Tropical Storm Debby: Earliest 4th Atlantic "Named" Storm by 11 Days

Continuing the record early pace of the 2012 Atlantic tropical season, Tropical Storm Debby, named by the National Hurricane Center (NHC) at 5 pm today, is the earliest 4th named storm or equivalent of the season. According to the NHC historical storm database (dating back to 1851) and counting tropical cyclones prior to the introduction of names in 1950 as well as subtropical cyclones, the previous earliest 4th storm was Dennis, which originated on July 4, 2005. The average date for the 4th Atlantic storm of the tropical season is September 1.

Awfully Arid August

Now

Hot but dry. A bright August sun pushed the temperature to 91° by 3pm this afternoon. The humidity is only slightly higher than yesterday with dewpoints hovering near 60°. A strong thunderstorm developed along the coast near Ocean City, but otherwise regional radar is dry.

Tonight and Tomorrow

Mostly dry. A stationary front hanging around the Mason-Dixon line could help spark a few scattered thunderstorms this evening; otherwise, lows will be near 70 in the city to the mid 60s in the 'burbs under partly cloudy skies. Tomorrow will be sunny with highs near 90° and moderate humidity.

Scroll down to Josh's post below for the outlook through the weekend and Larson's Long-Range.

Tropical Topics

Debby continues to be an underachiever with maximum winds of 50 mph through today and little change expected in the near future. The forecast track keeps it away from land.

The tropical wave near the Windward Islands has developed a closed circulation according to this afternoon's reconnaissance report. It became TD 5 in the 5pm advisory with maximum winds of 35 mph and expectations of becoming a tropical storm in the next 24 hours.

Squandered Surplus

The large precipitation surplus which developed early this summer is being steadily eroded by the recent lack of rainfall. Although July as a whole was near average, most of that fell early in the month, and the accumulated deficit since July 1 is now over 1.5". No measurable rain has fallen at National Airport since the 0.17" on Aug. 10. At this rate, we are on track for a top-10 driest August.

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

A Quiznos Kind of Day

Now

Mm, mm, toasty! The official Washington temperature reached 90° at 2pm, but a mainly northerly breeze and dewpoints in the mid 50s have helped to keep it quite comfortable for August. The radar is totally dry in all directions for hundreds of miles, despite a weak front hovering near the Mason-Dixon line.

Tonight and Tomorrow

Warm, becoming more humid. Tonight should be fairly pleasant, but humidity is likely to creep upward by morning. Lows should be more of "the usual": near 70 city, mid 60s 'burbs. Tomorrow will be mostly sunny and a little more humid with a slight chance of PM showers or thunderstorms and highs in the upper 80s.

Scroll down to Dan's post below for the outlook through the weekend.

Tropical Topics

Debby gained a little strength in the eastern Atlantic with maximum winds of 50 mph this morning, but it is back down to 45 mph on the latest advisory. The expected track still keeps it well east of Bermuda.

An area of more potential threat is a tropical wave a couple of hundred miles east of the Windward Islands. It could develop into a tropical depression within 48 hours. A reconnaissance flight is tentatively scheduled for tomorrow to investigate.

Broadcast News

ABC News has announced that Sam Champion has been promoted from New York's WABC to be the weather anchor for "Good Morning America", beginning on Sept. 5. He will also be weather editor for ABC News and "will contribute feature reports on the environment and weather-related issues."

Photo from ABC News