Mountain West Discussion

[Chinook]

The models are consistent with a low pressure in Colorado on Tuesday. So far, no models are showing much precipitation.

Today's models have a large storm for next Fri-Sat, so that is definitely something that could be discussed over the next week. Today's ECMWF has 987mb near Colorado Springs next Friday and snow at Denver. 

[n1vek]

Where that Fri-Sat low ejects looks nice. Still a long way to go, but the wind field should be decent for upslope?

 

And also (tell me if I am wrong), a lot of the long-range models (GFS, Euro) account for terrain variability, but not nearly as much as the mesoscale models do. Curious if in marginal moisture situations this results in some of the ranges being underdone? Maybe I am just being a weenie here. 

[ValpoVike]

Off topic, but what a sunset this evening along the front range. I captured this photo on my way back home from the airport today.  After 7 long days away, the mountains were a welcome sight. 

[mayjawintastawm]

On 12/3/2021 at 3:24 PM, n1vek said:

Where that Fri-Sat low ejects looks nice. Still a long way to go, but the wind field should be decent for upslope?

 

And also (tell me if I am wrong), a lot of the long-range models (GFS, Euro) account for terrain variability, but not nearly as much as the mesoscale models do. Curious if in marginal moisture situations this results in some of the ranges being underdone? Maybe I am just being a weenie here. 

Yeah, looking OK but so far away...

My sense is that the QPF is not so much underdone with mesoscale features as that the variability is underdone. Commonly, the typical upslope places (along the Peak-to-Peak, Boulder) get more than predicted, while downsloping places (often Fort Collins, CO Spgs) get less than predicted.

Today I looked at the July-Nov climate data for most reporting stations in AZ, NM and CO. The only place that got less precipitation than Denver was Yuma, AZ. How about that.

[Chinook]

1 hour ago, ValpoVike said:

Off topic, but what a sunset this evening along the front range. I captured this photo on my way back home from the airport today.  After 7 long days away, the mountains were a welcome sight. 

Loveland, Route 34?

It really has been a nice time to get outside and do some walking and jogging,  and get going in the morning without having to scrape off a ton of frost or snow. But it does look like winter is coming. Tomorrow, shallow cold front will move in to the I-25 area from the east, and it will stay. The 30-degree cold air mass will be in northeast Colorado for Monday.

Most likely, there will be a significant storm at the end of the week. The models have some consensus that the upper level trough will drop down from the Pac NW on Thursday to Utah on Friday, with significant snow possible for Nevada, Utah, northern Arizona, and western Colorado. As for the Plains, today's models have variable predictions of QPF for Larimer County, SE Wyoming, and western Nebraska. That, is, of course, the main question. It is 6-7 days away, so I guess we won't know yet. This upcoming storm will obviously bring a significant increase in snow cover over 9000 ft.

 

and here's something you might not want to see

[stormdragonwx]

I think its fair to assume you guys are about to end your snow drought late next week. 

[ValpoVike]

9 hours ago, Chinook said:

Loveland, Route 34?

It really has been a nice time to get outside and do some walking and jogging,  and get going in the morning without having to scrape off a ton of frost or snow. But it does look like winter is coming. Tomorrow, shallow cold front will move in to the I-25 area from the east, and it will stay. The 30-degree cold air mass will be in northeast Colorado for Monday.

Most likely, there will be a significant storm at the end of the week. The models have some consensus that the upper level trough will drop down from the Pac NW on Thursday to Utah on Friday, with significant snow possible for Nevada, Utah, northern Arizona, and western Colorado. As for the Plains, today's models have variable predictions of QPF for Larimer County, SE Wyoming, and western Nebraska. That, is, of course, the main question. It is 6-7 days away, so I guess we won't know yet. This upcoming storm will obviously bring a significant increase in snow cover over 9000 ft.

 

and here's something you might not want to see

Yep, Hwy 34 on my drive up to Glen Haven. I saw those records on a Facebook post and it is shocking.  

[smokeybandit]

In typical GFS fashion within 7 days, it has really shrunk the upcoming storm to just the mountains.

[Chinook]

--- and that's why I didn't post a snow or QPF map last night

quick temp drop at Greeley, Fort Collins, Loveland, not really lined up with any clouds on the satellite map. My place dropped off from the 60's to the 50's very recently. 

Edit: Fort Collins dropped from 61.8 to 32.4 in 2 hours.

Edit: Loveland mesonet station dropped from 65 to 24 in just this afternoon to early evening.

[mayjawintastawm]

Yup, we dropped 21 degrees (from 58 to 37) from 3 to 4 PM with the ever-interesting "BLDU" at APA, another 9 degrees the hour after that, and now it's in the upper teens.

[Chinook]

Good news. The Canadian, UK, and ECMWF have shifted back to give Larimer/Boulder counties some snow on Thursday night/ Friday. The GFS still pretty much has small stuff for Denver to Cheyenne. I don't know if this trend will continue. The forecast inconsistency is still pretty annoying for the most populated areas right now.

[smokeybandit]

The NAM says "what snow?" for the Front Range.

[mayjawintastawm]

If I had a nickel for every time I saw this in the BOU AFD, I wouldn't need the CARES Act...

our snowfall forecast for the
Denver metro continues to decrease as most guidance has trended
much drier. 

[stormdragonwx]

Sorry guys, I jinxed it.

[Tlagon]

Moved to Thornton from North Carolina on July 4.  It has precipitated enough to give the ground a good soaking at my house once.  Once in over 5 months.  I have researched detailed historical data and understand how abnormal this is, but my goodness.  I am truly hoping there is no measurable snowfall at DIA tomorrow to keep the streak intact as a .02 QPF drivel will not help the situation at all.

[finnster]

I was looking at historical records for snowfall in Fort Collins.  Here are the top 5 lowest snowfall seasons:

1. 1945-46 - 8.5”

2. 1903-04 - 10.5”

3. 1934-35 - 11.7”

4. 1933-34 - 15.4”

5. 1924-25 - 21.2”

As you can see there have been some really low snowfall seasons. There have also been numerous seasons in the 20-30” range.  The way things are trending currently I could see this snowfall season breaking into the top 5 group above.  I hope I’m wrong!
 

I also looked for years that 0 or near 0 snowfall during October-November-December.  There were no such years in the Fort Collins records but a few came close:

1934 - .5”

1914 - .7”

1904 - 1.0”

Fort Collins now sits at .7” snow so far, so if nothing more happens this month we will be in the top 3 years for lowest snowfall October-December.

Denver of course has NO snowfall so far this season, and is smashing their latest first snow record - the way it’s looking they could break it by a month or more which is both incredible and scary.  What in the world happened to the weather pattern in the last 6 months?!?!

 

[ValpoVike]

About an inch up here so far this evening.  It's crazy to be excited about that, but here we are.

[mayjawintastawm]

Late post: 0.9" snow Friday morning. First of the season. Let 'er rip... 

[stormdragonwx]

Congrats on your no snow streak finally ending! That was totally crazy to be this late in the season.

[Chinook]

A high wind watch issued for much of the Plains, sections of NM, AZ, UT, and WY. Winds of 30kt to 70kt winds will exist at 1000m (or 3000ft) above ground in eastern Colorado on Wednesday

[Chinook]

I have finally done it. I have made an animated GIF of the HRRR model cross-section prediction of winds. The high winds, above hurricane force (purple) will develop in and above the mountains next to Boulder and work eastward and downwards. This could give hurricane-force gusts to Boulder, and then weaken, as the high wind sector seems to fade out. As you can see, varying winds above gale-force (green) to 50kt (orange) are just above ground for eastern Colorado

[Chinook]

There are already a few isolated hurricane-force wind gusts at KBJC (near Boulder), west Loveland mesonet station, and near Colorado Springs and near Pueblo.

KBJC 151745Z 27056G73KT 10SM BKN065 BKN085 07/M14 A2924 RMK PEAK GUST 75
KBJC 151700Z 27035G53KT 10SM BKN065 OVC085 05/M09 A2926 RMK PEAK GUST 70
KBJC 151647Z 32024G41KT 10SM SCT026 BKN065 OVC085 06/M07 A2930
KBJC 151630Z 32024G41KT 10SM SCT026 BKN065 OVC085 06/M07 A2930
KBJC 151547Z 31012G21KT 10SM -RA SCT026 BKN065 OVC085 05/M02 A2933
KBJC 151515Z 28018G35KT 3SM -RA SCT007 BKN012 OVC048 04/00 A2935
KBJC 151445Z 28035G50KT 3/4SM RA OVC012 07/00 A2935

[ValpoVike]

I recorded a 68MPH gust up here at 11:08am.  So far (and thankfully) a rather run of the mill winter wind event up in this part of the foothills.  I think it is perhaps a bit different story from Boulder and points south, like Bailey and Evergreen areas.  It would be interesting to see more reports from down in that area.

 

[smokeybandit]

Barely any wind to speak of here. The front came through and put down nearly an inch of sleet/snow, but otherwise winds were typical

[ValpoVike]

LOL I spoke too soon and clocked 87MPH at 3:25pm.  There is a nice Davis station a bit further up in the neighborhood that hit 93MPH around the same time.  Pretty intense.

[Chinook]

In town in Loveland got peak gusts just over 50mph, but there was a peak wind of 79mph next to the foothills. I didn't watch it a lot. It was a crazy day to watch some storm reports across the country, like 463 convective storm reports, hundreds of non-convective wind reports, and spreading wildfires and dust storms. There was a "Fire Warning" for Russell, Kansas. I hope it didn't hurt anybody! As mentioned before the "PEAK GUST 75" at Broomfield-Jeffco does translate to 84mph!

[Chinook]

improvements in West Coast - intermountain West snow basins. 56% to 79% for Upper Colorado River.

 

[Chinook]

Fort Collins and Loveland today were up to 53-60 degrees, with 61-65 at Longmont. If you look closely at the average temperatures, the days of Dec 20-21 is on average the coldest in our area. Apparently, the lowest amount of sunlight directly correlates to the lowest climate-average temperature. So were were about 13 degrees above average for the high temp, given a value of 56 vs 43. In the East, where I used to live, the lowest average daily temperature was on Jan 19 or Jan 20th, as colder air is always kind of hanging around many days after the Winter Solstice.

[ValpoVike]

12 hours ago, Chinook said:

Fort Collins and Loveland today were up to 53-60 degrees, with 61-65 at Longmont. If you look closely at the average temperatures, the days of Dec 20-21 is on average the coldest in our area. Apparently, the lowest amount of sunlight directly correlates to the lowest climate-average temperature. So were were about 13 degrees above average for the high temp, given a value of 56 vs 43. In the East, where I used to live, the lowest average daily temperature was on Jan 19 or Jan 20th, as colder air is always kind of hanging around many days after the Winter Solstice.

That's really quite interesting.  Up here in the Larimer foothills, there seems to be a real lack of climatological data however my experience over the past 8 years is that mid to late January is typically the coldest.  This is very similar to what I experienced in my years of living in Ohio and Indiana.  I wonder if there is something inherently different (altitude, LOL) in the short distance between Loveland and 7k+ feet up...or if the past 8 years have generally been anomalous up here.  Not the first or last time that I wish there was good climate data up here.

[mayjawintastawm]

6 hours ago, ValpoVike said:

That's really quite interesting.  Up here in the Larimer foothills, there seems to be a real lack of climatological data however my experience over the past 8 years is that mid to late January is typically the coldest.  This is very similar to what I experienced in my years of living in Ohio and Indiana.  I wonder if there is something inherently different (altitude, LOL) in the short distance between Loveland and 7k+ feet up...or if the past 8 years have generally been anomalous up here.  Not the first or last time that I wish there was good climate data up here.

That is really interesting. When I lived in MA (most of my life) it was sometimes even a bit later, like end of January, as the ocean tempered things a little earlier in the season. The Denver climatology curve is really dead-flat in terms of average temps from now through mid-January. Anecdotally, some of the lowest temps IMBY occur later in the season (early Feb) when there is more snow cover, but are balanced by slightly higher highs.