Spring Break - March 21, 2018

Boston, MA
Temperature: 38°F
Dew Point: 27°F
Wind: NE 16 mph
Clouds: Cloudy
Precipitation: 35%

In the northeast region of the US, there is winds also coming from the NNE. Typically, when winds comes from this direction a weather event occurs. However, a NE storm is not as strong as a NW wind storm. Today, Boston was predicted to have a large quantities of snow originally starting at 12 pm. It is currently 10 pm and there has not been an ounce of snow that fell on the ground. Why?

Figure 1. Current surface winds and temperature (earth.nullschool.net).

 
When there is precipitation in the air, that does not necessarily mean that there will be a weather event. For an area that was predicted to snow for over 24 hours, the precipitation in the air is about 40%. Looking at Figure 2, there is still moisture in the air, however, there is more dry air coming from the south and pushing north.

Figure 2. Northeast Regional Colored Water Vapor Satellite (accuweather.com).

 For areas like Boston, specifically, the reason that there is no snow (compared to some snow like New York City), could be due to the jet stream. Boston is currently in the trough of the jet stream and is not bringing in any new current weather events.

Figure 3. Jet stream at 251 hPa (earth.nullschool.net).