Another storm system has its eyes on Quebec today which means we’re once again on the warm side. Southwest winds and partly to mostly sunny skies will push temps into the mid 30s up in the mountains and mid 40s along most of the coastal plain. Parts of southern NH may get dangerously close to 50. While skies will start out mostly clear (except for up in the mountains and some of the interior foothills), clouds will slowly gain the upper hand as the day goes on and the system draws closer. A few late day showers, either rain or snow, are possible up in the mountains but most precip will remain north of the border until tomorrow.
Mild and unsettled weather is expected today as a weak clipper tracks up through Quebec, sending a cold front in our direction. Ahead of the front, southwest winds and patchy sunshine will push temps into the mid 30s in the mountains and mid 40s in southern NH. As cold air moves in aloft this afternoon, the faster change in temperature with height will support some instability. As a result, whatever sunshine you see this morning will become increasingly obscured by clouds this afternoon. Those clouds will also be producing all manner of precipitation types from snow up in the mountains to a mix of rain, snow, graupel, and maybe even a few very small hailstones.
Showers will be most widespread and long-lived in the mountains but anyone has a chance at some precipitation. Temps will fall quickly behind a cold front tonight so watch for slick spots as residual moisture freezes up.
An Alberta Clipper will slide across the Great Lakes today meaning winds will flip back around to the southwest and we’ll be dealing with milder air and sunnier skies. Look for high temps ranging from the low 30s up in the mountains to around 40 along the NH/MA border. Some upslope clouds continue to linger in the last bit of NW flow this morning, but those should fade quickly in the next few hours with generally sunny skies prevailing thereafter.
Today will feature the slow departure of our sloppy winter storm as low pressure slips slowly towards Nova Scotia. Current precip types as I write this around 7 AM range from plain old rain along the coast, where temps range from 33 at PWM to 37 up in Wiscasset, to sleet/freezing rain in the foothills and snow up in the mountains where temps range from the upper 20s to low 30s. The general trend today will be towards less sleet/ice and more rain/snow as temperatures cool aloft and warm near the surface. Plain old rain should be able to make some more inland progress thanks to the stronger sun and thinning cloud deck, along with some downsloping on northwesterly breezes. However, temps will also be cooling aloft and that should help keep the mountains snowing.
Overall, another 1-3″ seems likely in the mountains with a slushy coating at best in the foothills and plain old rain along the coast. Temps across most of the area outside the higher terrain will crack the freezing mark this afternoon so treated roads should be in pretty good shape. Parts of southern NH where breaks of sun are likely after noon should make a solid run at 40.
Precipitation will taper off from southwest to northeast during the afternoon hours though upslope snow may continue well into the evening on the favored NW-facing slopes.
With the darkest quarter of the year (solar winter) behind us, low-level temperatures borderline, and time of day somewhat relevant to the snowfall accumulation forecast, it’s time to declare this the first storm of late winter. This may be good or bad news depending on your perspective, but all of us should remember that late winter can last quite a long time here in northern New England and even early spring (whenever we get to that) can be snowy.
The storm arriving today will be of the messy and mostly unpleasant sort, both for those of us forecasting it and those of you experiencing it.
Southerly winds will continue to push warmer air into the region this morning, leading to initially chilly temps rising quickly towards the mid 20s up north and mid 30s along the Midcoast. Any glimpses of the sun this morning will be short-lived as clouds advance from the west.
Precipitation will arrive from the south starting around noon but it’s not clear exactly what form it will take. Temperatures west of I-95 will be cold enough for frozen something, but there’s likely to be too much dry air aloft to support much snow. So expect the event to start off with a period of “snizzle” i.e. some snow and some freezing drizzle. It won’t accumulate much, but it will be quite slippery for those surfaces that don’t get a dusting of sand this morning.
Forecast map valid 5 PM today showing rain near the coast and snow inland. This map doesn’t show freezing drizzle which is expected in parts of Maine away from the coast during this time. Temperatures (small numbers and background non-precip shading) should be within a few degrees of freezing even inland, so treated roads shouldn’t be too bad.
Proper snow will develop from southwest to northeast this evening as better moisture and lift move into place. Most spots SE of I-93/NH101/I-95 in NH and I-95/I-295/US1 in ME will start this event with plain old rain thanks to onshore winds. As per usual, my money is on the surface cold air hanging tough in the foothills and mountains especially given our relatively deep/fresh snowpack. So watch for slick spots away from the coast during the evening commute today but overall no major issues are expected.
Model guidance is rather optimistic, I believe too much so, regarding the ability of above-freezing air to surge inland overnight. I think the freezing line will be able to push towards Sebago Lake/Lewison/Augusta, but better lift and heavier precipitation will likely keep precip types leaning towards snow. By tomorrow morning, the rising sun may push the 32F line up towards the mountains while cooling aloft pushes the rain/snow line closer to the coast. Yes you can get snow even with surface temps above freezing if it’s cold enough aloft and the near-surface warmth is very shallow. That said, warmer temperatures near the ground will support a much wetter snow than our past couple storms which means we’ll open the door to some power outage concerns especially inland.
Now for the age-old question: how much snow do I think will fall?
Here’s my current thinking given plenty of uncertainty both in temperature profiles but also how much precipitation will fall period. There’s still some model guidance that keeps the steadiest/heaviest stuff to our east which is one thing to watch out for in terms of bust potential.
The jackpot will, as is so often the case, be up in the mountains. Most of the ski areas can look forward to a solid 4-8″ and I wouldn’t be surprised if Sugarloaf and Saddleback especially can challenge the higher end of that. This will be a slightly wetter snow, especially at the onset, but with an already-deep base up there the skiing will be good regardless.
Most of the Maine foothills should come in around 4″ with the tops of the hills doing better than the valleys. Most of the I-95 corridor is looking at about 2″ of heavy wet snow while the coast is likely limited to a dusting or an inch at best as colder air wraps into the back of the system tomorrow.
As a general rule, 4-6″ is the threshold for power outage concerns with this type of heavy/wet snow, so be prepared for that if you’re up in the inner foothills/mountains.
The storm will depart from west to east tomorrow afternoon.
Generally quiet weather will continue today as high pressure slowly slips offshore. Look for morning sunshine to give way to midday/afternoon clouds moving in both from the west (especially in the mountains) and the south (along the coast). The clouds advancing up the coast will be provided courtesy of the Gulf of Maine, and may contain some ocean-effect snow showers especially east of Brunswick this afternoon/evening. No accumulation of note is expected.
With winds shifting around to the south, temps will rise considerably from morning lows near zero (or a bit below if you’re inland) to the low 10s up north and mid 20s in the south by this afternoon.
Today will feature cooler temperatures and mostly sunny skies as yesterday’s storm rolls on east towards Nova Scotia. There are still a few leftover clouds, mostly thin/high cirrus drifting over the coastal plain and some stratus banked up against the mountains. Both should diminish in coverage over the next few hours, though some parts of Coos County in NH will likely see upslope cloudiness linger for quite a while. Otherwise, today will be quiet with NW winds bringing cooler and drier air into the area. High temps will range from around 10 up north to around 20 right along the coast.
The messy winter storm that began yesterday afternoon in the mountains and last night closer to the coast will continue throughout the day today as waves of low pressure move along the frontal boundary currently racing south over Southern New England. The airmass battle lines are drawn fairly clearly this morning with the mountains and most of the foothills experiencing pure snow while the coastal plain sees a mix of sleet and freezing rain thanks to a layer of warm air aloft. At this point, nobody is reporting a temperature above freezing and that will remain the case through the rest of the day.
The gradual trend today will be towards cooling of the middle atmosphere, albeit slowly. As a result, look for the sleet/snow line to gradually work its way southeast throughout the day. It should be out of the Lewiston area in the next couple hours, while Portland and Rockland may have to wait until the early afternoon to change over to snow. Around a half-inch of liquid is expected to pile up between now and the middle of the afternoon which should translate to another 4-6″ of snow inland (on top of what you measure walking out the door this morning) and 1-2″ of sleet along the coast.
Another wave of low pressure will pass by during the late afternoon/early evening hours, finally dragging the warm layer aloft offshore. It will bring another ~quarter inch of liquid which will fall as 1-3″ of snow across the entire area. For spots south of Portland especially, that’s most if not all of the snow you’re going to get out of this, though you’ll end up with a nice 4-6″ glacier of extremely heavy/dense snow/sleet mix.
Most of the area has been lucky enough to avoid major ice issues, the exception being far southern NH as expected. Freezing rain will continue mainly south of 101 through the next few hours with up to a quarter inch of accretion possible. That’s enough to cause some problems, especially up on the hills where amounts may be a bit higher, but a changeover to sleet midday should prevent the worst power outage impacts.
Precipitation will wind down from west to east between 7 and 10 PM though flurries may linger into tomorrow morning especially up in the mountains.
Temps today will fall from the mid 10s up north and mid 20s down south this morning to the mid 0s up north and mid 10s down south by this evening.
Another winter storm is on our doorstep this morning, and what this one will lack in ferocity it will make up in longevity. Light precipitation is already falling across parts of the area this morning, mostly in the form of rain as several days of southerly winds have finally pushed temps above freezing across most of the area outside the mountains.
Rain will continue on and off through the midday/early afternoon hours with only the higher summits enjoying snow. However, a powerful cold front lurks just to our northwest over the Saint Lawrence Valley and will arrive on the scene later this afternoon. As the front pushes south, rain will give way to a myriad of messy frozen precipitation.
The lower elevations up in the mountains will change over to snow starting mid afternoon, and the rain/snow line will crash rapidly SE reaching the Belfast-Brunswick-Fryeburg corridor by 8 PM or so. That’s where the advance of freezing air will slow to a crawl aloft while continuing near the surface. As a result, expect a corridor of notable sleet/ice from the Midcoast into Cumberland/York Counties and southern NH.
At the moment, it looks like the near-surface cold layer will be more than deep enough to refreeze falling raindrops into sleet. That’s great news for trees and powerlines, but tough news for shoveling. Sleet is extremely dense (about 2″ depth for every 1″ of liquid) and extremely slippery (small balls of ice that like to roll around) so take extra care when removing it from your outside surfaces. The area to watch for ice will be southern York County and southern NH, especially south of 101. Up to a quarter inch of ice may accumulate here which is starting to knock on the door of potential power outage issues.
Farther north, this will be an all-snow endeavor once the changeover happens this afternoon. The mountains should get a solid foot of snow with higher totals up above 3.000 feet where the changeover will occur earlier today. Most of the foothills, especially northeast, should come in between 8-12″ while the coastal plain gets a messy mix of 4-8″ initially as sleet before changing over to snow later tomorrow. The event will end with snow across the area which will give points south of Portland a quick 2-4″.
Today will feature significantly warmer temperatures as southerly winds push mild air into the region ahead of an approaching cold front. Temps will rise into the mid 30s up north and upper 30s down south under partly to mostly cloudy skies. Patchy fog may develop along the coast where higher dewpoints move over the snowpack from last weekend’s storm. Some drizzle and scattered rain showers are possible along the coast especially this afternoon but overall precipitation looks minimal.
Fear not, fellow winter-lovers our favorite old man is on his way back into town tomorrow with another solid snowstorm for most of the region.
Forecasterjack 