I hope everyone had a good and safe summer! I am stoked to greet you on this first week of meteorological autumn with news of an unseasonably early--and potentially historic--winter storm that will impact New Mexico from Tuesday to Thursday. Our storm is dropping down from Canada and will settle into the Four Corners on Tuesday where it will stall and spin for a couple of days bringing a blast of cold, strong winds, and heavy precipitation across northern and central New Mexico. 

All of the necessary ingredients for significant snowfall in the northern mountains--cold air, high moisture, strong storm energy/lift, and favorable wind direction--should be in place. The biggest caveat will be how much snow actually sticks to the ground given how hot it has been in the days leading up to the storm. Look for the peaks of northern New Mexico to be snow-capped on Wednesday and Thursday mornings, and I think there is a decent chance that some high-elevation grassy slopes in the northern Sangres will have measurable snow ...and maybe even enough to get some early-season grassy pow turns!

While snow-capped peaks in September are not uncommon in northern New Mexico, measurable snow in New Mexico towns certainly is. We will be closely monitoring how far south the coldest air will drop and the associated snow levels to see if we can break any records for the earliest first snowfall. Here are the current first measurable snowfall records in some notable northern New Mexico towns (measurable snowfall is defined as being greater than or equal to 0.1 inches).

As far as our storm, the latest trajectory and timing are shown below. You can see the storm indicated in blue colors descending into the Four Corners from Alberta on Tuesday where it cuts off and forms its own low-pressure system and stalls out.

The storm will achieve cyclonic shape and rotation over the Four Corners generating tremendous energy and winds that will be the engine for our precipitation and snowfall. A storm of this stature and potency would be remarkable in January or February, let alone September.

 

Moisture levels in the atmosphere at 10,000ft elevation go from bone dry (browns) to very moist (purples) thanks to our storm and this should set up nicely for precipitation across northern New Mexico.

If I had to pick one wildcard in our set up it would be cold air. Will sufficient cold air drop into New Mexico for significant snowfall AND to cool the ground sufficiently for the snow to stick? The latest models show temperatures into the 20's F at 10,000ft (grey/teal colors) which should be cold enough for snowflakes to make it to the ground but in terms of sticking, we will have to wait and see.

This storm has taken a lot of different twists and turns the last few days and so models are all over the place regarding snowfall forecasts in the northern Sangres. Below are three different models ranging from less bullish 1-6 inches (Canadian) to moderate 2-10 inches (National Weather Service's NDFD) to very bullish 6-18 inches (GFS).

If you have a favorite high-elevation grassy slope for early-season turns in the northern mountains, I would keep an eye out for Tuesday sunset, Wednesday morning/afternoon, and even Thursday morning if the storm hangs around as long as some models predict. And if you love to take in snow-capped peaks on a crisp cool bluebird autumn day, I would aim to get out for a scenic drive or hike on Friday.

After our winter storm exits on Thursday, we should see a return to warm and dry weather. Here is the NOAA 8-14 day outlook showing above normal temperature and below normal precipitation for New Mexico through September 20. Hopefully, the Sept. 8-10 storm will provide a much-needed respite to the extreme fire danger conditions.

¡Que viva la nieve!

¡Que viva Nuevo Mexico!

JULIEN ROSS
[email protected]

COVID-19
While this early and potentially historic winter storm is a nice dose of fun and snowy news, we are still in the middle of a pandemic. Continue to stay safe out there and do our part with social distancing, masks, and following all of the state and local precautions to make sure New Mexico contributes to our collective victory over this devastating virus.

We are all closely monitoring and patiently awaiting how our beloved New Mexico ski resorts will handle the 2020-2021 season. Follow your favorite mountain on social media for the latest updates and I will also try to provide updates on the NM Daily Snow.

OpenSummit → Autumn Weather Forecasts

We will still be in hiking and biking season after this storm exits, so if you haven't yet, check out OpenSummit, our summer/fall service that provides precipitation, lightning, temperature, wind, cloud cover, smoke fire, and other forecasts for over 1,000 locations across the United States.

Visit OpenSummit.com and download the OpenSummit app.

Also, ONE login and ONE subscription is all you need to see the All-Access features on BOTH OpenSnow and OpenSummit. Click HERE for more details.