March is coming in like a lion, that's for sure. A powerful storm system is on its way into the California and promises to bring much needed moisture from there to Oklahoma and beyond. However, that moisture is meeting up with some true Arctic air to cause some big issues by Sunday.
The ingredients are still coming together Saturday. The atmosphere will begin to moisten up, the upper-level energy for the storm draws closer, and the Arctic air begins to spill southward. However, the bulk of Saturday should be a rather calm, even seasonable day. By Saturday night, all of those aforementioned ingredients combine to give us a wintry mess.
Why ice and not snow? Snow in early March is very common. In fact, we see some of our heaviest snows this time of year. However, this Arctic air that moves in by Sunday is very shallow. The precipitation will actually form in a warmer-than-freezing layer of air. It will then fall into this very cold air mass and either freeze on contact or freeze into ice pellets (aka sleet) by the time it reaches the ground. Due to the very cold air that seeps into the northeast Oklahoma by Sunday morning, sleet is most likely. A corridor of freezing rain is more likely in southeast and east-central Oklahoma. Up to a quarter-inch of accretion is possible. Sleet totals will likely range between a half inch and inch with locally more.
This storm system will take its dear sweet time to move out. We will see a light wintry mix for most of the day Sunday with temperatures falling into the teens. Whatever falls will stick, especially on untreated roads. Outside of a few heavier bursts of precipitation, it won't be a heavy dousing, but a gradual build-up of ice on roads that will make driving still very treacherous.
As deeper cold air finally moves in by late afternoon, we will see a transition to actual snow. The computer models are still not locked down on snow amounts or where the heaviest band of snow will travel. However, an inch to several inches of snow is possible as the system pulls away by late Sunday evening.
The bottom line is this: travel will be fine on Saturday, but very difficult and potentially dangerous on Sunday. Temperatures will be dropping on Sunday with a brisk northerly wind, allowing wind chill values to fall to or below 0. Just because we're into March doesn't mean we can't deal with a serious bout of Arctic air. Single-digit lows are likely by Monday morning. We may not get to thaw out much until Tuesday afternoon when temperatures will climb above freezing. Plan for to 2 or 3 days of messy road conditions and bitterly cold air. The impacts of this system are certainly not locked into place, but it is just about a certainty that Old Man Winter isn't done with us yet!
There is a light at the end of this frigid tunnel. By late next week, our highs are back in the 60s! In the meantime, be sure to follow me on Twitter (@GroganontheGO) and like my page on Facebook for the latest winter storm information!