1996: 46.0 inches (Rank: 3rd)

2002-2003: 40.1 inches (Rank: Tied for 7th place)

2013-2014: 15.5 inches (through Feb. 22nd).

Source here.

Every other winter in the period 1984 - 2013 has featured less than the "average" snowfall*. In other words, years with average (mean) snowfall are actually rare in D.C.

*Yes, that average changed slightly with the decadal update from the 1971 - 2000 base period to the 1981 - 2010 base period that occurred in 2010. Also of note, the winter of 2009 - 2010 actually helped keep the 30-year average more or less steady.

As I recall, the big snowfall drop at KDCA and KBWI (about 15 percent each) occurred in 2001 when the 1961 - 1990 period was replaced by the 1971 - 2000 base period. You can avoid this by just taking a full record period average.

The median KDCA snowfall for the period 1989 - 2013 is closer to 10 inches. This is probably a more accurate measurement for a "typical" D.C. winter.

A graph from the above CWG entry showing snowfall totals for the past 25 years including this winter's total through Feb. 18th, 2014.


The Washington Dulles International Airport climate station (KIAD) had 0.5 inches Monday night into Tuesday morning and its 2013 - 2014 seasonal total is 31.0 inches -- not only double the KDCA total but is 9.0 inches above its 30-year (1981 - 2010) seasonal average (mean) of 22.0 inches.

Finally, Baltimore/Washington International Thurgood Marshall Airport climate station (KBWI) had 0.9 inches Tuesday morning, bringing its 30-year (1981 - 2010) seasonal average (mean) of 25.7 inches or 5.6 inches above its seasonal average of 20.1 inches.

A light and fluffy snow dusts the small yard of 1737 New Hampshire Avenue and the neighboring yards, Washington, D.C., around 9:40AM February 18, 2014.


The fact that KDCA is so much lower than KIAD or KBWI is testament to how marginal our temperatures are for all snow / mixed precipitation or even plain rain in the Metro D.C./Baltimore areas and, yes, to what a dreadful place National Airport is to take snow (or indeed any weather) measurements. It's sort of like a micro-Norfolk / Newport News climate in D.C. But we won't get into that topic again right now. (FYI: KDCA has been the spot for snow measurements since about 1945; prior to that, snow records were kept at various places in D.C. Official snow records for D.C. start in January 1888.)

Schematic diagram of the Arctic Oscillation negative phase.


Schematic diagram of the Arctic Oscillation positive phase.


In the case of this winter, the Arctic Oscillation (AO) has been quite negative -- see above positive and negative AO schematic images -- for much of January and February and the polar vortex has repeatedly "slide" off the North Pole / high Arctic into the sub-Arctic and middle latitudes of the "Western" Hemisphere over eastern North America. By contrast, there was record warmth in parts of Eurasia this winter. (I think it was last year or maybe the year before that there was a similar "slide" except it was into the Eastern Hemisphere including Japan and eastern China.)

A colorful representation from the NASA Goddard Space Flight Center scientists showing the polar vortex (or at least a big "piece" of it) sliding into the middle latitudes of eastern North America in January 2014. I'm not sure exactly what day this is or what the colors represent (probably 500mb geopotential heights, although it could be geopotential height anomalies or perhaps just temperature at some level). Source here.


Looking ahead, the models (both the GFS and the Euro) are suggesting that the polar vortex will again "slide" out of the Arctic source region into eastern North America centered over central Ontario by next week. This would be the third time that there has been a major Arctic outbreak with the biggest in early January.

Today's 12Z GFS showing 500mb geopotential heights, 500mb temperatures (C), and winds (knots) for North America valid at hour 114 / 06Z (1AM EST) February 27, 2014. The closed geopotential height contours mark the Arctic polar vortex in the upcoming cold wave.

I supposed you could say the very center of the polar vortex in this image is over the sub-Arctic Canadian indigenous community of Fort Severn First Nation, Ontario.


Here are two relevant CWG entries from this past week (links embedded):

The Arctic Oscillation (AO) Index observed between October 26, 2013 and February 22, 2014 with the ensemble forecast through mid-March 2014. This plot shows a 7-day, 10-day, and 14-day forecast for the 1000mb height surface. The y-axis is a positive or negative standard deviation corresponding to a positive or negative AO Index.

** Note: All my AO, NAO, and PNA large plot images have a spurious "J" in the file name ("22JFeb"). At this point, I'm not going to change it. **


Unfortunately, there is no major snowstorm for D.C. during this time -- the jet stream energy just isn't phasing and there is no Greenland high pressure block (i.e., a really negative NAO -- see below). 

Thereafter, the pattern should start to relax and the seasonal change will start to overwhelm any transitory jet stream pattern.

A map of snowfall totals for selected cities through Feb. 17, 2014. Click on image for larger version. (These totals may have increased in certain cities in the past five days.)


It is quite possible that shrinking Arctic sea ice may be contributing to these oscillations of the polar vortex. But there are also the sudden stratospheric warming (SSW) episodes that (as I understand) are sometimes linked to Arctic outbreaks into the middle latitudes. (I really should ask Kristof about this -- he is one of the world's experts in the field of stratospheric - tropospheric interactions and SSWs, except he's not a meteorologist.)

This is a map I got from Gary that was produced by one of his NASA Goddard colleagues showing the seasonal trend in Arctic Ocean sea ice coverage between November and March compared to 2012 - 2013 and 2013 - 2014 (through last week). The x-axis is the period November - May. The y-axis is millions of square kilometers of sea ice (i.e., the areal extent).

The dark gray line is the 1981 - 2010 average sea ice extent with the gray region representing plus or minus two standard deviations from the mean. 2011 - 2013 is the dashed green line and 2013 - 2014 bright blue line is 2013 - 2014.  It shows that the areal extent of sea ice has been just about 2 sigma (standard deviations) below the mean for much of this season and as of February had actually slipped below that (i.e., outside of the gray region).

At this rate, by summer 2024, there may very well be open sea water at Earth's geographic North Pole.

Yes, Mr. American Rightwing Talk Radio Listener and Mrs. American "Fox & Friends" Viewer: THIS is manmade global warming in action.


Long story short, to a zeroeth order approximation, in a globally warming world, it can and will sometimes get colder in the middle latitude winters. However, some climate scientists oppose making this causality. Here is yet another CWG article (link embedded): Scientists: Don't make "extreme cold" centerpiece of global warming argument.

However, I think these scientists are making the issue too obtuse and allowing the Flat Earther crowd to have the dominate position. They're just being too subtle and nuanced.


A side-by-side schematic comparison of the positive and negative phases of the AO and attendant synoptic scale weather patterns.


Because, yet again, to a zeroeth order approximation, a warming Arctic and sub-Arctic with shrinking sea ice and warmer sea surface temperatures in the northern Pacific and Atlantic are causing the polar vortex to wander more and more. Ditto with increased high pressure blocks and warming over Greenland.

Schematic of the jet stream pattern in the positive and negative phases of the North Atlantic Oscillation (NAO) and the attendant synoptic-scale air pressure and weather patterns. Note the high pressure block near / over Greenland.


Anyway, as for U.S. East Coast coldness this year, the North Atlantic Oscillation (NAO) -- an oscillatory climate phenomenon across the central North Atlantic between Greenland / Iceland and the Azores whose fundamental relationship with the AO (which one is physically more "real") is not yet decided -- was weakly negative in January and weakly positive in February. This has constrained any really MAJOR East Coast nor'easters (last week's notwithstanding).

The North Atlantic Oscillation (NAO) Index observed between October 26, 2013 and February 22, 2014 with the ensemble forecast through mid-March 2014. This plot shows a 7-day, 10-day, and 14-day forecast for the 500mb height surface. The y-axis is a positive or negative standard deviation corresponding to a positive or negative NAO Index.


The AO and NAO are typically in phase but they can be out of phase. Oh, and then there is the Pacific / North American (PNA) pattern that in January was in a positive phase and is now in a negative phase. The positive PNA with high pressure over the Western U.S. is probably contributing to the severe drought in California.

This is a nice schematic diagram from The Weather Channel (yes, The Weather Channel) showing a positive PNA (Western U.S. high pressure ridge) and a very negative NAO (with high pressure block over Greenland). For a classic East Coast storm -- the Miller A or Miller B -- you would need the jet stream to run parallel to the Gulf Stream.

The Greenland block keeps the low from being too progressive and facilitates the negative tilt. The intense baroclinicity and the tremendous oceanic latent heat fluxes of this arrangement with phasing of the southern and northern jet branches is perfect for spinning up / bombing out a storm (i.e., explosive cyclogenesis).

Of course, the low can't be too close to the coast or else the coastal plain gets flooded with warmer air (resulting in rain).


The Pacific / North American Index observed between October 26, 2013 and February 22, 2014 with the ensemble forecast through mid-March 2014. This plot shows a 7-day, 10-day, and 14-day forecast for the 500mb height surface. The y-axis is a positive or negative standard deviation corresponding to a positive or negative PNA Index.


Political Commentary ...

Speaking of these U.S. extremes, as well as those abroad -- such as record rainfall in Great Britain and scorching heat in Australia (haven't I written that sentence before?)-- prompted the Sunday talk shows to return to the issue of anthropogenic climate change (global warming). I refer to (in Bartcop's wonderful phraseology) Face the Whore, Meet the Whore, This Whore, and Fox Whore Sunday.

Move over Lincoln-Douglas Debates and Scopes Monkey Trial: The early 21st Century has just surpassed you: The David Gregory-moderated "debate" between Bill Nye and Congresswoman Marsha Blackburn on Meet the Press last Sunday on climate change.


The first three (i.e., the long-established commercial network shows) have ignored the topic for years (since it ceased to be interesting to them about six years ago) except very rarely to talk about it strictly in political horseracing terms while Fox -- the main media/entertainment division of the billionaire crank / corporate oligarchical / foundation-funded GOP Agit-Prop Machine -- has continued to mock and belittle and run an attempted intimidation campaign against climate scientists.

Anyway, below are two links discussing what happens when the Sunday talk shows try to tackle climate change. It wasn't pretty. And its kind of infuriating, but it's also good to know.

In short, three commercial ones maintain their Fred Hiatt-like false-balance equivalencies and treat the issue as something to be won by Republicans, or that Democrats should just stop talking about so as not to upset Republicans.

This is how you REGULARLY get in the American media entire "news" segments discussing anthropogenic climate change with NO ACTUAL CLIMATE CIENTISTS and instead featuring nothing but rightwing pundits, propagandists, and GOP politicians who as opinionated as they are totally uninformed on the topic.

As for the Fox News Channel crowd, it's even worse as they mock, belittle, and propagandize on an issue they truly know nothing about. It's even worse when they try to ask a question. It's painfully embarrassing.

Salon (link embedded): Sunday shows' climate disgrace: Cluelessness and false balance could cost lives by Brad Friedman

Esquire (link embedded): What Are The Gobshites Saying These Days? by Charles B. Pierce.

Media Matters also covered the issue but in a less politically incendiary way (link embedded): Sunday Shows' Climate Coverage Shows Media Vulnerability.

As described in the Salon piece:

Out of all four of them, just "This Week" and "Face the Nation" bothered to book an actual climate scientist to take part in the conversation with their various bevies of political and journalistic deniers and non-scientists. Only "Face the Nation" offered a one-on-one with a climate scientist before then bringing on the denier.

The denier was North Carolina Gov. Pat McCrory.

McCrory may not be THE WORST governor ever in the Old Confederacy (that's admittedly a high low bar to reach) but he's certainly the corporate sleazy - smarmiest. He's the kind of guy that if the South ever broke away (GO...!) would soon run a "shareholder profit-maximizing agrarian enterprise" and brag that all the slaves workers have access to healthy food AND a hot shower.

"Studies show our slaves, er, I mean, workers in North Carolina are the HAPPIEST!"

As for Bob Schieffer, my understanding is that a recent radiocarbon dating places his age at approximately 350.

On Meet the Whore, David Gregory -- aptly described by Pierce as a "noodlebrained bag of useless flesh" -- had Bill Nye, the Science Guy media personality, debate the neo-Confederate Congresswoman from Tennessee Marsha Blackburn.

Is it just me or does Marsha Blackburn look like the kind of woman who in high school took out her cheerleading squad main rival and now has a cuckold husband who lives in dread fear of her??

"Jesus has been talking to me. He said I should have you over for one of my Southern home-cooked meals."

The Fox "coverage" doesn't even warrant the respect or dignity of a description other than to say it was the usual crap.

One interesting point: Apparently the GOP Agit-Prop Machine is trying to follow Frank Luntz's 2003 dictim to use the term "climate change" instead of "global warming." While climate scientists have long done this, the GOP position is based on total misunderstanding (there is no "global warming" but "climate change" can naturally happen and the term is less scary to "typical voters").

So there you have it.

Another picture of the lightly snow-covered sidewalk in the 1900 block of New Hampshire Avenue, Washington, D.C., 9:36AM February 18, 2014.


OK, that FINALLY wraps up this entry. It took me in all about 9 hours -- stretched over three days -- to compose this entry. That's ridiculous. I know that. Going forward, I need to make these entries shorter, more concise, and possibly even length / word / image limited.

It's Saturday night now and I intend to post my jukebox Saturday night entry along with a brief update.


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