Winter weather more likely for upcoming weekend; see what’s different with this set-up :: WRAL.com
Rain and snow were actively falling on Sunday afternoon, and we were already getting questions about next weekend, Jan. 24 and 25.
To help you understand what we know and what we don’t, we’ll keep you updated all week as the forecast models develop.
Let’s start with the fact that the signal for winter weather is more impressive for the coming weekend than we saw for Jan. 17-18, when some of you saw a dusting of snow. Virtually every forecast model that’s used for this medium-range of forecasting shows this active storm track blending with an incoming Arctic air mass from the north.
High pressure brings in the cold air while the jet stream and low pressure pump in Gulf moisture
What makes the pattern more promising this weekend?
Should the moisture and cold air come together in perfect harmony, we’ll have a pretty long-track winter storm across the Southern U.S.
We didn’t have that cold air support this past Sunday. The high pressure supplying the cold air was in Texas. This upcoming weekend, high pressure is closer to the midwest and better placed to continuously supply cold air. Having it this time around would put us in a stronger position to see winter weather.
The other benefit for snow-lovers with this set-up is that the low pressure track will help to pull in Gulf moisture. Gulf moisture is often a better supply than the Atlantic moisture.
Similar to the last system, the track of low pressure will still be very important in determining precipitation types. The only way things may not happen is if the high to the north is too strong and suppresses all moisture to the south.
WRAL’s forecast
While we live in a day and age of instant gratification, that still is not how weather forecasting works — especially as it pertains to winter weather in the south.
So while you may see the app on your phone saying, 6-8″ of snow or 12-15″ of snow, let’s limit those expectations for the time being.
The skill in forecasting five or six days away is limited to diagnosing whether something is likely or not, not the details of when, where, how much.
Why is that?
It’s because the system of interest is spinning (and doing so slowly) over the eastern Pacific Ocean, about 3,500 miles away from us.
It’s possible — if not likely — that we get winter weather out of this pattern during the weekend of Saturday, Jan. 24, and Sunday, 25.
When should we know more?
Details like precipitation type, timing, totals, impact, etc. won’t really come into view until one to three days before the storm arrives. We are able to nail down things like overall impacts a little bit earlier.
This is due to the fact that there’s crucial observational data that’s missing in the forecast models. It’s also worth noting that high-resolution (more detailed) forecast models only go out anywhere from two to three days before any weather arrives.
If you feel like spending the early part of the week reviewing your winter weather plan, have at it. Just understand that we won’t be able to give you snow/ice totals with any shred of confidence until probably Thursday.
