Friday, October 23, 2009
Update On Severe Potential
The atmosphere still looks marginally unstable heading into Saturday afternoon, however, there will be strong "lift" in the atmosphere to create a few thunderstorms. Right now it looks like the best chances for severe storms will be in our area and especially farther north. This is still a developing situation, so we will have more updates soon.
Thursday, October 22, 2009
Severe Thunderstorms Saturday?
A few thunderstorms will be possible on Saturday as a cold front passes the area. The front will be along I-81 during the late afternoon.

Jet stream winds will provide strong speed shear (winds increasing with height).


Jet stream winds will provide strong speed shear (winds increasing with height).

And there should be enough instability in the atmosphere to support thunderstorm development.

One limiting factor on Saturday will be cloud cover, which will reduce instability. In addition, there could be too much shear, which would inhibit thunderstorm development.
This is something we are watching closely and will have more updates in the next couple days.

One limiting factor on Saturday will be cloud cover, which will reduce instability. In addition, there could be too much shear, which would inhibit thunderstorm development.
This is something we are watching closely and will have more updates in the next couple days.
Tuesday, October 20, 2009
Meteor Shower Wednesday Morning

(Composite Image: Chris Peterson, Guffey, Colorado, Oct. 21, 2008)
The Orionids Meteor Shower will peak in the pre-dawn hours of Wednesday morning, October 21. This meteor shower is caused annually when the Earth passes through debris from Halley's Comet on its orbit around the Sun. The past several years have produced a good show, with up to 60 meteors visible to the naked eye per hour. All you have to do is go outside in the few hours before Dawn, and patiently keep your eyes trained to the Southeastern sky.
(Image: NASA)
You should see several dozen bright, long streaks of light per hour, originating from in-between the Orion and Gemini constellations.
Several factors are making this year's show a good one, including the nearly-New Moon completely absent from the pre-dawn sky and clear skies expected over Central Virginia Wednesday morning. Also, the meteors will be beautifully surrounded by some of the brightest stars and planets in our night sky right now, including Venus, Mars, Sirius, and the constellations Orion, Gemini, and Taurus. So why have the last several years produced such good meteor showers? NASA scientist Dr. Tony Phillips explains:
"According to Japanese meteor scientists Mikiya Sato and Jun-ichi Watanabe, 2006 marked Earth's first encounter with some very old debris. 'We have found that the [elevated activity of 2006] was caused by dust trails ejected from 1P/Halley in 1266 BC, 1198 BC, and 911 BC,' they wrote in the August 2007 edition of Publications of the Astronomical Society of Japan. In their paper "Origin of the 2006 Orionid Outburst," Sato and Watanabe used a computer to model the structure and evolution of Halley's many debris streams stretching back in time as far as 3400 years. The debris that hit Earth in 2006 was among the oldest they studied and was rich in large fireball-producing meteoroids."
So all these factors should make for an excellent Orionids viewing Wednesday morning. Don't worry, it won't be in the 30's in Central Virginia like it has been the past couple mornings! The morning low Wednesday in Richmond should be around 47 degrees. So take advantage of our ideal viewing conditions and check out some several-thousand-year-old debris smacking into the Earth's atmosphere.
Several factors are making this year's show a good one, including the nearly-New Moon completely absent from the pre-dawn sky and clear skies expected over Central Virginia Wednesday morning. Also, the meteors will be beautifully surrounded by some of the brightest stars and planets in our night sky right now, including Venus, Mars, Sirius, and the constellations Orion, Gemini, and Taurus. So why have the last several years produced such good meteor showers? NASA scientist Dr. Tony Phillips explains:
"According to Japanese meteor scientists Mikiya Sato and Jun-ichi Watanabe, 2006 marked Earth's first encounter with some very old debris. 'We have found that the [elevated activity of 2006] was caused by dust trails ejected from 1P/Halley in 1266 BC, 1198 BC, and 911 BC,' they wrote in the August 2007 edition of Publications of the Astronomical Society of Japan. In their paper "Origin of the 2006 Orionid Outburst," Sato and Watanabe used a computer to model the structure and evolution of Halley's many debris streams stretching back in time as far as 3400 years. The debris that hit Earth in 2006 was among the oldest they studied and was rich in large fireball-producing meteoroids."
So all these factors should make for an excellent Orionids viewing Wednesday morning. Don't worry, it won't be in the 30's in Central Virginia like it has been the past couple mornings! The morning low Wednesday in Richmond should be around 47 degrees. So take advantage of our ideal viewing conditions and check out some several-thousand-year-old debris smacking into the Earth's atmosphere.
Subscribe to:
Posts (Atom)
