With high pressure and drier air moving into our region today, there is a reasonable chance we'll see tomorrow's pre-dawn lunar eclipse. On the other hand, forecasters expect a wind shift tonight. Easterly winds off the ocean will eventually bring higher humidities, and that would create murkier viewing by dawn. But the betting in Sterling this morning was that humidity will hold off, and skies will remain "mostly clear overnight."

That said, this eclipse - the second full lunar eclipse of the year for Maryland - was never destined to be a memorable one. Here's why:

The full August "Fruit Moon" is set to slip into the darkest part of the conical shadow the Earth casts into space - the "umbra" - at 4:51 a.m. Tuesday morning. Observers with a clear view toward the west will notice the upper left edge of the full moon's disk becoming noticeably dimmer.

Here's a cool animation of what you'll see. Cloudy skies? Too lazy to go outside and watch? You can find live coverage, online, by clicking here.

The moon will continue to plunge into the shadow for about an hour. By 5:52 a.m., it will be in full eclipse. Provided clouds, humidity or air pollution near the western horizon don't obscure it entirely, it may appear to have a dull red or coppery color. For an astronaut standing on the moon looking back, the dark, night side of the Earth would appear to be eclipsing the sun, surrounded by a reddish ring of light - the combined glow of all the planet's sunrises and sunsets. It's that light, scattered by the clouds and atmospheric dust, that paints the reddish color across the moon's surface as seen from Earth's night side.

NASA scientists will be using the period of totality to scan the moon's darkened surface for flashes of light caused by the impacts of meteors. You can read more about that here.

Unfortunately, our view of totality will be a fleeting one at best. Sunrise in Baltimore tomrrow will occur at 6:31 a.m. EDT, just a bit more than a half hour after totality begins. And the moon itself is scheduled to set below the western horizon just a few minutes later, at 6:34 a.m. 

So, the sky will be brightening throughout the short time we have to observe totality, washing out our view. And the moon will be sinking deeper into the murky skies close to the horizon, further dimming the scene.

For a better view, hop a plane today and head west. The entire eclipse will be visible from the West Coast. Totality will start there at 2:52 a.m. Pacific Daylight Time, and end at 4:23 a.m. PDT, with the partial phase winding up at 5:24 a.m. PDT. 

Our next opportunity to see a full lunar eclipse, from start to finish (provided skies are clear, and it's not snowing), will come on the evening of Feb. 20, 2008.