Friday's Debrief - Yesterday we had a good deal of sun, temps got mild and breezes picked up.
Quick Forecast for Today (Saturday) :
Aspen: A decent amount of sun with breezes. High 55 Aspen, 60 Basalt. SW wind increasing to 11 to 22mph with a few gusts. Low 25 to 30.
On-Mtn: A decent amount of sun and breezy/windy. High 41 at mid-slope, 38 near 11K. Wind SW 13 to 25mph, stronger speeds above 11K. It will be windy up high tonight.
Today (Saturday)...Updated 600am - Today we are ahead of an upper air trough. Our air mass remains dry as we lack upper air support and we also have a downslope SW wind. The long story short about today, it will be balmy and breezy with a decent amount of sun. I'm expecting mid 50s around Aspen this afternoon, upper 50s to 60 down valley near Basalt.
I will also keep tonight dry because the downslope SW wind component is too strong for any snow to survive.
Sunday (Updated 600am) - So let's break down the upper air trough that's coming during Sunday. There are some decent parameters but we also have negatives.
The negatives are this trough does not have much ambient water, in my mind this is a big negative as our dewpoints stay below 15 all day. This equates roughly to to 2G/KG of ambient water which is low. The next negative is we have a downslope SW wind until the front passes late morning/early afternoon.
The positives are we have a decent cold front that will pass late morning into the early afternoon hours. I would like to see better moisture convergence along this boundary, we do have some speed convergence which is good. Overall, having a front is a positve. Our mid/high level energy along the front is good, hopefully this will lead to some decent radar echoes. Mid/high level energy a few hours behind the front is OK but not great. Our thermal profile is immediately 'Fluff Worthy' as soon as the front gets close. Our wind profile goes upslope W at 40mph at mountain top (14K) as soon as the front passes, this is very good. The wind goes NW upslope early in the evening. Lastly, instability is very good along and behind the front.
Summation, the positives outweigh the negatives but the lack of ambient water is concerning. I will call it a day where snow/snow showers develop. Temps will fall a bit later in the afternoon behind the cold front. In terms of snow, I will go 2 to 6" at the ski resorts for this reason. I will be forecasting 2 to 4" at Buttermilk, 2 to 5" at Aspen Mtn, 3 to 5" at Highlands, and 3 to 6" at Snowmass. In the valleys, it's probably 1 to 2" in the lower elevation because we lack ambient water, 2 to 4" could happen in the higher valleys above 7500ft.
Note - We are likely going to need an inch or two extra after the cold front passes and I'm hoping snow showers and the W wind at the ski areas will provide this. If we don't get the extra inch or two late day and the first half of the night, amounts will end up at the low end of the ranges.
Monday (Updated 600am) - Monday will be a cold day with very little ambient water and not a whole lot of upper air support. My guess is we have mixed clouds and sun with widely scattered snow showers here and there. My guess right now is only Trace amounts of snow will fall at most locations. High temps stay below 32 in Aspen.
Extended Fcst (Tues-Thur 3/6-3/8) - We do have some mid-level energy on Tuesday, I will keep us dry for now as it does not look like enough energy to bring saturation. Temps on Tuesday stay chilly.
I believe upper air ridging will dominate Wednesday and Thursday so I will have a dry forecast.
Month of March - Probably the easiest way to sum up what I think happens is this. Don't give up on March just because it does not look like February to start out. We have high latitude blocking going on all month and this is dangerous. I'm pretty sure SNOW surprises will be coming down the road. I'll even make a guess, watch out for March 10th to March 12th. Also watch out for the last 15 days.