Posted 9:30 AM Monday, February 15, 2021
It appears that our winter storm is off to a good start this morning. Our first thump of snow is moving through out ahead of the main low pressure is moving through. Early snow reports from a few locations around the Valley indicate about a ballpark 1″ to 3″ coating of fresh snow.
This first round will continue through mid-morning before tapering off and ending. Mostly snowless conditions should then set up for the bulk of the afternoon. Hopefully, this brief lull will give road crews a chance to clean up a bit before snow moves back in late in the day.
The second round of snow gets underway late this afternoon/this evening. It will bring heavier snowfall and higher accumulation and be much more impactful than the first round.
After looking at the morning high resolution models I’m becoming more concerned about that warm air aloft migrating northward. The morning data suggests an increased intrusion north. This trend not only increases the potential for sleet but now freezing rain may become an issue for our southern-most communities.
I still think snow will be the main precipitation type for communities around New Phila and north. For those locations south, sleet will likely bring a little less snow. The closer a community is to I-70, the better odds of freezing rain. I’ve adjusted the snowfall map a bit this morning to reflect that idea. IMPORTANT: This is in addition to what has already fallen.
Snow will start to move back in from the south as we approach sunset this evening. Snow will continue to be the primary p-type this evening through around 8:00/9:00 PM. This will likely be the time where we can see the heaviest snowfall rates – perhaps rates as high as a half an inch to one-inch per hour. The threat for sleet and freezing rain will begin entering the picture from south to north after 9:00 PM this evening.
Snow, sleet, and freezing rain will continue for several hours overnight before things start to wind down early Tuesday morning. While some areas in the southern portions will likely see less snow, the combination of sleet and freezing rain will still bring travel impacts well into the Tuesday morning commute. Much will depend on how quickly the mid-level warm air slides in overhead.
Impacts locally will still be high – especially tonight and early Tuesday morning. Since Freezing rain has become more of a concern, I’ve increased the impacts ice may have on portions of the area. Road crews will have a difficult time keeping up. Travel will be challenging tonight and Tuesday morning.
Substantially colder air will move in for Tuesday night. We can expect nighttime lows in the single-digits locally. High pressure will keep the area dry through Wednesday.
The next storm system will impact the region on Thursday. This next storm follows a very similar track through the area. It also will be a stronger storm but temperature profiles appear warmer. Precipitation types and amounts with this next system remain highly variable. I will say it looks very similar to the current storm with a little higher potential for sleet/ice. I’ll devote more time to this next system in future updates.
Updates posted here and on Twitter (@tuscwx). Facebook not so much. Be safe out there.