A quick update tonight on the next messy storm in the lineup which arrives Wednesday. This one looks to be a fairly simple storm with mountain snow/mix, inland snow/mix/rain and coastal mix/rain. The challenge, as always, will be to pinpoint exactly where those transition spots will set up. The actual storm looks to track right over us and any nudge in the track would result in big changes to the forecast.
Low pressure that passed north of the region today left a cold front behind and that is currently sitting across the region this evening. Low pressure will develop along the front to our SW tomorrow and will move into our area overnight Wednesday. The low currently looks to track right over the area which means that we get the best of both worlds depending on location. The low passes south of the mountains so they get mainly snow with some respectable amounts possible especially the farther NW you go. The low looks to pass over the foothills so they get the full house of snow, sleet, ice, and rain. The low passes NW of the coast so they get the warm rain treatment. The exact lines between these zones are still blurry and will remain that way until things start playing out Wednesday morning.
The trick to this forecast will be temps aloft. The mid level low will track over the mountains which should let them stay mostly snow. Farther south, even the foothills are on the warm side of the low which means that the stage is set for mixed precip likely in the form of freezing rain. Significant accumulations are not expected but there will likely be widespread slick spots away from the coast Wednesday. Should the track of the mid level low shift to the north, even the mountains mix and less snow falls. If it shifts to the south, the mainly snow area could shift down towards the foothills. Both options are on the table at this point.
Here is what I’m thinking in terms of accumulation for various precip types. The only area that could get a significant storm looks to be the northern mountains. Everyone else mixes with an assortment of precip types.
A coastal storm misses south late week and then a ridge builds into the east coast which leaves us with building heat heading into next week.
Today will feel a lot like April or even early May as low pressure again passes west of the area. Look for partly to mostly cloudy skies along with a shower this afternoon. Highs will reach the low to mid 40’s north and upper 50’s to low 60’s south.
A cold front will bisect the region today resulting in a dramatic contrast temperature wise. North of the front, rather cold air will be building in resulting in below normal highs in the upper 20’s/low 30’s. South of the front, look for springlike heat with highs soaring into the 40’s and 50’s. Because of the sharp temp contrast, more clouds will be out and about today but some sun is definitely expected.
Our cold front has moved through and now it’s time to experience the final season given to us by our storm: fall. Temps will be falling today and we’re currently starting a few degrees on either side of freezing depending on location. By the end of the day, we’ll be a few degrees on either side of 15 or so, colder north, warmer south. Skies will be mainly cloudy in the north where upsloping could keep a few snow showers around. In the south, downsloping will act to clear skies out resulting in mainly sunny conditions.
Today will feature a wild day of weather as a decaying storm passes just to our west. Thunderstorms are cranking through the region this morning though they should clear the Midcoast by around 7AM. In the wake of these storms, some partial clearing is possible this morning before we get hit by the back side of the storm. Right now, it looks like this will feature mainly rain showers this afternoon and evening though snow will be mixing in from north to south. I have doubts as to whether the snow line can make it all the way to the coast before precip departs but the mountains will likely see a period of accumulating snow this afternoon/evening mainly in the higher terrain where a couple of inches are possible. The foothills could see a coating especially at elevation and especially in the northern areas while the coast likely escapes any snow. Rain and snow move out late tonight/early tomorrow morning.
Here’s the HRRR model showing heavy precip moving out this morning followed by lighter precip this evening. Notice the mountains beginning to change to snow at the end of the loop. I expect snow to push as far south as the foothills before precip moves out. Little to no accumulation is expected outside of the higher elevations where upsloping will help enhance precip.
Surface observations indicate some sub-freezing holdouts in the foothills this morning with Bethel, Paris, and Livermore all reporting below freezing conditions. In those areas, watch for slick spots as some black ice is certainly possible. Any remaining pockets of could air could wash out in southerly flow this morning though the cold front is already just west of NYC and racing east so that window is closing. Farther south, record high temps have already been broken this morning as temps jumped into the 50’s. I could see a few more degrees of warming before the sun comes up but after the cold front passes later this morning, expect temps to slowly begin to cool.
An absolute mess is occurring across the region with surface observations showing below freezing temps across much of the interior. With moderate to heavy rain falling, ice accretion remains a fairly significant concern. Freezing rain will slowly transition to rain this evening as warm air noses in from the east. This transition will be slow to occur especially over inland areas. Storm total ice is likely to be in the .25-.5″ range which is in line with my forecast from last night.
Rain will continue to increase in intensity this evening and the heaviest precip will arrive in the form of a line of showers and thunderstorms late tonight into early tomorrow morning. By this time, cold air should be pushed well to the north and no icing concerns are expected. The concern with this will be winds and heavy rain which could lead to power outages and some nuisance flooding respectively. Winds could gust to 45mph in the stronger storms.
Winds and rain move out Thursday afternoon with some breaks of sun possible. Clouds move back in Thursday evening and a little more snow is possible for the mountains as upsloping kicks in. Accumulations should remain under 3″ and will be confined to the higher elevations.
Today will feature the first round of our messy storm as cold air tries to remain locked in this morning. Winds are out of the north-east at the surface and everyone, all the way down to the coast, is below freezing. Snow is falling across the area as of 5:30 but warm air is about to punch in aloft as winds at about 2,500 feet are out of the south-east. Warm air is just starting to punch into the midcoast at that level as of 5:30 and the rest of the coast will soon follow.
Taking a look at surface obs, NE winds are evident across the entire region which is helping to lock in the cold. This is expected to continue this morning even for the coast and a Winter Weather Advisory has been issued for the entire region which was just expanded to include the coast. Notice easterly winds over the Gulf of Maine. These are warm winds and will eventually cause temps to rise above freezing from SE to NW this evening.
Snow will slowly go over to freezing rain this morning which will slowly go over to rain this afternoon as shown above. Notice the pockets of freezing rain still holding on in the mountains even this evening. Some of the mountain valleys and some of the higher elevations of the coastal plain could hold onto the rain through around 7-9 PM this evening. In places still below 32 around that time, around a half inch of ice is possible which is more than enough to cause tree damage.
Heavy rain and wind move in tonight, I’ll have another update more focused on that this evening.
Another storm is tracking up the Ohio River Valley this week and it will bring with it a mix of snow, sleet, freezing rain, and rain with the chance for a rumble or two of thunder. This storm is really two storms, one moving offshore tomorrow and another moving to our west Thursday. The first storm has the frozen precip while the second storm has the liquid precip. I’ll break down each and every impact below starting with some snow tonight into early tomorrow morning.
First Storm: Snow
Low pressure is moving NE offshore this evening and will bring us a round of precip tonight into tomorrow morning. Due to a cold dry airmass out ahead of the storm, this precip will start out as snow tonight with a couple inches of accumulation. Warm air will be blasting in aloft and will change snow over to sleet and freezing rain for the AM commute tomorrow. Before the changeover, a few inches of snow are expected but accumulations should remain fairly light. The snow combined with the icy mix will make for a very slick AM commute so be sure to allow extra time for slow travel tomorrow morning.
Here is what I expect for snowfall accumulations. The immediate coast could go over to rain fairly quickly so little accumulation is expected there. Most areas see 1-3″ but areas in the far north are likely looking at a good 3-6″ before warm air aloft finally gets up there mid day tomorrow.
First Storm: Ice
Warm air aloft will easily move in tomorrow morning. At the surface however, the cold will put up a solid fight. As a result, freezing rain is expected to be widespread tomorrow. This vertical profile of the atmosphere tomorrow afternoon near Rumford shows what I’m talking about. Snow will form and fall in the upper levels of the atmosphere which are below freezing (upper blue area). They will then fall into an above freezing layer which will feature temps near 5C (41F) and the snow will melt. Just before it falls to the surface, it will encounter more below freezing air. This won’t be cold enough for long enough to refreeze the rain back into sleet but it will be cold enough to allow the rain to freeze on whatever it hits. This is how we get freezing rain. As long as the lowest levels of the atmosphere stay below 32F, ice will continue to pile up. The greatest risk for solid ice accumulation is in the mountains and foothills where cold remains in place the longest. Closer to the coast, the very bottom of the atmosphere will warm faster but a sliver of below freezing air will remain between 500 and 1500 feet in elevation. If you live between those elevations anywhere in Maine, you are at risk for a fairly significant ice event.
Here are my thoughts on ice accumulation. Keep in mind, areas between 500 and 1500 feet in elevation run the risk of up to .5″ of ice even towards the coast. At lower elevations near the coast, less ice is expected and the immediate shorelines will likely escape the ice for the most part as temps quickly rise to above 32F. Also keep in mind that a half inch (.5″) of ice is enough to cause tree damage so power outages are definitely possible during this time in any areas that do get close to that half inch mark.
Second Storm: Rain
Strong southerly winds eventually get rid of any remaining holdouts of cold air. This will occur from SE to NW Wednesday evening into Wednesday night and the job won’t be completely done for the mountain valleys until the wee hours of the morning Thursday just before the heavy precip moves in. When the heavy stuff does move in, temps will be above freezing for all. While the frozen precip risk will be diminished at this point, we do still have two threats: rain and wind. Between 1 and 2″ of rain is expected for everyone across the area and this combined with warm temps could result in some minor drainage flooding. More impactful river flooding is unlikely though we do run the risk of ice jams on the bigger rivers which very well could cause problems. High winds will be possible with a line of heavy showers Thursday morning and a rumble of thunder cannot be ruled out. Heavy rain clears Thursday afternoon with just residual showers through Thursday evening. Gusty westerly winds will bring temps back below freezing Thursday night and an inch or two of upslope snow is likely during this time as well.
Second Storm: Wind
A band of strong winds aloft will be moving through at the same time the heavy rain will be and thus we run the risk of some of those winds being mixed down to the surface. While these winds could be strong, notice the lack of bright pink/purple we saw last week indicating these winds will be weaker. While I don’t expect any major issues with these winds, I am worried about scattered power outages especially in areas where ice from tomorrow has weakened trees. In terms of how strong I expect the winds to be, coastal areas could see gusts to 50 mph while the rest of the area sees gusts to 40 mph. Winds turn westerly Thursday afternoon and remain gusty but calm down into the 20-30 mph range which should limit any impacts after noon ish Thursday.
To recap, snow moves in tonight followed by ice tomorrow morning. Ice slowly changes to rain from SE to NW Wednesday night with everyone seeing rain by the time heavy precip arrives Thursday morning. Heavy rain will mix down some high winds Thursday morning causing scattered power outages especially in areas where ice on Wednesday has weakened trees. Rain and wind clears out Thursday afternoon as westerly winds bring in cooler and drier air. Upsloping will keep precip up and running in the mountains where an inch or two of snow is likely into Friday morning.
A cold front passes through Saturday night followed by a warm front Monday. Another cold front arrives Tuesday followed by colder temps.
Today will feature mainly cloudy skies as low pressure moves north. Look for any morning sun to quickly fade to overcast skies and winds will turn northeasterly which will begin funneling cold air south. Highs will be cool today with temps expected to get into the upper 20’s north and lower 30’s south. For details on the upcoming storm, check out my update from last night. I’ll have more this evening.