From the ABC 7 Weather team

Archive for category Just For Fun July 2014

Haze in D.C. today most likely smoke from Canadian wildfires

July 29, 2014 - 11:45 AM

What a beautiful morning it has been, with lows in the 50s and 60s across the region, including a record-tying low of 59 degrees at BWI Marshall. With such low humidity levels across the region though, you would expect to see deep blue colored skies with now a few white puffy cumulus clouds. Instead, a haze has settled in over the region.

Visible satellite image after 11am

Take a look at the visible satellite image above. Just by looking at this image by itself without motion, it is very hard to see anything that may signify smoke over the D.C. area. But click here to see the satellite in motion. Did you happen to see the very light colored area over D.C. right after sunrise? This is showing the possibility of either some extremely thin clouds, or more than likely, a very thin layer of smoke in the atmosphere.

Courtesy: NASA MODIS

A number of fires have not only been burning in the Pacific Northwest, but also well north of the border in the Northwest Territories of Canada. Above is a look at the NASA MODIS satellite world view which I stumbled upon while perusing the web. I circled the regions of smoke that were showing up yesterday in Northern Canada and over the Hudson Bay. Given the flow of the atmosphere, much of the smoke more than likely was pushed south and eventually southeast into the Midwestern U.S., Northeast and Mid Atlantic States.

Water Vapor Imagery Tuesday Morning the 29th

The upper-level flow shows a large trough through the eastern part of the U.S. and a large ridge over the western U.S. The resulting steering flow has been from Northern Canada southeast through the Midwestern States and directly into the D.C. area. Check out the water vapor loop here. Keep in mind the orange, black and dark grey show very dry air while the purple, blue and white areas show increased levels of atmospheric moisture.

The effects from smoke in the D.C. area will be minimal and air quality is still expected to be good through the next few days, though the haze may hang around tomorrow and Thursday.

NASA MODIS image from July 23rd

The fires have burned over two million acres of land in the Northwest Territories and are thought to have been caused by lightning.

Photos of the fires near Yellowknife, Canada.

Continue Reading

Average hottest days in D.C. in the rearview, daylight diminishes

July 23, 2014 - 12:18 PM

With temperatures forecast to be in the low to mid 90s, one wouldn't think the average hottest days are behind us, but the average high drops to 88 today. Don't worry, cold air isn't exactly going to march right into the D.C. area, as the average high temperature remains in the mid to upper 80s through the month of August. August also averages nearly 10 90-degree days, something we haven't seen too much of this year.

90 degree days in D.C.

In fact, D.C. is actually below average for 90-degree days so far this summer, with only 15 this year. Compare that to last year, which recorded 21 by the same time. Typically there are around 36 90-degree days per year in the D.C. area, so it appears this summer may go down as below average in that category. Ninety-degree days or not, this summer has still been above average, with temperature departures of +2°F in June and +0.5°F so far in July. We'll see how August fares.

Looking ahead, the heat will briefly subside Thursday and Friday but will return for the weekend. Highs should top out in the 90s both Saturday and Sunday, prior to a big-time cool down next Tuesday through the end of the month. Highs may only reach the 80-degree mark next Tuesday!

Duration of daylight for D.C.

Daylight continues to diminish since the summer Solstice, with 28 minutes gone in just a month's time. An additional 14 minutes of daylight will be lost by the end of the month, and over an hour more will be lost by the end of August, so enjoy it while it's here.

While this may be a depressing blog post for some, after summer, there's always cooler and crisp days, fall colors, the Nats playing in October, the Skins taking the field, and plenty of other great things to look forward to. Here's to a fantastic last 39 days of meteorological summer to go!

Continue Reading

45th Anniversary of Landing on the Moon

July 20, 2014 - 05:00 AM

"One small step for man, one giant leap for mankind".  These are the words Neil Armstrong said 45 years ago today after he stepped onto the surface of the moon.

Astronauts Neil Armstrong, Buzz Aldrin, and Michael Collins were all aboard the infamous Apollo 11 flight to the moon.


The three launched into space aboard Apollo 11 on July 16, 1969 via the Saturn V rocket at the Kennedy Space Center in Florida.  Armstrong and Aldrin then climbed into the lunar module Eagle (below) that would descend onto the moon, while Collins orbited in command module Columbia.


At 4:18pm EDT, Armstrong connected with mission control in Houston saying "Houston, Tranquility base here.  The Eagle has landed". 

At 10:56 pm EST, Armstrong set foot onto the surface of the moon.  You can see in the image below the American flag the astronauts planted on the lunar surface.


Buzz Aldrin then joined Armstrong on the moon and the two spent time deploying instruments that would be used for experiments, gathering samples of lunar soil, and taking pictures. 

Here's a great "Moonwalk Montage" that takes us back to that day:


The three astronauts accomplished something the Russians had not.  NASA states they did not want to focus on the "victory" of the mission, but rather emphasized the "peaceful lunar landing by the United States. 

The patch designed for the mission was created by Michael Collins.  On the patch, the American Bald Eagle is depicted landing on the lunar surface, delivering an olive branch of peace.   The words "Apollo 11" were chosen for the top of the patch above a distance crescent shaped Earth.


The United State's determination in exploration through the Space program has taken us to the point where we now have a rover on Mars.  The mission 45 years ago today reemphasizes the spirit of our country and the desire to explore and discover outer space.

Continue Reading


Full "Supermoon" Tonight

July 11, 2014 - 09:42 AM

It's that time of the lunar calendar where we approach full moon status.  The moon will be full tomorrow morning at 7:25am.  But even tonight, expect a 14% bigger and 30% brighter full moon than full moons of 2013.  The reason?

The moon is in perigee.  The terms perigee and apogee refer to the distance of the moon from the earth.  During perigee the moon is closest to Earth.  The opposite is true when the moon is at apogee. 


Tonight's full moon will be the first of three supermoons this year.  The next will occur on August 10th and the final on September 9th.  The full moon tonight will be less than 224,851 miles away from Earth.  To put that in perspective, at apogee the moon is roughly 252,000 miles away from Earth.  Here's a photograph of the two full moons overlayed on one another. 


The July full moon is referred to as the "Buck" or "Thunder" moon.  The buck moon came from deer's antlers pushing out of their forehead.  The moon is also referred to as the thunder moon because July is the most common month for thunderstorms.


Weather conditions for supermoon-viewing will fairly good. Aside from a few scattered clouds, the sky should feature the bright moon rising at 6:46pm tonight and setting at 5:02am tomorrow morning. If you take some moon pictures, we'd love to see and share them! Happy moon viewing!

Continue Reading


Arthur Update and Fireworks Forecast

July 4, 2014 - 09:05 AM

Hurricane Arthur has put a damper on numerous firework's displays with many locations having to postpone or cancel.  Fortunately for us, the fireworks should be able to get off without a hitch in the Nation's Capital.  Here's a list of cities where fireworks have been rescheduled.

Hurricane Arthur made landfall near Beaufort, N.C. around 11:15 p.m. Thursday night.  Arthur was downgraded to a category 1 hurricane with winds at 90 mph as of the 9 a.m. update from the National Hurricane Center.  The storm has moved off the coast of the Outer Banks, NC and is quickly moving northeast.
(National Hurricane Center)
As a cold front slides through our area and Arthur moves farther out to sea, skies will clear from west to east, as drier air filters in.  It'll also be quite breezy, with winds gusting to around 30 mph through the day.
Winds will subside by the time the fireworks are set to go off downtown at 9:10pm.  And we couldn't ask for a more pleasant fireworks forecast.  It will be very comfortable, with low humidity and still just a bit breezy.  Click here for a full list of Fourth of July parades, events, and fireworks' displays.
The rest of the holiday weekend looks fantastic!  The humidity will remain low with plenty of sunshine and seasonable temperatures.

Continue Reading