March 12, 2018

Temperature: 40°F
Dew Point: 16°F
Wind: NNW 14 mph
Clouds: Cloudy

The jet stream in moving over the souther half of the United states. The circled area in Figure 1 indicates the cold air that is moving in known as the continental polar. 

Figure 1. jet stream at 250 hPa (earth.nullschool.net).

The western half of the US (and part of the south) is covered with the high pressure system. While, the area that is in the low pressure system is bringing the cooler temperatures and potential for another snow storm.

Figure 2. current surface (intellicast.com).

The high pressure system contains temperatures that are 60°F and greater. The low pressure system contains cool temperatures from about 15-30°F.

Figure 3. Current conditions temperature map for the US (wunderground.com).

By 2:00 am this evening, the NE will be experiencing the worst of the snow. Gaining multiple inches of snow that will effect travel conditions.

Figure 4. Forecast map of weather events (wunderground.com).