I think there are good explanations about why our forecasts was so off this weekend. For me, it starts with me growing dependence on the computer models. I haven’t been looking at the data about the real weather as much as I used to. The models are usually pretty darn good. So, I didn’t look to see how much water content was coming our way.
Water vapor satellite image. Orange indicates areas of dryness. Greens and blues indicate moisture
Still I might have missed it here. Notice how much orange, dry air is south and west of us. These areas are typically our moisture supply in the winter. For this weekend, our moisture has come from the north and west; Nevada and Utah. I this that might have thrown me. I need to keep looking at data like this.
The next problem I should have considered on Friday. If you read my post from Friday morning, you’ll notice that I pointed out that a single, high-resolution model had over an inch of water for us. When massive storms happen, especially in heavily populated areas, the National Weather Service focuses their time, energy and computer models on those storms. The model that had the accurate prediction of lots of water, focuses only on the Western United States. National forecasters can be distracted while the strong nor’easter hit New England. The National Weather Service tweaks their models to give better detail at times of concern like this. It also means that less populated areas, like the Desert Southwest, get less attention and less accurate forecasts. They may disagree, but it seems real.
Here is the latest 48-hour total precipitation forecast from the high-resolution model I mentioned before.
ARW high-resolution precipitation model for 48 hours.
We are in for a lot more snow and very cold wintry conditions for the next few days. Between now and Monday evening, we are looking at 6-18 inches depending on luck and location. Some places will see more that this. Notice that this storm leaves areas south of the Mogollon Rim mostly dry. This points back to the moisture coming from the northwest.
Sorry for missing this one.