Mountain West Discussion

[Chinook]

This is the new thread for discussing events in the Mountain West.

Looks like ABQ got 0.40" of rain last night, plus more for the Sandia mountains.

[raindancewx]

September finished slightly wetter than average here with the rains yesterday. Tentative precipitation analogs for Albuquerque, based on July-Sept objective matches are 1950, 1954, 1974, 1983, 2004 as a blend. That's a pretty mixed period for Oct-May - with some dry and some wet months. Matching on the wet September definitely moved the matches to wetter for Oct-May. 

The GFS still has a major low south of Kamchatka on 10/2 in the evening. Have to watch 10/19-10/23 in our area for something pretty big. That's actually pretty close to one of the recurring wet-periods locally (10/18 would be 46 days or so after the remnants of Nora, which followed the mid July and early June rains, and so on). The rain yesterday also followed at a 46-day lag from the mid-Aug and early July and late May rains here. The WPO doesn't flip phases super often, so could be in for a good pattern for a while. The historic snows last October down to Mexico were also fairly close to the 10/19-10/23 time-frame, but the setup looks pretty different even this far out.

[Chinook]

For my area, it was mainly 4.0 degrees F above average, to possibly 5 degrees above average according to this chart.  I believe it was the 2nd warmest September for Fort Collins, and 3rd warmest for Denver. In my opinion, it's an extension of the drought in the north and west this summer. Also, the ridge in the West seems to be a teleconnection with the average trough in the Gulf of Alaska in September.

[Chinook]

mini-rainy season

 

 

[Chinook]

On 10/1/2021 at 6:49 PM, raindancewx said:

September finished slightly wetter than average here with the rains yesterday. Tentative precipitation analogs for Albuquerque, based on July-Sept objective matches are 1950, 1954, 1974, 1983, 2004 as a blend. That's a pretty mixed period for Oct-May - with some dry and some wet months. Matching on the wet September definitely moved the matches to wetter for Oct-May. 

The GFS still has a major low south of Kamchatka on 10/2 in the evening. Have to watch 10/19-10/23 in our area for something pretty big. That's actually pretty close to one of the recurring wet-periods locally (10/18 would be 46 days or so after the remnants of Nora, which followed the mid July and early June rains, and so on). The rain yesterday also followed at a 46-day lag from the mid-Aug and early July and late May rains here. The WPO doesn't flip phases super often, so could be in for a good pattern for a while. The historic snows last October down to Mexico were also fairly close to the 10/19-10/23 time-frame, but the setup looks pretty different even this far out.

 

This seems intriguing.  Perhaps 10/9 might be an interesting day to see what the ensemble averages have for 10/19

[marsman]

Been keeping an eye out for some purple and pink in the NWS map for the lower 48. WWA for the Yosemite, CA area:

Quote

URGENT - WINTER WEATHER MESSAGE
National Weather Service Hanford CA
128 PM PDT Thu Oct 7 2021

CAZ323-080430-
/O.NEW.KHNX.WW.Y.0009.211008T1200Z-211009T0000Z/
Yosemite NP outside of the valley-
128 PM PDT Thu Oct 7 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 AM TO 5 PM PDT FRIDAY
ABOVE 7000 FEET...

* WHAT...Snow expected above 7000 feet. Total snow accumulations
  of 4 to 6 inches.

* WHERE...Yosemite NP outside of the valley.

* WHEN...From 5 AM to 5 PM PDT Friday.

* IMPACTS...Travel could be very difficult in these areas due to
  slippery and snow covered roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

BSO

Snippets from the Reno AFD:

 

Quote

  System for this afternoon and Friday remains on track with the  
  potential for the first round of snow in the Sierra near and above   
  8000 feet. Meanwhile, showers and a couple thunderstorms may kick 
  off over western NV this afternoon as instability increases with  
  the approaching low. Best timing for heavier rain/high elevation  
  snow is late tonight into Friday morning as the forcing mechanisms 
  cross into Nevada. Precipitation chances will continue into  
  Friday afternoon with most activity over Pershing, Churchill, and  
  Mineral Counties. 
   
  ...
   
  Snow levels should remain near 8000 feet as the precipitation  
  band moves into the Sierra. Simulations are leaning towards 2-4  
  inches of snow with localized areas of 6 inches along the Mono  
  County crest if everything comes together. CalTrans is raising  
  travel restrictions for the High Sierra passes this afternoon, 
  main snow impact is to hikers/campers in the backcountry.  
  Rainfall totals across western NV should range from 0.10 to 0.40  
  inch, with localized amounts near and above 0.50 inch. 

 

[ValpoVike]

On 10/3/2021 at 7:01 PM, Chinook said:

This seems intriguing.  Perhaps 10/9 might be an interesting day to see what the ensemble averages have for 10/19

GFS is starting to show something way out at +384, which is a few days later...around the 22nd, with highest impact for NM.  It will be interesting to watch this one as we move out of fantasy land.  

[smokeybandit]

GFS in midseason form with some of its insane snow totals the last couple runs

[Chinook]

5 hours ago, smokeybandit said:

GFS in midseason form with some of its insane snow totals the last couple runs

hey, King Euro had some fantasy snow for me, for one run.

[Chinook]

NWS-WPC 168-hr precip map expecting up to 1" to 1.5" of QPF for western Colorado, and also including upper Larimer County, and 1.0"-2.0" for Wyoming, so possibly high-impact snowfall for areas up near Casper, WY. And, of course, the first snow storm for Colorado for the season, certainly above 6000-7000 ft for the west and central.

[raindancewx]

Date	Tahiti (hPa)	Darwin (hPa)	Daily Contribution	30 day Av. SOI	90 day Av. SOI
9 Oct 2021	1012.98	1009.70	2.51	10.87	9.55
8 Oct 2021	1014.42	1009.50	13.08	11.04	9.69

That supports something around 10/19. Have to see if it drops again tonight. 

 

[Chinook]

Believe it or not, this is an oak tree. Many of the cottonwoods haven't changed to bright yellow yet.

[ValpoVike]

Just a few more days of color to go up here, but I did capture this yesterday looking down from my deck to the North Fork of the Big Thompson.  

[Chinook]

might as well post this. NWS point forecasts for RMNP have 4"-8" at high elevations

[AlaskaETC]

1 hour ago, Chinook said:

might as well post this. NWS point forecasts for RMNP have 4"-8" at high elevations

Nice little early snowstorm for my backyard in Central WY. 

[Chinook]

Interesting weather note this evening. The upper level low over the Southwest is bringing in so much wind, the flags are flying at Dodger Stadium, the likes of which I've almost never seen for a southern California baseball game.

[AlaskaETC]

 

[ValpoVike]

We had 20 minutes of heavy snow and lots of lightning up here this evening.  Love these October squall like conditions. 

[yoda]

 

Mesoscale Discussion 1851
   NWS Storm Prediction Center Norman OK
   0458 AM CDT Wed Oct 13 2021

   Areas affected...Portions of eastern WY...the extreme western NE
   Panhandle...the far western Dakotas...and southeastern into
   east-central MT

   Concerning...Heavy snow 

   Valid 130958Z - 131600Z

   SUMMARY...Moderate to heavy snowfall, with rates around 1-1.5 inches
   per hour, should occur this morning. Near-blizzard conditions are
   also possible with strong/gusty winds.

   DISCUSSION...A mature mid/upper-level cyclone evident on water vapor
   satellite imagery will continue to eject northeastward across the
   central/northern High Plains this morning. A deformation band on the
   back side of the cyclone is beginning to fill in as low/mid-level
   frontogenetic forcing increases. Current expectations are that a
   mostly north-south oriented band of moderate to heavy snow will
   develop over parts of eastern WY/MT into the western Dakotas over
   the next few hours this morning, and gradually shift northward with
   time. Even though low-level temperatures are marginal (generally
   28-33 degrees F), strong cooling aloft associated with the upper low
   should support snow as the main precipitation type. Lift through the
   saturated dendritic-growth layer and consensus of latest
   high-resolution guidance both suggest snowfall rates of 1-1.5 inches
   per hours will likely be common, with locally greater rates
   possible. Finally, near-blizzard conditions with reduced
   visibilities should also occur across this region, as a strong
   pressure gradient and gusty winds will exist on the back side of a
   surface low that will develop northward from NE into central SD this
   morning. Indeed, blizzard conditions have recently been reported at
   KDGW in eastern WY.

   ..Gleason.. 10/13/2021

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...BIS...UNR...CYS...BYZ...GGW...RIW...

[Chinook]

21 hours ago, ValpoVike said:

We had 20 minutes of heavy snow and lots of lightning up here this evening.  Love these October squall like conditions. 

My area had a few minutes of rain, graupel, and lightning, and even thunder somewhat close by. Then, today turned out to be pretty nice, not too windy like Cheyenne.

[finnster]

Our area (Bellvue vicinity) also had 10 minutes or so of rain the other night, but it was over all too soon.  That has been the case going back to late May - I don’t think we’ve had a single precipitation event since then that has been over a quarter-inch or so.  We missed the monsoon showers that were good to the south, and now storms are tracking to the north (Wyo & SD just got dumped on).  We seem to be in no-mans land in between.

Now a bonafide La Niña pattern seems to be getting established - those typically do not bode well for the front range as far as beneficial moisture.  We mainly get wind. The northern mountains can do well with snow though.  We’ll just have to see.

My wife have been traveling around quite a bit the past few months in CO, WY, and SD.  I don’t need to tell anyone this, but it is so dry out there - reservoirs are WAY down and streams in many cases are all but dried up.  It will take a sustained, very wet period to restore fresh water supplies, that’s for sure.  And to start healing all the forest fire damage from the past two decades….

[smokeybandit]

Got our first snowflakes of the season, but just too little too fast to even attempt to accumulate

[ValpoVike]

Today marks the 1 year anniversary of Cameron Peak making it's final big run (and the start of my 3 week evacuation), as well as the start of the East Troublesome fire.  What a difference a year makes.  We actually had a decent monsoon up here this year, which was very fortunate as we were trending the same direction as last year before it kicked in.

[finnster]

16 hours ago, ValpoVike said:

Today marks the 1 year anniversary of Cameron Peak making it's final big run (and the start of my 3 week evacuation), as well as the start of the East Troublesome fire.  What a difference a year makes.  We actually had a decent monsoon up here this year, which was very fortunate as we were trending the same direction as last year before it kicked in.

Yea we were evacuated for a week a year ago as well.  I feel like our immediate area is as dry as last summer but fortunately no fires (most everything around has burned already ).

it’s interesting that as the crow flies we’re not far from Glen Haven but have missed the summer precipitation you were fortunate to get….

[ValpoVike]

55 minutes ago, finnster said:

Yea we were evacuated for a week a year ago as well.  I feel like our immediate area is as dry as last summer but fortunately no fires (most everything around has burned already ).

it’s interesting that as the crow flies we’re not far from Glen Haven but have missed the summer precipitation you were fortunate to get….

It was a mixed blessing.  We had 13 flash flood warnings during the Monsoon season, due to the burn scars.  Are you up near Horsetooth?

[Chinook]

mountains partially clouded (Wednesday)

 

 

[finnster]

On 10/15/2021 at 9:23 AM, ValpoVike said:

It was a mixed blessing.  We had 13 flash flood warnings during the Monsoon season, due to the burn scars.  Are you up near Horsetooth?

Yes we’re west of the north end of Horsetooth, right next to Lory State Park.

[Chinook]

Here are some more maple leafs. Well, not Toronto Maple Leafs. 2nd picture: ash. 3rd picture: some type of bush where the leaves resemble maple leaves.

 

 

 

[Chinook]

On 10/9/2021 at 12:47 PM, raindancewx said:

Date	Tahiti (hPa)	Darwin (hPa)	Daily Contribution	30 day Av. SOI	90 day Av. SOI
9 Oct 2021	1012.98	1009.70	2.51	10.87	9.55
8 Oct 2021	1014.42	1009.50	13.08	11.04	9.69

That supports something around 10/19. Have to see if it drops again tonight. 

 

It's now 10/17. And Raindance was... right. A compact 500mb low is cutting off right now near the Sierra Nevada, and will track through Wyoming, bringing snow to some areas of the Sierra Nevada to Wyoming. Winter storm watch for some areas of Wyoming

[raindancewx]

It's forecast to be a 999 mb low at the surface on one of the models I saw. Not too bad really. I think with the PDO so negative at the moment a lot of these "Bering Sea" translations are going to be somewhat north of where they would be normally in the West, although the jet shifts south with time.

From the local NWS - 

Strong winds aloft rounding the base of an eastward moving upper low, currently over south central NV, will overtake our area tonight
into Tuesday morning as the low continues east into CO.

Breezy to windy conditions are developing across our area ahead of the upper low, as a lee side trough deepens to 999mb at the surface.

My matching precipitation analogs to each month of July-June 2020-21 in Albuquerque did pretty well for the monsoon (I created a blend that was within 0.2 inches of observed precipitation each month for an entire year, and rolled it forward). Will be curious to see how that continues or breaks. Years included 1937-38 for 2020-21, so 1938 had the hurricane hit on New England, similar to this year. Have to see if I can find the image I have of that blend somewhere.