Monday, 11:30 a.m.
Fresh off the long Thanksgiving weekend, I'm looking at a rather weak storm that will bring accumulating snow to parts of the Northeast over the next 36 hours. As storms go, it will be fast-moving, and the upper-level trough is a positively tilted one. In other words, the base of the trough will lag behind the top end of the trough. Visually you can see that here off the NAM 36-hour 500mb forecast for tomorrow evening:
This means the total snow accumulation where it is all snow will at best be a few inches. The air mass ahead of this just isn't all that moist, and it's moving along quickly. Only so much moisture can be handed off from the southern branch to the northern branch feature before it is all pushed aside late tomorrow and tomorrow night. Here's the latest forecast from AccuWeather.com:
Behind this feature, the cold will be slow to exit. The temperature anomaly forecast from the GFS ensembles shows you how chilly it'll likely be Thursday:
In areas where there is still some snow on the ground Wednesday night and it is clear and calm underneath high pressure, temperatures could slip into the teens.
The cold will hang in there through Friday before the last of the reinforcing highs clears the deck. This last one will move into New England Friday and Friday night, keeping it cold there into Saturday while areas back in the Ohio Valley will warm very nicely this weekend.
The rest of the country? Mild, in a word. Not bad at all for the end of November. There's still a general lack of snow cover in much of the nation right now, even though there is plenty just across the border. The most recent snow cover analysis:
The only other weather of note this week will come later in the week as a massive storm in the Gulf of Alaska wobbles closer to the Northwest coast, spreading rain into the northern half of California, as well as portions of Oregon and Washington. It won't be the most prolific of rain events, but it will be mild and wet with relatively high snow levels. They will begin to lower Thursday afternoon and Thursday night as a weak front moves inland. However, the air mass overall in the West will remain mild into and through the weekend.
Over the weekend, with the lack of snow cover on the Plains, it will become quite balmy with many places up into South Dakota and maybe even southeastern Montana reaching the 50s and lower 60s Saturday and Sunday, and 70s perhaps up into parts of southern Kansas. Some of this incredibly mild air will find its way to the East Sunday and Monday, though the departures from normal will not be as large there as they will be on the Plains this weekend into at least the start of next week.
The pieces are falling into place for a powerful storm to develop in the central Plains this afternoon and strengthen tomorrow night as it crosses Pennsylvania into southern and eastern New England.
While the deep winter cold is on a temporary hiatus, it will come back in the wake of a potent storm at midweek, a storm that will deposit its heaviest snow on New York state and northern New England.
Once the storm off the Carolina coast pulls away from the coast tonight, the weather pattern will be rather quiet in much of the country into early next week, and it will also be rather mild in much of the nation. That will all change with a storm during the middle of next week that could dump heavy snow from parts of the Ohio Valley to the Northeast, and it will be followed by another blast of very cold air for the second half of next week into next weekend.
Cold and wintry weather is not leaving any time soon, though there will be a couple of breaks in the cold over the next week that will offer up some spring teases.
The worst of the bitter arctic air is easing over the next 24 hours, but there's still plenty of cold air in the pattern, and there will be a storm next week that may spell trouble as it runs from the Northwest early Monday to the East late Wednesday.
A record-setting cold air mass is in place from the southern Plains to the East Coast today. It will ease later this week, and another of its kind is unlikely, but the pattern remains cold for much of the next two weeks.