First, a friendly reminder -- I'm not a meteorologist and for the most part, don't know what the heck I'm talking about. But I follow it as a hobby and can aggregate for you what the REAL experts think.
So, here's the story:
Confidence grows that we will see SOME sort of winter weather, starting Thursday morning.
The key factors:
1) The track of low pressure in the Gulf of Mexico -- over the last 48 hours, models have been nudging that to the north which makes our temperature forecast razor thin when it comes to winter precip.
2) The strength of the low and of the high pressure to the north. On the former, it means more precip on the latter it means a stronger CAD. The latest run of the short-range model NAM spit out more than .8 inches of precip -- if that was all frozen, any combination of snow and ice would be serious. For example if 1/4 was snow, then the rest ice, we'd be talking 1-2 inches of snow then .3 to .4 inches of ice -- a killer ice storm. If 1/2 and 1/2, it would be 2-4 inches of snow, then .1-.2 inches of ice -- still very dangerous.
3) The TIMING of the low -- if it lollygags, we'll see less snow and a quicker changeover to ice then rain. If it scoots in here quickly, we'll see more snow on the front end.
Now, we need to talk about that "i" word I mentioned before: ice. There are indications that the changeover from snow could happen quickly and that it would be to mostly freezing rain. Still too early to pin this down, but something that must be monitored.
Also, I should note that the coldest sustained airmass of the season (as alluded to last week) will move in behind this system. We will see a number of days in a row with highs in the 30s and 40s and lows in the teens and 20s -- maybe even lower.
So, here's the latest breakdown:
No precipitation to speak of: <1 percent
All rain: 30 percent
Marginal winter event (a dusting to less than an inch of snow/slight ice coating) 30 percent
Minor winter event (1-2 inches of snow/minor ice coating) 24 percent
Moderate winter event (3-5 inches of snow/moderate icing) 14 percent
Major winter event (6 or inches of snow/major icing) 2 percent
Adding most of the new weight to marginal and minor event.
GFS just rolling in -- pretty much holding serve.
By tomorrow morning we'll be within 48 hours!