mayjawintastawm

13 hours ago, Chinook said:

Snow with a weak disturbance, with winter storm watches/winter weather advisories above 6000 ft

 

Yawn. (except for the far northeast plains) Even the mountains only get an advisory for this one. Wake me when severe season starts. 

42 minutes ago, Chinook said:

I think they said 2ft-4ft for the Sierra summits. It has mostly already happened.

Point and click forecast for the middle of Lake Tahoe this afternoon was somewhere between 50 and 90 inches for the entire storm, including 3-4 feet tonight. Wow. That's like 3-4 inches an hour for 12 straight hours. 

5 minutes ago, katabatic said:

Airbnb…and a wide open wallet. 

Pics or it didn't happen. But stay safe!!

Cherry Creek Lake is now ice-free (after a low of 11 F this AM), pointing out just how little cold we had in February. Not a top 20 warmest for Denver so far (we could just squeak in depending on temps today and tomorrow), but no sustained cold to keep the ice around. A pair of bald eagles was fishing this afternoon.

And this AM it was 44 at 7:30, 31 at 7:40, and 23 by 8:30. We got a neat 2 inches of snow in an hour and a half, bringing my monthly total to 14.1" and season to 36.4", just average for this date. Not bad for a weird mostly warm regime.

5 hours ago, Chinook said:

There are lots of watches warnings, and advisories. It is snowing, windy, or on fire. Maybe half the country is on fire. We are not sure.

 

 

In Colorado it can sometimes be snowing, windy, and on fire all at the same time. Maybe even all in the same place.

6 hours ago, Chinook said:

Here is the precipitation percent of normal and snowfall percent of normal since the beginning of December. From the recent storms, the snowpack snow water equivalent is above normal for the Southwest and below normal for the northern Rockies.

Wow, look at the Mid Atlantic/Northeast and Minnesota. Shows just how warm it's been... wet but not snowy at all.

Was away and nobody at home measured, but averaging the two closest COCORaHS sites we'll call it 4" for a total over the two days. that was a weird "storm".

Nobody's really talking about it, but forecasts have been pretty consistent the last 24 hrs giving much of the Denver metro around 6 inches of snow Friday night through Saturday night. Of course I'll be away at a conference in soggy CA...

And now the Mother of All Dryslots is plaguing most of CO except for a very narrow band along the foothills. It's like the storm is 70% dryslot. So weird. 6 inches on the nose, probably 1" WE when you include the rain.

1 hour ago, smokeybandit said:

About 4" so far. Back end of the storm already well in sight though. Doesn't seem like any more than 2" left

I don't know. That band that pivoted west and is pummelling the west C-470 corridor now has to come back east at some point as the energy inches south and east later. 3" here as of 11:30, an inch an hour average. I'm guessing we'll wind up with 8-9" when all is done, you may get 10".

Just mixed then flipped from rain to snow here at 5650' as the temp dropped from 35 to 33 in the last half hour. 0.31" rain before the change- more rain than we've seen since October!

OK, looking at pivotalweather before bed, 00Z GFS gives me 14", NAM 11", GEFS 9" and SREF 4". Huge differences within 5 miles or so. This is getting interesting. Light rain here now, 41 F.

Squinting to the point I'm getting a headache trying to resolve the street-by-street gradient on the 12z model output. It looks like both the GFS and NAM give me 4" of snow, with GFS higher in QPF (1"+ compared to 0.8").  At least the QPF is getting more consistent across what models I can see. I don't think we'll get skunked with precip. Vertical motion and upslope will tell. A barrier jet would be nice, though I think the last time we had one of those it was so tight against the foothills that only places within 10 miles of the hills (Littleton, Golden, Boulder) got a lot.

11 hours ago, GansettBay said:

This will be my second winter in Boulder. I have seen some of the heaviest snow rates in my life since moving here, but I think we only had one storm hit around a 9" total and nothing above 7" since then. 

I know that temperature is going to be a big issue with this one as well. Is there any shot that the models are overestimating the warmth or is our best hope for this storm to happen at night?

You might be in a key position to illustrate the variability around Boulder and in Boulder County. As Chinook said, most measuring sites around Boulder tend to report jackpots- BUT they are likely west of US 36. I bet there is often a big gradient SW-NE across town. I wonder if Longmont has a reliable long-term measurement anywhere.

To answer your question, I suspect both answers are right. The BOU AFD this morning is a good read.

And honestly, big dumps are pretty uncommon. A 12" snowfall happens about every other year in areas below about 7000 feet. It's the 1-2-4" that add up to the average of 50-60 inches.

A guy named Steven over on Weather5280 looked at all precip events >0.4" water during Feb 1-20 at the Stapleton site over the last 75 years. Exactly zero of 16 were all rain, and the lowest snow/water ratio was 8. So two messages from that: this is indeed unusual, and we still are not at the time of year for big dumps yet, as ValpoVike says. I'm guessing that in RI, there were probably 100 events >0.4" water over that same time period 1948-2023 and probably half were all rain. (I lived in RI 1983-1987 so I get it too). But I'm not going to talk about the Blizzard of '78... 

27 minutes ago, GansettBay said:

Would you kindly elaborate on these thoughts for a layman such as myself? I moved to the Front Range from the Northeast a couple of years ago and miss the highly detailed weather discussions in those forums. Nice to see that there's a few of you on here though!

Welcome! Basically since there isn't as much measurement in the middle of the Pacific, it's harder to tell the fine details of upstream weather that feeds into the prediction models. But Chinook is a real met and could be more specific.

At least around here we don't have to worry as much about rain/snow lines with winter storms... except maybe for this one. Might be a Spring-like elevation storm. My biggest take-home message about winter storms since moving from central MA in 2010 is that QPF can magically go "poof" and vanish at the last minute. Dryness is a bigger enemy than marine warmth. Then, of course, you get things like the storm last May that dumped 6 inches of rain in 30 hours at my house.

What do folks think in terms of this idea of rain vs. snow? I've not experienced significant rain in Dec-Jan-Feb in my 14 winters here; then again, we haven't had a strong El Nino since we moved. Any kind of upslope before mid-April has always meant snow. The forecasters at Weather5280 are skeptical of rain at this point, favoring mostly snow for most of the Front Range areas.

23 hours ago, ValpoVike said:

I just saw that too.  The Euro in particular has some crazy accumulations. 

I have a feeling in my bones....

No actually, I need to decide whether to ski tomorrow (bluebird skies, probably no powder but decent conditions) or a day next weekend (chance of huge powder, also possible horrendous traffic and no visibility).  I know the best answer is "both" but that's not really an option.  Good problem to have, I suppose.

2.0"/0.14" at my house, pretty nice compared to predicted. Looks like we'll have 5.4" total for the month and 22.3" season to date. Come on, February!

8 hours ago, smokeybandit said:

I love me some fantasyland GFS

 

Could happen... nah.

Might be fun for some bored mets to add up long-range snow totals from the GFS (say, hour 240 and bigger) in different places over a winter and see what happens. Tens of feet, I'm sure.

On a more serious/scientific note, is there a point to these super long-range forecasts? Are they just a starting point for model improvements to see what happens year over year? I'd guess there are some poor souls up in Boulder or somewhere tasked with improving the GFS at hours 240-384.

It would be nice to have something in between the very broad-brush probabilistic outlooks for temp and precip that CPC creates and the super-precise but completely unreliable model outputs we get. (also the CPC outlooks page looks like it hasn't been redesigned since the last millennium).

I've been out of town this whole time, was planning to fly back this evening but flight canceled - grr.

will have to make do with the archive of my thermometer and snow estimates from COCORAHS. Looks like 1.3" total from the whole event. Anyway, kudos to all who managed this crazy cold.

5 hours ago, smokeybandit said:

I have only been in Colorado for 4 winters so far, but that snow was the lightest and fluffiest I've seen here. Which is good since I found drifts 18"+ I had to take care of

A year or two ago I had 3" of fluff in my driveway that I was able to move by getting down on my knees and blowing. That was probably 30-40:1. Ridiculous.

15 hours ago, smokeybandit said:

This snow is going to be impossible to measure due to the wind. Some spots I have nothing, some spots 6+ inches.

My picnic table is affected a lot by NW winds and was mostly scoured clean. Best average I could find around here poking around with my ruler was 2.1". Probably 15:1 ratio. COCORAHS spotters were pretty consistent around 2.5" south, east and west of here by a few miles, so I'd trust this.

9 hours ago, Roger Smith said:

Snow situation much improved here now, 10" fell on Saturday and another 1-2" today, 15-20" reported in alpine ski areas. Full operations possible for first time this winter ere. Temp around 28 F. 

Great news. My home area (Loveland) still is only 20% open and maybe will get another 5-6" by next weekend, an inch at a time. Still waiting for more than dust. All the energy keeps going south and east. Good thing I'm planning an East coast trip to visit relatives next weekend- will experience their bulletproof glacier by Friday with a foot and a half of snow today followed by 2.5" rain on Wednesday then a freeze-up. Don't miss that a whole lot.