With the warm temps and cloudless skies, it's a bit hard to imagine winter is just around the corner. For many, the waiting is getting tough. I am now scrambling to tune skis and boards because...here comes the change with 6''-12"+ possible for Wednesday/Thursday this week.
Being a Meteorologist for a very long time in Utah, you get used to reading the maps and watching the patterns. In years past with a dominant high, it takes awhile to break it down. I refer to this pattern like a giant stream in a river. After all, the jet stream, which controls the storms directions, is just a "river in the sky". Imagine you are standing on a cliff overlooking the Colorado River and looking down at all the rocks, boulders and sides of the river that have been eroded away from the flow of water. When the water is flowing at a "normal" speed, it follows the river bottom and moves gently right over the small rocks and around the boulders. As the water rises, gets more powerful, it starts to erode away at the river walls and plows over the boulders-at times even pushing them. The jet stream and the storms are much like this. The dominant high pressure is that giant boulder in the stream as depicted by this satellite photo showing the clear skies over the west.
Turning to the second graphic, we look into the Pacific for our weather and for a cloud photo that looks like "popcorn". This is an indication of cold air pushing south. With enough push and a consistent push of several storms, it will start to erode away at that high pressure "boulder". This is indicated looking into the Pacific. Note the blue over the Aleutians of Alaska and even further west (or left) in the photo. These are storms starting to dig or form.
This is good news. However, patience is key here. Just like the river, when a huge surge of water comes and goes, the boulder may nudge a little, but it takes consistent higher water to push that boulder downstream.
Here's what we'll see within the next couple of weeks:
1. First "surge" comes on Wednesday night-Thursday night. There will be a very cold storm dropping over Utah. This will bring a good shot of snow for a 12-18 hour period. The snow will start up in the mountains later Wednesday. Once the front swings in late Wednesday, the snow kicks in and the snow levels lower. The big "if" is will the Great Salt Lake kick in to give extra totals to the mountains southeast of the lake. If it does, it will be short lived as the storm lifts out late Thursday. Is this the "big one"? No, it's not. That's not the point; what this does do is open the door and start to nudge the boulder. The cold air will move in for a few days, however, the boulder of high pressure is still not quite bumped out yet, but starting to weaken it's grip.
2. By Monday of Thanksgiving week, things are going to get more unsettled. As long as we can get a persistent flow of moisture and cooler air in the picture, things are starting to move. It is that persistence that will finally get the boulder moving and our winter started. The computer models are getting more active and sending in small storms right through the end of the month with possibly a bigger storm rounding out November. This is good news indicating that indeed, this storm Wednesday has done it's job, has opened the door and the moisture and the storms are lining up. Remember, it's more important to get a moisture and storm train started than just one storm. This sets a great base for the entire season.
3. With that said, looking at computer models, especially during a major pattern shift, can be tricky. Timing and intensity can be a challenge. But in seeing the movement and activity in the Pacific, things will finally start to get more active which is what we need to get this ski party started!
On a side note, La Nina has arrived. Either El Nino or La Nina tends to affect the northern or southern tier of the US by swinging averages more than the central US. During a La Nina-in general- the Pacific Northwest tends to be cooler and wetter than normal. This could be good for Utah as the storms plow onshore and we get at least a tail end of a storm scraping through if not direct hits from the storms. I have people ask me all the time about "what does this winter hold"? Like with any predictions, it's hard to say.
As always, I welcome questions on weather and kids going through the season. My kids have far exceeded me in ability years ago, but I continue to learn the ins and outs of skiing and boarding with kids. Even as they get older, the challenges are still there. From equipment, gear, snacks and conditions...they are still kiddos and still need you to guide them.