After one of the coldest starts to winter in decades for the eastern third of the United States, it finally appears that some relief is on the way. Since the middle of December, we’ve been locked into a very rigid pattern, with a big trough sitting in the east and a large ridge out west. This has allowed frigid air from Canada to dive directly into the east, while the west has stayed dry and hot. The major California wildfires and lack of snow across the Rockies are a direct result from this pattern that has held serve for nearly an entire month.
Looking at the temperature anomaly report above from weathermodels.com, you can see just how abnormally cold the end of December through early January has been for every state east of the Rockies. Many records were shattered both across the Midwest and the Northeast, and snow visited Florida two different times.
Starting tomorrow though, we expect a new pattern to emerge, likely making those who live in the east much happier than they’ve been in recent weeks. It appears things will reverse, with strong ridging moving into the east, and troughing moving into the west. This means the opposite effect takes place, where warmer than normal temperatures overwhelm the east and cooler than normal temperatures inundate the west.
Tomorrow through the end of the week, this is the turn pattern we expect to takeover the country. West of the Mississippi turns cool, east of the Mississippi turns warm, and our storm track tries to move in somewhere between the two massive air-masses.
What’s important to note about this new pattern though, is that it looks to be transient, meaning nothing will hold for very long. Going into the following week, we see a quick reverse once again with a shot of cold in the east and a shot of warmth in the west. Then another flip, and so on and so forth.
What this means for the pattern as a whole is that most locations across the nation will go from slightly above average temperatures with a chance for wet weather to slightly below average temperatures with a chance for snow. Not one single pattern type will dominate from more than 4-7 days. That looks to last through at least the middle of the month, but there are already signals that towards the end of the month and heading into February, we slip into a more dominant colder pattern once again. Too early to tell at this point though, of course.
For now, enjoy the brief warmups and breaks between the wintry weather, and stay tuned for updates as the pattern becomes more active towards the middle and end of the month.