- Friday – few afternoon storms near/east of divide
- Saturday & Sunday – mostly dry, mostly sunny
- Monday through Wednesday – cooler, some snow above 10,000ft
- General weather pattern is warm through mid October
- Maybe changes during second half of October
The first of two cut-off storms will affect Colorado’s weather on Friday into Saturday. Friday will start out mostly sunny over most mountains west of the divide, but as the storm approaches, a few showers and thunderstorms will form during the mid to late afternoon. These storms will target areas near and east of the continental divide as they rapidly move from southwest to northeast. Any mountains in the path of these storms could see snow flakes down to 10,000-11,000 feet.
In the wake of these storm, Saturday and Sunday should be generally nice days with temperatures closer to autumn averages. Wrap-around flow behind Friday night’s storm could generate clouds over the northern half of the state on Saturday (from Aspen north to I-70 and Steamboat), but overall this should be a nice fall weekend with only a few showers near and east of the divide. Enjoy the weekend!
Next week, the second cut-off storm will slowly move east from California, and it’ll likely affect our weather from at least Monday through Wednesday, potentially lasting through Friday. Storms that are cut off from the main west-to-east flow of weather can move very slowly, and the models are hinting that this storm will be no different. Watch as the storm weakens and moves slowly from California to New Mexico.
Source: European WMO Essential from Weatherbell.com
Here’s the likely way the storm will affect Colorado next week…
From Monday into Tuesday morning, winds from the south will push a lot of moisture into southern and extreme western Colorado. Look for times of heavy rain and snow in the San Juan mountains and close to the Utah border. The snow level will likely be above 10,000 feet, with the best accumulations above 11,000 feet. The San Juans could see more than an inch of precipitation, which could mean more than 6 inches of snow. Watch for Silverton Mountain to post a picture of one of its patrollers skiing the new snow by the middle of next week. Silverton loves to do this early in the season and this picture will be shared all over Facebook.
From Tuesday into Wednesday, precipitation will spread across the rest of the state. This is likely the best time for mountains outside of the San Juans to see a couple of inches of snow, again with the snow level around 10,000 feet and the best accumulations above 11,000 feet.
On Wednesday, there could be a period of heavier precipitation along and east of the divide, from about I-70 north to the Wyoming border. This heavy precipitation is very uncertain, as it’ll require perfect timing of winds switching to blow from the east combined with added lift from the cut-off storm. If it happens, mountains around Rocky Mountain National Park could see 3-6 inches of snow up high. We’ll see.
The storm will finally move away later next week, but it’ll be close enough that we might still see a few clouds and showers extend into Thursday and Friday. Right now, I’d say that Thu/Fri has a 50/50 shot of either returning to perfect sunny fall weather or hanging on to some clouds and moisture. We’ll see. Cut off storms are hard to deal with.
Despite the cooler temperatures next week, the long range outlook through mid October is for warm weather to continue. The 6-10 day outlook from October 7-11 shows lots of warm temperatures (except for New Mexico where the cut-off storm will keep temps cooler).
And the 8-14 day outlook from October 9-15 continues to show warm temperatures. We might see a storm or two side swipe Colorado from the north during this period, but even if this happens, it likely will only bring a brief period of cooler temperatures to the northern part of the state.
I just took a look at the 30-day European model forecast, and it does show a trend toward cooler and stormy weather during about the last 10 days of October. This isn’t anything to hang your hat on, but I would welcome this timing. If this forecast holds true, Abasin and Loveland might have trouble opening by their average times of mid to late October. But in my book, this is OK. Cold weather and snowfall in October is often wasted as temperatures warm back up and much of the snow melts. I’d rather have the cold weather start in November and then last for at least 4-6 weeks, giving us a great start to the ski season.
Lastly, there has been a meteorological battle this week concerning the forecast of Hurricane Joaquin. This storm is over the Bahamas, and potentially could have headed north and hit the east coast, much like Hurricane (Superstorm) Sandy in the fall of 2012.
On Wednesday, virtually every weather model showed Joaquin hitting the east coast. However, the European model was hedging its bets with higher odds of the storm heading out to sea. Sure enough, one day later, almost all of the other models did a major flip flop and agreed with the European, forecasting that the storm would head out to sea.
This story isn’t over, so we can’t declare victory for the European model just yet. BUT, this is another highly visible victory for the European model, as you might remember that the Euro also correctly forecasted Hurricane Sandy’s left turn into the east coast in 2012, days before other models.
The Euro model is NOT always right, but it’s more consistent and more accurate than any other model that I’ve seen, and I’m glad we’re making use of it here on OpenSnow.com for most of our forecasts. Utilizing the average of the European Ensemble forecast (made up of 50 runs of the European model) is the way to go, and that’s exactly what we’re doing for most of our medium and longer range forecasts.
Have a great weekend and I’ll write another update on Monday about the upcoming high-elevation snow and the track and timing of our cut-off storm.