Focus remains on the Sunday setup and the cold that follows...
This afternoon Minor snow/sleet mix north.
Sunday Rain to Snow. *Potential* Winter Storm.
Next Thursday-Saturday Snow to Rain.
As far as Sunday goes... this looks to have all the ingredients for a stripe of moderate to heavy snow to fall from Missouri east into the Appalachians. It will have snow north, rain south. There will be a transition line in the middle but it looks to be fairly quick on any transition... so this is a rain or snow deal.
Several things we are watching to influence the outcome of this...
- Ridging of the Polar Jet near Alaska/Western Canada
- Timing of energy ejecting from the Rockies
- Warm air Saturday in advance of this system
- Time period of rain vs snow
- Track of the surface low (heaviest snow right at the rain/snow line roughly 150 miles NW of the track)
- Temperature drop behind as the low moves to our east
All of the above will factor into how this plays out. So it is not as simple as “which track?” The models are giving us the best guess right now of the above elements. Our job as meteorologists is to figure out the trends in the data we see on each of these factors and to identify which “don’t make sense” given how the atmosphere really works.
Now for the bad/frustrating news. The energy that will be our ‘storm’ is still out in the Pacific. It will not enter fully into our upper air network until Saturday at the earliest! This means some adjustments could still take place 24-36 hours from this event. In other words, we have to go slow with the evolution of the forecast details.
While we wait, one of the factors above that I am really try to narrow down is the duration of rain before we transition to snow. And I do see that we ALL will go from rain to snow at some point. But WHEN is going to be key on how much snow you pick up.
The amount of cold on the back of this low Sunday night is overwhelming and I do see travel issues even if we get minor snowfall out of this. The trend is to start off pre-dawn Sunday in the 40 degree range,...fall into the mid 30s by midday Sunday. Lower 30s by afternoon. 20s during the evening/midnight. And finally end up in the mid teens by rush hour Monday. You can see the issue there when it comes to freezing things up.
I will try to explain all of this the best way I can in today’s video.
The cold that follows will depend on how much snow we pick up as well.
Little to no snow cover: Highs sub-freezing a couple of days, lows in the teens, wind chills briefly in the single digits of couple of mornings
Decent snow pack: Highs barely into the 20s a couple of days, lows in the single digits, wind chills below zero and approaching advisory level for a couple of mornings
So there is lots to track over the next 3-6 days. Hang tight as we continue to analyze the data and trend the forecast according to confidence level.