Hello everyone!

A cold front is sinking south across the region currently as high pressure builds in from the north. Look for mainly cloudy skies with the chance for a shower or two as this front moves south. Temps will rise into the low to mid 30’s north and the upper 30’s to low 40’s south.

-Jack

Hello everyone!

Like a bad reality TV show, winter’s last stand looks to have several unwanted episodes as we head into early April. Having already seen our first event out of this newly active pattern, our attention now turns to the next two threats for winter weather which are on the horizon in the coming week.

Our first shot at winter weather arrives tonight in the form of a weak burst of warm air aloft which will set off some light snow in the mountains. This activity will also be associated with the push south of cold air at the surface in the form of a backdoor cold front. The combo of surface cold front and mid level warm front will lead to light snow in the overnight hours across the north country. Mainly snow is expected with light accumulations.

This light snow will provide the first ingredient for late week trouble: cold air. A sprawling Canadian high pressure system will build south behind this backdoor cold front delivering more cold air. This won’t be Arctic air but it will be cold enough to make precip that falls when low pressure approaches from the west fall in the form of snow/sleet/freezing rain for many as opposed to rain. Guidance is still struggling to figure out how long the cold will last but seeing as this is looking like a nearly classic Cold Air Damming (CAD) situation, I think it best to go with the old rule of thumb: CAD will always last longer than you think, even if you think it will last longer than you think. The long and the short of it is, cold air in Maine leaves when it’s good and ready, not when warm air tells it to and it’s about as motivated as a teenage boy.

Here’s the setup late Thursday evening as low pressure approaches from the west. Cold, dry air will be in place shown by isobars bending over our area and shades of Grey appearing in the Precipitable Water (PWAT) fields. The scale on the right shows how grey colors represent low PWATs and thus dry air. The image also shows sea level pressure which shows high pressure anchored to our NE feeding cold air south. The wavy nature of the warm front also signals the lack of a concentrated push north of warm air as well as the potential for redevelopment of low pressure offshore. The secondary coastal storm is something that guidance is hinting at and with the strong high pressure trying to ‘split’ the storm in two, this seems like a reasonable possibility. This is unlikely to lead to a strong coastal storm and precip is likely to remain light to moderate through the duration but it would help to keep that cold air locked in across the area.

In terms of impacts, this one will be a mix of snow, sleet, and freezing rain for most of the area with the far north possibly holding on to mostly snow and the coast seeing a change to rain at some point. Everyone will see slick travel Friday during the morning commute and roads are likely to remain slick for the evening commute away from the coast. While it is still a little early to call exact amounts, I expect a widespread 1-3″ of snow with coatings along the coast and 4 or 5″ possible in northern Franklin and Somerset counties. In terms of ice accretion, light to moderate amounts are likely and in some areas, especially inland, it could be enough to threaten power lines. This does not however look to be a major ice event. With the storm weakening and possibly splitting, there does not look to be enough precip to cause major issues.

I’ll have more info in the coming days on the Friday event.

Another round of wintry weather is possible early next week. While it is still a week away, there are reasonably strong signals we see some sort of precip. As always this far out, any and all solutions are on the table from snowstorm to rain storm to sunny day. More on that as we get closer.

-Jack

Hello everyone!

A rather nice Spring day is on the way this morning as temps currently below freezing rise into the low to mid 30’s north and mid to upper 40’s south. West/North West winds will be busy today with gusts over 20 mph possible. This will lead to the classic upslope/downslope pattern where the mountains see clouds and flurries while the coast enjoys warm, sunny conditions. Skies will be mainly sunny but clouds will be on the increase this evening ahead of our next storm.

More details on that this evening

-Jack

Hello everyone!

Our storm from this morning is now racing NE and most of the area is seeing sunny skies . Coastal areas saw 4-8″ while inland areas saw 2-4″. The forecast worked out great for the Midcoast but busted fairly badly west of Brunswick. The culprit was a westward shift in mid level (5,00-10,000 feet up) storm systems. I’ll try to get a full post out at some point explaining that.

In the meantime, we have more winter to look forward to! Following nice weather tomorrow, a weak clipper will drive a backdoor cold front through the region Wednesday. Behind it, cold Canadian high pressure will settle in for Thursday which sets up episode 2 of winter’s last stand. A low pressure system will move along or a little north of this front drawing warm air north as it goes. We’ve seen this a million times before, when warm air crashes into cold air, trouble ensues and this time is no different. Precip likely breaks out Thursday afternoon/evening and lasts through Friday midday.

Cold high pressure to the north will play a big part in this forecast. One of the things you learn in forecasting, especially forecasting in Maine, is never to bet against Canadian high pressure. Cold air at the surface always lasts longer than you think, even if you think it will last longer than you think. Guidance is still split on exactly how this storm pans out. It is still 3-4 days away as well which means that there is more than enough time for the forecast to change. However, looking at the overall pattern, the solution the 12Z GEM (shown in maps given here) portrays is one I could absolutely see happening.

While the details of how much precip/precip type/exact timing/etc are still to be worked out, it looks like we’re in for another shot of wintry weather to close out the week. The greatest threat for this one is in the mountains and ski areas could very well see some snow out of this one in addition to any mixed precip warm air aloft could cause.

More on this in the coming days as the details come into focus.

-Jack

Hello everyone!

Today will feature snowy conditions for many as a coastal storm moves to our east. Snow is already falling this morning and will continue to do so through the early afternoon before tapering off. My snowfall forecast from last evening still looks good for most though short range guidance and radar trends are suggesting areas just inland could do a little better than thought due to the nature of the banding structure this morning. Temps will begin in the 20’s but will quickly rise into the low to mid 30’s which will melt some of the new snow. Roads will be slick for this morning’s commute and many schools have delayed or closed. Local media has the comprehensive lists on who is delayed/closed so check with them or your local school district for that information.

Episode two of winter’s last stand is later this week as a front stalls near or over us which could bring snow/sleet/freezing rain/rain depending on where it sets up. More on that in the coming days.

-Jack

Hello everyone!

Today will feature increasing clouds, cool temps, light northerly winds, and lots of confusion for meteorologists as our next storm approaches. The first ingredient for snow is cold air and that’s the ingredient we got Friday. It will make its presence felt today as highs struggle into the mid to upper 20’s north and low to mid 30’s south. Snow should hold off until late tonight but clouds will be spreading north throughout the day.

In terms of our storm, nothing big has changed from last night’s thoughts. Guidance has unanimously indicated overnight that more snow may be in store but it’s hard to say at the moment if that’s fully true. As I mentioned in last night’s update, the forecast hinges on how quickly energy diving SE across Canada (currently approaching Lake Superior) can get here to pull the storm west. 500mb analysis also paints a similar picture. Based on that, there is reason to think that guidance pointing to a little more snow may indeed be correct. 6″ of snow is not out of the question along all immediate coastal areas and a Winter Storm Watch is up for the immediate coast due to the threat for 6″ or more of snow. The Midcoast still looks to take home the biggest trophy with 8″ of snow possible there. I’ll have a full update this evening.

-Jack

Hello everyone!

Boy has this been a fun one to forecast. As one of your sources for weather information (you should always consult the NWS and local media too!), the last thing I want to do is lead you on a roller coaster ride in terms of the forecast. To flip flop the forecast each day heading into a storm is something I hate doing. I want to give you a good idea of what to expect a few days out and then fine tune the details as we approach the event. With that said, this storm has led me on a wild goose chase in that every day, everything I look to points to something different. This isn’t just the whims of the model guidance I use to make forecasts, this is observations and satellite imagery painting completely different pictures. There are many moving pieces and it’s hard to figure out where they’re all going to go and what they’re all going to do. If life was full of easy forecasts, I wouldn’t be doing this. With all that out of the way, let’s try to figure out the forecast.

Water Vapor satellite imagery this evening shows all the parts of our storm. I’ve marked the disturbances and where the surface low will form and where it could possibly track (approximately). The ULL over Iowa is diving SE and will merge with a weak disturbance embedded in a deep plume of subtropical moisture which is marked in Green. Their interaction is beginning to form a storm over the SE US. When they merge, the storm will intensify a little bit as it begins to move NE. The real question has to do with Polar energy dropping down from the Western side of Hudson Bay. It has until Sunday night to get all the way to NY (about 1500 miles). It’s a race against time. If that energy crosses the finish line in time, it intensifies the storm, helps tilt the upper trough negative, and in turn wraps heavy precip back into our area. If it doesn’t, the storm continues at a moderately weak intensity ENE out to sea leaving us with but an inch or two.

It is becoming more and more clear that this storm isn’t going to drop a lot of liquid. However, given cold temps and a reasonably solid snow growth setup (see right), the snow could fluff up enough to lead to a couple of inches despite a lack of liquid. I don’t think this will be pure powder snow, but I also don’t see it being cement. Look as much or as little as you like at the image above, it shows/explains a little what you need for snow to form and what we have. Much like a Venn diagram, where they all intersect is where the snowflakes are forming. Based on this info, expect snow to start tomorrow evening. I suspect this may be a little late as the mid level dry air isn’t too stubborn compared to some other events. Snow looks to be light to moderate through the event before ending midday Monday. The ‘heaviest’ of the snow will be during the Monday AM commute though I don’t see it being all that heavy.

Here are my thoughts on snowfall. Earlier today, I was ready to pull the trigger on lower snowfall amounts but afternoon guidance and a couple of things I noticed on the WV satellite and in the observations this afternoon have led me to remain more or less unchanged with my snow map from yesterday. I cut back a little on the back edge of the precip as all indications are that this will feature a sharp cutoff. I bumped up snowfall a little along the midcoast where the heaviest snow looks to fall. While 8″ seems like a stretch, 5 and 6″ amounts seem very reasonable along the Midcoast. Unfortunately for ski areas looking to refresh the base, this one looks a little too far east. Thankfully for skiers, both Sugarloaf and Sunday River have fired up the snow guns again! With cold temps lasting through midweek next week, snowmaking will remain possible for a solid few days.

A warm up is in store headed towards the end of next week and some wild temperature swings are looking likely heading into April.

I’ll have another storm forecast tomorrow evening.

-Jack

Hello everyone!

Today will feature mainly sunny skies, cool temps, and decreasing winds. NW winds behind a cold front have brought in much cooler air and we will be feeling that throughout the weekend. NW winds are still blowing this morning but will be settling down as time goes on. Look for highs in the 20’s north and 30’s south.

The Sunday/Monday storm looks to head mainly out to sea. I’ll have an update on that this evening.

-Jack