December Rollercoaster

Now

Clear, mild. After a solid week of lows below freezing, this morning's official low was only 33°. Brilliantly clear skies and some downslope air flow have allowed even the weak December sun to push temperatures into the low 60s and above in the Washington metro region this afternoon. Highs were 63° at National and BWI, 62° at Dulles.

Some clouds and a more easterly wind direction will likely put a somewhat lower lid on temperatures tomorrow, although the exact extent of the cooling is a bit uncertain.

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

Tonight and Tomorrow

Some clouds, seasonably mild. With a few scattered clouds, tonight's lows will be near 38° downtown to around 30° in the cooler 'burbs. Clouds will increase somewhat tomorrow with highs in the mid 50s.

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

Climate Corner

The National Center for Atmospheric Research (NCAR) announced today the results of a study being published tomorrow in the scientific journal Geophysical Research Letters. The study results, which are also being presented at the annual Fall Meeting of the American Geophysical Union this week in San Francisco, indicate that Arctic sea ice melting is likely to accelerate to the extent that the polar region will be essentially ice-free in summer as early as 2040. The researchers, from NCAR, University of Washington, and McGill University state

We examine the trajectory of Arctic summer sea ice in future climate projections and find that abrupt transitions are a common feature of 21st century model simulations. These events have decreasing trends in September ice extent that are typically 4 times larger than comparable observed trends. One event exhibits a decrease from 6 million km² to 2 million km² in 10 years, reaching essentially ice-free September conditions by 2040. In the simulations, ice retreat accelerates as thinning increases the efficiency of open water formation for a given melt rate and the ice-albedo feedback increases shortwave absorption. In one climate model, the retreat is abrupt when ocean heat transport to the Arctic is rapidly increasing. Analysis from multiple climate models and three different future forcing scenarios suggests that reductions in future greenhouse gas emissions moderate the likelihood and severity of these events.

Political Science: End of an Error

Yesterday's WaPo editorial, "Mr. Inhofe's Last Hearing", bids a not-so-fond farewell to the reign of error by the Senator from Oilahoma. RealClimate.org's post last week, "Inhofe’s last stand", however, admits a touch of nostalgia in noting the last performance at the political theater formerly known as the U.S. Senate Committee on Environment & Public Works.