Today will feature the arrival of warm air as a storm system cruises up the Saint Lawrence Valley and pushes a cold front in our direction. Ahead of that front, southwesterly breezes will be responsible for pushing warm air in our direction. This time of year, southwesterly winds are actually fairly cool for the Midcoast (east of Brunswick) because the Gulf of Maine is still fairly chilly. Similarly, some residual snowpack and the usual terrain features will conspire to keep cooler air locked in across the usual mountain/interior foothill spots. Both of these areas will are high temps in the upper 40s to low 50s today. Along the coastal plain of Maine, temps will be a bit warmer ranging from the mid/upper 50s near Augusta to around 60 in Portland to the upper 60s in interior York County. The warmest air will be reserved for southern NH where temps will soar above 70 today including right at the seacoast. A quick glance at satellite imagery shows just about no chance for sunshine anywhere in the region today as the clear skies associated with the system’s warm sector (behind the warm front and ahead of the cold front which is where we’ll be today) look to remain south of New York City.
As the cold front approaches this afternoon/evening, we’ll have to start thinking about the chance for showers and thunderstorms. A line of storms will form in New York early this afternoon before moving quickly east. They should arrive in western NH around 4-5 PM and may be strong enough to produce a damaging wind gust or two in the southwestern part of the state. Storms will weaken as they move east, and by the time they arrive in Maine around 6-7PM, they may not even be strong enough to produce thunder. Showers and storms will continue fading as they move offshore tonight.
Cooler and drier weather will return tomorrow.