One and a half billion people across four continents will have a theoretical opportunity to sneak a peak at a rare total lunar eclipse which begins late tonight in the Pacific Northwest.

One and a half billion people across four continents will have a theoretical opportunity to sneak a peak at a rare total lunar eclipse which begins late tonight in the Pacific Northwest.

But Rogue Valley fans of celestial events will need a break from Mother Nature to view the eclipse. A series of winter storms is making the possibility of moon-gazing look a bit cloudy, not to mention wet and cold.

Snow flurries and frequent showers will be decreasing through Wednesday. But the clouds are expected to remain for the next several days, said Rick Holtz, meteorologist for the National Weather Service in Medford.

"There's going to be pretty heavy cloud cover Monday night," Holtz said.

Whether or not it's visible, the eclipse — which is occurring during the winter solstice for the first time in centuries — will begin at 10:33 p.m tonight.

The Earth's shadow will first appear "as a dark-red bite at the edge of the lunar disk," according to the NASA website at http://science.nasa.gov/science-news/science-at-nasa/2010/17dec_solsticeeclipse/.

It will take about an hour for the "bite" to expand and swallow the entire Moon. Totality, the period when the Moon is completely in the Earth's shadow, commences at 11:41 p.m., and lasts for 72 minutes, the site said.

Holtz said overnight low temperatures should be in the low to mid 30s through Wednesday.

If you're the hopeful and sturdy sort, still planning to dash out for one quick peek at this rare eclipse,­ bundle up and choose 17 minutes past midnight.

NASA says that's when the Moon will be in deepest shadow, displaying the most fantastic shades of coppery red.

Why red? Here's what NASA has to say:

"A quick trip to the moon provides the answer: Imagine yourself standing on a dusty lunar plain looking up at the sky. Overhead hangs Earth, nightside down, completely hiding the sun behind it. The eclipse is under way. You might expect Earth seen in this way to be utterly dark, but it's not. The rim of the planet is on fire.

"As you scan your eye around Earth's circumference, you're seeing every sunrise and every sunset in the world, all of them, all at once. This incredible light beams into the heart of Earth's shadow, filling it with a coppery glow and transforming the moon into a great red orb."

If you miss the show, a partial eclipse is to take place Dec. 20, 2011. The next total lunar eclipse that will be visible to Pacific Northwest residents won't happen until April 2014.

Reach reporter Sanne Specht at 541-776-4497 or e-mail sspecht@mailtribune.com.