Saturday, January 19, 2013

The Anatomies of a Typical D.C. Snow Forecast Bust and Crummy Response: Gong the CW Gang

**Updated 11:54PM 6/17/2014: See bottom of entry.**

This entry was posted on January 19, 2013.

The Capitol grounds and National Mall with downtown Washington, D.C., in the background as seen on a snowy day in February 2010. This was during one of our triple-whammy snowstorms in the record snowy winter of 2009 - 2010 that we are not likely to repeat for a long time.

I was working as as 1099 independent contractor for the vicious Japanese turkey farm in Bethesda at the time and in an American corporate and libertarian delight nightmare state, so I couldn't really enjoy the snowstorms.


Another view from the same spot overlooking the U.S. Capitol grounds in the February 2010 snowstorm. These two images and two others are from here.


So the would-be snow event in Washington, D.C., OF COURSE did not occur. It collapsed into nothingness, which is totally what I expected. The particulars are not important -- a low pressure riding along an east-west frontal boundary extending across the Carolinas that was unable to progress northward into dry air.

The big issue is why the National Weather Service -- specifically, our Baltimore / Washington area regional forecast office located in Sterling, Virginia and referred to by its three-letter identifier "LWX" -- bought so heavily into what was always just a chance of accumulating snowfall and even issued a winter storm watch for the D.C. area and points south.

The part that's really annoying for me is the self-congratulatory circle-jerk occurring over on Capital Weather Gang which has reached new heights of annoyance and tackiness.

It has been like this since Thursday with all the CWG crew led by Jason Samenow with a lot of peanut gallery internet comments.

We get it, Jason Samenow.

You are a weather god with god-like knowledge -- all the more so because you actually managed to do what is almost impossible: You accurately predicted that a possible snow event would fail to hit D.C.

That's quite an achievement, and I shall return to this topic later in this entry.

First, though, let's watch the evolution of the snow totals for this event as shown on that damn "experimental graphic" map LWX has been using since late 2010 -- right about when the current snow drought hit (we are in our longest stretch ever without at least 2" of snow in a single event with the last time occurring on Jan. 26, 2011).

Above is the original snowfall map forecast total through 4AM EST January 18, 2013 for the LWX county warning area (CWA) generated at 11:34AM January 16, 2013.

The District of Columbia is -- incredibly -- in the 4 to 6 inch range.


The revised snowfall map forecast total through 4AM EST January 18, 2013 for the LWX CWA generated at 10:11PM January 16, 2013.

The District of Columbia is now in the 2 to 4 inch range.


Yet another revised snowfall map forecast total through 4AM January 18, 2013 for the LWX CWA generated at 2:23PM January 17, 2013.

The District of Columbia is now in the less than 1 inch range.  (There was an intermediate map showing D.C. in the 1 to 2 inch range.)


And now, let's bring it on home ...

And yet another revised snowfall map forecast total through 4AM EST January 18, 2013 for the LWX CWA generated at 5:19PM January 17, 2013.

This is the update that Gary and I were waiting for -- where the lowest map color (light blue) just brushes the Capital Beltway (in this case on the south side by the Wilson Bridge).


From tragedy to farce ...

And finally we get the last update of that map showing the LWX CWA snowfall map forecast total through 3AM (not 4AM) January 18, 2013 issued at 10:13 January 17, 2013.


Wah-wah-wah-waahhh ...

That snow map graphic is the kiss of death for any snowfall in D.C. As soon as I see it posted with a measurable range for D.C., as sure as the day is long, I know the "arc" it is going to follow.


Here is how the original winter storm watch appeared at the start of (midnight on) January 17, 2013:

This is the Sterling LWX county warning area map on its website with advisories in place as of midnight on January 17, 2013.


Here was the same LWX website CWA map as of 5:05PM EST on January 17, 2013 as everything was swiftly falling apart. By this point, the winter weather advisories have been pared back to well south of the District.


And here was the same map seven hours later at 12:04AM January 18, 2013.



Below are a series of images showing is a portion of the East Coast radar mosaic (a mosaic or "composite" of numerous radar and in "composite mode" for each radar -- those aren't the same things).

A portion of East Coast radar mosaic at 1948UTC (2:48PM EST) January 17, 2013. I use a screen capture / clipping tool for part of the large national radar mosaic to get these images.

This shows the upper level low nearing the Atlanta area while the surface low nears far western South Carolina and basically flows an east-west elongated frontal boundary that will take it to the Outer Banks. Precipitation north of the frontal boundary is unable to move farther northward due to dry air infiltration.


The same general radar mosaic image but at 0408UTC (11:08PM EST) on January 18 (17th), 2013.

The surface low has reached the Outer Banks while the upper level low spins behind it somewhere near Charlotte, N.C. The precipitation asssociated with the system appears to be dissipating as the dynamics sort of die out (with no coastal redevelopment).  It's over.


Some Thoughts on Capital Weather Gang's Ongoing Self-Congratulations ...

As for the meteorologically good and great Jason Samenow -- he of the endlessly annoying Capital Weather Gang (on the WaHoPo website) with their wintertime schizophrenic "We want 70F warmth and we want heavy snowfall!" -- I think the very public criticisms of LWX are unwarranted and tacky.

They are unwarranted because LWX has a very specific mission and defined set of responsibilities and the meteorologists there did the best they could with the information they had coming in. (Whether it's info overload and/or there are other ways to disseminate probabilities and "risk" to the public is a separate topic.) It is also tacky because Samenow really should know better.

But more to my point, "forecasting" a snow bust in Washington, D.C., hardly takes skill considering how frequently advertised snow events fail partially or entirely to materialize. However, in D.C., as with all other aspects of life in this enervating place, the weather is an intensely political and politicized thing, especially snowfalls, prolonged heat waves, and droughts.

Yes, Jason Samenow, the Weather gods are indeed impressed with your incredible forecasting abilities.

You win the Sue Palka-Cabra Award! Huzzah!

This award entitles you to and two weeks in a hot, arid climate of her choosing.

It also entitles you to a free McDonalds cheeseburger and supersized French Fries with large soft drink.

With this magnificent victory under your belt, Jason Samenow, you can BOLDLY go where no D.C. area weather forecaster has ever gone and predict NO SNOW this winter.


It is true that city road crews here in D.C. and in the suburbs put down a shit-ton of toxic rock salt and sand in anticipation of the snowstorm. And there was the usual hyper-overreaction with schools closing, like, days in advance.

Here is a literal "berm" of sand down the middle of Massachusetts Avenue as seen from 17th Street NW created by passing traffic as seen at 10:23PM on January 17, 2013.

This sand had been put down by the city road crews hours earlier.


As for Sterling LWX, I'll keep reading them, partly because there isn't a whole lot of legitimate options -- this and especially this don't count -- and partly because it's the "Devil You Know" kind of thing.

Anyway, at this point, the forecast calls an actual Arctic outbreak by Monday night with high temps. only around 30F at KDCA on Tuesday and 29F on Wednesday and lows in the teens. This will be the biggest Arctic outbreak in at least 2 years. There may also be some snow showers / snow squalls on Monday ahead of the actual Arctic blast. If so, it would not be a total waste of cold air.

However, the Sterling LWX experimental snow map just was updated and shows this for the period through 7PM EST on January 21, 2013:

This means, of course, we won't get ANYTHING.

My only hope is that it is a wet year. As you may know, we've been below normal on precip. for much of the last six months with some exceptions (most notably October).

Rain is good for the hydrological cycle as spring begins (and, undoubtedly, it will begin weeks earlier than "normal" -- though whatever "normal" is now us problematic).

Yes, soon spring will be here and all the flowers and tender buds will blossom and bloom even as the world comes alive.

**Updated 11:54PM 6/17/2014: Content removed.**

OK, that's all for now.

I intend to post one more update later this evening -- but after I've gone grocery shopping and started my laundry.


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