Andy's Weather

We’re waking up to snow covered and slick roads up in the High Country on this Thursday morning. (Pictured below)

I-70 near Vail Pass Thursday Morning

Sunrise over Colorado Photo: Jason Lowry on Twitter @jmowry11

So – here’s the sitch. We have a pretty significant storm rolling into California. Some areas have already picked up severel inches of rain and the Sierra Nevada mountains are doing well in the snow department. This is a mess of a storm for Cal/Nevada by the way.

Weather alerts across California and Nevada Thursday

A lot of that energy is moving into Colorado at this time. So what we look at when we’re forecasting snow in the mountains is how much moisture do we have to work with, how much energy and upper level support do we have, where is the wind coming from and of course temperatures. Most parameters are showing up pretty good over the next few days. The mountains as we move into tonight and Friday will continue to see an increase of clouds (if they saw clearing at all) and an increase in snow shower activity from SW to NNE. This is due to the position of the jet. The trough (or U-shaped curve rolling from Cali to the Central Plains) is our storm – see below.

That is essentially the feature that is bringing us snow and will eventually bring the Plains and Midwest a big snow this weekend. So what happens is these storms that roll into the West get torn up by the Rocky Mountains but the energy never really goes completely away. What’s happening in particular with this storm is that the energy is going to redevelop into a winter storm east of the Rockies. Once it gets into the Plains, instead of taking moisture from the Pacific, it begins to take moisture from the Gulf of Mexico! This is where the moisture is coming from for the Plains snowstorm this weekend.

Okay, I get away from Colorado too much but there’s a bigger picture to look at here! Bringing it back. Lets talk Denver. Denver is tricky, we know this. Here’s the thing, remember how I mentioned that moisture and energy kind of hops and skips over the Rockies? Well, that does happen and since Denver is so close in proximity to the mountains – we can assume (we know what that does to people) that the energy is going to skip over us. That will happen to an extent. There will be the slightest amount of precip. that will creep down the Front Range and make it into Denver Friday night and into Saturday morning. During this period there is a chance of rain and snow only because temperatures are going to be in the upper 30s to lower 40s for highs on Friday which puts a crucial pressure on timing of the precip. 

Snow Through Sunday AM

It’s not looking great but flakes will fly Friday PM into Saturday AM which means we could wake up to a dusting and at most an inch of snow (which is more likely in the NE corner of Colorado). Also, the mountains which could see another Winter Weather Advisory for 4-8″ of snow. This time the SW mountains (the San Juans) will pick up decent snow this go around!

NEXT STORM:
We’ve been mentioning the fact that Sunday’s storm could be pretty good for Denver. Well meh, the GFS (which showed more snow for Denver) is aligning (for now) with the Euro (which showed less snow overall). So for right now, can’t say too much. Just that we’ll have to watch a couple of specifics. 

1) The speed at which this next storm (Friday’s storm) move’s out
2) How much moisture lingers across the Plains following that storm
3) How strong our next burst of energy is that is coming from the Great Basin of Nevada is

As of now, it’s looking like there will be enough residual moisture around to produce at least measurable snow for Denver from Sunday to Monday. I won’t show model accumulations right now.

In conclusion – it’s a tricky forecast as per usual and I’ll keep you updated amidst any big changes.

~ Rain or shine
   I’m Andy Stein