ValpoVike

That sort of rainfall can indeed happen in Colorado, but with devastating effects. The 1976 Big Thompson flood is quite the example. From Wiki: On July 31, 1976, during the celebration of Colorado's centennial, the Big Thompson Canyon was the site of a devastating flash flood that swept down the steep and narrow canyon, claiming the lives of 143 people, 5 of whom were never found. This flood was triggered by a nearly stationary thunderstorm near the upper section of the canyon that dumped 300 millimeters (12 inches) of rain in less than 4 hours (more than 3/4 of the average annual rainfall for the area). Little rain fell over the lower section of the canyon, where many of the victims were. Around 9 p.m., a wall of water more than 6 meters (20 ft) high raced down the canyon at about 6 m/s (14 mph), destroying 400 cars, 418 houses and 52 businesses and washing out most of U.S. Route 34.[6] This flood was more than 4 times as strong as any in the 112-year record available in 1976, with a discharge of 1,000 cubic meters per second (35,000 ft³/s).

We got more this evening, about .3". It's crazy to see the feast or famine over the past 6 weeks. Regarding the boulders, this road is directly below a ridge that was burned in Cameron Peak fire last summer...hence the unobstructed flows coming down the mountain in the drainages. Burn Scar flooding is no joke we are learning, and it doesn't require a huge rain dump.

It's hard to be ungrateful for additional monsoonal moisture, but we've had enough up here. This photo is of Black Creek Road in our neighborhood. It is one of two county owned roads in the neighborhood, and Larimer has rebuilt it twice since July 4th. This is it's current state which is amazing and frankly hard to believe considering that most of the series of floods have been caused by events of an inch or less of rain. There are homes on this road, so not just a minor nuisance.

It's way too early to tell based on smoke forecasts, but given that Idaho and Montana have a lot of wildfires currently ongoing....I would expect those areas to be inundated. Wyoming would likely have more dependency on the smoke impacts from wildfires in neighboring states.

This morning the divide looks remarkably clear to my west. Fingers crossed that we get one day of semi-clear air. Between the days and days of rain up here and the days and days of smoke, we haven't seen any bluebird days in quite some time.

Yup and that is my neighborhood (The Retreat). We have been having burn scar flooding periodically since July 4th. We have already lost two roads in the neighborhood from crazy washout. Today was the roughest though. Several hours of rain today but it has stopped for now. The North Fork is fine but pretty full. It gets dicey where the Miller Fork meets it. Coal black water...

A tragic day of flooding yesterday on Hwy 14 along the Poudre River, in the Cameron Peak burn scar. This from the Larimer County Sherriff's Facebook page: I just returned from the Poudre Canyon flood incident that originated around Black Hollow Road, just west of Rustic earlier tonight. A resident from Black Hollow Road described a fairly typical rain coming down just prior to the flooding, which came down Black Hollow Creek. He said that the washing of soil and trees came as a complete surprise. We don’t have a definitive count, but it appears several structures along Black Hollow Road were damaged or destroyed. We do know that some residents did get out from that neighborhood safely. We are working from reports of three unaccounted for persons from that area. We have located one deceased victim in the area, but were unable to recover the body tonight. Those operations will be resume tomorrow morning. We also believe there may be two more people still missing from today’s flooding. A short distance west of Black Hollow Road, a significant amount of debris washed across Hwy 14, blocking the road. CDOT is working to remove that debris. I personally witnessed significant debris and damage in the area, caused by downed trees, damaged and destroyed homes and mudflow in the area. During this event, we evacuated the canyon- not knowing how this debris might impact persons and property downstream. Mandatory evacuations were lifted later in the evening. However, forecasts for Wednesday include the possibility for similar weather in coming days. The risk of debris flow damage remains and we caution any resident or visitors the canyon to remain vigilant. Our deepest sympathy goes out to the yet unidentified victim of this flooding and their family along with any other potential victims yet to be located. We cannot speak to the status of Hwy 14 as it falls under the authority of CDOT. However, we expect some level of travel restrictions as we resume recovery operations tomorrow. I want to thank all of the wonderful residents and visitors of the Poudre Canyon for their cooperation. I also want to thank all of the responders who have been and continue to be integral in our response to this tragic event. Those responders are absolutely amazing people!!! Our office will report more information as the details become more readily available.

2021 Monsoon part 2 on it's way today and thru the week. I am cautiously optimistic that we won't have the insane repeat of last years conditions. The two "long duration" fires, Muddy Creek and Morgan Creek, are not rapidly growing. Still a lot of fire season to go, but at least we are getting decent monsoons this year.

We got hit today by 3 strong cells. And we also got hit by the most specific flash flood warning I have seen, for only our neighborhood. The burn scars sent a nice wall of water down two streams and took out a couple of roads. It has rained for 9 out of the last 10 days now. This is the Larimer County Sheriff's Office with an emergency message. Dangerous flooding is occurring in The Retreat Area of Glen Haven. Streamside Dr and Fishermans Ln are the most impacted areas at this time. Immediately reach higher ground by any means necessary. Avoid area subject to flooding including dips, low spots, ditches, etc. and do not attempt to cross flowing streams or creeks. If driving, be aware that the road may not be intact under flood waters. Never drive through flooded roadways - turn around and go another way. If your vehicle stalls, leave it immediately and seek higher ground.

FoCo kinda stands out here:

Some Lenticular clouds starting to form. It is hard to tell from my vantage, but looks like it may be over Long's.

This moisture has been great to see. Rain every day since Thursday. Perhaps a bit too much on Saturday night when we had a rather long duration of several hours of moderate rain and we had some burn scar issues up here. We lost a portion of a road in our neighborhood due to a blowout upstream with debris flowing down. But I'll take that over last summer's relentless drought.

I shot this off my deck this evening. This is looking east towards Loveland.

I watched the radar loop on this on Sunday, and it was the oddest storm motion that I can recall. It stumbled like a drunken pirate...moving northeast, then west, then a very sudden about-face to move east before dissipating. The anvil was a beautiful site from up here though.

A typical summer pattern so far the past week. Up here in Glen Haven we thankfully have had good short lived heavy rain the past couple of days, but that is just by luck as most of the front range has not seen these. You're spot on that it comes down to the monsoon. Western Colorado is still in a rather dire scenario that the monsoon won't fix.

That is a cool photo. Below is a photo of fresh snowfall that I shot yesterday/Sunday evening from my deck looking west up the North Fork of the Big Thompson. Signal Mtn is on the right and Mt Dickinson to the left, with Mummy Mtn off camera a bit further left. Right of center are some burn scars from the Cameron Peak fire which have been quite useful in revealing snow coverage from a couple of miles away. Anyways, it is stunning out with all of the green popping out everywhere with the backdrop of fresh snowfall.

This year GFS = Generously Forecasting Snow

Not too bad up here. Woke up to about 2" this morning, that melted by noon despite steady snow. It started accumulating again in the early afternoon and we are probably back up to 3" of new accumulation. It's not really accumulating on road surfaces, just on decks and grass. All in all a very typical May snow.

Yet another juicy storm on tap for early this week. I think this makes the 3rd "early in the week" storm in a row with generous QPF. This one feels a bit more interesting with respect to snow accumulation. It looks like 6500 feet and higher may do pretty well this time around, versus the 8000 foot consistency in the prior two weeks. Not that I am pulling for 10-12" up here, I'm kind of done, but I think it is possible.

Here ya go. Very good improvement over the northeast.

I came across this from NWS Boulder's Facebook.

I'm not sold on this. I think it will end up a lot like this week's storm....good for the mountains but a melty mix for lower elevations. Perhaps I am wishcasting a bit as I am really ready for winter weather to end . I am at ~7300' and my home is surrounded by 9k'+ mountains....this week was interesting as I could see a clear snowline just over my head, probably around 8k'

Feels to me like timing for a spring summer thread is just about right.

It really comes down to the Monsoon. We were in great shape exiting snow season last year, but no monsoon. Raindance, do you happen to track analogs for the regional monsoon season?

Well, at least some good news for portions of Larimer and Boulder counties.