The northern tier of the United States has generally been under zonal flow for the latter part of this week. Zonal flow occurs when the jet stream is in a more stable state, lying “flat” across the United States. This allows for a strong west-to-east motion when it comes to weather events moving across the country. A strong west-to-east motion allows for weather systems to move across the country fairly quickly, both high and low pressure systems.
This will continue with high pressure sliding offshore today as a weak low pressure system pushes to the north of New England this evening into Saturday morning. This system will drag its cold front across the region, resulting in scattered showers. These showers will push northwest to southeast this evening through Saturday. Showers will be most numerous across northern New England, closer to the center of the low, with more scattered activity in southern New England.
Showers will end by Saturday morning for most in New England, with clouds from the front clearing out by the afternoon. The exception will be eastern Maine, who may see showers last for much of the day. Showers won’t have much to work with, so they will be light. Total rainfall should be no more than a quarter inch across northern New England with many in southern New England not seeing measurable precipitation.