Humidity was delightfully low today, but no shortage of sunshine helped us log our 47th 90+ day of 2012. We likely tack on number 48 Friday before scattered showers and storms arrive in the early evening hours.

Through Tonight: A picture perfect summer evening with low humidity levels and temperatures slowly falling back through the 80s. Humidity does slowly increase overnight from low to moderate levels. So lows are a little warmer than last night, ranging from near 60 in the cooler suburbs to the upper 60s downtown.

Friday: Most of us awaken to comfortable 60s and tolerable humidity levels. But winds from the southwest (near 10 mph) and morning sunshine quickly push temperatures through the 70s and 80s. Afternoon highs reach 90-95. Yes, we have a chance to tie 1980’s record for most 95+ days at 28 (27 so far). Clouds start to bubble up mid-to-late afternoon, with showers and storms possible, particularly in the 5-11 p.m. window during the evening. A few storms could be strong.

See David Streit’s forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter. For related traffic news, check out Dr. Gridlock.

National Weather Service Sterling, Va. open house: On the weekend of September 22-23, our local NWS office will open its doors. Tours, weather balloon launches, kid-friendly experiments and a speaker series featuring NOAA Administrator Jane Lubchenco and Congressman Frank Wolf are planned. More information.

Pollen: Trees and grasses are LOW, weeds are LOW-MODERATE, and mold spores are MODERATE.

Neil and Sara Tow, the former local couple who’ve trained for the past year to make an epic swim across Lake Michigan, made a heroic effort (covering 40 miles), but unfortunately, fell about 10 miles short. During the final leg, not only were they ravaged by dehydration and a general deterioration of their medical condition, but strong lake currents threw them so much off course that they couldn’t continue.

Link: Cool thoughts: awaiting an epic swim across Lake Michigan by local couple

The Tows believe, however, that their swim has drawn national attention to perinatal depression, a condition that can affect both men and women and has. in fact, plagued both Jeff and his wife, Sara, after the birth of each of their children.

Tropical storm Gordon (NOAA) The tropical Atlantic got its 7th named storm of the 2012 season this morning. Gordon developed over the open Atlantic and has intensified into a 50 mph tropical storm. As of 11 a.m. it was 640 miles east of Bermuda, heading northeast at 16 mph.

The National Hurricane Center predicts Gordon will become a hurricane Saturday, but its track projection keeps it over the eastern Atlantic. By early next week, it is forecast to transition to an extra-tropical storm and could impact Europe later in the week.

The debate has raged for decades: does it make sense to observe Washington, D.C.’s weather in Arlington, Virginia at Reagan National Airport (DCA)?

Temperatures measured at DCA are often among the highest, if not the highest in the entire metro region. And snowfall measurements often are among the lowest.

Robert Leffler, a retired climatologist for the National Weather Service (NWS) and co-author of the 1981 journal article “Unrepresentative Temperatures at a First Order Meteorological Station: Washington National Airport,” has long tried to build the case for identifying a different observing site.

“[DCA temperatures] are unrepresentative of where most of your readers and the TV listening audience live, work, play, and grow their food. ” he wrote to me in an email.

He added: “How many readers live within 100 feet of the Potomac River on airport runways at sea level? None I know of.”

Update, 9:40 a.m. EDT, Thursday (9:40 p.m. Hong Kong local time): Kai-tak has been upgraded to a typhoon, with maximum sustained winds of around 75 mph. The track forecast has shifted the expected landfall to the south and west, steering the brunt of the storm south of Hong Kong in western Guangdong. Nevertheless, the Hong Kong Observatory has a signal no. 3 bulletin, meaning strong winds of 25-40 mph are likely. It expects to raise this to signal no. 8 indicating the potential for gale to storm force winds overnight tonight.
Track forecast for tropical storm Kai-tak, predicted to become a typhoon (Joint Typhoon Warning Center)

From 3:06 p.m. EDT Wednesday (3:06 a.m. Thursday, Hong Kong local time): A strong tropical storm that slammed the northern Philippines has its sights set on the region around Hong Kong.

Named Kai-tak but known as Helen locally, the storm has maximum sustained winds of about 65 mph and was positioned 370 miles east-southeast of Hong Kong at 8 p.m. local time (8 a.m. EDT) in the south China Sea.

The Joint Typhoon Warning Center projects the storm’s peak winds to increase to 85 mph in the next day, which would make it a low-end typhoon.

SEA SURFACE TEMPERATURES REMAIN VERY FAVORABLE [FOR INTENSIFICATION] (29 TO 30 CELSIUS) WITH A NOTABLE WARM POOL LOCATED ALONG COASTAL CHINA

It is predicted to make landfall around 8 p.m. local time (8 a.m. EDT) Thursday just west of Hong Kong in southern China.