Front Range snowstorm nowcast/conditions 3/13-15

[STILL N OF PIKE]

3 minutes ago, smokeybandit said:

THe pessimist in me expects to wake up with like 2" more than I have now.

That area from Fort Collins into S WYoming (Cheyenne) is cranking right now.  Solid wall of deep greens and yellows intensifying on radar ...hopefully that fills in SW . 

[skierinvermont]

3" here, radar looks to be filling in finally

[AlaskaETC]

The 0Z HRRR plasters the entire area from just south of Casper to Cheyenne. Wide swaths of 30" or more

[mayjawintastawm]

1 hour ago, Chinook said:

Because of daylight savings time, there will no snow between 2:00 AM and 3:00 AM.

But of course! Only time I've ever had to time measurements according to GMT. Geez.

First 6-hr measurement=1.8 inches, though probably another inch since then. Steady accumulation now. Roads are officially slick in DTC.

[STILL N OF PIKE]

29 minutes ago, AlaskaETC said:

The 0Z HRRR plasters the entire area from just south of Casper to Cheyenne. Wide swaths of 30" or more

I think that’s playing out. No real places to stay just  S of The Casper  area . (high mountain  area) while  Casper  and north should see heavy shadowing . Cheyenne looks like money 

IF H5 track is a hair or two south or plays out like 18z gfs then Denver could still crush 

[AlaskaETC]

The 0z 3k NAM nukes the Cheyenne area from 12:00AM-7:00 AM. It is still kind to the Casper area, giving 20-25" verbatim. 

[Heisy]

Still has that damn hole over Estes. Well see

[smokeybandit]

Looks like round 2 is starting to wrap up south to north.

Now we wait the supposed "good stuff" starting in a couple hours.

[ValpoVike]

Finally, starting to crank in Glen Haven.

[MidlothianWX]

Measured just under 4" as round two ends.

[AlaskaETC]

Bit of a dry spot developing on the radar between Casper and Douglas. A bit concerning but I assume it will fill in soon.

[skierinvermont]

4 minutes ago, MidlothianWX said:

Measured just under 4" as round two ends.

same (3.75 20 min ago)

[ValpoVike]

I am going with absolute faith that the massive gap around Denver fills in soon.

[skierinvermont]

Just now, ValpoVike said:

I am going with absolute faith that the massive gap around Denver fills in soon.

haha right, gaping hole. good thing things seem to be moving quickly still

[ValpoVike]

Just now, skierinvermont said:

haha right, gaping hole. good thing things seem to be moving quickly still

Yeah, returns are cranking to the NNW.  Much faster.

[Chinook]

I have gotten about 3" - 3.5" of snow. There are some moderate values on radar, kind of medium dendrites.  I guess it is something. Earlier this week, I would have assumed I would have 10 or 15" by this time in the day.

this better actually happen!!!

[ValpoVike]

It is looking like upslope is finally kicking in based on the pop ups over central/western Boulder County. 

[rockymountainhigh]

Were at about 6-7" so far here - which seems to be in line with the models. off and on heavy and then light. 

[AlaskaETC]

The radar returns look a little dry across the board. I wonder if the convection further east is stealing some moisture.

[Ji]

The radar returns look a little dry across the board. I wonder if the convection further east is stealing some moisture.

Lol sounds like a dc ob smh

[ValpoVike]

Yup, it's made the turn from the east.  This should be really good

 

[AlaskaETC]

1 minute ago, Ji said:

3 minutes ago, AlaskaETC said:

The radar returns look a little dry across the board. I wonder if the convection further east is stealing some moisture.

Lol sounds like a dc ob smh

Cheyenne looks like Jackpotville right now

[Chinook]

The 3-km NAM still has 2.05" of QPF for me, and that's from 00z, not that long ago, so that would be roughly 20" from 5:00PM onward-- and I've only gotten about 2+ inches since 5:00PM.

[ValpoVike]

8 minutes ago, Chinook said:

The 3-km NAM still has 2.05" of QPF for me, and that's from 00z, not that long ago, so that would be roughly 20" from 5:00PM onward-- and I've only gotten about 2+ inches since 5:00PM.

I think you have a shot to get it.  Take a look at the river coming in from the east, this is classic.

[MidlothianWX]

11 minutes ago, Chinook said:

The 3-km NAM still has 2.05" of QPF for me, and that's from 00z, not that long ago, so that would be roughly 20" from 5:00PM onward-- and I've only gotten about 2+ inches since 5:00PM.

Nearly the same story here - 0z has about 2" of QPF for Boulder from this point forward (4-5" are on the ground right now). Weirdly enough there is a 4"+ jackpot just to my SW, maybe around Eldo Springs.

[Wttnwx]

Wind has really picked up here in Laramie.

[ValpoVike]

I25 just closed btwn Wellington and WY border.

[skierinvermont]

22 minutes ago, Chinook said:

The 3-km NAM still has 2.05" of QPF for me, and that's from 00z, not that long ago, so that would be roughly 20" from 5:00PM onward-- and I've only gotten about 2+ inches since 5:00PM.

I noticed that too.. and almost all that qpf was after 03z.

[MidlothianWX]

BOU is still optimistic:

Quote

With these signs as well as reviewing the latest model guidance
and not seeing any huge glaring trend in the models, will keep the
forecast going. Expect increasing snow tonight, with some seeing
rates of 1-2 inch per hour rates across the urban corridor, with
upwards of 3 inches per hour in the foothills and eastern slopes
of the Front Range mountains. Further east onto the plains, snow
will mix with rain the further east you go, with light drizzle far
east. More snow will mix in Sunday morning into the afternoon out
there. Winds continue to be slightly weaker in the forecast and
less of a concern for sharp impacts on visibility, however some
blowing and drifting snow will still be expected.

 

[AlaskaETC]

This from NWS Cheyenne earlier, but this Forecast Discussion is worth reposting -

 

Quote

Area Forecast Discussion National Weather Service Cheyenne WY 458 PM MST Sat Mar 13 2021 .SHORT TERM...(Tonight - Monday Night) Issued at 335 PM MST Sat Mar 13 2021

...HISTORIC AND POTENTIALLY CRIPPLING BLIZZARD ON TRACK TO SEVERELY IMPACT SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE OVER THE NEXT 24 TO 36 HOURS...

A broad area of moderate to heavy snow is quickly spreading across the region this afternoon as vigorous, deep cyclogenesis continues across the 4 Corners region. An impressive GOES-16 WV display with a beautiful baroclinic leaf to support the intense organization of the expansive extratropical cyclone. Snow was very slow to develop today, but recent surface & upper air analyses confirm that models remain on track with the storm position & intensity. We could have a brief period of dry slotting, but radar trends indicate that new precipitation is already beginning to develop upstream due to very intense upper-level difluence. We will definitely see a very brief decrease in snowfall rates this evening, but fully expect snowfall to pick up again during the late evening and overnight hours, with conditions rapidly worsening through early Sunday. Synoptic set up is there for this storm to stall over east central Colorado during the next day or two, w/ a persistent TROWAL & deep low-lvl upslope maintaining heavy snowfall rates through late Sunday. SFC pressure falls are evident over eastern Colorado at this hour, contributing to increased confidence in a favorable position of the surface low for high-end snowfall in the region. In addition, models are still hinting at the development of a strong barrier jet in the vicinity of the front range, making the synoptic setup extremely similar to historical snow storms including the legendary March 2003 storm in this region. High-resolution models and GFS/ECM ensembles continue to show impressive totals of 2-3 feet over the I-25 corridor. This is likely to be a record-shattering storm.

Winds have trended stronger with 700 millibar flow of 50 to 60 kts overspreading the entire area overnight tonight through mid day on Sunday. Deep unidirectional east-northeast flow suggests gusts for many areas in excess of 50 MPH, which prompted earlier upgrades to a Blizzard Warning for all of the eastern plains along and east of the Laramie Range. As strong winds coincide with the heaviest snow rates tonight and early Sunday, this is when conditions will be at their worst. Travel will be extremely dangerous, if not impossible and conditions will be life threatening w/ whiteout conditions for many areas. Power outages are also likely with power lines already stressed due to the icing this AM. Severe conditions will continue through Sunday afternoon with a gradual decrease in winds and snow rates heading into the evening and early Monday.