Years of planning, months of speculation, a week of long-range cloud forecasts, and now we have reached the nail-biting phase of tracking each slight change in the short-range models. So, what location will have the clearest skies for the eclipse?
Here is my best shot at the forecast. Remember, forecasting the general area of cloudiness is very hard, and forecasting the exact location of a specific cloud is impossible. So like all forecasts, be ready to make real-time adjustments if you can.
Situation on Sunday
Here is the satellite animation on Sunday morning. Notice a system in the northwest, and another over New Mexico. These are the players that could affect the sky cover on Monday.
Thanks to the new GEOS-16 weather satellite (made possible by your tax dollars!), we have high-resolution images that can show us added detail. The image below is from Sunday morning.
The high clouds at the bottom of the image filter the sunlight. These high clouds will be moving north toward Wyoming, Colorado, and Nebraska and could impact viewing.
Also, notice the smoke in the northwest, which shows up as the hazy, milky white color. This also filters the sunlight, but shouldn't impact viewing too much unless you want to have a perfectly clear sky necessary for high-resolution photography or video.
The smoke forecast for Monday
First, here is the smoke forecast during the eclipse, thanks to the Canadian FireWork model. Some issues in parts of Oregon and Idaho, and perhaps light haze from the smoke through Wyoming. Something to keep in mind, but not a deal breaker unless you are very close to the source of a fire.
The cloud forecast for Monday
Remember that no weather model can perfectly predict clouds, so take these prognostications as a guide but not an absolute. Also, as Dr. Jim Steenburgh points out, just one rogue cloud can make or break the experience (http://wasatchweatherweenies.blogspot.com/2017/08/potentially-harsh-realities-of-eclipse.html).
The model below shows some high cloud over Colorado, southeast Wyoming, and Nebraska. There is also a thin area of cloud over western Wyoming into southeast Idaho. Eastern Oregon looks good.
The model below is similar to the first with high clouds over Colorado, Nebraska, and eastern Wyoming, with the thin area of cloud over western Wyoming and Idaho just a bit further east than the first model. Again, eastern Oregon looks good.
Since one model can't perfectly predict clouds, it's useful to look at many versions of one model. Here is the NCAR ensemble, relatively agreeing with the previous two models but also showing some variation.
Bottom line - where should you go for the clearest skies?
The odds are highest that eastern Oregon will have clear skies with maybe a bit of haze from wildfire smoke. Western Idaho should also be good.
The majority of Wyoming should/could have clear skies as well, but there may be a thin line of clouds over the middle or western part of the state, as well as some high clouds over the east. Wish for a bit of luck if you're in Wyoming.
Nebraska should also have some high clouds, so you'll need some luck there as well.
If it's cloudy, will my experience be ruined?
Nope. A little bit of haze or high cloud is likely ok, except for those wishing to take perfect, clear-sky, high-resolution pictures.
And if it is cloudy, enjoy the experience and remember that it's better than being at a desk looking at spreadsheets!
If you have the ability to adjust your position based on clouds and want to look at real-time satellite imagery on Monday morning, here are two links:
Free, high-resolution GEOS-16:
There are some other weather apps that show satellite images, but I like these two links the most due to their high-resolution (GEOS-16) and county maps (WeatherTap).
Good luck and have fun!
Update at 7 am MDT on Monday...
The current satellite image looks like this:
And here are two cloud forecasts for around noon:
Oregon looks clear.
Idaho looks clear.
Wyoming will have a thin area of high clouds over the western/central part of the state. West of and east of this line should be clear.