Wednesday Speedy Storm Update

12:30

I am geeky enough that even when storms come in unfavorably, I like to see how the models and maps handle them. Will start with the radar and compare that to how the Hi-res model did this morning. We compare actual radar to model simulated radar.

Actual

Screenshot 2018-12-12 at 12.23.33 PM.png

Model simulated for 1 pm

121212zWRF

Next, surface maps. Usually chaos…

TWC

Screenshot 2018-12-12 at 12.13.44 PM

WU

Screenshot 2018-12-12 at 11.58.25 AM

Screenshot 2018-12-12 at 12.26.14 PM

It never ceases to amaze me and frustrate me how far apart these maps always are. If you have followed for a while you have heard me talk about this countless times before. I usually default to WU.

Back to the HiRes model as it takes us through the afternoon.

2 pm

2pm

4 pm

 

4pm

5pm

6 pm

6pm

8 pm

8pm

This all looks a lot better on radar, keep in mind most of the snow won’t fall to the ground. All said and done it looks like this.

hires_snow_colorado_25

I still have my eyes open in case something pops up and will post if I see it. It would not be the first time did, in fact, I think it would be the first time something anomalous didn’t pop up before or after.

 

 

 

Speedy Storm

1:30 pm

Before I give you the info on this fast-moving storm, what do you want me to cover between storms? We have a pain in the butt lull coming up, it was about a week ago as all of the doom and gloom was coming out, that I mentioned we may actually be in for a bit of a warm-up before the end of the month. We may have 10 days of a bad pattern. These things can change pretty quickly, so don’t sell your snowblower.  So let me know in comments, here on the page or the FB post what you want to read about. If there is a  consensus then I will cover that topic if not I will choose some.

So it is likely that sometime in the afternoon tomorrow that storm is going to pass through the northern forecast area. As I mentioned yesterday, the models are planning on rewarding the Telluride-Red Mountain-Ouray triangle with this system with 2-5″, but there may be some surprises. We also don’t know if there will be any ripples prior to or after the storm.  The earliest I may know is with the morning run of the WRF HiRes model. Or, with Step 1. If we don’t I would say Purgatory would be very lucky to get 1 or 2″.

GFS

121112zgfs

Euro

121112zeuro

WRF

wrf121118z

 

 

Slight Jet event possible

5:30  am

Yesterday I mentioned flurries for today from Purg to Red Mountain. It looks like the jet and moisture could mix with the jet over the next few hours and trigger a more widespread event, I still don’t anticipate accumulations, but let me know if you are seeing anything in your area.

Low impact storm

You may have read that a storm is on the way,  you may not have read that it is not coming in favorably for us.  It is going to come in and ride along the ridge in the Pacific Northwest. We need our storms to come in from the southwest, or Central California, or if they come from from the Pacific Northwest we need them to dive south in Nevada or Western Utah. None of these things are likely to happen. At the moment the timing for this system is Wednesday afternoon/evening. However, there is a small system crossing  Idaho today that the models project will split when it reaches northern Wyoming, a small piece of this system could set off some flurries tomorrow from Purgatory to Red Mountain, if this occurs, I do not expect any accumulation. On Wednesday the stronger storm will be moving into the area. Northerly and Northwesterly flow will accompany the storm as it passes through. If this occurs as the models show at the moment, this is a 1-2″ for Purgatory (if we are lucky). Telluride and Red Mountain to Ouray could get 2-5″ but there could be a surprise if the flow is more Northerly.

Here are the projected totals:

GFS

121012zgfs

Euro

1210euro12z

Nam (low-resolution WRF)

121012nam

Could we have another “not storm” out of this?  Too early to tell, just remember Step 1.

Interesting week ahead

Noon

The models have been inconsistent on the week ahead. There is a reason, let’s go back to the MJO. If you are new or don’t remember my past references to it, the Madden-Julian Oscillation is a tropical disturbance that moves clouds, winds and precipitation and pressure changes eastward around the global tropics about every 30-60 days.

It has a huge effect on our weather, especially in the winter. There are phases in the MJO cycle and models predict where the cycle is headed generally 14 days in advance.  Below are the MJO forecasts form the US and European Models. The numbers 1 through 8 correspond to the 8 phases of the MJO cycle. The red and purple lines are the past, the green line with black dots is the forecast for the future.  The black dots on the green line are days  You literally have to count the dots on the green line because only the past dates are listed (on the purple and red).

GFS

GFSmjo129Capture

This is a fairly confident forecast. If you follow the bright green line, you see we are leaving phase 2 and heading into phase 3. I circled3 dots on the line, that is December 12th-14th. That is a moderate phase 3, you then see it diving into phase 4 and towards that circle which is a null phase by the 19th. The null phase means the MJO is not affecting our weather pattern. In fuschia, I circled a bunch of squiggly yellow lines. Those are “model members” whereas the green line we follow is the average position of all of the members(technically the mean). The fact that most of them are in that null phase, indicates the consensus is that it will dig into the null phase, hopefully, we will then see it venture back to phase 1.

Stay with me, I will show what each phase means this time of year after we look at the Euro.

Euro

mjo129euro

The Euro looks, on the surface pretty similar, until you look at its model members (yellow squiggly lines) they are all over the place, starting tomorrow. This is a disaster and tells me I really cannot rely on the Euro past a couple of days out if that.

Here are a couple of charts that you can follow to see what each phase means for us. Remember the further the forecast (green) line tracks away from the center of the square, the more of an effect the MJO will have on us.

Temps (4,5,6 are bad for us)

ndjtempsCapture

NDJprecipCapture

This week, I have low confidence in the incoming storm, we need it to dig in more to the south. For now, my eyes are on the MJO. Next update Monday.

It was a “Not Storm”

7 am

For those of you who have been following,  you remember I spent a good amount of time talking about “Not Storms”. Yesterday was the perfect picture of confusion, nobody really picked up on what was going on until it was over. People have already told me the storm went south etc. etc. No, it didn’t. The truth is it is going to but has not yet. So here is “The Storm”.

Current US Surface map, the low pressure is circled in yellow.

Capture

 

So what was yesterday? A couple of things, mostly the jet-induced precipitation. All sorts of mini disturbances can travel along the jet undetected until they show. They are not really predictable until after they appear. Yesterday, as I looked at the surface maps I noted a couple of anomalies that I saved for future reference. First, keep in mind surface maps update every 3 hours, and similar to models, they take a while to be available, so the 8 am surface map is usually available at about 10 am. So here was the 8 am for yesterday  I circled a shortwave trough in red.

sw1

Then the 11 am surface map.

SW

Once that disturbance passed completely through the area, things slowed down considerably. So the embedded disturbance was our (Not) Storm.

Since I started writing this the latest (5 am) surface map is out.

newCapture

Look another shortwave. No, I don’t expect this to affect us. But it shows you how unpredictable storms can be.

And the winner is…

5 am

URGENT - WINTER WEATHER MESSAGE  
NATIONAL WEATHER SERVICE GRAND JUNCTION CO  
228 AM MST FRI DEC 7 2018  
  
COZ018-019-022-023-071030-  
/O.CAN.KGJT.WW.Y.0036.000000T0000Z-181207T1600Z/  
NORTHWEST SAN JUAN MOUNTAINS-SOUTHWEST SAN JUAN MOUNTAINS-  
ANIMAS RIVER BASIN-SAN JUAN RIVER BASIN-  
228 AM MST FRI DEC 7 2018  
   
..WINTER WEATHER ADVISORY IS CANCELLED  
  
LIGHT SNOW SHOWERS AND AREAS OF FOG WILL PERSIST ACROSS SOUTHWEST  
COLORADO THROUGH THIS MORNING. HOWEVER, WIDESPREAD SIGNIFICANT   
SNOW ACCUMULATIONS ARE NO LONGER EXPECTED. THEREFORE, THE WINTER   
WEATHER ADVISORY HAS BEEN CANCELLED.   
  
MOTORISTS SHOULD STILL BE PREPARED FOR ICY CONDITIONS ALONG WITH   
VISIBILITY UNDER ONE MILE IN SPOTS DUE TO THE FOG AND LIGHT SNOW   
SHOWERS. CONDITIONS WILL SLOWLY IMPROVE AFTER 9 AM MST.  
  

Clearly, all they had to do was change the start time of the lower altitude advisory as most of the areas actually hit at least that 2″ minimum before some melting.  As far as the higher altitudes go, it was a blanket advisory therefore one of the areas mentioned will get that amount and others won’t, it is almost impossible to be wrong that way.  It is no different than when they issue an advisory after the snow has fallen, which we see a lot down here.  Don’t worry,  there are 2 to 4 storms to track before Christmas!

Tonight: NWS vs the models

5 pm

Just so we are on the same page, none of the models are projecting significant snow this evening. They all had the majority of the activity occurring during the day today. That was my issue with the wording on the 2-5 inches at lower elevations that they had at 6 tonight.  As I said earlier this super southern storm track (Mexico) is atypical and not something I have not dealt with a lot. To further complicate things, the point forecasts I believe are all 1-3 inches. We will see who wins.

So far so good!

Noon

I like the advisory for the lower elevations, I just think that they should have started it earlier, especially with the 60+ snow reports I have already gotten in the last hour.

The Euro really picks things up between 11 am and 5 pm. It does have a lull this evening as does the WRF, they both bring another wave through for the morning commute. The Euro has rain below 6,500′. That could be a mess.

As far as the 8,500+’ goes the 4-8″ I suppose is fine but I think somewhere in the middle will be more common.  The greatest amounts should fall in the La Platas and north of Mancos to Dolores.

The jet is very favorable this afternoon, it will shut off later, that is when the lull will happen, then switch to NW flow which should only benefit a few areas. The darker blue indicates heavier snow.

Here is the EURO between 11-5pm.euro115

 

Here is the jet picking up at 1 pm1jet

As I said this morning I would act as if the advisory is already in place (I still don’t understand why they haven’t changed it). I would also tell you that as we have seen a couple of times, there may be changes as this approaches.

Check out the surface map, I circled a shortwave trough extending all of the way to Arizona, north of us is stationary front that I have a hunch is dropping south and lastly notice “the storm” is still off the California coast spinning around. In other words, there are a lot of components, and they can move in and out of our favor.

As I finish this, I just glanced at the waper vapor imagery and it appears it has jogged just slightly south and east. But there is another wave behind it.

 

 

 

Advisories Issued (High and Low)

5:30 am

I am not going to have time to break this all down in the time I have. This whole weather set up for our area is very atypical in Winter. However, I think this is similar to what we will see between large systems this Winter so I am going to have to get used to it.

The models are still struggling, at issue is going to be the rain snow level. When these advisories were issued it is apparent to me that the incident forecaster was influenced by last nights GFS and mostly the EURO. The overnight GFS went ahead and sped things up even more, and the overnight WRF did the same thing, with much higher snow amounts during the day today. I certainly understand the earlier start for the higher altitudes, I am pretty sure looking at the water vapor it has already started in some areas. Looking at my model that predicts the snow levels it actually has them low until noon tomorrow, when they shoot up to 7,500′. Of course, according to the NWS everything should be done by then. This would indicate that we will be cooling the entire time the precip is increasing.

Bottom line, absolutely almost everything is out of sync, that being said I would take these advisories seriously as the start times may be moved up.

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service Grand Junction CO
342 AM MST Thu Dec 6 2018

COZ022-023-062230-
/O.NEW.KGJT.WW.Y.0036.181207T0100Z-181207T1600Z/
Animas River Basin-San Juan River Basin-
Including the cities of Durango, Bayfield, Ignacio,
and Pagosa Springs
342 AM MST Thu Dec 6 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
9 AM MST FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 inches
  expected with locally higher amounts in the vicinity of Pagosa
  Springs. The snow may be mixed with rain early this evening.

* WHERE...Animas River Basin and San Juan River Basin.

* WHEN...From 6 PM this evening to 9 AM MST Friday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. The
  hazardous conditions could impact the evening commute,
  especially along Highways 160 and 550.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Expect snow covered roads
and limited visibilities, and use caution while driving.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.
URGENT - WINTER WEATHER MESSAGE
National Weather Service Grand Junction CO
342 AM MST Thu Dec 6 2018

COZ018-019-062230-
/O.NEW.KGJT.WW.Y.0036.181206T1900Z-181207T1600Z/
Northwest San Juan Mountains-Southwest San Juan Mountains-
Including the cities of Telluride, Ouray, Lake City, Silverton,
Rico, and Hesperus
342 AM MST Thu Dec 6 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO 9 AM MST
FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 4 to 8 inches
  expected.

* WHERE...Northwest San Juan Mountains and Southwest San Juan
  Mountains.

* WHEN...From noon today to 9 AM MST Friday.

* ADDITIONAL DETAILS...Plan on slippery road conditions,
  especially over Red Mountain, Coal Bank and Molas Passes on
  Highway 550, Lizard Head Pass on Highway 145 and Slumgullion
  Pass on Highway 149.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Expect snow covered roads
and limited visibilities, and use caution while driving.

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