Plants to People: Chill Out!

Now

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.

Temperature Temperance

Now

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.

24 Days and Counting

Now

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.

CapitalWeather.com 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 CapitalWeather.com 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 CapitalWeather.com to separate fact from fiction. Like alternative histories, however, alternative futures can often provide interesting and useful insights.

December Extender

Now

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.

ISO Snow IV

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.

It Came Upon a Midnight Drear

Now

Showers, cool. As the low which brought all that snow to Denver gradually spins down over the Great Lakes, convergence of Atlantic and Gulf moisture to the east is putting a damper on holiday cheer along much of the East Coast. Here in the Washington metro area, persistent light rain showers had put a mere 0.04" of water into the official measuring bucket by early afternoon, although that total has now slightly more than doubled. This month has just today been mathematically eliminated from breaking the record for driest December (0.19" in 1889), although only by a few hundredths of an inch so far.

Temperatures have barely budged all day, staying in the range of 45-48° for the last 24 hours. This Seattle-like pattern will be slow to clear out as we head into the holiday weekend.

Surface weather map and satellite picture at 1m today from HPC/NCEP/NWS

Tonight and Tomorrow

Showers continuing, cool. Showers, fog, and possibly some periods of heavier rain will continue through this evening and overnight. Temperatures will remain within a couple of degrees of where they are now, in the upper 40s. Conditions will start to dry out by the middle of the day tomorrow. If enough sun breaks out by early afternoon, highs could reach 60°, although the models are being somewhat optimistic about the timing on this, IMHO.

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

Mediaorology

Andrew's Sunday Undercast on why climate change and broadcast meteorology don't seem to mix was picked up by the USA Today Weather Guys on Wednesday and by the Weather Channel blog yesterday. Both of them had some very thoughtful responses to the issues raised; I think Dr. Cullen's were especially insightful. WeatherTalkers, are you listening?

One thing I noticed about the posts at USA Today and TWC was the fact that, despite being national in scope, they each had only 1 comment. The one at USA Today was especially bogus. We are fortunate here at CapitalWeather.com to have such a literate, well-informed, and enthusiastic audience. Please continue to share your input with us in the future (but be prepared to be challenged if you don't back up your assertions with facts).

Programming note: PM Update will be on "standby mode" next week. To steal a phrase from Comedy Central, however, whenever weather breaks, we'll fix it, posting as news warrants. We look forward to sharing with you the wonderfully wild and wacky world of Washington winter weather when our regular schedule resumes after New Year's. In the meantime, we send best wishes to you and your families for a happy, healthy holiday.

Happy Solstice!

Now

Cloudy, cool. Winter solstice is at 7:22pm tonight. A few peeks of sun and a southerly breeze were no match for a mid-level overcast and a few minor sprinkles of rain on one of the shortest days of the year in the Washington metro area. The temperature in most places stayed below 50°; the highs were 46° at National, 47° at Dulles, but 53° at BWI. Clouds will become thicker and showers will develop through the day tomorrow.

Tonight and Tomorrow

Showers developing, cool. Tonight will be overcast with a 40% chance of showers by dawn; lows will be in the low 40s in town, a couple of degrees cooler in the 'burbs. Tomorrow will be cloudy with showers likely, especially in the afternoon and earlier west of the mountains, with highs in the upper 40s.

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

ISO Snow III

If you've been with us since last year (if so, thanks; if not, welcome!), you may recall we did some fun-with-numbers analysis of the relationship between December and January in Washington. Considering the amount of wailing and gnashing of teeth going on lately in the Comments section about the End of Winter As We Know It, this is probably a good time to take a second look at the data. The gist of the results is that, despite any amount of wishcasting, guessing, golden childhood memories, El Niño, NAO, or EIEIO, snow in Washington is enough of a random event that there is almost no connection whatsoever between the amount of snow in December and the amount in January. Anyone who tells you differently should be closely examined for controlled substances. In fact, the nearly microscopic amount of correlation (¼%) which does exist is actually slightly negative.

Since this December is well on its way to the "bust" category for snowfall, it's relevant to look more closely at the data points huddled along the y-axis in the original chart. The January snowfall for the 30 winters with December snowfall of 0.1" or less is shown in the chart above. Included in that set are 2 Januaries with over 20" each. The average amount of 5.6" is not very far from the January average of 6.6" for the entire period of record.

Although Mr. GW may have his greasy carbon-bloated thumb on the scale over at Momma Nature's Weather Grill and Deli, reports of winter's demise are certainly premature. (Before you fire up the political flamethrowers, please note that "GW" refers to "global warming", not a certain person's initials, but you knew that anyway, didn't you? )

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

Clarification: In the interest of full disclosure, we should point out that a site visitor noted that the Union of Concerned Scientists climate projection map posted yesterday was based only on summer heat index. A projection based on the entire year would show a smaller geographic change.

Snow Crash

Now

Sunny, cool. There was a rare sight for the current season in this part of MoCo this morning, a hard frost which persisted in north-facing areas until close to noon. Following the cold lows, a high layer of broken clouds defied the southerly wind direction to keep temperatures a couple of degrees cooler than yesterday. Highs were 48° at National and Dulles, one degree higher at BWI.

Clouds will be increasing as the blizzard walloping the Front Range of the Rockies heads toward the Great Lakes. As noted in Jason's post below, the SLCB isn't dead, it's just sleeping.

Tonight and Tomorrow

Increasing clouds, cool. Clouds will increase toward morning as lows tonight reach the mid 30s downtown and closer to 30° in the burbclaves. Tomorrow will be mostly cloudy with highs near 51°.

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

ISO Snow II

The WaPo Washington plant climate article cited in Jason's earlier post is consistent with a study, "Climate Change in the U.S. Northeast", published a couple of months ago by the Union of Concerned Scientists. Depending on the level of greenhouse gas emissions, Massachusetts could be passing what used to be DC climatologically by mid-century on its way to the former South Carolina.

Accompanying the plant article on carbon-based page A1 is an article about the lack of snow so far this season in Europe as well. In Moscow, where 5 daily temperature records have already been set this month, street cleaners have put aside their ice axes and are reduced to picking up cigarette butts. Britain's Met Office reports that 2006 may turn out to be the warmest since temperature records began in England almost 350 years ago. A climatologist at the Central Institute for Meteorology and Geodynamics in Vienna (the other one) says, "We are currently experiencing the warmest period in the Alpine region in 1,300 years." An EU climate study has found that the current warming already exceeds warming periods in the 10th and 12th centuries.

Meanwhile, snow fans in the Rockies are happy, at least. A blizzard has shut down the United Airlines Denver hub as well as Colorado's 3 interstate highways, I-70, I-25, and I-76. There was a 20-car wreck on I-25 near Colorado Springs; at least 5 were injured. I-80 was also closed from Cheyenne, WY, to Ogallala, NE. Snow totals early this afternoon ranged up to 15" at Telluride, CO. (SUV drivers, please check out the photo in the link above before you try any stunts on the Beltway this winter.)