The State of the Atmosphere: Sunday, March 13, 2016

The theme for the coming week will be a gradual cool down, breezy days, and a chance for snow by week's end in Denver.

Monday looks to be the warmest day of the week, with highs once more climbing into the low to mid 60s across the metro area. By Tuesday we drop those temperatures by 10 to 15 degrees, with highs near 50 in Denver, and breezy conditions. Wednesday will be very similar, though may end up a few degrees cooler than Tuesday, again with windy conditions at times. Overnight lows by mid-week will drop below freezing, for the first time in some time for many locales.

Snowfall through Wednesday will largely be confined to the north-central mountains of Colorado, with little precipitation to speak of east of the mountains over the next several days:

GFS snowfall forecast through Thursday morning | Weather5280 Models

It's Thursday night into Friday that we'll need to watch for the chance of snow at lower elevations. You'll recall on Friday we said this would be the system to watch, and it appears that remains the case. While maybe not a blockbuster storm at lower elevations (especially considering how warm surface temperatures are now) there is better agreement between models that accumulating snow will be possible along the Front Range and urban corridor, as well as much colder temperatures by Friday than we have seen in some weeks.

Ironically, the Canadian which showed snow for Denver all last week has now back off, and keeps the best energy associated with our Thursday/Friday system too far west for much snow at lower elevations, except across southeast Colorado on Friday. The GFS and EURO on the other hand are a bit more gung-ho, and bring a pretty good upslope event for us Thursday night, with much colder temperatures as well.

GFS model shows widespread snowfall by early Friday morning across eastern Colorado | Weather5280 Models

If the GFS verifies, temperature readings will dip well below normal Friday, with midday temperatures only in the 20s across the urban corridor. The Canadian is a bit warmer, but still tops highs out near freezing on Friday. So while snowfall remains in question – much colder temperatures than we have seen in recent weeks are the way:

Temperature anomaly forecast for late morning Friday – temperatures from 15 - 25 degrees below normal across eastern Colorado | Weather5280 Models

As for how much snow to expect? It's still far too early to say. Even with better agreement between the various global operational models, there are still notable differences. The latest Canadian produces virtually no snowfall across the Denver area (again, in stark contrast to how it looked all last week), while the GFS/EURO produce several inches (ignoring surface temperatures). Then there are the ensembles which also have their differences – though today the Euro deterministic run and its ensemble mean are finally very close, which lends confidence a few inches may be possible should things stay on track.

For now, plan on temperatures cooling through the week with breezy conditions at times. By Thursday we may see some rain showers develop during the day, before mixing with snow Thursday night into Friday. Exactly where the best energy ends up tracking will eventually determine our chances for accumulating snow at lower elevations or not.

Of course we'll continue to track things closely here at Weather5280, and offer updates throughout the week. Not huge confidence in if/how much snow we'll see at lower elevations to end the week, but the potential is there, as well as a big change in temperatures. Models are also trying to bring another system through by early the next week, so could lead to a handful of active days across the region should thing stay intact. As always, subscribe to Weather5280 to stay up to date with all the latest!

Brendan Heberton

Brendan is founder of Weather5280. He is co-founder of FreshyMap, and develops software for geospatial data analysis and visualization.

Denver, Colorado
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