As a quick note, this post is coming out later than it should because while I had everything written up at 6:00, for whatever reason I forgot to hit the send button. While this means that the forecast information is perhaps less useful than it should be, I’ve opted to post anyway because I find it neat that we’re seeing a lake effect streamer stretch all the way from Lake Superior to the mountains of Maine, and couldn’t pass up the opportunity to mention that along with some relevant satellite imagery.
Cooler temps will return to the region today as yesterday’s storm starts spinning itself out over Quebec. The cooler air is arriving on west-southwest winds which may seem counterintuitive. Usually that’s a warm wind direction for us! It turns out that the way our storm ended up developing, it got knocked on its side a bit. This means that the coldest air lies not to the northwest of the storm, but instead to the southwest.
Why does this matter for our forecast? Whenever you get strong cold air advection on WSW winds, and Lake Ontario is warm and mostly ice-free as it is now, you get a big band of lake effect snow to develop over the Tug Hill Plateau. Why does that matter for our forecast? This band is so strong that it’s actually making it all the way to the mountains of western ME/NH!
As a result of this lake effect band (plus some upsloping), the mountains can expect mostly cloudy skies along with periodic snow showers, possibly accumulating 1-3″ in the higher terrain.
Downwind of the mountains, downsloping has produced mostly clear skies which will continue through the rest of the day.
High temps will range from around 20 in the mountains to around 40 near the NH/MA border.
After several days of quiet weather, it’s finally time for our next storm. This one is already impacting the region with moderate rain and snow as of 6:15 AM.
Rounds of heavier precipitation will arrive from the south over the next couple hours ahead of the storm’s occluded front which will be moving northeast. Behind that front, dry air will quickly race into the area and shut off precipitation. For SW NH, this could happen as soon as 8-9 AM. For Portland, this will likely happen around 11 AM or 12 PM, and for northeastern parts of the region, precip will linger until 2-4 PM.
This simulated radar loop from the HRRR highlights the rapid forward motion of this system. Most of the precip in any given area will fall over a roughly 6 hour period. For the coast and southern foothills, this means a period of moderate to possibly heavy rain. While some ponding on roads is possible, I don’t see any major impacts from the warm side of this system. For the mountains, this heavy precipitation means extremely high snowfall rates possibly in excess of 2″ per hour at times this morning. Be sure to take it easy out on the roads if your plans take you into the hills north of route 2 this morning.
As far as accumulation goes, here’s what the NWS is expecting for this storm. As usual, every forecaster would draw their lines slightly differently but overall my thinking is very much in line with theirs. The southern half of the area will remain plain rain with no snowfall accumulation while the mountains hang onto the cold air end end up with 8-12″ or possibly a little more. The cutoff between 0″ of snow and >6″ of snow will be remarkably tight with this system. That divide should set up just northwest of a Fryeburg-Augusta line.
As this system is rapidly intensifying, it will bring plenty of gusty winds to the region both out of the east-northeast ahead of the occluded front and out of the west-southwest behind it. So far Portland has gusted around 40 mph which is blustery but nothing too out of the ordinary. I wouldn’t expect any widespread disruptions to power from these winds, but some outages are possible in the mountains where trees and lines will be weighed down with the heavy snow.
Cold air is slowly filtering back into the region as our next storm system slowly develops to our southwest. That means we’ll see chillier high temps (though still way too warm for this time of year) along with plenty of clouds. While the storm is close enough to bring us overcast skies, it needs a bit more time to develop before it can send any precipitation our way. Precip should begin this evening in the form of light snow across the mountains and light rain elsewhere. By tomorrow morning, heavier precipitation will arrive and some parts of the foothills may flip back from rain to snow. I’ll discuss all that in more detail tomorrow morning. For now, expect a dry and overcast day today with highs ranging from 35 in the north to 45 in southern NH.
Today will feature continued warm temperatures as cool air struggles to work its way south ahead of an approaching storm over the Ohio River Valley. Expect overcast skies across the region due to moisture from that storm. High temps will range from the upper 30’s in the mountains to the mid 50’s in southern NH. While a couple showers are possible in NH this afternoon, most of us will stay dry until tomorrow night.
Today will feature another day of misplaced April weather as southwesterly flow continues to torch the area with air originating in Mexico. High temps will soar even higher today, ranging from around 45 in the north to near 60 along the MA border. Outrageously, we may even see a sea breeze develop this afternoon which could keep the Midcoast a bit on the cooler side. Skies will remain mostly sunny until later this afternoon when some clouds will begin approaching from the west.
Today will feature outrageously mild temperatures as southwestern flow remains locked in place across most of North America between a storm near Hudson Bay and a strong area of high pressure near North Carolina. Expect high temps ranging from 40 in the north to 50 in southern NH. Mostly sunny skies are expected once again, though I’m seeing a few mid/high clouds as I wake up here in Central New York that appear to be headed your way. Based on satellite trends, they should arrive early/mid afternoon.
Today will feature the beginning of a multi-day warming trend as a large area of high pressure moves offshore and southwesterly flow develops from Texas all the way to Labrador. A few high clouds might cross the region this afternoon in response to a passing upper level disturbance, but otherwise expect mostly sunny skies across the area. High temps will range from 30 in the mountains to 40 in SE NH.