Before we talk about the snow potential for the weekend, we will have some strong wind to deal with on Friday. Wind gusts in the foothills will likely be 50 mph or better. Some of that strong wind will also sweep through Denver and adjacent areas to the east. Temperatures will top out in the 40s and lower 50s, so while it won't be a cold day, the wind with those temperatures will make you want to keep the coat handy.
Not a huge amount of change in the modeling today from our update last night. That's good news. The bad news is there was and still, is plenty of uncertainty concerning snowfall potential along the I-25 corridor, namely from the Colorado Springs area up north into the Denver metro area.
Most of the data indicate the heaviest snow in this area will fall along and south of the Palmer Divide, with lower totals in Denver and particularly points north. A few models (such as the GFS) have generally been further north with the placement of heavier snow until tonight's GFS, which has backed off on low country snowfall.
We will hedge south until convinced otherwise. With that, we think the Winter Storm Watch posted for the greater Colorado Springs area makes sense. The Watch goes into effect Saturday night and extends into early Monday morning. We think most totals here will land in the 3 - 6" range, though totals from 5 - 10" will be possible at higher elevations north and west of the Springs.
For Denver, it's a tough call. The GFS would suggest the southern and western suburbs could do well (again in the 3 - 6" or even 4 - 8" range). Other models are less pronounced. We would not be shocked to see the National Weather Service in Boulder issue a Watch for these areas as well, but still, lots of time to narrow in on totals, and if we need to go with a lower range for our official forecast.
For downtown Denver and points north/northeast, we expect totals to drop off. Right now, a Trace to 3" or seems to cover areas north and northeast of the city just fine. Denver proper could do 1 - 4", or if things come only a few miles north perhaps a bit more.
The big story will be in the high country. Expect travel to be very difficult much of the weekend with heavy snow and strong winds expected to make travel near impossible at times. Totals for the high country will be in the 1 to 3-foot range through Monday morning before things quiet down.
Boundaries are a bit rough in spots, but to give some graphical representation of what we're thinking see below:
Probabilistically we see the greatest odds for a moderate snow event shaping up south and west of Denver. The European ensemble has downtown Denver at about 30% odds for 3" or more of snow this weekend, but more like 60 to 70% for the western and southern suburbs. For the Springs those probabilities are healthy too, from 50 to 65% across western El Paso County:
Timing and impacts
Mountain snowfall gets going tonight and will continue off and on through the weekend. Expect plenty of travel issues in the mountains over the next three days or so, with wind and heavy snow expected off and on through the weekend.
East of the hills, timing is a bit harder. Some models show a bit of snow Saturday pulling off the mountains; this we'll need to watch for. The "main event" if you will looks to come Saturday night through Sunday night for most areas. We expect travel to deteriorate between Denver and Colorado Springs late Saturday night and remain difficult through the day Sunday with off and on snow and cold temperatures.
The European ensemble model has temperatures near freezing Saturday for Denver, then into the 20s for Sunday, Monday, and Tuesday. GFS MOS is a bit warmer but is still showing temperatures in the 20s Sunday and Monday before mid-30s for Tuesday. Overnight lows are likely to be in the teens and single digits several nights in a row.
Temperatures rebound nicely, and we dry out by the middle of next week. So big focus will be on this weekend and if and how much snow we'll see along the urban corridor. For Colorado Springs odds are looking good for several inches, for Denver and areas north... still a bit of a wait and see.