Thursday, March 16, 2023

Break in the Storms

All is quiet for now on the western front.  Yesterday's storm is off wreaking havoc in Colorado and the high plains and, believe it or not, we are in split flow today with the GFS forecast valid at 1800 UTC 16 March (Noon MDT Thursday) showing two branches of the jet, one moving over the ridge centered over the Pacific Northwest and British Columbia and the other around a broad trough over the Southwest, with Utah in the middle.  

That general pattern predominates through the weekend as the GFS forecast valid 0000 UTC 20 March (6 PM MDT Sunday) continues to feature weak flow over Utah with one branch of the jet moving up and through northern Canada and the other plunging down through Mexico.  

If you had to summarize a pattern like this in one word it would probably be fair.  A few weak systems will move through the split, but for the most part skies will either feature high clouds or be clear.  Unlike a high-amplitude ridge, which would result in above average temperatures, temperatures will be a bit below or near seasonal norms. The 700-mb (crest-level) temperatures this afternoon and Friday will be around -10C and Saturday and Sunday around -6C to -7C.  Average for this time of year is about -5C.  That will help with powder preservation, but it is mid March and the sun is getting intense so I'd expect a melt-freeze cycle on the southern half of the compass, western aspects, and low-and-mid elevation terrain.  The lower temps will help some with powder preservation today and tomorrow, but you can't stop the sun.  

There is another possible warm, windy storm next week.  Stay tuned.

2 comments:

  1. I don't know what the actual numbers say, but it feels like this has been a pretty cold winter compared to recent years. Especially now - it's mid-March, the average high is 56, and there isn't a temp within 5 degrees of that in the entire 10-day forecast.

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  2. Yeah, I did a ski tour this morning and had to put my puffy on during the climb. That's unusual. "A bit below" seasonal norms in the post above wasn't a good summary as yesterday and today we are running well below. This weekend we'll be a bit below.

    For Nov-March 16, this season has an average temperature of 34.7F at the airport. That's 70th out of 149 winters, so over the full period of record it is still above median. We haven't had many warm days, but we haven't had many exceptionally cold days either. We've also gotten soft in recent years.

    For the past month, however, we've been running below median with an average temperature of 36.9˚F, which is 100th out of 149 winters (i.e., 49 winters are colder and 99 winters are warmer).



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