Hello everyone!

Today’s snowfall is kicking off an active pattern for at least the next 10 days. Snow will change to a messy mix tonight before moving out tomorrow morning. Temps will fall from near 50 Wednesday afternoon to right around 20 by Thursday morning as snow moves in associated with our next system. After some wind blown fluff Thursday, we’ll get a day off Friday before a clipper system approaches Saturday. Sunday morning will be the calm part of the weekend before more snow/mix arrives with a system Sunday night into Monday morning. Another system may be showing up on the horizon for the middle/latter part of next week but it’s too far out to say what any potential impacts from that may be.

This current system has been slightly misbehaved, the first round having arrived and departed early while the second round dragged its feet in getting here. There wasn’t a lot of data that supported a break in the action today but it happened going to show you that despite our best efforts as forecasters, mother nature is the one really in charge.

The rest of this storm does look to be fairly straightforward with the only major challenge yet to figure out being the timing of the freezing rain -> rain transition. Based on the above model simulation, it appears as though that may not occur until after most if not all the precip has left though other guidance suggests the coastal plain may warm up before then. Either way, a period of ice is likely to make the morning commute slick but temps in the 50’s will make sure any icy spots melt away for the PM commute. After that, temps take a nosedive after dark and end up back in the teens for Thursday morning. That’s when the next round of fun starts.

Everything starts at 500mb when it comes to coastal storms and all signals are pointing to a fairly impactful event. The all important trough orientation is forecast to be negative meaning the slope of the trough axis is negative. This allows for the energy that forms the storm to pull out ahead of the main trough where S/SE winds can push it right up the coast. The 500mb pattern is extremely conducive to a more westerly storm track which is why I’ve gone towards the upper range of guidance for snow totals (see map below).

The jet stream will be oriented in such a way that rapid intensification of the low is supported. While not textbook, there will be two jet streaks coupling to create enhanced divergence in the upper levels as we go through the morning Thursday. Notice the overlap between the right entrance region of the poleward jet and the left exit region of the equatorward jet. This is the area in which divergence is maximized. It lines right up with the coast of New England which is another factor that would support a low track closer to the coast.

Looking towards the mid levels, the exact placement of strong upward motion will determine who gets the heaviest banding. The jackpot is currently forecast to reside over MA and SNE leaving us with moderately heavy snowfall as opposed to very heavy snowfall. However, a tick NW in the storm track as supported by the 500mb maps would mean those heavier bands would move in our direction. There’s a fine line to walk here and I suspect we’ll have more confidence by the time tomorrow rolls around.

Here’s my thinking for total snowfall Thursday. There’s room for these numbers to go up depending on the exact track. I also think this storm will follow the typical pattern of sharp gradients on the NW edge so a downward adjustment is possible across the mountains. I’ll finalize these numbers tomorrow.

Snow will move out Thursday evening leaving a cold and breezy but dry Friday. By Saturday though a clipper system will approach from the west bringing with it more snow. This system looks colder than the one today and lighter than the one forecast for Thursday. A general 1-3″ looks to be a solid early guesstimate on accumulations as guidance is fairly locked in at this point. A little coastal enhancement could develop Saturday night which may result in some moderate snow but otherwise this looks like a fairly benign system.

The clipper will move out Sunday morning leaving about 12-18 hours of calm before our next storm arrives Sunday night. This one will track right over us, approaching from the west then redeveloping offshore. The exact timing/details have yet to be determined but we have cold high pressure in place and a sharp frontal zone to our south so this one looks fairly likely to cause some trouble as we begin the next week. We’ll discuss amounts as we get closer.

The next storm in our parade is scheduled for the second half of next week but is way too far out to discuss potential timing/impacts/amounts. We’ll keep an eye on it as we get closer!

Beyond that, all indications are that we stay in an active pattern for at least the next couple weeks. Welcome to winter’s comeback!

-Jack

Hello everyone!

Today will feature light to moderate snow this morning becoming heavier by this evening. Look for 3-6″ to pile up through the day with a couple more possible tonight up in the mountains. Snow will change to sleet from SW to NE late in the evening putting an end to meaningful accumulation. Temps will slowly rise from the 10’s this morning to the 20’s by this evening. For all the details/analysis for this storm, check out last evening’s writeup.

More snow on the way Thursday, Saturday, and Sunday/Monday. Seeing as I’m off school today, I’ll have info on each system in this evening’s update.

-Jack

Hello everyone!

Last night we witnessed the greatest comeback in Superbowl history and over the next 7 days we’re likely to witness a robust comeback in terms of winter weather. An icy storm will bring snow, sleet, and ice to the region tonight through Wednesday. This will be quickly followed by a storm threat for Thursday as colder air pours into the region. Lighter snow is forecast for Saturday before another mess takes shape late in the day Sunday into Monday. Welcome back to winter!

Seeing as we have many storms in the forecast and I’d like to get this done by midnight, the analysis for each storm won’t be as beautifully detailed as I might like. Hopefully we can pull a snowday out of the hat tomorrow for more detailed coverage.

Mess #1- Tonight Through Wednesday Morning

A weak upper level disturbance will approach tonight and in advance of it, snow will break out. There’s lots of dry air for this system to overcome and so I don’t expect much snow to actually make it to the ground until later this evening for NH and later tonight/early tomorrow morning for Maine. Snow will continue through tomorrow before changing to sleet/freezing rain tomorrow night and into Wednesday morning. Expect right around an inch on the ground by the time the commute arrives tomorrow morning.

Light to moderate snow will be the rule for most of tomorrow as warm air moves up and over the cold air near the surface. The main low pressure system will track well to our west though a secondary wave of low pressure will develop along a bump in the warm front near Cape Cod. This will keep those NNE winds going strong keeping cold air locked in place at the surface. As the warm air advection aloft intensifies, precip will too. We’ve already gone over how heavier precip keeps cold air in place due to latent heat transfer from phase changes (melting precip cools air as snowflakes require energy to move from solid to liquid state) however strong WAA will eventually overcome this process aloft changing precip over to sleet and freezing rain.

As evening approaches tomorrow so too will warm air in the mid levels of the atmosphere. This cross section from VA (left) to NB (right) goes right through Maine (middle/right) and shows a cold frontal surface to facilitate overrunning precip tomorrow as well as a change to mixed precip tomorrow night. Warm air being forced up and over this low level cold dome will give us the snow tomorrow and the warmth eventually becomes warm enough to melt the snow into sleet and freezing rain.

Here’s what the result of that process looks like early Wednesday morning. Notice the warmth aloft has made it well north into Canada and a secondary low pressure system off Portland is locking in the cold at the surface. As a result, look for an icy mix to last into the morning commute Wednesday even along much of the coastline. The exception will be in the usual spots along the midcoast where the secondary low could mix up the atmosphere enough to draw down some of the warmer air aloft.

The event ends Wednesday with a temperature roller coaster along with slick travel for the morning commute. As the deeper moisture and best dynamics lift off to the NE. we’ll be left with freezing drizzle for the morning commute Wednesday. Temps will rapidly jump up into the 50’s for a few hours around noon Wednesday for most (possibly excluding the northern mountains) as the warm front lifts north and the cold air dam mixes out. The cold front will put a quick end to the spring like temps Wednesday evening as temps will quickly drop back below freezing. The refreezing of any water/slush on Wednesday evening will be something to watch as a potential hazard for the Wednesday evening commute and/or the Thursday morning commute. Black ice will be something to watch for in that timeframe.

Our next storm will develop right on the heels of our Tuesday-Wednesday mess. The cold front that will put an end to our brief few hours of spring weather will stall out over the Mid Atlantic and incoming Pacific energy will form a storm along the front Wednesday evening. Exact interactions between all the various disturbances will determine if that storm intensifies up the coast resulting in a sizeable snow storm or if it zooms harmlessly out to sea. Right now, I’d lean towards a light/moderate snow event beginning Thursday morning and ending Thursday evening. The best chance for several inches of snow will be along the coast though even there, dustings could be the upper limit if the storm tracks a little farther out to sea.

Looking past Thursday, a light snow event is in the works for Saturday with another messier system for Sunday night into Monday. More details on those as we go through the week.

-Jack

Hello everyone!

Today will feature a temporary return of our NW wind pattern as a cold front moved through last night. This time, however, real cold air is set to move in as opposed to that pseudo cold behind last week’s fronts. Temps will start in the 20’s to low 30’s this morning before falling into the 10’s/low 20’s by this afternoon. Skies will start mainly sunny but will gradually turn cloudier as our next storm system approaches. I hope to have a more detailed update on it this evening.

-Jack

Hello everyone!

Our WNW wind pattern will finally be broken today as a clipper system moves to our north. Look for slightly milder temps along with more clouds and SW breezes. Some snow showers will be scattered about the north country where an inch of accumulation is possible in spots. Things are expected to remain mostly dry in the south. Highs will range from around 20 in the north to right around freezing along the coast.

Messier weather arrives Tuesday morning but as a result of Patriot domination forecast this evening, my full update on that will be pushed back to tomorrow night.

-Jack

Hello everyone!

Our recent upslope/downslope pattern will still be going strong today as westerly winds drive our weather. Up in the mountains, look for cool temps, more clouds than sun, and the chance for a flurry or two. Highs in the mountains will be in the mid to upper 10’s. Along the coast, more sun than clouds is expected along with dry conditions and milder temps. Highs along the coast are expected to top out right around freezing.

Some light snow is possible in spots tomorrow before heavier snow/sleet/ice moves in Tuesday into Wednesday.

-Jack

Hello everyone!

We’ll continue our stretch of weather being governed by W/NW winds today as light breezes continue behind a cold front that passed through yesterday. Some colder air moved into the region behind that front and as a result, highs today look to be a bit cooler than they have been in recent days. Look for temps to top out just shy of 20 in the north and just shy of 30 in the south. Skies will feature a mix of sun and clouds with more clouds than sun up in the mountains and vice versa along the coast. Mountain snow showers will continue today but will be lighter and less widespread as the moisture supply gradually dries up.

More interesting weather is on tap for early next week.

-Jack

Hello everyone!

Today will feature moderate temps, a mix of sun and clouds, and the chance for snow showers or squalls as a cold front moves through. Look for highs to range from the low 20’s north to just above freezing in the south. A passing cold front will bring more snow showers and squalls to the region beginning in the mountains around noon and ending up on the coastal plain by 3 or 4 PM. They’ll move offshore by sundown. They’ll bring low visibility and a quick coating to possibly an inch of snow so look out if traveling this afternoon.

Here’s a visualization of the snow squalls. Not everyone will get one but many will, especially in Maine. It might be a little touchier in NH.

Some more light snow is possible Sunday before a larger storm of unknown impact next week.

-Jack

Hello everyone!

Today will feature light snow this morning followed by partial clearing in the afternoon. Look for a general 1-3″ of snow with a few 4″ amounts possible along the coast. Light snow will continue through around noon when it will taper off to snow showers from SW to NE. Most areas should be dry and starting to catch glimpses of the sun by 3 or 4 in the afternoon. These glimpses will be most likely in the SW where they are expected to bring temps a little above freezing for highs. Farther NE, the clouds will keep the cold air in place and thus temps will be a bit cooler in the 23-28 range.

-Jack

Hello everyone!

Today will feature partly to mostly sunny skies, cool temps, and light winds as we’re left in a little bit of a weather purgatory, removed from the direct influence of any strong weather system. Look for highs right around 20 in the north and right around 30 in the south. Clouds will eventually edge out the sun as it sets below the horizon this afternoon as a clipper type system kicks us out of purgatory. Some light snow is expected by sundown across southern NH but we’ll have to wait until the early hours tomorrow morning for the next little disturbance to bring us some flakes. In terms of accumulations, a widespread coating-2″ is forecast with a few spots along the coast and midcoast especially seeing 2-4″. I’ll tweet out a snowfall accumulation map at some point today and post one here in tomorrow morning’s update. Snow will be generally light so no major issues are expected.

-Jack