For those hoping to get a glimpse of Monday’s rare transit of the planet Mercury across the face of the sun, the weather across the United States will either be very good, with clear skies and excellent viewing prospects, or very bad, with cloud-filled skies and perhaps some rain or wintry precipitation thrown in for bad measure.
The national weather map for Monday morning (Nov.11) – when the transit will underway across the United States – shows a cold front extending southwestward from eastern Maine to a developing storm system over northern Texas. Another cold front will stretch southeast from Washington State, down into northern New Mexico. Meanwhile, a large and unusually cold (for November) high pressure system will be centered near eastern Montana and the western Dakotas.
Poor viewing odds for parts of U.S.
Unfortunately, a large swath of dense clouds are expected to cover much of Texas and Oklahoma, as well as the central Great Plains, the Great Lakes region, much of the Greater Ohio Valley, as well as parts of the Deep South, upstate New York and central and northern New England. In addition, rain and showers are expected to fall across the central and southern Plains, perhaps mixed with wet snow for upstate New York and central and northern New England.
Out west, where it will be much colder, up to 4-inches of snow could be on the ground by Monday morning for parts of southern and central Montana, northeast Wyoming, central and western sections of South Dakota and northern Nebraska. And snow showers and flurries may be falling over the Upper Peninsula of Michigan.
But if you live anywhere else, the weather for getting at least some periodic views of the transit looks just fine.
Fair-to-good chance to get a view
Clear, sunny skies should be the rule across the Pacific Northwest, California, most of the Rocky Mountains west of the Continental Divide and the Desert Southwest. Parts of the Northern Plains near to the Canadian border could get some fortuitous cloud breaks allowing for some views of the sun during transit time.
Similarly, a blend of sunshine and scattered-to-occasionally broken cloud cover is expected across southern New England, southeast New York (including New York City), northern New Jersey, and southeast Pennsylvania.
Fair skies with just some occasional scattered clouds is anticipated for the Middle Atlantic Coast, Piedmont and Southeast Coast as well as Florida and Alabama.
Safe Observing Tips
Those in the favored regions for viewing should be sure to bundle up.
In the East, temperatures are expected to be generally in the 30s and 40s, except over Florida where temperatures should range from the mid-50s north to the low 70s south.
Out West, expect temperatures to range from the 20’s in Rockies, to the 40’s and 50’s near to the Pacific coast and near 60 in the Southwest Desert.
And for those places in the Northern Plains that have a view of the sun, bitter cold temperatures in the single digits to near zero will prevail. Brrr!
Keep in mind that the forecast that we present here is merely a "broad brush generalization." To obtain the very latest weather forecast, tailored specifically for your hometown, click on this NOAA link.
You will find links to National Weather Service Forecast Offices across the United States, as well for Puerto Rico and American Samoa. Just locate your region and click on the weather office nearest to your location; from there you’ll be able to get the latest weather outlook.
For those who will miss the transit because of poor weather, we normally would say: "Wait till next the next one." Unfortunately, after this year, the next transits of Mercury will come on Nov. 13, 2032 and Nov. 7th, 2039, but neither one will visible from North America (Europe, Africa and Asia will be turned toward the sun during those respective transits).
The next transit of Mercury that will be accessible from North America will be on Friday, May 7, 2049. Mercury will take six hours and 41 minutes to cross the solar disk.
And finally ...
If you live across the central and western US, be sure to have a clear and unobstructed view toward the east-southeast horizon, as the rising sun will already have the tiny dot of Mercury on its disk; in the Pacific Time Zone, the transit will already be half over by the time the sun has cleared the horizon.
In contrast, those living in the Eastern Time Zone will be able to watch Mercury’s entire crossing of the sun’s disk from start to finish.
Editor's Note: Visit Space.com on Nov. 11 to see live webcast views of the rare Mercury transit as shown from telescopes on Earth and in space, along with complete coverage of the celestial event. If you SAFELY capture a photo of the transit of Mercury and would like to share it with Space.com and our news partners for a story or gallery, you can send images and comments in to firstname.lastname@example.org.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications, and he is also an on-camera meteorologist for Verizon FiOS1 News in New York's lower Hudson Valley. Follow us on Twitter @Spacedotcom and on Facebook.