I'll not write a lot about the storm that's beginning to take shape over the southern Plains right now. The lowest pressure on the weather map is in West Texas, with some rain spreading across the state into northwestern Louisiana, across eastern Oklahoma, Arkansas and Missouri. And it is just that, for the most part so far - rain. There has been some icing so far today in the Ozarks, but as the air aloft warms some more ahead of the trough, the temperature at the surface will inch their way past the 32-degree mark, temporarily ending the slippery travel concerns. I say temporarily, as once the storm moves by, the air will turn colder, and many places that go to a cold rain will wind up with some snow for a time.
Snow will also blanket a good bit of the Ohio Valley, as well as parts of the Midwest and Great Lakes:
Here's the latest NAM forecast of total precipitation from 12z today through tomorrow evening:
As is often the case, the NAM quantitative precipitation (QPF) forecast is probably overdone, but it gives you the idea that across the mid-Mississippi Valley there could easily be one-half inch of precipitation. Where that's all snow, there could be a half a foot of the white stuff.
Once the coastal storm takes over late tomorrow, then the precipitation rates should increase from the mid-Atlantic into New England. Look at the same image through the entire storm, focused on the Northeast and mid-Atlantic:
Again, where that's all snow in central and interior southern New England, that could mean more than foot of snow:
Please refer to the AccuWeather.com website over the next 24 hours or so for the latest on the storm!
Now, after the storm, it gets quiet again for a while. The coldest air will be aimed at the Great Lakes and Northeast Sunday and Monday, while it's colder, but not exceptionally so across the South. That area will more easily warm from the west and south as next week unfolds, while another upper-level trough rolls through the Midwest Monday night, then across the Great Lakes and Ohio Valley Tuesday before clearing the East Coast late Tuesday night. Tuesday will turn milder in the Ohio Valley and mid-Atlantic states with and ahead of this feature, but it will turn much colder behind it once again from the Midwest to the Northeast on Wednesday.
After that, we'll have to turn our attention to another significant buckling of the jet stream, one that promises to pull another bitterly cold air mass into the Rockies and Plains over the weekend, reaching the East Coast later Sunday. There will be a wonderful surge of balmy air ahead of this storm, especially into the East, but the warmth will be ephemeral. Here's a snapshot of the Saturday morning forecast 'guess' from the 12z GFS:
This promises to be a wild transition from very mild to extreme cold, so I'm pretty certain there will be a big storm with lots of rain and probably rare December thunderstorms, maybe even some severe weather. On the flip side, though there will be some rough patches of ice and snow from the southern Plains to the Great Lakes as the cold air drills in behind the storm and the front.
It's very probable that where snow is put down behind this storm from the northern and eastern Rockies and across the Plains to the Midwest and Great Lakes, it will still be there come Christmas morning. It's hard to envision much melting taking place next weekend and the days leading up to Christmas given how cold the models are currently projecting this air to get. And it would not shock me if it ended up colder than forecast!
With the storm rolling away from the Southeast this afternoon and tonight, a more typical west-to-east flow pattern will take over in much of the nation heading into the middle of October.
Heavy rains are exiting the Northeast this afternoon, but more excessive rains will return to the mid-Atlantic later tomorrow and Friday. Hurricane Joaquin is lurking near the Bahamas, and may make the situation worse this weekend.
The system along the Southeast coast will spread heavy rain from parts of Georgia into Virginia heading into the weekend, while most of the rest of the country is dry and warm.
It may now be autumn, but much of the country will be warmer than average for the rest of the week and into the weekend.
Fall begins one week from today, but there's still plenty of warmth to go around the rest of this week, with more to follow again next week.
Record heat blistered the East yesterday, but it is about to end. Still, another surge of very warm weather is likely next week to extend summer a little while longer.