Precip is already falling across much of the area as our next storm moves in. Expect snow to flip quickly to freezing rain/rain along the coast but remain all snow inland this evening. Currently, some weak divergence aloft is causing a heavy snow band to move through Cumberland County on its way NE.
This divergence is causing a brief heavy snow burst which, despite warm temps, is accumulating on some of the roads so use caution if you happen to be driving this afternoon.
Warmer air will continue to flood into coastal regions this afternoon though after looking at data from a special sounding (vertical profile of the atmosphere) from the NWS in Gray, models appear to have had a warm bias with this event and thus a tad more frozen precip is expected especially away from the immediate coast.
Here is the HRRR model’s take on what the first phase of our storm will look like through the wee hours of tomorrow morning. This model does a good job showing the rain/snow line advancing this evening with heavy snow across the interior and rain across coastal areas. I would advise taking this model with a grain of salt however as it shoots the rain line past Lewiston. When accounting for the warm bias of the models for this event, the rain line should approach the Lewiston area but is not likely to pass it especially considering the snowpack we still have on the ground.
The second phase of the storm occurs tomorrow when a strong upper low crosses the area. Expect temps to crash tonight as NW winds behind a developing secondary low move cold air into the region. As a result, tomorrow’s part of the storm will be an mostly snow event which is where the coast picks up their accumulation. There is still some debate as to if/when/where an inverted trough might setup to help focus the precip so uncertainty still remains. Precip looks to move out tomorrow evening from west to east.
Here is the latest snowfall forecast showing the coast escaping with little more than a dusting while the mountains see the jackpot with 8-12″. Due to warmer temps, this will be a wet and heavy snow so watch for a few isolated power outages as trees sag under the weight of the snow.