3rd Rockies Snowstorm In 3 Weeks & Not Even Mid October? More To Follow?

Written by on October 6, 2013 in United States of America with 0 Comments

We look back at what will go down as one of the great storms in South Dakota history. We of course saw 48 inches fall 2 miles from Deadwood while an impressive 43 inches fell in the Black Hills town of Lead. What’s interesting about Lead, SD is that while this snowstorm was impressive there and it’s within the top 5, in fact it was 4th biggest.. it’s also amazing to think that there was 3 others that were bigger than what we’ve just seen. The greatest snow total ever in one storm was 52 inches which came down in March 1973 followed by 45 inches in November 2008 then followed by 44.5 inches in April 2006. This city within the Black Hills in amongst the snowiest in the United States. The amount of snow which fell in just 36 hours here was more than what many city’s across the typically colder, snowier city’s get in an entire winter.

Check out this amazing satellite imagery capturing the fresh snow cover over western South Dakota this morning.


Here’s a look at the snow cover from the storm.


This pattern with the -PNA and -AO is supporting the continuation of a western trough-eastern ridge and this upcoming week may bring a 3rd big Pacific storm system which recarves another deep trough over the West. In just the last 2 weeks, we’ve seen two snowstorms impact the Northern Rockies and we may well see another at the close of the upcoming 7 day period. That’s impressive even by Rocky Mountain standards this early on.

Here’s the PNA showing the continued negative signal which supports a western trough.


Interesting to note the trend towards positive in the later of the upcoming 15 days.

The ECMWF shows the recarve of a new trough which even digs deeper than the one we’ve just seen. It drops all the way into Southern California, likely to bring rain, wind, high level thunderstorms and potentially water spouts off the coast. Expect to see High Sierra snow and much colder temperatures all the way to San Diego.

Here 72 hrs or Wed

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

[s2If current_user_can(access_s2member_level1)]

96 hrs (Thu)

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

By Saturday the system winds up over South Dakota and this could bring another sizable snowstorm to the Black Hills as well as back west over the Wyoming and Colorado Rockies.

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

Another TWO To Follow?

Once next week’s system kicks out yet another Pacific storm enters the PNW and this too looks set to carve out a western trough presenting another chance of snow for the Rockies including Cheyenne and Denver. This system looks to have less cold air available as the jet splits with one branch (northern) staying in Canada while the other dives south. Of course the storm itself can produce enough cold air of it’s own underneath to bring snow so it’s a complex situation which bears close watching.

Here’s 168 hrs (Sun 13)

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

Note in the below 192 hrs (Mon 14) chart a system crossing the Midwest (1st storm which arrives this week) while another enters the West Coast. With both systems on the chart, one must consider a longer wave or broader based trough. However, these are more upper level cut off features with the real cold air staying up in Canada.

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

By Tuesday the 15th yet more storminess strikes the West Coast so according to the latest run of the ECMWF, the Pacific storm train remains active BUT with the AO going +, one must wonder how much cold comes south with these storms crossing the northern tier.

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

All in all, the pattern remains active and chilly in the west with an additional 2-3 more systems which could bring snow to the Rockies and High Plains over the next 10 days. So long as the PNA remain negative, so the trough persists in the west but interestingly the trough does appear to broad, perhaps covering much of the country by mid month just as the GFS ensemble suggests more of a positive PNA.

The AO is going positive BUT looks set to go back negative later in the month. Lots to look at for sure.

Be sure to watch the video just posted.

[/s2If][s2If is_user_logged_in() AND current_user_cannot(access_s2member_level1)]

That’s it, [s2Get constant=”S2MEMBER_CURRENT_USER_DISPLAY_NAME” /]!

To continue reading, you need to have a valid subscription to access premium content exclusive to members. Please join a subscription plan if you would like to continue.[/s2If][s2If !is_user_logged_in()]

Sign in to read the full forecast…

Not yet a member? Join today for unlimited access

Sign up to markvoganweather.com today to get unlimited access to Mark Vogan’s premium articles, video forecasts and expert analysis.

Tags: , , ,

Follow us

Connect with Mark Vogan on social media to get notified about new posts and for the latest weather updates.

Subscribe via RSS Feed Connect on YouTube

Leave a Reply