A messy "inside runner" storm is heading towards Maine this evening. Typically when a storm tracks this far west of us, we are all rain, all the way. However, due to a ridge of high pressure to the north supplying cold air at the surface for the next 12-15 hours, many of us will instead be dealing with snow, sleet and freezing rain. The last part of that, the freezing rain, is my biggest area of concern.
First thing's first...if you have to travel tonight, any time before 1 AM you are all set. The precipitation doesn't break out until the early morning hours on Monday.
Since your experience will vary so much depending on your location, the only way I can see making sense of this forecast is to divide the state into regions (Please don't whine about how I define the regions...I will turn this forecast RIGHT AROUND!!)
The Coast (Portsmouth to Portland to Rockland to Bar Harbor and about 40 miles inland.)- Yawn. Rain. Temperatures will be borderline at the very beginning of this event so we could see a brief burst of snow, maybe up to two hours over the Midcoast and Downeast, but that's about it. The wind turns east and warm air invades rapidly after that. By the time most of us wake up on Monday morning (Lee, Kevin and Sharon excluded) it will just be a cold rain with no snow on the ground. Notable exception: Only about 15-20 miles inland over Downeast over Washington and Hancock Counties will see largely snow as warm air isn't able to push as far inland there.
Interior Maine (Draw a line from Fryeburg to Lewiston to Augusta to Bangor and then end it in Calias-if you are west of this line but NOT in the mountains...this is your hood)- Snow to start everywhere in this zone. Snow begins around Midnight-2 AM over southern areas but doesn't arrive until 6-7 AM towards Bangor. Snow holds on until 8 or 9 AM before the change to sleet and freezing rain. Snowfall amounts before this changeover will be in the 1-3" range with the highest amounts further north. Once freezing rain begins it will last the longest towards Fryeburg and into North Conway. THIS is the area I'm most concerned about for ice accretion. It looks like freezing rain could continue until noon and at that point ice amounts will be between 1/4" and 1/2" in a fairly wide swath. Power outages are likely here. There will be a break in the precipitation through the early afternoon, and at that point the warm air will win out so that when the cold front comes through by 5 or 6 PM it will be all rain.
Mountains and higher foothills (This one's pretty easy)- Similar timeline to Interior Maine but higher snowfall amounts before the changeover to freezing rain. I'm thinking 3-5" is a pretty good bet before freezing rain develops through mid morning. Once the freezing rain begins, it will last until 11 AM or so and then the warm air will move in and the rest of the storm will be plain rain. Ice accretion amounts won't be QUITE as high here but still a coating to 1/4" of ice is likely.
Northern Maine (North of Millinocket and west to Jackman)- Mostly just snow and sleet here with accumulations of 3-5" likely. There will be a very brief period of freezing rain possible around noon, but it shouldn't cause too many problems as far as ice accretion. HOWEVER, while the rest of the state warms up and changes over to all rain by Monday evening, this area will be dealing with a wintry mix until around midnight so it could get messy at that point.
Phew. Ok. Got it?
If words aren't your thing I've included plenty of special graphics on our website and on our Facebook page.
This storm is on the way out by Tuesday morning, and after a brief coastal shower look for mostly sunny conditions.
It looks sunny but a bit chilly for Wednesday, Thursday and Friday. Overall though, pretty quiet.
Ok, I'm out of here.