Weekend Winter Weather Update posted 5:30am 12/6/18
Good Thursday morning! We are now getting into the window where the short range models will start to come into play to help paint a clearer picture of what will occur this weekend. Some subtle changes but not enough for me to make many adjustments to the forecast. Let's take a look at the latest model data. We will start with an image from the NAM model and then move to the GFS for the remainder. As we continue to get closer to the duration of the event the NAM data will be the data I share. The forecast I produce is based on all of the available model data.
Saturday afternoon just after lunch we will begin to see rain move into the county. The good news is based on current data if you have any plans Saturday that involve travel. You should be good until late Saturday evening. The chance for rain changing over to freezing rain or sleet increases late Saturday.
During the overnight hours on Sunday morning we will be gin to see the precipitation around the county change over to snow. At this point it appears we will deal with mainly snow with occasional mixing of a wintry mix to include rain, snow, sleet & freezing rain.
During the afternoon hours of Sunday a warm nose of air will likely move in over the county causing melting of the precipitation and refreezing on the way down to the ground in the form of sleet. This will be a concern as ice accumulation will become a factor.
Sunday evening we may see the warmer air above us becoming a little more dense bringing in a mix of snow and freezing rain. This will have the county dealing with several hours of a mix from Sunday afternoon into Sunday evening. This will have an impact on the potential snow accumulation and increase the chance for ice accumulation.
Monday morning we could be dealing with freezing rain around the county as the warm air aloft continues to win out continuing to reduce snowfall totals and increasing ice accumulation totals. Based on model data at this moment we are looking at around 10-12 hours of a possible mix of snow and ice from Sunday afternoon into Monday morning. If you have travel plans for Monday morning. Please consider changing them as the road conditions will be treacherous by this point.
As we continue to move through the day on Monday we will see cold air win back out and the precipitation will change back to al snow. We will potentially see brief periods of heavy snowfall during this time. The system will start to pull away form the area on Tuesday bringing the precipitation to an end during the early morning hours on Tuesday.
Let's look at what the models are calling for in terms of snowfall totals.
The GFS model above is indicating 20 inches of snowfall accumulation around the county. I urge you to keep in mind that this would include rain, sleet, freezing rain and snow accumulation to really inflate those totals. It is likely the over all accumulation we see from this will be far less than 20 inches of total snowfall. I will summarize my thoughts on the forecast at the end of this blog.
The European Model is indicating 17 inches of total snowfall around the county. Again inflated totals once you consider the other accumulations involved.
The Ensemble Models are indicating 13 inches of total snowfall from this system. This is a little more realistic but still inflated based on the other types of accumulation that will be involved.
Here is my current forecast based on the available data that is out there. These totals will begin to fluctuate a little over the next 24-36 hours as we get closer to the event and I am able to get closer to pinpointing the track of the system as it moves through the region.
- Saturday afternoon we will see rain begin to move into the county. If you have plans for travel on Saturday you are good until late Saturday evening.
- During the overnight hours of Sunday morning we will see transitions from rain to a mix to all snow.
- Sunday during the afternoon we will see a warm nose of air in the atmosphere above us that will change precipitation to a snow ice mix. This will begin have an impact from how much snow accumulation to how much ice accumulation we get.
- Monday morning we will see cold air win out in the atmosphere and precipitation returns back to all snow. This will lead to the possibility of periods of heavy snow.
- Snowfall accumulation around the county will vary. As of now I am forecasting 3-7 inches of snowfall around the county. That's a bit of a larger range than I typically do. I will adjust and tighten up the totals over the next 24-36 hours.
- Ice accumulations of around a tenth to a quarter of an inch are possible around the county. This total will likely stay the same unless models start to indicate longer periods of colder air above us here in the county.
I will continue to provide updates as we move closer to the weekend right here and on social media. As always thank you for following Rowan County Weather!