Summer Ending on a Crisp Note

Now

Sunny, chilly. After morning lows of 50° at National and 43° at Dulles, temperatures have rebounded nicely, but they were still only in the upper 60s by mid afternoon. The Dulles low was only 1° above the record of 42° set in 1991. Today is the latest date in the year which has never seen a low below 40° there. Not only is the radar clear in all directions, but skies are virtually cloudless throughout the region south of the Mason-Dixon line.

Tonight and Tomorrow

Continued crisp. Lows tonight under clear skies will be chilly again, near 50° in the warmest urban areas to the low 40s in the coolest 'burbs. Get your excuses ready; tomorrow will be the perfect Friday for a "sick" day: Sunny, highs in the low 70s.

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

Pictured above: The map of surface pressure (solid lines) and 500 mb height (color shading) this morning from Unisys shows an unusually high amplitude pattern for late summer, with Helene moving around a high pressure area in the central Atlantic and our next weather maker, a strong low which brought substantial snow to portions of the central Rockies.

Tropical Topics

Hurricane Helene has turned north as expected well east of Bermuda, and a more easterly track is expected. Maximum winds are 80 mph.

The tropical wave west of the Cape Verde Islands hasn't become better organized yet, but gradual development is possible in the next couple of days as it continues moving westward.

Political Science

Today's NYT reports that, given the lack of action at the federal level, the state of California is suing the 6 largest auto makers over air pollution. The state Attorney General claims, "Global warming is causing significant harm to California's environment, economy, agriculture and public health." The suit is the first attempt to hold the companies liable for producing greenhouse gases. Articles on the lawsuit also appeared in the BoGlo (from the AP), LaTi, and UK Telegraph, among others. (Interestingly, the San Jose Mercury News has a story bylined from the WaPo, but a Google search of the online WaPo turns up only the AP and Reuters wire service reports.)

Feel of Fall

Now

Breezy, cool. Northwesterly breezes gusting as high as 25 mph at times have brought a definite fall feel to the Washington DC metro area this afternoon. With the sun impeded by the clouds associated with the large upper-level trough which helped bring the cold front through the area yesterday, temperatures are having a hard time reaching 70°. The highest official hourly reading has been 69° at 2pm, after which scattered clouds gave way to a broken overcast and a temperature drop of 3°. The fall crispness is especially noticeable with the dewpoint readings in the low 40s, which are as much as 20° below the level of 24 hours ago. The composite radar image shows virtually no precipitation east of the Rockies, except for some showers enhanced by the eastern Great Lakes and some thunderstorms in southern Florida.

Tonight and Tomorrow

Cool. Winds will diminish somewhat after dark, but persistence of the cloud cover with the trough aloft will prevent low temperatures in many places from reaching the levels which could be implied from the low dewpoints. Lows should range from the low 50s downtown to the upper 40s outside the Beltway. Tomorrow will be partly cloudy, less windy, and cool with highs around 70°.

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

Tropical Topics

After giving a quick hit to the Azores, Tropical Storm Gordon has weakened, although it still maintained its tropical characteristics this morning; peak winds were 60 mph. It is becoming extratropical after a journey of almost 10 days through the Atlantic. Maximum winds are now 50 mph; the last tropical advisory was issued at 5pm.

Hurricane Helene weakened slightly to 105 mph this morning. The storm has begun a northward turn, moving northwest at 9 mph. It is still expected to remain east of longitude 60W. Its strength, large size, and persistence in the central Atlantic, however, have caused swells to increase along the East Coast.

Potentially the next tropical system is a large wave with strong showers and thunderstorms several hundred miles southwest of the Cape Verde Islands.

Falling Back to Autumn

Now

Decreasing clouds, cooler. The official Washington temperature peaked at 80° just before a cold front passed through around 1pm today. Precipitation was extremely spotty, with only a trace at National and BWI, and nothing at Dulles. Despite a northwesterly breeze, cooler temperatures will be slow to filter into the area through the evening as clouds gradually decrease.

Tonight and Tomorrow

Cool, drier. Under clearing skies, low temperatures tonight will be near 60° downtown to the mid 50s in the cooler 'burbs with much lower humidity. Tomorrow will be sunny and dry with highs in the low 70s.

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

Tropical Topics

Hurricane Gordon is racing eastward at 33 mph with maximum winds of 85 mph toward the Azores, where a hurricane warning is in effect. The storm should have enough forward momentum to hit northern Portugal or Spain. If it retains its tropical characteristics in doing so, it would be only the second such tropical storm in history, after last year's Vince.

Helene remains a large hurricane with top winds of 115 mph this morning, down slightly to 110 mph at 5pm. It is currently moving west-northwest. Persistence on this track would take it toward the Bahamas and southern Florida, but the models are unanimous in steering the storm northward and then northeastward well east of longitude 60W.

Mediarology: She Blinded Me with Science

Somehow we don't think the audience will be tuning in for the science when The Weather Channel continues the rollout of its new show lineup. Abrams and Bettes: Beyond the Forecast, premiering next Monday night at 8, will be a one-hour Monday-Friday program covering "topical weather stories by going behind-the-scenes of high-profile weather events live and on-location, in an off-the-cuff irreverent style." Co-host Stephanie Abrams and her "breezy style" were recently profiled in the Palm Beach Post. For an even more "breezy and irreverent" take on the subject, see monkeycube.com.

The following Sunday, October 1, is the premiere of The Climate Code, which was previewed recently in PM Update.

Photo of Stephanie Abrams from Palm Beach Post

Summery Summary

Now

Summery. After nearly a week in which temperatures barely made it into the 70s, the Washington metro area has been enjoying much more summer-like conditions since yesterday. Yesterday's official high of 81° was matched by 2pm today, and readings around the region are mostly in the mid 80s. There is no rain east of the mountains, but a vigorous cold front pushing eastward from the Ohio Valley is bringing showers and thunderstorms from southern Canada all the way to the Gulf States.

Tonight and Tomorrow

Increasing clouds, chance of showers. Clouds will increase overnight toward morning with lows in the mid to upper 60s. Tomorrow will be mostly cloudy with a 50% chance of showers or thunderstorms in the afternoon and highs from 75° to 78°

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

Tropical Topics

Helene strengthened this morning to 125 mph (strong Category 3) based on satellite observations but was lowered to 115 mph in the 5pm advisory after a NOAA research plane made some measurements. After moving north-northwestward for a while, it is now turning more westward. A continued westerly track could have the potential to threaten land, but Dr. Jeff Masters points out in his blog that of the 16 hurricanes in history which have passed within 300 miles of Helene's position, the only one to make landfall in the U.S. was Isabel (2003). Furthermore, Isabel started out more southerly than Helene. None of the latest models brings the storm even as far as longitude 60W (about the eastern tip of Nova Scotia). The official forecast track, which had been further west than any of the models, has now been shifted east of 60W.

Gordon has intensified to 90 mph as it continues moving eastward in the open Atlantic toward the Azores. A tropical storm watch is now in effect for the Azores.

Historical hurricane track map from Wunderground.com

Climate Corner

Dr. Barrie Pittock's talk at Busboys and Poets is tomorrow evening. Details are in Friday's PM Update.

Big Mr. Cloudiness

Now

Improving. Big Mr. Cloudiness has obscured Little Miss Sunshine through much of the day in the Washington metro area, holding temperatures below the more optimistic readings promoted in this space yesterday. Nevertheless, the low 70s at lunch time were much more pleasant than yesterday's damp 60s, and many places reached the mid 70s by early afternoon. By late afternoon, some scattered showers were breaking out, especially north of the Beltway. More widespread showers were in the Baltimore area.

Tonight and Tomorrow

Better yet. Clouds will be slow to decrease overnight with lows in the lower 60s and a slight chance of showers. Tomorrow will see more sun than clouds, particularly in the afternoon, with highs from 75° to 77°.
For the CW outlook by CW through the rest of the weekend, scroll on down to Camden's post below.

Tropical Topics

Gordon was still a Category 2 hurricane this morning, but it continues to weaken. It was downgraded to Category 1 at 5pm as it moved slowly northeastward away from any land, becoming nearly stationary in the latest advisory.

Helene strengthened earlier today to maximum winds of 60 mph and reached 70 mph in the 5pm advisory, but it, too, is on a Track to Nowhere.

Of much more concern to land, however, is Tormenta Tropical Lane in the Eastern Pacific. Watches and warnings have been posted for Hurricane Lane to impact lower Baja California and the western Mexican coast by this weekend. Based on reconnaissance reports this afternoon, Lane was upgraded to a hurricane with maximum winds of 80 mph and further strengthening expected.

Meet a Climate Expert

Climate researcher Dr. Barrie Pittock will be speaking next Tuesday, the 19th, at 6pm at the Busboys and Poets bookstore. Dr. Pittock is the author of the recent book, Climate Change: Turning Up the Heat. The book describes the historical and scientific basis for climate change and projections for the future. It also analyzes the national and international politics of greenhouse gas restrictions. These political issues are examined within the context of technological prospects for adaptation to, and mitigation of, the effects of climate change. The first chapter of the book is available online.

The author, a native of Australia, was a senior atmospheric scientist for over 30 years at the Australian research organization CSIRO, where he led the Climate Impact Group until he retired in 1999. He is the author of over 200 scientific papers and is currently on the editorial board for the journal Climatic Change. While he is in Washington, Dr. Pittock will be presenting a talk, "Ten Reasons Why Climate Change May Be More Severe than Projected" at the Washington Summit on Climate Stabilization organized by the Climate Institute.

Busboys and Poets is located at 2021 14th St., NW.

Stay tuned next week for CapitalWeather.com's exclusive online Q&A with Barrie Pittock.

Little Mist; Sunshine?

Now

Some drizzle, cool. After about 2/3" of rain this morning in the Washington metro area, skies are overcast this afternoon with some persistent patches of drizzle and light rain. Nearby to the west, however, some sunshine has appeared; the robo-observer at Manassas is claiming partly sunny conditions and Winchester is up to 73° with mostly sunny skies. Here in MoCo north of the Beltway and west of I-270, the sky is distinctly brighter to the northwest, and pavements are mostly dry. Just to the east of the Beltway, however, a more widespread area of rain and showers is moving northeastward, where it can threaten at least some delays in the O's Zone as the Birdies take on the Crimson Hose.

Pictured: Surface pressure (solid lines) and 500 mb height (color shading) map this morning from Unisys shows an upper-level trough (yellow) approaching the East Coast, while Gordon moves around a large ridge in the central Atlantic, and Helene follows in the wings. The remnant of Florence is the intense low to the east of Newfoundland.

Tonight and Tomorrow

Gradually improving. With an upper-level trough approaching gradually from the west, conditions will be slow to improve, but we should see a decent amount of sun, at least by late afternoon, tomorrow. Lows tonight will be near 58° in the coolest spots to around 62° in the city. Highs tomorrow should be in the upper 70s, or about 80° if we get enough sun.

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

Tropical Topics

Gordon has become the first major (category 3) hurricane of this season, with maximum winds of 120 mph. It has a very impressive looking eye on satellite images. The track continues northeastward away from any land, except perhaps for an approach to the northwest of the Canary Islands as a tropical storm early next week.

TD 8 became Helene last night and continues to strengthen slowly, with maximum winds of 45 mph. Images of the storm show a lot of "raw material." If it gets organized, it could be a very large storm by area. It's now moving westward, but there is wide disagreement (about 450 miles worth) among the models on the future track. The official track is based on a consensus of the models and takes it northwesterly southeast of Bermuda in 5 days.

Climate Corner: DC Event

World-recognized Australian climate expert Dr. Barrie Pittock will be speaking at Busboys and Poets bookstore in DC next Tuesday evening. Stay tuned to CapitalWeather.com for more details and an exclusive Q&A with Dr. Pittock.

Sixes Wild, Rain on the Way Return of the Nino?

Now

Cloudy, cool. No less than 6 out of the 10 local NWS Regional Roundup stations were reporting temperatures of 66° at mid afternoon today; the other 4 were a few degrees higher. After some very light rain (trace at National, 0.02" at Dulles) early this morning, skies are overcast throughout the area with rain on regional radar mainly south of Richmond.

Tonight and Tomorrow

Rain, cool. The chance of rain will increase from about 40% through midnight to near 100% by tomorrow morning. Rain or showers are likely to continue through early afternoon. Lows tonight will be in the low 60s, highs tomorrow in the low 70s.

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

Tropical Topics

Storm Eight remains tropically depressed, with top winds of 35 mph as of 5pm, continuing to move away from the Cape Verde Islands. It is still expected to become a hurricane as it turns more northwestward this weekend.

A tropical storm warning is in effect for much of coastal eastern and southern Newfoundland from Post-Tropical Storm (Tempete Post-Tropicale) Florence. The major impact was being felt on the southern coast this afternoon. Some power outages were reported in St. John's as the storm moved eastward, brushing by Cape Race.

Photo of wind and rain in St. John's NL today from CBC

El Nino Returns?

NOAA issued an unscheduled El Nino advisory today, announcing that increasing Pacific Ocean temperatures in the last 2 weeks have led to a weak El Nino condition. This event is expected to continue into 2007, and it has the potential to become moderate this winter. Expected El Nino effects this winter

include warmer-than-average temperatures over western and central Canada, and over the western and northern United States. Wetter-than-average conditions are likely over portions of the U.S. Gulf Coast and Florida, while drier-than-average conditions can be expected in the Ohio Valley and the Pacific Northwest.