Friday, January 5, 2007

Plants to People: Chill Out!


Cloudy, damp, mild. After this morning's showers, it's a foggy, misty afternoon here in the Washington metro area, but temperatures are quite mild for the season, generally in the upper 50s and low 60s. A few more showers, and possibly thundershowers, will give way to near-record temperatures tomorrow while a more seasonable cold snap gathers on the horizon for the early to mid part of next week.

Tonight and Tomorrow

Showers ending, near-record warmth. There is a 50% chance of showers, possibly scattered thundershowers, overnight with lows only in the mid to upper 50s. Clouds will give way to sunshine during the day tomorrow with highs near 70°.

For the outlook through the rest of the weekend, scroll on down to Jason's post below.

Plant Patrol

An article, "Kept From Hibernation By a Lingering Warmth", in today's WaPo Metro section surveys the recent unusual (and more usual) blooming patterns of the region's gardens. It quotes several local experts as saying that the plants will still be able to survive when the inevitable cold snap (and there will certainly be one) does occur.

Mediarology: Hype-ocracy

Having rerun all possible past disasters into oblivion, The Weather Channel is rolling out a new series of imaginary disasters The Day After Tomorrow (Sunday, 9-10pm). According to the on-air promos, these are the cities scheduled to die to the tune of a continuously pounding soundtrack in the new season of "It Could Happen Tomorrow": St. Louis (F5 tornado), Chicago (F5), Austin (wildfires), Houston (Cat 5 hurricane), Las Vegas (8.0 earthquake). The state of Hawaii is also scheduled to be demolished via tsunami, and there is an untitled shot of a crumbling Capitol dome under a looming presumably F5 attack. The TiVo on-screen schedule shows the Chicago and Houston programs to be the premiere back-to-back episodes of the new season.

Last January, when this series first went on the air, PM Update cautioned that the continued blurring of the line between news and entertainment can lead to a "cry wolf" effect that threatens to outweigh the possible educational benefits. The Weather Channel's Climate Code, which also debuted last year, is a very different kind of show, but it has sometimes been criticized by being lumped together in the same category. It has gone to great lengths to be objective and non-partisan (or at least bi-partisan; a Democratic and Republican governor were interviewed in the same segment), but it has still been accused of having a ratings-driven agenda. If this show is driven by ratings, why was it put on at 5pm Sunday . . . during football season?

Another example of the confusion between reality and image is the reaction to last year's documentary, "An Inconvenient Truth." It has been attacked for hyping a 50-ft wall of water demolishing New York. Guess what? The drowning Statue of Liberty was in a completely different movie, although a comparable scene was used to promote "It Could Happen Tomorrow." If you're keeping score at home, turn to scene 21, time 1:00:23, of the DVD, to see how New York is presented. For reference, here is what the book, which is an extended version of the movie script, says about Manhattan (starting on page 196):
"If Greenland melted or broke up and slipped into the sea---or if half of Greenland and half of Antarctica melted or broke up and slipped into the sea, sea levels worldwide would increase by between 18 and 20 feet. . .
[quotation from Tony Blair's advisor]
[several pages of illustrations of Florida, San Francisco Bay, Netherlands, Beijing, Shanghai, Calcutta, Bangladesh]
. . . the picture at right shows what would happen to Manhattan if sea levels rose 20 feet worldwide. The site of the World Trade Center Memorial would be underwater. Is it possible that we should prepare for other serious threats in addition to terrorism? Maybe it's time to focus on other dangers as well."
Which particular part of that includes the hysterical 50-ft wall of water?

The plants may be more rational than the humans.

Thursday, January 4, 2007

Temperature Temperance


Sunny, mild. Under some scattered high clouds and a southerly breeze, temperatures have reached the 60s this afternoon in the Washington metro area; the official high was 62°. Clouds will increase tonight, and showers will arrive tomorrow, as a low pressure area developing along the Gulf Coast moves toward the Ohio Valley.

Tonight and Tomorrow

Increasing clouds, mild; showers developing. Clouds will increase tonight with lows in the upper 40s to 50°. Showers will develop after dawn tomorrow morning, continuing through the afternoon. The heaviest rain, however, should remain west of the mountains and through the Ohio Valley. Highs will be in the low 60s.

For the outlook through the weekend and beyond with Larson's Long-Range, scroll on down to Josh's post below.

Warmth in Perspective

While today's temperatures certainly felt out of place for January, they were well short of the record 73° for the date. In fact, only 4 dates in January have failed to ever reach 70° in Washington. (Interestingly, this is 2 fewer than the 6 in December.) Two of them have already passed, including the lowest, 68° on the 3rd. What is noteworthy about the current warmth, however, is its persistence. The current string of 25 consecutive above-average days is longer than last January's run. Although there were only 3 average or below days in January 2006, they were scattered through the month.

The warmth is also pervasive through the whole country. The plot above of temperatures at midnight last night (from Unisys) shows only a very small extent of sub-30° temperatures (blue and blue-green), nearly all in the southern Rockies. The daily high temperature map shows above-freezing temperatures in all 48 states. I could find only 4 locations with temperatures below 32°. If you can find more, please let us know in the comments where they are located.

Modeling Myths

A common myth, especially, it seems, among operational meteorologists, is that climate models must be inaccurate simply because daily forecast models become inaccurate beyond about a week with current technology. Therefore, the argument goes, how can you possibly forecast years, decades, centuries into the future? A "Quick Study" in the latest (January 2007) issue of Physics Today called "The physics of climate modeling" helps to explain this apparent paradox. The article is open to non-subscribers and is quite accessible, no equations necessary. The key distinction between the two types of models is the following:
Weather concerns an initial value problem: Given today's situation, what will tomorrow bring? Weather is chaotic; imperceptible differences in the initial state of the atmosphere lead to radically different conditions in a week or so. Climate is instead a boundary value problem-a statistical description of the mean state and variability of a system, not an individual path through phase space. Current climate models yield stable and nonchaotic climates, which implies that questions regarding the sensitivity of climate to, say, an increase in greenhouse gases are well posed and can be justifiably asked of the models.
Unfortunately, the online version omits a figure from the carbon-based version which shows how well climate models are able to reproduce the effects from the eruption of Mt. Pinatubo in 1991, although the results are described in the text. Hopefully this will appear in the pdf version, which is not yet online.

Also pertinent to this question is the article "Belief and knowledge-a plea about language" in the same issue. It discusses how different meanings for the same words can produce misunderstandings about scientific concepts. Saying "I don't believe the results of climate models" without verifiable contrary data is simply an ideological assertion. On the other hand, the statement, "[Scientists believe that] climate is changing in many ways, and there is strong observational and scientific evidence that, at least over the last 50 years, human activities are the major contributor to climate change," reflects the current state of scientific knowledge.

Wednesday, January 3, 2007

24 Days and Counting


Clear, mild. After a frosty start, it's a brilliantly sunny mid March day here in the Washington metro area. The official high was 56°, equal to the climatological average high for March 16-18. This is now the 24th consecutive day of above-average temperatures, and there are at least several more on tap. The PM Update mobile unit observed numerous walkers, joggers (note to spellcheck: not jokers!), and bicyclists enjoying the conditions along Beach Drive in the Kensington-Bethesda area early this afternoon.

Tonight and Tomorrow

Continued seasonably mild; some increase in clouds. Under mainly clear skies, low temperatures tonight will be in the upper 30s downtown to near freezing in the 'burbies. Clouds will increase somewhat tomorrow, particularly late in the day, with highs near 60°

For the outlook through the weekend, scroll down to Dan's post below.

The Trend is Your Friend?

The trend is definitely not your friend if you're a snow-lover. As we've cautioned many times, however, "past performance is no guarantee of future results". Matt recapped December in his Tuesday post. The chart to the right summarizes the temperature part of the story. Note the 2 daily record highs, but also the fact that the linear trend (dashed line) of the highs is actually slightly upward, despite the usual downward trend of the average during the month. chart from NWS data, photo © Kevin Ambrose

Science Fact and Fiction

Dan poses the intriguing question of what Washington would be like under a different climate in his earlier post. For a really far out consideration of this question, check out the science fiction section of the new store. Kim Stanley Robinson's trilogy is based right here in a future DC. The second volume comes out in paperback at the end of the month and is available for pre-order; the third book is scheduled for release in February.

In case you missed it, let me repeat that this is fiction, although the first one (I haven't yet read the other two) is much more plausible than, say, "The Day After Tomorrow." Unlike some people who run energy industry lobbying operations from their $1.2 million Potomac homes, we are extremely careful here at to separate fact from fiction. Like alternative histories, however, alternative futures can often provide interesting and useful insights.

Tuesday, January 2, 2007

December Extender


Clear, mild. Despite northwesterly breezes, temperatures reached 50° or higher throughout the Washington metro area this afternoon. The official high was 51°; the low so far of 42° is just 1° below the average high for the date and 43° above the record set in 1899. BWI and Dulles were both at 50°. The national weather map shows high pressure from coast to coast with the only significant precipitation in the Pacific Northwest and extreme northern Rockies.

Tonight and Tomorrow

Continued clear and seasonably mild. Clear skies should continue through tomorrow, with lows tonight from the mid 30s downtown to the upper 20s in 'burbland. Tomorrow will be even milder than today, highs near 57°.

For the outlook through the rest of the week, scroll down to Jason's post below.

Season of Lights

The upcoming seasonably mild and dry evenings provide a last chance this week to enjoy the Garden of Lights display at Brookside Gardens in Wheaton. The scenes displayed in lights include a rainstorm, lightning, and a rainbow. Even with over 600,000 lights, it was a little hard to tell in the dark, but some kind of cherry-like tree was in full bloom there last night. That would be consistent with reports from several site visitors in recent days and an article ("Trees Abloom Amid Winter Warm Spell") in yesterday's WaPo.


If nothing else works, try a time machine: The 1780 major East Coast snowstorm noted tersely in "Today in Weather History" was the second of three major nor'easters from Virginia northward over a 10-day period which "rank with the greatest such combinations in our meteorological history", according to the definitive work on the subject, "Early American Winters", by David Ludlam. Following these storms, snow covered the fence tops in southern Connecticut and depths in the woods were 42-48 inches. Drifts were estimated at 6 to 10 feet in New Haven, on the coast.

Political Science

In an impressive display of journalistic ambidexterity, today's carbon-based WaPo has an article both above ("Arlington Takes On") and below ("Global Warming") the fold. It describes the actions of the Arlington County Board in reducing CO2 emissions. We'll leave it to the tin-foil-hat types to decode the agenda, but the article is written by the Arlington/Alexandria reporter, while the erstwhile environment reporter returns to her former political beat to take the page A1 pole position with an article analyzing the House Democrats' legislative plans in the new Congress.

Seasonal Outlook

Latest seasonal forecast: Click here.

Latest 3-month temperature outlook from Climate Prediction Center/NWS/NOAA.