In our previous article, we discussed some of the features in the upcoming hemispheric pattern that could support a winter weather event. These features were particularly evident during the period from January 16th to 20th. As we have gotten closer to this time period, forecast models have come into much better agreement on exactly how these features will evolve.
An impressive storm system is going to effect the Tri-State area this weekend into early Monday morning. The set-up in the upper atmosphere (500 mb) supports a long duration rain storm with frequent moderate to heavy rains which increases the flood threat, especially in areas where there is still snow / ice and if you live in a flood prone zone.
Timing:
Start: 12pm-1pm Saturday
End: 5am-7am Monday
This equates to 40+ hours of rain falling which when all is said and done could add up to 4+ inches of rain in some spots of the Northeast. Obviously the rain is not going to be heavy for 40+ hours. In fact, there may even be a brief break in the action before it starts up again. Nonetheless, we are still looking at a washout weekend with a potent coastal storm developing.
If you are a fan of changeable weather, today is for you. A major storm system, developing as a result of a mid level phase, will organize over the Tennessee Valley and shift northeastward to a position near New York City late tonight. The track will mean significant winter weather for our friends in Northern New England (including many of the major ski resorts), but more notably one of the more dramatic swings in sensible weather our area has seen in months. Temperatures will swing from the mid 60s to 70s in some spots this afternoon, all the way down into the 20s by Thursday morning.
Not surprisingly, the significant storm system moving through the Northeast US Wednesday into Thursday will feature a powerful thermal gradient and cold front. Initially, the thermal gradient will develop along a warm front which will stretch from southwest to northeast through the Northeast Wednesday afternoon. Parts of New Jersey could eclipse 70 degrees as southerly winds increase and temperatures increase in the low levels. Forecast models show drizzle and rain eventually increasing in coverage and intensity by Wednesday evening as moisture and lift begin to increase and the frontal boundary approaches Central Pennsylvania.
Regional radar imagery showing precipitation approaching the area as of 9:15am (weather tap).
A pre-thanksgiving storm system will create a travel nightmare from Tuesday Night through Wednesday, providing a myriad of threats up and down the east coast. Before we dive into the details of the storm system, what’s causing it to occur, and what you can expect in our area, we can lay out a few things we know as fact as of Tuesday morning. First, there will be significant travel delays on Wednesday. If you’re driving, flying, or using some other form of travel in the Mid-Atlantic or Northeast US, expect delays…likely significant. Second, Thanksgiving day itself won’t be all that bad. So once you make it where you need to be, the weather for actual Turkey Day looks to be fairly pleasant, albeit a bit cold. In our post below, we break down the storm system and what you can expect from it.
Visible satellite imagery from Tuesday morning, showing a significant storm system forming in the Southeast US.
What’s the deal, how is this storm forming?
Two pieces of energy in the jet stream across the Central and Eastern United States will phase on Wednesday, essentially very close to our forecast area. A low pressure area will develop from the Southeast States northeastward into New England. As it does so, warm air will stream up the Eastern Seaboard — as will significant amounts of precipitation in association with a strong low level jet and moisture transport. The low pressure system will then rapidly deepen as it moves to our north through New England and into Eastern Canada.