Thursday, July 12, 2007

DC: Deliciously Crisp


Sunny, warm, low humidity. Thank you, Canada, for your favorite summer export. Following yesterday's somewhat skimpy showers in many places, the humidity began to drop in earnest around midnight, and by early this afternoon many locations in the metro area were reporting dewpoints in the very crisp upper 40s. Combined with temperatures in the mid 80s, relative humidities were in the low 30% range and less. A northwesterly breeze gusting over 20 mph at times just added frosting to the comfort concoction. Heat relief should last into the weekend.

Tonight and Tomorrow

Open the windows! If you haven't already done so, turn off the AC for a mostly clear and comfortable night. Lows should easily reach the mid 60s in the city and as low as the mid 50s in the outer 'burbosphere. Tomorrow should also be quite comfortable, but with some more clouds in the afternoon and a slight chance of showers or thunderstorms. Highs will be 83-87°.

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

Climate Clues: The Sun Also Falls

If you missed our preview Monday of an important new paper on the effect of solar activity on climate, it's now being featured more broadly in the press (although apparently not in the WaPo). The Beeb has an excellent summary, and there are articles at New Scientist online and the Wired science blog. Of course, if you really want to do your homework, the actual paper (pdf) is also available.

The cable noise networks and squawk radio like to dismiss climate change issues and especially greenhouse gas mitigation as "just politics", but an article, "Florida's Governor To Limit Emissions", on the front page of today's WaPo business section contradicts that viewpoint. (See also the Miami Herald). The Republican Gov. Crist of Florida is following the lead of the Republican Gov. Schwarzenegger of California in setting standards for greenhouse gas emissions from automobiles. Also in the same article is a description of the climate-change bill introduced yesterday with bipartisan support by Sen. Jeff Bingaman (D-N.M.).

Chart from Proceedings of the Royal Society, via BBC.

Tropical Troubles

The Florida Sun-Sentinel has a new interview today with former National Hurricane Center Director Proenza.

Wednesday, July 11, 2007

Scattered Storms, Then No Regrets


Muggy, scattered showers. Once again, lunch time popup thunderstorms have knocked temperatures back down from earlier highs in parts of the metro area, while other places, especially to the north and west, have remained dry. National, which received 0.73" yesterday, got another 0.40" in today's storm, but Dulles and large parts of Montgomery County are still bone dry. Temperatures at mid afternoon varied widely from the low 80s where it had rained to 90° on the southern fringes of the region, such as Stafford and Culpeper.

Scattered storms, which are breaking out ahead of a cold front marching steadily eastward from the Ohio Valley, are likely to affect at least parts of the area through this evening, followed by cooler and drier conditions tomorrow.

Tonight and Tomorrow

Muggy, chance of thunderstorms, then less humid. After a 60% chance of showers or thunderstorms through this evening, skies will gradually clear towards morning with lows in the upper 60s in town to the low 60s in the 'burbs. Tomorrow will be mostly sunny and much less humid with highs 83-87°.

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

Rainfall Report

While National (0.73") and especially BWI (1.84") were in the bullseye for yesterday's storms, many area lawns and gardens are still feeling neglected. Most places north and west of the Beltway received little or no rain.

Precipitation in 24 hr. ending 8am this morning from NWS Experimental Precipitation Analysis.

Tropical Trouble

Today's WaPo Federal Diary recaps the National Hurricane Center Proenza affair, but as has been the case all along, the best reporting on the subject continues to be by Martin Merzer in the McClatchy Company's Miami Herald. Today's Herald article, "Proenza: I have no regrets", includes an interview with the former Director in which he refuses to apologize for his earlier criticism of NOAA, but does reaffirm his confidence in the capabilities of the NHC. The article says that Proenza has been ordered "not to communicate with the staff of the hurricane center in any way."

The issues with NHC are much more complicated than classic whistle-blowing, but it is becoming increasingly clear that "government science" is firmly establishing its position along with "military intelligence" in the ranks of oxymoronism.

Click on "Comment" below for more current links on Proenza.

Tuesday, July 10, 2007

Still Muggy, But Relief on the Way


Muggy, scattered showers. Increased humidity arriving last night and temperatures soaring to at least 96° by noon prompted a Heat Advisory to be issued for the Washington metro region around lunch time. Scattered thunderstorms popping up in the early afternoon quickly dropped temperatures 20° or more in some places, however, causing the Heat Advisory to be cancelled by 4pm. Although National Airport got about ¼" of rain, Dulles remained dry and many other areas north and west of the Beltway had nothing more than the rumble of thunder.

Real heat relief, in the form of a strong cold front for the season, is still on tap for Thursday, and it should last into the weekend.

Tonight and Tomorrow

Muggy, chance of thunderstorms decreasing, then increasing. The chance of showers or thunderstorms will decrease this evening, but it will remain muggy under mostly cloudy skies. Lows should be in the upper 70s downtown to the low 70s in the 'burbs. Tomorrow will be muggy with variable cloudiness and an increasing chance (50%) of showers and thunderstorms in the afternoon and evening. Highs will be 89-93°.

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

Keeping Cool: WaPo Chat

A transcript of today's discussion on the heat and its effects is posted at the online WaPo.

Tropical Trouble

As the analysis of the Proenza affair at the National Hurricane Center continues, the prize for the best headline has to go to . . .
"The 'Cane Mutiny".

Monday, July 9, 2007

Heat Index: High, Not Horrendous


Sunny, hot. It could be worse: Temperatures are in the mid to upper 90s this afternoon, but dewpoints generally in the low 60s and even some upper 50s have kept heat indices mostly out of triple digits. By late this afternoon, all 3 major airports in the region had reached at least 96°. The relatively moderate humidity means that already parched lawns and gardens are likely to continue turning brown for at least another day, however.

Heat relief on tap by Thursday should last into the weekend. chart from heat index equation at

Tonight and Tomorrow

Hazy, hot, increasing humidity. Under mostly cloudless but hazy skies tonight, lows will be in the upper 70s downtown and in the upper 60s to low 70s in the 'burbs. Tomorrow will be continued hazy and hot, but with gradually increasing humidity and highs again in the upper 90s. Heat indices will be near 100.

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

Staying Cool: WaPo Chat

Join us tomorrow at 2pm for a live discussion on the heat at the online WaPo.

Mediarology: Tornado Diary

The first show in a 3-part BBC-produced series, "Tornado Diary", will appear on WETA-TV, Channel 26, at 9pm tomorrow. The first episode, "Oklahoma City", focuses on the notorious F5 storm of May 3, 1999 (also excellently described by local author Nancy Mathis in "Storm Warning"). The program will be repeated Thursday at 1am and Sunday at 5pm. The other 2 episodes will be shown on succeeding Tuesdays.

Climate Clues

A tip of the Rabett ears for a pointer to an important article scheduled to appear tomorrow in the Proceedings of the Royal Academy. The paper, by M. Lockwood and C. Frohlich, was featured as a news item in the July 5 issue of the journal Nature. It is described as "the final nail in the coffin for people who would like to make the Sun responsible for current global warming." Based on solar data for the last 100 years, the authors were able to show that recent trends in solar activity are actually opposite to those required to explain global warming. The results are also discussed in the UK Guardian.

Seasonal Outlook

Latest seasonal forecast: Click here.

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