Mountain West Discussion

[raindancewx]

https://xmacis.rcc-acis.org/

That's where the data is. It's pretty poorly maintained for a lot of sites, but it's generally very good for the airports and other major spots.

[Iceresistance]

1 hour ago, ValpoVike said:

Or super overcooked right up to the final days....like what it did last spring in the 90"+ storm for the Front Range that turned out to be 2'-3'.

Yeah, I can confirm that this also happened when the GFS-Para existed as well.

[Chinook]

2 hours ago, Iceresistance said:

Yeah, I can confirm that this also happened when the GFS-Para existed as well.

We're using the GFS, which used to be the parallel-GFS. They were testing out the new computer code, but now it's the operational one. Not sure if there were any bug-fixes which would have made the crazy 30" snowstorms go away. 

I personally think the models have been all over the place with weather patterns at 7 days+. So good luck trying to find a fantasy snowstorm. There may be some. The two good things about Mountain Standard Time now are: more light at 7:00AM, and the evening models come in 1 hour earlier, so the 00z NAM-12km should be partially done by 7:30PM, 00z GFS, maybe 9:00 and later.

[raindancewx]

The local NWS was talking about the "convection near 10N/110W" today...and when I looked I saw it and got excited. But then I remembered it's a tropical depression / remnant low. Don't really agree that this is a moderate La Nina either. It's pretty weak, and the warmth below the surface is already pushing into western Nino 3.4.

I did have a big pattern shift in my winter outlook for mid-November, and I do agree a pretty big change is likely in the 11/15-11/20 time frame. Conceptually, we've had good rains and good cold shots here every 46 days for the 9/30-->8/15-->7/1 ish time frame, works into May too. So next shot is ~11/16 ish. When I see good rains, I mean 0.10"+ at each 46 day interval. I had modeled November after August - and August started with a hot West / cold East look, similar to what we've seen this month. Will be curious how if the later August look, which got pretty cold in the Northwest actually verifies. CPC certainly has that.

The high and dry weather continues through next weekend but there
are signs of major changes toward the middle of next week. The
anomalous deep convection near 10N and 110W is a very good sign
(drawing the storm track southward) not just for next week but for
the winter in general. November climate models runs are out and
they are more encouraging with regard to precipitation for DJF given
a negative PDO and moderate La Nina. A comprehensive winter outlook
will be released via social media and on weather.gov/abq later this
week.

[Chinook]

Models/ensembles now showing some version of a change to colder temperatures around 11/17-11/18.

[raindancewx]

More than the dryness, I hate how boring La Ninas are.

I'm relatively optimistic that these giant lows / 'atmospheric river' events will eventually translate further south around the Christmas to mid-February time frame and that we'll see some rain/snow pretty deep into the Southwest. 

Fall has actually annoyed me too. The analogs I had showed several hurricanes hitting Mexico, but the WPO / trof positioning was in the right phase to not shunt the moisture to Texas like we had several times this year. All that moisture went to waste.

[finnster]

As if we haven’t seen enough records broken for heat/drought in recent years on the front range here’s more:

-Denver’s latest first measurable snowfall on record is Nov. 21, and that could broken this year.  Boulder also has not yet received its first measurable snow and latest date on record is Nov. 19.  

Fort Collins did receive its first measurable snow in October but only by a whimper - .4”

-I saw this past Sunday Denver reached a high of 80 degrees, the second highest temp ever recorded in November (it reached 81 in November 2017).  It looks like temperatures are really going to warm up early next week (into the 70s), so who knows we may not be done with 80 degree temp yet….

Was hoping to start seeing signs of climbing out of this drought but it is getting worse not better 

 

 

[TugHillMatt]

23 hours ago, finnster said:

As if we haven’t seen enough records broken for heat/drought in recent years on the front range here’s more:

-Denver’s latest first measurable snowfall on record is Nov. 21, and that could broken this year.  Boulder also has not yet received its first measurable snow and latest date on record is Nov. 19.  

Fort Collins did receive its first measurable snow in October but only by a whimper - .4”

-I saw this past Sunday Denver reached a high of 80 degrees, the second highest temp ever recorded in November (it reached 81 in November 2017).  It looks like temperatures are really going to warm up early next week (into the 70s), so who knows we may not be done with 80 degree temp yet….

Was hoping to start seeing signs of climbing out of this drought but it is getting worse not better 

 

 

So when you guys get these warm periods, do you have any flowers/plants that rebloom/start budding, or are most of the plants of an adaptation that they just go dormant for good for the winter? I would imagine you might have some deciduous plants that don't lose their vegetation completely even during the winter?

[Chinook]

20 hours ago, TugHillMatt said:

So when you guys get these warm periods, do you have any flowers/plants that rebloom/start budding, or are most of the plants of an adaptation that they just go dormant for good for the winter? I would imagine you might have some deciduous plants that don't lose their vegetation completely even during the winter?

maybe only some very specialized backyard stuff. Otherwise soil moisture is low. I don't think any trees like to do any flowering in November. They could get fooled by weather in March and April, as frost can come after 80 degree temps.

Sunset 11/12

[smokeybandit]

GFS wants to bring in a big cold blast and widespread snow for post-Thanksgiving

[raindancewx]

Fairly optimistic for a storm now. SOI crash, but also models consistently showing a good storm moving into Southern California and then moving east. The storm going into California looks right...not sold on the path at all this early.

[Chinook]

Today, my area was over 65 degrees after midnight, it cooled down at random times in the morning hours, then got to 70 degrees with scattered clouds/ lenticular clouds. Now it is 50 degrees.  I kept looking for a possible lenticular picture, but I have nothing to show for it. I was busy at sunset, which would have been a good time to take a picture. Typical high/low is 53/26. As mentioned by RaindanceWX, the daily SOI value has dropped to a negative value. I have not followed this much, but seems to be correlated with something going on in the subtropical jet stream in several days (10 days?) Maybe hard to get a subtropical something-or-other going during a La Nina. GEFS means show not a whole lot of reason to believe in sustained upper level troughs in the West.  Also, not too much QPF by any model in the near future. Well, maybe the 12z Canadian came up with something crazy, but that's about it.

[raindancewx]

The Euro run from this morning had a lot of precipitation in the day 8 and day 9 period for New Mexico. GFS has naturally backed off. Canadian is in between.

At this point, it's essentially day 7.5-8.5, and day 8.5-9.5, so still far out. We're about due for something I think down here. Long-term, from 1950-2020, the ACE index is pretty correlated to Nov-Jan precipitation in the Southwest (r-squared is about 0.13 for the 70-year period).

As much as I like the very dry 2017-18 as an analog for winter, we ran 80 ACE points less than that year. So a 96 day period in Albuquerque, or a five month period in Amarillo without measurable precipitation was never super likely to happen. When I ran the data locally, the hottest Septembers (+2F high or hotter) in the past 100 years tend to see a wet month in October-December, and the strongest signal is November. This is true even in non-El Nino years. It was about a 75% (3:1) setup for one (or more) wet months in Oct-Dec after a hot September.

Conceptually, the drop from 11/14-11/15 favors a big system around 11/25, which is what we have above. The drop from 11/13-11/15 is pretty massive too actually.

Date	Tahiti (hPa)	Darwin (hPa)	Daily Contribution	30 day Av. SOI	90 day Av. SOI
16 Nov 2021	1012.45	1009.25	2.03	6.11	9.19
15 Nov 2021	1010.86	1009.05	-6.81	6.70	9.13
14 Nov 2021	1012.05	1008.05	7.12	7.88	9.19
13 Nov 2021	1012.51	1007.50	13.55	8.36	9.16
12 Nov 2021	1012.61	1007.40	14.82	8.47	9.01
11 Nov 2021	1013.19	1006.85	22.01	8.46	8.80

[Chinook]

 

 

 

 

 

[raindancewx]

1 hour ago, Chinook said:

 

 

 

 

 

You know Chinook, there are platforms to sell custom amateur photography. You could make some decent money. I'm invested in a lot things, but at one point I was looking at a contributing seed money for an early state company in need of capital on one of the crowd funding sites for young companies.

In the meantime, the Euro, Canadian and even GFS are all still showing some kind of storm in the same time frame as yesterday.

[mayjawintastawm]

On 11/12/2021 at 9:39 PM, TugHillMatt said:

So when you guys get these warm periods, do you have any flowers/plants that rebloom/start budding, or are most of the plants of an adaptation that they just go dormant for good for the winter? I would imagine you might have some deciduous plants that don't lose their vegetation completely even during the winter?

It takes a certain length of time of freezing weather (? weeks) to reset the clock on most plants. They are vulnerable if it freezes very hard (<15 F soon after the 60s) in the fall, or if there is a warmup followed by a hard freeze in April/May. This happens with some regularity. Between that and chronic dryness, the Front Range is a tough place to be a tree. On the bright side, this past Spring's moisture and lack of hard freezes produced some of the best fruit crops in many years... apples from our tree are still in the fridge.

[ValpoVike]

Tonight a weak mountain wave has developed overhead and has been reforming continuously.  The full moon makes it an even more amazing sight. 

[raindancewx]

Do I get a cookie Chinook?

[n1vek]

This is getting depressing.

[Chinook]

22 hours ago, raindancewx said:

Do I get a cookie Chinook?

Of course, it's 70 degrees at a couple of spots around Denver, because it has to be. And it's nice to go outside.  After several months of drought in the West, and there's not a cold pattern at all. Upper level trough: minimal. Precipitation: yes, some. Return to warmth: yes.

[raindancewx]

1 hour ago, Chinook said:

Of course, it's 70 degrees at a couple of spots around Denver, because it has to be. And it's nice to go outside.  After several months of drought in the West, and there's not a cold pattern at all. Upper level trough: minimal. Precipitation: yes, some. Return to warmth: yes.

I had 2017 double weighted for this winter - take what you can get. I did try to cool it off though, 11/2017 was a +9F month here.

[mayjawintastawm]

I'm beginning to think "above normal precipitation" means a relative humidity of 50%. Heck, I'd be excited for a little frost at this point.

[smokeybandit]

The GFS amuses me.

 

12z had a huge snowstorm next weekend affecting 1/3 of the country.

 

18z it was gone except for light snow along I25

[n1vek]

4 hours ago, smokeybandit said:

The GFS amuses me.

 

12z had a huge snowstorm next weekend affecting 1/3 of the country.

 

18z it was gone except for light snow along I25

Just assume the dry scenario will play out.

[raindancewx]

The recent SOI crash has been showing as a decent storm around 12/7 for a while now. Canadian also has a fairly active December. Might be too far south for Colorado to cash in though.

[Chinook]

Hey, I found something that looks like a moderate snowstorm for Wyoming and the mountains of Colorado.

[Chinook]

11/29

 

[mayjawintastawm]

As my wife's Brooklyn relatives would say, looks like a flying sorcerer.

[n1vek]

A lot of the ski & weather social-media accounts are getting onboard for a nice pattern change/stormy December. Operational models, ensembles, teleconnections are supporting the idea. 

One more weekend of mountain biking at elevation and then hopefully it is ski season.

[Chinook]

record breaking in Montana

Quote

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT


...RECORD WARM MAXIMUM TEMPERATURES FOR THE MONTH OF DECEMBER...

LOCATION           NEW RECORD    OLD RECORD    DATE SET  RECORDS BEGAN
GREAT FALLS APT        69   (TIED)   69       12/05/1939     1886
HELENA                 70            64       12/27/1980     1866



...RECORD WARM MAXIMUM TEMPERATURES FOR METEOROLOGICAL WINTER...

NOTE: METEOROLOGICAL WINTER IS DECEMBER 1 THROUGH FEBRUARY 28/29

LOCATION           NEW RECORD    OLD RECORD    DATE SET  RECORDS BEGAN
HELENA                 70            69       02/24/1995     1866