November Prepares to Leave Town Cool and Dry

Now

Clear, mild. After some morning cloudiness, clear skies ahead of an approaching cold front have been accompanied by southerly winds and temperatures a bit milder than expected. Readings were at least 60° in most parts of the Washington metro area this afternoon, with highs of 61° at National, 60° at Dulles, and 58° at BWI.

Meanwhile, the long-term dryness continues as we roll on toward closing out the month with just over 50% below average rainfall. The fall season (Sept-Nov) is about 12% below, and the year to date is 17% under average. The yearly total is now running over 10" below last year's wet pace. The next precipitation, from a storm system emerging out of the Southwest toward the Great Lakes, is likely this weekend.

Tonight and Tomorrow

Mostly clear, colder. Under clear skies tonight, lows will range from the low 30s in the city to the upper 20s in the 'burbosphere. Tomorrow will be sunny and colder with highs 46-50°.

For the outlook through the weekend and beyond, scroll on down to Josh's post below.

Winter Outlooks

In case you missed it, CapitalWeather.com's winter outlook is here, and NOAA's final winter forecast update is here.

As a reminder that the rest of the Northern Hemisphere has winter around this time also, Japan's JMA is predicting "mostly average to milder-than-average winter weather", and the UK Met Office expects the winter to be "warmer than average, particularly in northern Europe, but cooler than last year". Environment Canada also produces an extensive set of seasonal forecasts. The current forecast (Nov-Dec-Jan) calls for over a 50% chance of below-normal temperatures over most of the northern half of the country.

November Rollercoaster Continues

Now

Clear, cool. Under mostly clear skies with some approaching high clouds from the southwest, temperatures are somewhat cooler this afternoon in the Washington metro area. Most locations remained in the upper 40s, with highs of 49° at National, 46° at Dulles, and 45° at BWI. The air is also very dry, with most dewpoints in the teens or lower 20s yielding relative humidities of around 30-35%.

Temperatures will rebound upward tomorrow before turning colder again toward the weekend.

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

Tonight and Tomorrow

Partly cloudy, milder. Clouds will increase overnight with lows in the upper 30s in the city to the low and mid 30s in the 'burbosphere. Mostly cloudy skies tomorrow morning will become mostly sunny in the afternoon with highs 55-59°.

For the outlook through the rest of the week and weekend, as well as the temporary obituary of the Snow Lover's Crystal Ball, scroll on down to Jason's post below.

Bucket O' Bookmarks

As a prolific generator and consumer of real-time data, meteorology is a perfect match for the World Wide Web. In this occasional feature, Update will share some of the weather-related sites we've found useful, interesting, or just plain fun over the last decade and a half. At last count, we had accumulated close to 1000 links in several dozen folders (24 pages of 12-point Times New Roman type).

One of the newest web destinations is the completely redesigned National Weather Association site, which debuted last month. The site is well-organized and, very much appreciated by a former performance analyst here in the cone of broadband silence, it's very snappy to load. (Verizon, can you hear me now?) Some of the highlighted features include the first 2 downloadable modules of an introductory weather course for pilots and the recently announced list of winners of the 2007 Sol Hirsch Education Fund Grants. Once again, despite our prodding, there were no winners from the DC/MD/VA area among the 10 award recipients. Perhaps if you K-12 teachers work on your applications while you're clicking on "Reload" for the Snow Lover's Crystal Ball to reappear, the National Capital region can be better represented next year?

If you have a favorite weather site (other than CapitalWeather.com, of course!), let us know in the Comments.

Sunny, Seasonable Supplants Skimpy Showers

Now

Sunny, breezy. Following a midnight high of 64°, temperatures have trended generally downward today with the help of the early-morning passage of a cold front, but by mid afternoon they were still near the seasonal average in the mid 50s. With the arrival of a reinforcing shot of cold air, readings should be a little cooler tomorrow.

Despite yesterday's gloominess, rainfall amounts through this morning in the immediate metro area were nearly all less than 0.25", but higher toward the north and west. (The middle shade of blue in most of the western suburbs represents 0.10-0.25", while the District itself and points east are generally less than 0.10".)

Precipitation chart through 7am this morning from NWS Precipitation Analysis

Tonight and Tomorrow

Mostly clear, cool. Breezes will diminish tonight under clear skies with lows ranging from the mid 30s in the city to the upper 20s and low 30s in the 'burbosphere. Tomorrow will be sunny and a little cooler, with highs 48-51°.

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

Blogospheric Climate

The NYTi's Andrew Revkin reported in his DotEarth blog yesterday on the controversy surrounding the linguistic license used by Dr. James Hansen in his choice of metaphors for describing the consequences of global warming. David Roberts also has some extended comments at Gristmill. Dr. Hansen was one of the first scientists to publicly raise the issue of the policy implications of climate change.

SciAm has just started a new online feature called "Clash", which explores the policy issues related to various scientific topics. The inaugural posting discusses the question, "What Will Climate Change Cost Us?", with economist Sir Nicholas Stern, author Bjorn Lomborg, and a lead IPCC author Gary Yohe.

Where's the Rain?

Now

Showers, cool. This afternoon's local area forecast discussion was asking, "Where's the rain?", as a low pressure area moved northeastward through the Ohio Valley along with its associated complex warm fronts. Through mid day, metro area amounts were quite disappointing for the waning days of a month which so far had been nearly 50% below average. National picked up a mere 0.03" overnight, and Dulles had only a trace. By mid afternoon, however, showers had reached at least the western portion of the region, and Dulles had 0.14" in the hour ending at 4pm. There is still plenty of moisture around as a cold front extending southward from the low moves eastward, so showers and even some thunderstorms are likely through midnight tonight.

Surface weather map at 4pm today from IntelliWeather

Tonight and Tomorrow

Showers and mild, then clearing and cooler. Showers are likely through this evening and into tonight with chances decreasing to 20% by morning and lows 47-50°. Skies will clear by tomorrow afternoon with highs 55-59° and increasing northwesterly winds.

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

Tropical Topics

With the official Atlantic tropical season rapidly winding down, AccuWeather's Joe Bastardi was recently interviewed by the Sarasota Herald Tribune on the somewhat less than stellar results of his hurricane season forecast.

The Miami Herald's hurricane reporter Martin Merzer today reviews the Colorado State Gray/Klotzbach and NOAA tropical season forecasts and raises the interesting question of whether such forecasts (and, by implication, seasonal outlooks in general) do more harm than good by undermining confidence in short-term storm warnings.

Business Climate: Easy Being Green?

On a slow business news day, a local DC newspaper has a collection of articles on the attempts of Washington-area businesses to balance environmental challenges with opportunities for the pursuit of profit. Included are SunEdison and its CEO Thomas Rainwater (apparently his real name), Honest Tea, Marriott International, Tower Cos., and Trex. The Federal Diary covers the design of a new building for the National Renewable Energy Laboratory, and there is also a review of the recent Greater Washington Board of Trade conference "Green as a Competitive Advantage".

Winter Preview Continues

Now

Partly cloudy, windy, cold. Persistent winds kept last night's lows from being quite as cold as expected, but temperatures this afternoon have had a hard time maintaining the upper 40s in most of the Washington metro region. By mid afternoon, National was 46°, and Dulles was 44°. The highs were: National 48°, Dulles 46°, BWI 46°. The northwesterly wind gusting frequently over 25 mph has also brought drier air along with the cold; dewpoints are mainly in the low 20s with even a few upper teens. The nearest precipitation on radar consists of some snow flurries over the mountains of western Pennsylvania.

Tonight and Tomorrow

Cold overnight, then increasing clouds and milder. The drier air along with diminishing winds should bring lower lows tonight, near 35° downtown ranging to some upper 20s in 'burbland. A weak "clipper" system diving southeastward from the southern Great Lakes tomorrow will produce increasing clouds and somewhat milder temperatures by tomorrow afternoon with highs 49-53° and a chance of light rain or snow showers late in the day or at night.

For the outlook through the rest of the weekend and towards Thanksgiving, scroll on down to Matt's post below.

Winter Outlooks

• Matt reviewed Bob Ryan's winter outlook from last night in his earlier post.
• According to an on-air promo, the WUSA-TV, channel 9, outlook will be on the 5pm newscast tonight.
• Stay tuned here for the CapitalWeather.com winter outlook, coming soon.

Mediarology/Climate Corner/Political Science Trifecta

In what may be some kind of a Guinness World Record, 3 out of the 6 front-page articles in today's WaPo involve climate science and related policy:

• "Calif. Court Rejects SUV Mileage Rules" (above the fold): "A federal court in California yesterday rejected the Bush administration's new fuel economy standards for light trucks including SUVs, ruling that the government failed to take into account the effects of carbon emissions and their possible link to global warming."
• "Katrina, Rita Caused Forestry Disaster": The forest destruction caused by Rita and Katrina "was so massive that researchers say it will add significantly to the global greenhouse gas buildup -- ultimately putting as much carbon from dying vegetation into the air as the rest of the nation's forest takes out in a year of photosynthesis." (According to the article abstract in today's issue of Science Magazine, the storms caused "mortality and severe structural damage to ~320 million large trees totaling 105 teragrams of carbon, representing 50 to 140% of the net annual U.S. forest tree carbon sink.")
• "Scientists Fault Climate Exhibit Changes": "Some government scientists have complained that officials at the Smithsonian's National Museum of Natural History took steps to downplay global warming in a 2006 exhibit on the Arctic to avoid a political backlash, according to documents obtained by The Washington Post."

Programming note:PM Update will be off next week. Have a great Thanksgiving, everyone!

November Takes a Mid-Month Chillout

Now

Variable clouds, colder. Following the morning showers, heavy at times, which brought around ¾" of much-needed precipitation to the Washington metro area, some sunshine through scattered to broken clouds has allowed afternoon temperatures to reach at least 50° in most locations. Westerly winds gusting as high as 30 mph have added to the the chilling effect, however. The day's highs occurred in the early morning hours: National 65°(3:54 am), Dulles 63° (2:41 am), BWI 63° (5:48 am), and the lows so far have been right around noon.

Tonight and Tomorrow

Clearing, cold. A lingering shower is possible through early evening, then clouds will decrease overnight with lows 34-39°. Tomorrow will be mostly sunny and breezy with some passing clouds and highs only 46-49°.

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

Tropical Topics

The Associated Press and AFP covered the landfall of severe Cyclone Sidr, which occurred on the southwestern coast of Bangladesh shortly before noon, Washington time. Preliminary reports indicate that huge evacuations, prompted by early warnings, may have substantially reduced potential casualties.

The official site of the Bangladesh Meteorological Department has apparently been offline, but the India Meteorological Department issued a cyclone warning for the West Bengal-Orissa coast. Stu Ostro has been updating his entry at the Weather Channel blog with reports and graphics of the storm.

Sidr track from Joint Typhoon Warning Center

Mediarology

Bob Ryan is scheduled to present his winter outlook at 11 tonight on WRC-TV, channel 4.

Also tonight, at 7 and 11, The Weather Channel's Epic Conditions series covers Chesapeake Bay sailing.

Model Muddle Temperatures to drop sharply, then some uncertainty

Now

Mostly sunny, mild. After a brief step backward, the seasonal calendar is about to take a jump forward to more wintry temperatures. What happens thereafter is subject to a bit of debate among the models, but the storm development noted in Dan's earlier post has disappeared from the run of the same model made 12 hours later.

By mid afternoon today, however, readings were well into the 60s throughout the area, with Dulles at 68° and National 66°. Salisbury, Culpeper, Leesburg, Manassas and Patuxent River all reached at least 70°. The air is also quite muggy with dewpoints generally in the mid to upper 50s.

Tonight and Tomorrow

Mostly cloudy, showers likely, then turning colder. Skies will become mostly cloudy overnight with showers likely and thunderstorms possible, mainly after midnight and through tomorrow morning. Lows will be 48-53°. Clouds will decrease tomorrow afternoon along with increasingly brisk and gusty northwesterly winds. After morning highs in the low 50s, temperatures will drop during the day to the low 40s by evening.

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

Climate Corner: New MIT Model Results

Prof. Peter Stone of the MIT Center for Global Change Science gave a very interesting presentation last night on the science behind climate change modeling. With the current model inconsistencies over what may or may not develop as soon as early next week, this is an especially relevant time to review the difference between weather and climate modeling. PM Update asked Dr. Stone how he would explain this, and his answer was very similar to what has been said here in the past, but it bears repeating:

Even though climate is the long-term average of the weather, and even though the basic laws of physics apply equally to both problems, climate modeling is not simply taking a weather prediction model and running it for a much longer time. It is much easier, and more accurate, to predict the average conditions produced from the long-term equilibrium of a set of forces than to predict the specific details of the evolution from a beginning state to some point in the future. For the more technically inclined, this is the difference between an initial-value problem (hard) and a boundary-value problem (not so much). Weather prediction is an initial-value problem; it starts from a given set of conditions and predicts the details of their change over time. Climate prediction is a boundary-value problem; it applies a set of forces to a beginning state and predicts the final equilibrium result.

In the course of his lecture, Prof. Stone disclosed some tentative results, now in peer review for future publication, regarding likely future temperature increases. Based on a "business as usual" scenario (no reduction in CO₂ emissions), his research indicates that the median prediction of the mean global temperature increase by the end of this century is 4.9°C, with a 90% confidence interval of 3.0-7.7°C. This is sharply higher than the results presented in the latest IPCC report of a range of 2.0°- 4.5°C for a doubling of CO₂. To put this into perspective, the predicted increase produces a higher mean temperature than has occurred in the last 3 million years.

The slides from Prof. Stone's lecture are available on the MIT Club Seminar Series website.