Before we get to the eclipse, coming up on Monday, August 21st, let’s talk about the current weather pattern in Colorado.

Right now in Colorado

It’s beautiful. Cool-ish temperatures and ample precipitation. It doesn’t get any better than that, especially during mid-August when the temperatures can be quite warm.

This is the view from the summit of Abasin on Monday morning, August 14th. Notice a few mid-level clouds associated with moisture pushing in from the west.

The 10-15 day forecast for Colorado

The forecast for the next 10+ days does NOT show any extreme warmth. At this point, it is very likely that there will be no more heat waves through the rest of 2017. Sure, the eastern plains might touch 90F again at some point, but the longer-range forecasts show below average temperatures persisting through most of the remainder of August, and after that, we’ll undoubtedly settle into standard, cooler fall weather.

Path of the Eclipse

The eclipse is coming. Nothing (that I know of) will stop it. The darkest time will be during the middle of the day next Monday, August 21st.

The path of totality (where it will be darkest) will not quite hit Colorado, but it’ll be close. The northern half of Colorado will be darker than the southern half, and the best chance for seeing the total eclipse will be to our north and east in Idaho, Wyoming, and Nebraska.

Map courtesy of https://www.timeanddate.com/eclipse/map/2017-august-21

Can we forecast clouds during the eclipse?

The path of totality WILL match the map above (unless a lot of scientists are all playing a joke on us, which is quite unlikely).

What we do not know is how the clouds will behave.

If you think forecasting snow 1 week ahead is tough, clouds are even more difficult.

Weather pattern during the eclipse

I have decent confidence in the weather pattern during the eclipse. All major models agree that we’ll see a trough over the west coast.

A trough is an area of storminess, but it doesn’t necessarily mean that areas directly under the trough will be cloudy or rainy. Weather is complicated.

With a standard though, there is more cloudiness ahead (east) of the trough. That means that there could be clouds east of the trough, including here in Colorado and north in Wyoming, which the destination for 50% of Colorado’s residents during the eclipse (I’m joking, but I would expect a LOT of traffic flowing north on I-25 on Sunday and Monday.

So, what about the clouds during the eclipse?

Here are two cloud forecasts during midday on Monday, August 21st, with the general path of totality shown in red.

I have three takeaways.

1) Based on the difference between these two forecasts, and that we’re still 7 days away, I have NO CONFIDENCE in the cloud forecast for next Monday.

2) Based on the weather pattern with the trough over the west coast, it is more likely than not that we’ll have dry weather during the eclipse in Wyoming, and perhaps in Colorado as well.

3) Based on the weather pattern with the trough over the west coast, it is somewhat likely that we’ll have mid-or-high level clouds covering some of Colorado or Wyoming. At best, this would only filter the view a little bit. At worst, this could block the view of the eclipse. Either way, make sure you have your eclipse glasses!).

I am somewhat concerned that there will be a push of moisture moving from the southwest toward the northeast over Colorado and Wyoming early next week. This will occur ahead of the trough.

Often, these pushes of moisture move a little more quickly than forecast, but at this point, seven days away, there’s really no point in worrying about a few hours one way or the other. A lot can and will change in the forecast.

Why this cloud forecast matters

It might not. If you want to see the eclipse, you’re likely already scouting out spots. I don’t have enough confidence in the cloud forecast to advise you to change any plans you have.

Next update

I’ll post again on Wednesday, Friday, and Sunday. Unless our son happens to decide to come into the world this week, in which case he will take priority over the cloud forecast:-)

Chat soon!

JOEL GRATZ