Updated Sat May 21, 2022 4:00pm MST | Published Sat May 21, 2022
- Impactful winter storm has cleared out.
- Temperature guidance looks much better than a couple days ago. Hard freeze unlikely tonight, and much more pleasant temps on Sunday.
- We remain cooler and unsettled into Tuesday, with more snow and rain possible.
- Warmer and dry from Wednesday to Saturday AM.
- More snow and rain possible from next Saturday to Monday.
Retrospective: Storm May 20-21
What a crazy 24 hours. An impactful winter storm slammed into Colorado as promised, with some deep powder up high and tree-destroying concrete down low.
Let’s get the burning question out of the way first: how did our snow forecast do? We think it did pretty well, especially in regards to timings and overall impacts.
The biggest issue with this storm was that it ended up being a bit front-loaded and quicker than expected. This meant that northern Colorado (particularly the northern foothills) got a lot more precipitation during the warmer part of the day, resulting in a lot of melting and compaction which took many inches off the final snowfall observations, even if the liquid precipitation was within range.
However, even the liquid precipitation came in a bit short in Larimer and Boulder counties – the upslope ended up being quite northerly, which is not a good setup for these areas. Instead, the focus was on Jefferson County and the Palmer Divide.
We did see deeper moisture end up further west which brought healthy snow totals to the west of Vail Pass – we weren’t banking on this. Great CSI-induced banding, isentropic ascent, and other small-scale dynamics hammered southern Summit County, Park County, Clear Creek County, and the Palmer Divide south. These areas blew our forecast out a bit. Shall we recall last night’s view of the A-Basin snow stake?
It was fun to watch, but can’t say we were interested to join 1500 people in skiing chowder on Humbug (one of the 12 runs still open).
The issue with these spring storms is that the snow tends to be highly variable, and as soon as the high spring sun comes up, things get really sloppy. This late in the season, it’s also difficult to tell if you’re skiing on a base of old snow or merely rocks and grass if you’re unfamiliar with the area and there’s enough new snow to cover up the landscape. We’ve heard less-than-stellar reports from various parts of the high country this morning, but it’s still nice to get out in the spring air!
Denver officially observed 2.3” of snow, which makes sense given how warm temperatures were. Much more snow than that actually fell, likely well within our 3-7” forecast. You can be the judge if that counts as a successful forecast or not, we feel we captured the magnitude accurately.
At Thomas’s place in Golden, accumulated snow remained at about 3” even as it snowed heavily for hours and hours. By the early morning hours, that creeped up to 5.5” – and a massive branch snapped off one of the backyard trees (almost 25% of the foliage), along with some other limbs.
Scenes of destruction have been rampant across the Front Range this morning, and at one point, Xcel Energy had indicated that 112,000 people were without power. Here are a few scenes from downtown Golden:
How much snow fell across Colorado through this morning? The SNODAS model has some estimated snow totals:
More importantly, the sheer amount of liquid water was badly needed, even if runoff and evaporation will rob us of much of it.
Scenes from satellite were impressive, showcasing a lot of dynamics at place from the lower levels of the atmosphere to higher up!
Cold air behind the cold front on Thursday night looked like Canada had dumped a bucket of soapy water into the northern United States:
Speaking of that cold front – quite the notable event which caught a lot of people’s attention.
On Friday, temperatures were 50 degrees colder than 24 hours prior.
Low temperatures this morning managed to stay right around freezing for most of the metro area, but some folks did see temperatures dip into the upper 20s.
Forecast Discussion: Tonight and Sunday
Luckily, with the speed that the system has cleared out (faster than expected), tonight’s low temperature forecast has bumped up a few degrees and most of the lower elevations of the Front Range should avoid a hard freeze.
Temperatures may jump right back up into the 50s and 60s in the Front Range tomorrow – a far cry from the 48 hours of 30s that were progged a few days ago.
Precipitation remains an issue along and south of the Palmer Divide into tonight. By tomorrow afternoon, northern Colorado should see another few rounds of heavier precipitation moving from the west, with snow mostly confined to the high country.
Forecast Discussion: Through Next Weekend
Though the strong shortwave that drove the past storm has cleared the area, there is still broad troughing over our region. Another shortwave embedded in this trough will continue to influence our weather through Tuesday, namely keeping it cooler and wetter.
Banded precipitation remains a concern this evening, tonight, and into tomorrow, with the greatest potential impacts in central and southern Colorado. However, parts of the Divide near Summit County could pick up a few inches of fresh snow into Monday morning.
Indeed, there are reports of several more inches of snow today in parts of Colorado’s high country. Any precipitation that makes it down to the lower reaches of the foothills and plains will likely be as rain.
There’s actually a decent amount of precipitation progged into Tuesday night for central and eastern Colorado, and lightning will have an increasing presence as we progress into the start of next week.
This may not translate into a ton of snow over the next four days for popular (backcountry) ski areas, but chances aren’t terrible. Right now, many areas are seeing a 20% chance of picking up another foot into Wednesday morning, which are better odds than you may think especially considering how these models handle uncertainty – these numbers should bump up over the next 24 hours.
Wednesday features a return to a drier, warmer regime as ridging takes hold over the western United States. Another trough looks to slide into the region by next weekend, which could bring snow and rain back to Colorado on Saturday and into Monday. Overall, the next 10 days or so looks like we’ll claw back a little bit of our precipitation deficit, though that may still not be the case in southwestern Colorado.