Hot, humid, scattered thunderstorms. Relief is arriving for the Washington area's record-breaking heat, but it comes with an asterisk; the temperature drop is likely to be short-lived, and there is little prospect for serious improvement in the deepening drought conditions.
A large complex of thunderstorms extending from north of Harrisburg through the Baltimore metro area to the northern DC suburbs early this afternoon helped reduce temperatures, but precipitation was mainly limited to north of the Beltway. BWI received almost half an inch (0.43") , but National got a mere 0.02" and Dulles had only a trace with some thunder . Despite the fierce appearance of the storms on radar, damage reports were relatively sparse. Temperatures were well into the 90s by 1pm, but they retreated to the 70s in areas with rain, where they have now rebounded to the low and mid 80s.
Another area of storms now in southwestern Pennsylvania is likely to take a similar track toward the northern portions of the region in the next couple of hours.
Tonight and Tomorrow
Hot, humid, scattered thunderstorms possible. There is still a 40% chance of thunderstorms through this evening, especially in northern areas. Lows will be in the upper 70s in the city to the mid 70s in the 'burbs with uncomfortable humidity. Tomorrow will be hot and humid with highs 90-95° and a 30% chance of showers or thunderstorms.
For the outlook through the weekend and beyond with Larson's Long-Range, scroll on down to Josh's post below.
The Climate Prediction Center and National Hurricane Center today released an updated hurricane season outlook. It continues to call for an above-normal season, with an 85% chance of greater than average tropical cyclone activity. The forecast includes a range of 13-16 named storms, 7-9 hurricanes, and 3-5 major hurricanes.
The August issue of Scientific American has an excellent non-technical article on "The Physical Science behind Climate Change". The authors were all members of Working Group I of the 2007 IPCC assessment. Besides reviewing the scientific evidence for global warming, the article also discusses the remaining uncertainties. The key concepts are summarized by the editors in the box to the right.
Humor Dept.: "There Once Was Some Wind Off Nantucket . . . "
The Daily Show's "Jason Jones 180" recently produced a hard-hitting investigation of Big Wind's shameless attempt to exploit the hapless natives of Nantucket.