Saturday 9/11/21 8:25 am
Everybody should know by now that I am not a big fan of boring weather. I have a confession to make, if the weather has to be boring, and the temperatures have to be slightly above average then the fall isn’t such a bad time for it to happen. Yesterday morning I was waiting for a tire repair sitting outside. The low humidity with the temperatures in the 70s was pretty nice, I have to admit.
If you too like these conditions I have good news, there is a lot more of that on the way. It is not going to last forever, and at this point, I don’t believe it is reflective of our upcoming winter. In the short term, there is just a slight chance of some mostly dry, afternoon high elevation convective showers developing Sunday afternoon.
Smoke from existing fires should not be an issue. The other day I mentioned the AQI monitor near the train was an anomaly. To clarify, I was not saying to ignore that reading, it is a real reading. It is an anomaly because it doesn’t reflect the air quality of the entire town, just that localized area.
Here is what boring-nice looks like over the next couple of weeks. When I talk about storms, not monsoonal flow, not afternoon convection, real storms, I am talking about upper air disturbances. During the fall we usually see the first low-pressure systems drop down from Canada into the lower 48 in late September and October.
To identify these, forecasters look at the upper air heights parameter of the ensemble model runs. They refer to these “charts” or maps as we now call them as “the 500 millibar”. So let’s look at the 500 mb for the next 15 days. First from the GFS ensemble mean forecast, then from Euro ensemble mean forecast. The blue indicates below-average heights (storminess), the yellow indicates above-average heights (usually benign, boring-nice weather). Are you enjoying my more positive take on boring weather?
Both models show a disturbance trying to dig in around the 21st. At the moment, they show it too far north to affect us. Things can change, and I will be keeping an eye on it.
We are going to have beautiful colors this year. This became evident to me with the precipitation we received in August. It is something I’ve meant to talk about but was reminded of the other day by the be snippet in the Durango Herald. I got an email from a loyal supporter of the site who was visiting Aspen. There was just a splash of color and he was trying to take a picture to send me. Because the colors were just starting the picture didn’t turn out as he hoped. I responded by saying delayed colors = great colors! That is what we are in for this year, and it was the impetus for me to dig out my photography equipment.
For the colors to be even better, here is the scenario we need. We need just a bit more rain. It does not have to be a lot, just a bit. Then we need a cold front to drop in. At this point, the origin is not that important. Ideally, it would be a west coast low that drifts across northern Arizona and southern Utah. That would be the best-case scenario, because it is likely that it would bring snow, especially above 8,000 feet. Even if we got a dry cold front from the northwest after a bit of rain it would really pop the colors. Specifically, below freezing at 6,500 feet. That is why I am keeping an eye on the upper air pattern to see if something becomes of that feature I mentioned earlier that shows up 10 days from now.
This is the time of year I start getting asked about winter. The Farmer’s Almanac forecast is out. There are even a few commercial preliminary forecasts out. One is Weather Bell Analytics. They do a pretty job every year. They consult corporations that have a vested interest in the weather, usually in energy and agriculture. They will update this preliminary forecast a couple of times before December when meteorological winter officially begins. They are calling for an average winter for our area, both in temperatures and precipitation.
I take preliminary winter forecasts pretty lightly. I am more interested in how they arrive at their conclusions. If a winter forecast is based solely on ENSO (El Nino, La Nina) I usually dismiss it completely. El Nino and La Nina are very small factors in our area. The heaviest snowfall winters in our area have been in ENSO neutral winters, referred to by some as La Nada. For what it is worth right now here is WeatherBell’s preliminary winter forecast.
Snowfall-From first flake to last flake as they say.
Courtesy Weather Bell Analytics LLC
Courtesy Weather Bell Analytics LLC
Here is the latest Euro weekly 46-day snowfall forecast (through October 24th).
Here is a wider view of that so you can see how much of that early season snow is staying in Canada.
It will be here before we know it.
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