Category Archives: Weather

“You are getting sleepy…very sleepy…”

Here’s a second interesting view of Isaac, now well inland over northern Louisiana.  This time it’s an animation of the surface wind field around Isaac at 11:00 a.m. CDT.  The creative and wonderfully imaginative people at Google’s Big Picture data visualization group created the surface wind visualization site (http://hint.fm/wind/index.html) which was the source for this animation.  The hypnotic swirl is mesmerizing.

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Hurricane Isaac Crosses the Coast

Here’s an interesting 22-hour radar loop from the New Orleans NEXRAD site (the National Weather Service’s weather radar site) showing hurricane Isaac very slowly crossing the coast and heading inland:

Today’s Stream of Consciousness

Today, I’m making my first attempt to create a blog entry on my iPad using the much-loveblogsy_icond blogsy app. The result: So far, so good. Intuitive (I haven’t looked at their tutorial videos yet), easy to use, designed for iPad’s touch-n-swipe interface. And, even better, a lot less frustrating compared to my initial experience with the WordPress app (which is fine for simple stuff, but is not very feature-rich…although the price is right!) [Update, January 28, 2016: Blogsy is no longer with us. Sigh.]

And, now for the abrupt change of subject (befitting the stream of consciousness)—

As the 11-year solar sunspot cycle continues to heat up…

…the effects of another impressive solar flare are headed towards Earth in the next 24 sxi_20120306_235815165_ba_15hours. Updates about expected impacts on radio transmissions, auroral activity, etc. are issued by NOAA’s Space Weather Prediction Center and posted here. It doesn’t look like the auroral activity will be seen this far south (40°N), but it really doesn’t matter because we’ll be covered in clouds through tonight.

Temperature at KDEN, past 2 days

And, just why is it so cloudy in Colorado? Because of a cold front which moved rapidly down the Front Range of the central Rockies last night. We went from 73°F yesterday (just 2°F shy of the record high temperature for March 6) to a current temperature of 27°F—a 45°F drop!

Hmmm…just ran across an oddity in blogsy. I wanted to use the degree symbol (HTML code: ° or °, but when I went into the HTML editor side of blogsy and put in the code, then returned to the rich text editor side (with a real-time preview of the blog entry), no degree symbol…just the actual HTML code is shown. We’ll see what happens after I post this to the WordPress site…
Update after my post: While blogsy does not show the degree symbol in its rich text editor, the degree symbol shows up just fine (as I had hoped) on the WordPress site. Good. Blogsy passes the test!

Snowless Winter? Not entirely snowless, but certainly snowstarved

There have been many headlines about the lack of snow over the conterminous U.S. this winter particularly because the northeastern U.S., a major source region for headlines, has experienced an unusually mild winter.  For instance:

Outdoor Enthusiasts Adapting to Snowless Winter West of Boston
Festival has Near Meltdown
Towns Save Money in Snowless Winter
Home Depot Given Warm Winter Boost

The less than normal snow extent also affects many parts of the western U.S. including where I live in Colorado.  It was visually evident during the President’s Day weekend when I noticed I could see most of my two-foot tall snow stake at our house at the 8300-ft level in the Colorado mountains:

Snow on the ground, Feb. 2012

That contrasted with the conditions of a year ago which were much different.  Just how different?  This picture from last year’s President’s Day weekend shows the same snow stake at the same location:

Snow on the ground, Feb. 2011

Ah yes!  What a difference a year makes.  Even more striking is the difference in the amount of water contained in the central Colorado snowpack this year as opposed to last.SWE in central Colorado, 21 February 2012  The graph to the right shows the snow water equivalent (SWE), the amount of water in the snowpack measured in inches, for a location not too far from the snow stake comparing Jan 1-Feb 21 of last year with the same period this year (last year=blue, this year=red).  Again, what a difference a year makes!  Last year the snowpack contained more than 3″ of water (if you were to melt all the snow in a column); this year the pack has about ¾”, just 25% of last year’s amount.

The dearth of snow in the Central Rockies is not confined to the area just around my snow stake.Colorado snowpack, 21 February 2012  This next map, from the Natural Resources Conservation Service (NRCS—a part of the U.S. Dept. of Agriculture), shows all of Colorado having a below average snow season this year. The NRCS collects data about the snowpack (snow depth, water content, etc.), both remotely and in-situ, and produces a variety of maps depicting the condition of the wintertime snow cover. Their Colorado map set can be accessed from here.

Snowpack over the western U.S., 21 February 2012
To the right is an even bigger picture view, again from the Natural Resources Conservation Service.  Most of the western U.S. except the far northern regions and a few spots in the southern Rockies have had a snowstarved winter.  If you are interested in monitoring changes in the snowpack across the western U.S., here’s where you can access daily updates to this map.

Much of this winter’s snowlessness across the U.S. is related to the location of the jet stream.250 mb average jet stream winds 24Nov11 to 21Feb12  Winter storms generally follow the path of the jet stream (Storms develop along thermal boundaries between cold air to the north and warm air to the south, in the Northern Hemisphere.  The jet stream is created by these same thermal differences.) Generally, cold air and snow will be more prevalent along and on the poleward side of the jet stream’s location.  This winter, on average, the jet stream has been farther north than normal especially over the western U.S. as this map shows (magenta arrows show average position of the jet stream).  Usually, those magenta arrows would be hundreds of miles farther south and the northward bulge over western North America would not be as pronounced.  This is a pattern which is often seen during La Niña conditions (cold water over the central Pacific Ocean) like what we have this winter—although this year the jet stream is even farther north than in typical La Niña years.

And, as with all things weather, by the time I post this missive it will be old news.  In the past few days the jet stream has shifted south and west (as shown by this satellite picture and wind speed map from today).
Jet Stream Over the U.S. 22 Feb. 2012It now enters the U.S. over the Pacific Northwest and dives down into the central Rockies.  Meanwhile over the eastern U.S., it’s farther south as well (and, not surprisingly, Richmond, VA had a few inches of snow this past weekend). For Colorado, this has meant a return to snowy conditions for our mountains with fresh powder at the ski resorts being measured in feet rather than inches.  This is good news for the western watersheds (but bad news for my snow stake).  And for the next 10 days, at least, it looks like the jet stream will remain closer to its normal position across the western U.S. leading to more normal wintertime weather.

Low Pressure Secrets

Quiz of the day:  What do all the following symbols depict?

Answer:  Well, you might think each is a different way to represent a surface low pressure system like what you might see on your favorite daily weather map (for example, from The Weather Channel).  [Note: Northern Hemisphere only.  Down south of the Equator, the winds spin clockwise around these things.]  It turns out, though, one is an outlier.  This symbol:

might look vaguely familiar—for it is the “History” button from the iPad Google Search App (Note: If you don’t have an iPad or the Google Search App, you can see a screen shot of what I’m talking about here.  The History icon is at the lower-left of the main screen.)  It looks like this:

Whoa!  Where did that come from?  And, when did the symbol for a low pressure system become an image to represent search history?  My best guess is one of the Google button-icon graphics artists secretly is a fanatical weather weenie, and this icon was a perfect way to subtly expose that interest.  Very clever!  Even more so, I bet if I were to hop on a plane to go taste a Barossa Valley Shiraz, the app would automagically respond to my hemispheric orientation and convert the icon to:

Very nice!

Reading a Storm

SnowstormMeteorology and poetry are often interrelated.  Poets write about what they see and feel. What they see and feel is influenced, changed, and shaped by the weather’s vagaries.  The association between the two can produce something like this:

The storm puts its mouth to the house
and blows to get a tone.
I toss and turn, my closed eyes
reading the storm’s text.

This is the first verse of a poem by the most recent winner of the Nobel Prize in Literature, Tomas Tranströmer.  The poem, entitled “storm,” was translated from Tomas’ native Swedish into English by the Scottish poet Robin Robertson and published in the short paperback, The Deleted World: Poems (see cover photo below).  This particular verse reminds me of what we all do when listening to the wind heralding the approaching onslaught—we attempt to “read the storm’s text.”  Meteorologists just tend to do it much more than normal folk.The Deleted World: Poems

Snowy Springtime Timelapse

During this transitional season from winter to summer, as the sun travels higher in the sky each day and hints of summer’s warmth become more frequent, the weather responds to the nature of the season as well.  Often, here in the central Rockies of Colorado, there are days when still-chilly northwesterly winds are accompanied by frequent snow showers in the unstable atmosphere of spring—unstable because the atmosphere retains its cold memory from winter, while the land rapidly warms from the relatively strong springtime sun.  The following timelapse animation shows an example of this, with daytime heating causing snow showers to form and spread southeastward pushed by strong, cold winds from the northwest:

The timelapse compresses about 3 hours of midday weather into 33 seconds of video.  It was taken yesterday (29 March), and the camera was pointed to the south-southeast.  The images used in the animation were taken once every 20 seconds.  The location was just west of the Continental Divide in the Colorado Rockies.

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