As the storm from overnight departs us, leaving a healthy dose of snow, there’s a good possibility of another, even bigger storm for someone in the northeast US come Monday and Tuesday. A rather potent clipper low will race across Kentucky and southern Virginia during the day on Monday, and provide light to moderate snow to the north of it’s track, across most of the mid-atlantic states.
Once this low reaches the North Carolina coast, the fun begins. Just 24-48 hours ago, all models had this storm exciting out to sea stage right. However, over the last 24 hours, the upper level pattern has been changing and favoring a low which develops faster and closer to the coast from NC northward. We’ll look at the NAM, although honestly, all of the models are showing similar trends across the board:
1/23 18z NAM 500mb:
1/24 0z NAM 500mb:
1/24 6z NAM 500mb:
1/24 12z NAM 500mb:
All of the troughs over the east coast late Monday afternoon are negatively tilted, which will allow any storm that forms to ride north and parallel the coastline. But looking closer, the trough axis (or position) has moved west with each successive run of the model. Furthermore, the trough is becoming progressively deeper and sharper over time as well.
Now, lets look at the surface maps:
1/23 18z NAM surface:
1/24 0z NAM surface:
1/24 06z surface:
1/24 12z surface:
The increasingly deeper and farther west position of the trough at H5 allow the low to begin development further southwest and closer to the coast. As a result, you go from a storm out to sea on the 18z NAM last evening to a blizzard over New England on the most recent 12z run today.
18z last evening, low harmlessly going out to sea:
12z today, blizzard for New England and Long Island:
So you can see the importance of the trough depth, sharpness, and its position. As I said before, ALL of the models are trending this way. Do I think this will continue to trend to the point that it affect most of the Mid-Atlantic with heavy snows? Outside of maybe eastern NJ and New York City, no, not at this time – but, it’s definitely something to watch over the next few days. One thing is becoming more and more likely – southeastern New England and at least eastern Long Island is going to be hit pretty hard with this one.
More on Facebook at doctoochweather as warranted….