Friday, June 15, 2007

Junier Conditions on the Way for Father's Day


Cloudy, cool. It's another cloudy and cool afternoon in the Washington DC metro region today as we close out the first half of the month. Temperatures have struggled to get out of the 60s, but by mid afternoon, all reporting locations in the immediate area were at 70° or a little above.

Radar is clear within about a 300 mile range, except for some very isolated showers in extreme southwestern Virginia. The good news is that sunnier, more June-like conditions are expected for the weekend. The bad news is that mugginess will increase also.

Tonight and Tomorrow

Clouds diminishing, warmer. As clouds decrease somewhat tonight, lows will range from the mid 50s ('burbs) to low 60s (urbs) with comfortable humidity. Tomorrow will be mainly sunny with highs near June averages at 80-84°. There is a slight chance of showers or thunderstorms in the afternoon.

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

Still Starving for Moisture

Although this week's rains have helped reduce the moderate drought which was developing in the region through June 9, the 60-day precipitation percentage of normal from NWS (right) shows large deficits through this morning. DC and all adjoining counties are at 75% or less of average, with wide areas at 25-50% (dark orange). Although measurable rain fell the last 3 days, National recorded less than ¼" total. Dulles, on the other hand, had 1.35", but BWI reported 0.12" on Wednesday and only a trace on each of Tuesday and Thursday.

Tropical Topics

A reconnaissance flight was tentatively scheduled today to investigate an area of shower activity over the northwestern Caribbean, but it was canceled because the showers had become less organized than yesterday.

Climate Corner

Last week's SciFri on NPR broadcast live both hours from Alaska on the effect of climate change on the Arctic. Podcasts are available on the web site.

Wednesday, June 13, 2007

Sit and Spin
Pesky low pressure to spawn evening storms

** Severe Thunderstorm Watch in Effect Until 9 PM **


Warm, humid, scattered thunderstorms. The persistent low pressure area off the coast that Dan noted earlier today continues to spin counterclockwise, sending a moist flow onto the coastal plain and piedmont of the Northeast and Mid Atlantic regions. The scattered thunderstorms erupting in this flow are once again moving from northeast to southwest across the Washington DC metro region, prompting severe thunderstorm warnings earlier this afternoon for portions of MoCo and Prince George's. Hail up to 1" was reported from the Four Corners and White Oak areas of Silver Spring and NASA in Greenbelt, as well as Herndon, Reston, and Chantilly in Virginia.

A large batch of storms scattered across central and southeastern Pennsylvania is also moving southwest and is likely to affect portions of the metro region in the next couple of hours. The leading group of these storms was already reaching Baltimore City and County by 4:30. Temperatures peaked just over 80° at noon at National, but tumbled to the upper 60s in thundershowers by mid afternoon.

Conditions should be somwhat drier and cooler tomorrow, but temperatures will warm over the weekend.

Pictured: Map of surface pressure (solid lines) and 500 mb height (color shading) this morning over North America and adjacent Atlantic from Unisys. Click here for more explanation.

Tonight and Tomorrow

Scattered showers diminishing, turning cooler. Some scattered showers and thunderstorms may continue through the evening. Otherwise, tonight will be partly cloudy with lows from the low 60s downtown to some upper 50s in the cooler 'burbs. Tomorrow will be mainly cloudy with highs only 69-74°.

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

Tropical Topics: 3-E is History

Depression 3-E in the eastern Pacific has been given last rites. The Atlantic is similarly comatose.

Climate Corner: How Many College Presidents Does It Take to Change a Light Bulb?

Yesterday's WaPo ("Colleges Pledge to Back Climate Initiative") described efforts by 280 college presidents to "raise awareness about global warming and limit their institutions' emissions in moving toward 'climate neutrality'." Local institutions participating include UMD, James Madison, and Howard Community. The subject was also covered by the Baltimore Sun and Chronicle of Higher Education (behind the pay wall).

Monday, June 11, 2007

Great Golfing Day


Sunny, warm. PM Update is blogging today from the beautiful grounds of Woodmont Country Club, where we're providing weather support for the Women's U.S. Open Sectional Qualifier. It's a fine afternoon for golf in the Washington metro area, as temperatures have reached the mid 80s by early afternoon and dewpoints have dropped to the more comfortable low and mid 50s on a northerly breeze around 10 mph. Regional radar around lunch time showed a small, but locally intense, cell southwest of Culpeper moving southeastward, but the immediate metro area has remained clear.

Tonight and Tomorrow

Continued warm, increasing chance of showers. There is a slight chance of isolated showers or thunderstorms through this evening, especially south of the immediate metro area. The rest of tonight will be partly cloudy, continued warm and moderately humid with lows in the upper 60s downtown to near 60° in the cooler 'burbs. Clouds will increase tomorrow afternoon with a 40% chance of showers or thunderstorms late in the day. Highs will be 80-84°.

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

Tropical Topics

The National Hurricane Center began issuing advisories this morning on TD 3-E in the Eastern Pacific. In the Atlantic Basin, tropical cyclone formation is not expected for the next 48 hours.

Climate Corner

The WaPo continued its coverage of Greenland climate changes on Saturday with an article, "In Arctic Ice, Lessons on Effects of Warming", about glacial melting, including the accelerating flow of the Jakobshavn Glacier. For an equal 60 seconds from the (Anti) Competitive Enterpise Institute, click here.

Seasonal Outlook

Latest seasonal forecast: Click here.

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