December 2020 Observations and Discussion

[Niko]

Hard to believe that Montreal, CA on Christmas Day will be in the mid to upper 50s w rain, just unreal!

[Clinton]

5 minutes ago, james1976 said:

Nice bullseye right over me

I got one of those too but in my case I'm afraid I'm going to have a significant amount of freezing rain and sleet I feel like I've seen this kind of setup before were the cold air gets trapped in but it's not deep enough to keep precipitation type of snow time will tell still lots of days to go.

[Niko]

8 minutes ago, Clinton said:

I got one of those too but in my case I'm afraid I'm going to have a significant amount of freezing rain and sleet I feel like I've seen this kind of setup before were the cold air gets trapped in but it's not deep enough to keep precipitation type of snow time will tell still lots of days to go.

Exactly bud. Many, many more models run to go, but If I were to guess, unless we get a GB going, this (for my area at least) looks to be a rainer.

[The Snowman]

6 hours ago, gabel23 said:

Euro with a record breaker for us if this came to fruition. 

Worth noting that the Euro will be upgraded in May 2021, and this upgraded version is running parallel to the operational. Parallel ECMWF attached, more or less in line with the operational one

 

Edit: note 10:1 ratios on this chart

[dubuque473]

DVN has me down for a 50% chance of snow already on Dec 30th...

[bud2380]

ICON has joined the north/warm camp 

[Clinton]

9 minutes ago, bud2380 said:

ICON has joined the north/warm camp 

Looks like it splits it into 2 pieces, looks funny to me.  Unless another model comes out with a similar solution I would scroll past this run.

[The Snowman]

4 minutes ago, Clinton said:

Looks like it splits it into 2 pieces, looks funny to me.  Unless another model comes out with a similar solution I would scroll past this run.

Unrelated but the ICON also has a low on Christmas morning here of -5, a solid twelve degrees colder than the NWS model blend and even more extreme relative to the GFS & ECMWF. Anyone have any performance stats from the ICON by chance?

[Clinton]

2 minutes ago, The Snowman said:

Unrelated but the ICON also has a low on Christmas morning here of -5, a solid twelve degrees colder than the NWS model blend and even more extreme relative to the GFS & ECMWF. Anyone have any performance stats from the ICON by chance?

Hasn't been good this year outside of 72hrs.  Has been know to sniff out a trend in the past.

[clintbeed1993]

4 minutes ago, The Snowman said:

Unrelated but the ICON also has a low on Christmas morning here of -5, a solid twelve degrees colder than the NWS model blend and even more extreme relative to the GFS & ECMWF. Anyone have any performance stats from the ICON by chance?

 

It's REALLY bad

[The Snowman]

3 minutes ago, Clinton said:

Hasn't been good this year outside of 72hrs.  Has been know to sniff out a trend in the past.

 

2 minutes ago, clintbeed1993 said:

 

It's REALLY bad

Found statistics from the CMC and ... yeah, not ideal.

24-hour RMSE isn't too bad relative to other models but 120-hour RMSE puts the ICON at accuracy levels of the JMA(!!)

[The Snowman]

Just now, The Snowman said:

 

Found statistics from the CMC and ... yeah, not ideal.

24-hour RMSE isn't too bad relative to other models but 120-hour RMSE puts the ICON at accuracy levels of the JMA(!!)

Last bit on this; a better view of RMSE for the month of November 2020 over forecast hours is attached, also from the CMC ... ICON definitely not ideal in timeframes beyond a day or two. Fascinating how the JMA apparently had slightly better verification in November than the ECMWF(!) from the 180hr - 216hr window.

 

 

[Hawkeye]

The GFS doesn't look any different than the last couple runs.

[The Snowman]

Perhaps not in the best taste to analyze model runs before they fully come out, but in any event I'm noticing the 0z GFS is a bit weaker & more detached with a piece of energy stringing on the tail end of our main system at the 120hr mark.

In the 18z run (attached) note that minor vorticity maxima in the Pacific Northwest; this eventually follows the main energy south and east and - at least in the 18z run - seemed to keep the trough a little more positively tilted. Wonder if more separation between the main trough & this secondary vorticity max could let the system dig a little more. Thinking out loud. 

[The Snowman]

0z GFS a tick north at hour 141 compared to the 18z as it brings that 996mb low into Kansas

[bud2380]

GFS still too far north for comfort here. Northern Iowa does well. 

[bud2380]

GFS has the low eventually tracking through Iowa. 

[Clinton]

5 straight runs the GFS has trended faster with the storms arrival.

[bud2380]

Not sure I’ve ever been more concerned or disappointed in a model showing about 10” for my backyard. I just have a bad feeling the trend will continue north. 

[james1976]

11" in mby by midnight Tuesday night at 10:1

[Money]

GFS trended stronger with the first wave for eastern WI and MI.

3-5 or so with that system 

[GDR]

[clintbeed1993]

That north nudge can stop any time. Getting way too close for comfort for Interstate 80 peeps

[bud2380]

Canadian stays further south than the gfs. 

[bud2380]

[Minny_Weather]

C'mon man. Next week's storm needs to move North.

Now I know how Sioux City felt during 2018-19, holy hell. Brown grass while everywhere North and South was measuring snow by the foot.

[The Snowman]

2 minutes ago, bud2380 said:

Brutal gradient for Nebraska but what a gift for southern Iowa if it were to verify verbatim

[The Snowman]

As far as I can tell by the snow footprint thru hour 162, 0z GFS ENS seem more or less the same as the 18z collection, built some more snow back in southwest NE into KS

[Niko]

Attm, getting some light spotty showers and its breezy as well. Turning colder tanite w snowshowers by morning.

[Clinton]

12z GFS mean.  Still a lot of spread among members.

[Niko]

3 minutes ago, Clinton said:

12z GFS mean.  Still a lot of spread among members.

#31 hammers your area amigo. It really destroys you. Hope that verifies for ya.

[Clinton]

5 minutes ago, Niko said:

#31 hammers your area amigo. It really destroys you. Hope that verifies for ya.

Thanks, I wish there was some artic air near by.  My gut says this guy goes north.

[Niko]

9 minutes ago, Clinton said:

Thanks, I wish there was some artic air near by.  My gut says this guy goes north.

I agree w you 100%. We need that GB to strengthened. We still have a few days to track this, but I could see this taking different paths. Tbh, my area is looking risky as well. Could go from snow (getting some accumulations ) to a cold, hvy rain or ice mix.

- I remember past Winters when there was deep arctic air in place and at the same time a snowstorm was brewing. Then, a couple days later, after a few days of sunny weather and frigid temps, another snowstorm followed. Now, that is what Winter should be like.

- Gotta admit, best part is seeing the clouds develop ahead of a major snowstorm, especially, when they lower and thicken, along w frigid temps.

[The Snowman]

Guess I'm staying up for the Euro, imagine my poor coffeemaker is gonna be running nonstop over the next few days...

[Stormy]

51 minutes ago, bud2380 said:

Perfect for me.....for now! Lol

[Hawkeye]

The UK is now getting into range and it's also warm.

[The Snowman]

2 minutes ago, Hawkeye said:

The UK is now getting into range and it's also warm.

South & weaker at hour 144 compared to the 00z GFS too (1000mb low vs 996mb; in northwest OK vs. northwest KS).

[bud2380]

The 850s on the UK are by far the warmest of the models so far. 

[The Snowman]

00z Euro coming out guns a-blazing at Hour 138 in terms of precipitation amounts compared to 12z

[Grizzcoat]

Euro seems to be a little cooler this time with thermals-- so far through 156