Well, we are getting a better look at it, and once again a conservative approach to forecasting seems to be winning. There is a reason I don’t go ‘full boar’ with these cold weather outbreaks near the Gulf Coast – they rarely verify.
Last week, recall that model guidance – both ensemble guidance and deterministic guidance – showed the potential for some pretty cold air to spill south toward the Gulf this week. Really cold stuff, too. Model data was showing lows in the single digits near I-20! Plus a round of two of snow! Even freezing rain along the coastline. Once-per-decade type stuff.
But that was last week. When the forecast was six to twelve days out. At this point, now that it is closer to four to seven days out, things are starting to look a bit clearer.
The data last week showed frigid cold seizing the south starting on Wednesday and lasting all the way through the weekend.
The latest data
Now the data is showing that cold air getting stuck a bit father north. Take a look at the trend from the GFS computer weather model during the last few days.
The ECMWF also pulled back on the very cold air spilling south.
That is just the deterministic guidance, though. It is always best to consult the ensembles, too.
Here is a look at the ECMWF ensemble data:
And from the GFS:
Notice that a majority of the ensemble data shows not-quite-as-cold-as-originally-suggested temperatures and the deterministic guidance shows the same.
So, no more cold?
Well, I’m not saying it will be hot. But the big drastic Arctic Outbreak isn’t looking as likely. While the south will see a few days of below average temperatures and – yeah! – some cold air. As of now, guidance is trending away from single digit lows, multiple rounds of snow and ice, and winter grinding life to a halt.
Instead, it looks like if you live along or south of I-20 in Louisiana, Mississippi and Alabama… this week may end up being pretty mild, because some cooler air filters into the area this weekend and – perhaps – into next week, too.
The Climate Prediction Center is showing a good shot for cooler than normal conditions by this weekend and into next week.
But, keep in mind, that this map doesn’t indicate ‘how cold?’ it will be but rather ‘what is the chance it will be above or below average?’
Is the forecast set in stone?
No. It may still flip back colder again. However, one ‘tell’ that the models are struggling and going ‘too cold’ is when the model data continues to show the coldest air showing up a day later every next day the models create output.
For example, the model data says “cold air gets here Wednesday!” then the next day it says, “The cold air gets here Thursday!” then the next day after that it says, “LOL JK mean Friday!” then the day after that it says, “Got’cha, meant Saturday!” and so on.
And that is exactly what has been happening. Give me very low confidence that the truly cold air will verify.
How cold are we talking, then?
Still not totally sure. I think lows in the 30s by this weekend and into next week for a night or two are a safe bet. Some folks will get into the 20s, too.
What days specifically? We are still trying to nail that down.
Outside of that, I can’t forecast anything else – snow, lows in the single digits, ice storms – on good conscience. Because there just isn’t enough evidence to support such a thing.
