Thursday, November 29, 2007

November Prepares to Leave Town Cool and Dry


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,'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.

Wednesday, November 28, 2007

November Rollercoaster Continues


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. 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, of course!), let us know in the Comments.

Tuesday, November 27, 2007

Sunny, Seasonable Supplants Skimpy Showers


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.

Monday, November 26, 2007

Where's the Rain?


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".

Seasonal Outlook

Latest seasonal forecast: Click here.

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