DC: Deliciously Crisp

Now

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.

Scattered Storms, Then No Regrets

Now

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.

Still Muggy, But Relief on the Way

Now

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 CapitalWeather.com 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".

Heat Index: High, Not Horrendous

Now

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.

CapitalWeather.com chart from heat index equation at zunis.org

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.

Weather Warms After Showers Subside

Now

Mostly cloudy, muggy, scattered showers. Following yesterday's storms which affected some parts of the area much more than others (see the rainfall map below), clouds and some showers have persisted today ahead of a cold front working its way southeastward through the Ohio Valley. National Airport, which eked out only 0.03" yesterday, picked up 0.11" in a heavy shower between 2pm and 3pm. Temperatures around the region are generally in the upper 70s with very humid dewpoints of 69-73°.

Scattered showers and some thunderstorms are likely through this evening as a line of storms now in southern Pennsylvania moves southeastward. Tomorrow, we clear things out and begin a warming trend. For the detailed outlook through the weekend and beyond, scroll on down to Josh's post below.

Rainfall Report

Where you stand on yesterday's storms depends on where you sit. While areas from southern Frederick Co. through Howard Co. and most of the immediate Baltimore metro area got nice soakings of ½" or more (shades of green), the amounts tailed off sharply to the south. Nearly all of the areas inside the DC Beltway got less than ¼" (lighter shades of blue), and there was virtually nothing south of Fairfax Co. in VA and central Prince George's Co. in MD.

Experimental precipitation map for 24 hr. ending 8am this morning from NWS

Bureaucratic Brouhaha

Considering that National Hurricane Center directors traditionally have come from within the ranks of the Center staff, the Proenza controversy (see "Havoc at the Hurricane Center" in Dan's post from yesterday) seems to be taking on at least some of the aspects of a bureaucratic food fight. Meanwhile, NOAA HQ is quoted as saying that the special assessment team currently evaluating the situation at NHC has nothing to do with Proenza's previous statements. Two Florida members of Congress, however, are questioning that assertion. Would you like an order of fries with that bridge you're buying, Admiral?

Wunderground hurricane blogger Jeff Masters weighed in last night with his opinion on Proenza's QuikSCAT satellite concerns. He concludes that "NHC official forecasts for landfalling storms in the Atlantic would not be significantly affected by the loss of the QuikSCAT satellite." On the other hand, Masters does strongly support Proenza's legitimate concerns regarding budgets for research in particular and the Hurricane Center overall, especially in light of NOAA's PR focus on brand identity and anniversary celebrations.

Mediarology: Earth Comes Alive on 07/07/07

The Weather Channel will be providing coverage of the Live Earth concerts on Saturday. Coverage begins with reports on "Abrams and Bettes" and "Evening Edition" Friday night and continues with live broadcasts from Giants Stadium on "Weekend View" Saturday morning (7-11am). "Forecast Earth" (Sunday 5-6pm) will take a broader look at Live Earth and the environmental issues it represents.

Widespread coverage is also scheduled on NBC and its affiliated networks. The NBC main network will have coverage from 8-11pm. Bravo will have coverage from 9am Saturday through 2:30am Sunday, Sundance will run from 4am Saturday through 2am Sunday, MSNBC will have periodic reports throughout the day, and CNBC will be on from 7pm Saturday through 2am Sunday. Some coverage will also be available on Telemundo and Univision.

Live streaming will be available on MSN. Radio broadcasting will be provided by both XM and Sirius.

Fine Fourth Foreseen Some Storms Possible

Now

Variable clouds, warm. The center of the high pressure area which brought several days of cool, dry weather to the Washington metro area is moving offshore along the Virginia/North Carolina coast today, swinging the wind direction to the south and southwest. Humidity has increased somewhat along with the cloudiness. Dewpoints in the low to mid 50s mean it is still quite comfortable, however, especially with temperatures barely into the 80s.

Humidity will continue to increase, along with the chances of late day thunderstorms, to potentially dampen some Fourth of July activities.

Tonight and Tomorrow

Warm, more humid, chance of showers. Lows tonight under partly cloudy skies will be from the mid 60s downtown to the low 60s in the 'burbs. Tomorrow will be mostly sunny and more humid with highs 82-87° and a 30% chance of late afternoon or evening thunderstorms.

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

Tropical Topics

The National Hurricane Center reports that a low pressure area about 1500 miles east of the Windward Islands has the potential to become a tropical depression in the next couple of days.

School Daze: Double Lives

The "two best things about being a teacher are July and August." This week's installment of the WaPo's "Secret Worlds of Summer" series describes the activities of teacher/lifeguards.

Accompanying that article is a story on what a Rockville science teacher did on his summer vacation. If you are a K-12 teacher and are interested in a more productive use for your summer, check out yesterday's Update for information on the NWA education fund grants program.

Have a great holiday!

DC: Dry, Cool

Now

Sunny, comfortable. June finished 1.6° above the long-term average, but a high pressure area centered over Michigan continues to pump unusually comfortable air for the season into the Washington metro region. At mid afternoon, temperatures were in the upper 70s and dewpoints were in the 40s, resulting in relative humidity as low as 26%. Northerly breezes were generally light, but some gusts were up to 20 mph.

Gradually increasing humidity tomorrow should lead to a somewhat muggy, but not hot, Fourth of July.

Tonight and Tomorrow

Partly cloudy, warm. A few clouds will develop overnight with lows near 60° downtown and in the 50s in the 'burbs. Tomorrow will be sunny and warm with a gradual increase in humidity and highs 80-84°.

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

School Daze: Attention K-12 Teachers!

The National Weather Association (NWA) is offering $500 Sol Hirsch Education Fund grants to K-12 teachers to help them improve their meteorology education programs. Applications, which are available through the NWA web site, are due by August 1. In reviewing past winners of the award, it appears that none of them has been from the Nation's Capital region. To help promote participation in this area, PM Update will match the NWA award with $100 of weather or climate books and/or videos from the CapitalWeather.com store for any winner from Maryland, DC, or Virginia. If you are a teacher from this area applying for the award, please let us know your name and school via email through the "Contact Us" link, and if you are selected, we will send you your choice of books or videos.

Snow News is Good News

It may be July, but the Beeb Weather Centre has a worldwide report on summer skiing conditions.

Mediarology

Beginning last night, it's "Viewers Favorites Week" on The Weather Channel's "Storm Stories" series at 7pm. Some of the episodes sheduled to be shown are: "Oklahoma Tornadoes", "Nebraska Weather Dog", and "Survival South Pole Cancer".