Hello everyone!

A pretty quiet day is in store today as yesterday’s storm moves off to the east while our next one gets going well off to our south. Gusty westerly winds will continue to bring in colder air today and temps will remain steady throughout the day in the 10’s for most areas. Wind chills however will be much colder remaining below zero for most of the day.

A messy system arrives Saturday night into Sunday with snow changing to rain along the coast. Details to come in later posts.

-Jack

Hello everyone!

Our heavy snow band has developed as expected this morning and after passing through York County last night, most activity is now focused along the midcoast extending back through Lewiston. In this band expect near zero visibilities and very heavy snowfall on the order of 1-3″ per hour.

The heavy band will continue to slowly drift NE today bringing more snow to the midcoast. Attention will then turn to the upper low behind it which will likely touch off some snow squalls this afternoon.

As the upper low swings through, another round of heavy snow is likely this afternoon in the form of a line of snow squalls similar to summer thunderstorms (without the thunder). While the line that the HRRR depicts looks to be a reasonable interpretation of how things could unfold, I think they may be a tad more hit or miss. If one manages to find its way to you, expect a brief period of very heavy snow and low visibilities. Accumulations from these squalls will be light with a coating to an inch in the heaviest precip. Snow squall activity looks to be focused between 1 and 4 PM this afternoon followed by… you guessed it! More bitter cold winds and falling temps.

Revised snow map including what has already fallen. Should have stuck the original map… Oh well. Here’s what changed. I’ve been mentioning the uncertainty in this forecast for a while now and I’m glad I did because as with any storm, there are surprises.

Here’s yesterday’s GFS showing winds, temps, and moisture (RH) for about 5,000 feet up. Notice all the green indicating plentiful moisture. The idea that there would be plentiful moisture around allowing for precip to continue through the day as a new low formed offshore was supported by all the models and the forecast was good to go.

However, bust potential was mentioned for a reason. Anytime you get this Norlun trough type setup, there are surprises and as is par for the course, we got one. This map is the same model for the same time with the same parameters just from this morning. Notice the light greens and yellows working their way into the region. This indicates a dry slot which has shut off the steady precip over SW areas today.

Another storm is looking likely for the weekend and is looking warmer with a heavy wet snow possibly changing to rain for the coast. Our next threat for an all snow event arrives in the middle part of next week along with even more of the frigid temps we love so well.

-Jack

Hello everyone!

Not much has changed from earlier updates regarding the incoming round of snow. Still a tricky forecast as whoever sits under the band the longest sees quite a bit of snow while everyone else sees much less accumulation. The storm will have two basic phases, the trough then the low. Let’s look at the trough first.

The first phase of our storm will involve the development of an inverted trough. While this is similar to a Norlun trough, a true Norlun event would involve a stationary band of snow whereas this band will likely move slowly east with time. Therefore it will be referred to as an inverted trough for this event.

Snow has already broken out across Southern Coastal ME with the bulk of the activity being across York County as of now. This will likely continue through this evening before activity shifts NE tonight. Snowfall rates will be very high in this band with 1-3″ per hour likely in the heaviest snow. The band will continue to develop this evening over York and Cumberland Counties before expanding inland and eastward through the morning. Midday tomorrow is when the next phase of the storm starts.

Once again, we look to the upper air map to tell us a lot about the storm. Let’s start with the dark blue circle over upstate NY/Southern Ontario. This is the closed upper low (note little black circle). This will add a snow squall dimension to the forecast especially over the mountains tomorrow. By snow squall, I really mean pockets of heavy snow as the trough should extend far enough inland to bring everyone some snow.

Next let’s focus on the green dashed line and green arrows. As a vigorous pocket of energy rounds the base of the trough tonight (yellow circle, has other implications later), the trough axis will be oriented from NW to SE, known in the meteorology world as a negative tilt which will turn the winds aloft out ahead of it to the SE (green arrows). When there are SE winds aloft, Atlantic moisture begins to become wrapped into the storm and more widespread snow soon follows. For this reason, even areas that don’t see the inverted trough band will see decent accumulations. Just a quick note, the light pink line over Maine shows the energy left over from the trough as it weakens and moves east.

The yellow circle off the coast is the final feature that I will point out on the map. Notice all the purple/white inside that circle. This is the vigorous energy that a. tilts the trough negative and b. forms a new storm off the coast. This is the second phase of our storm.

Once the new low forms offshore, intense upward motion will begin across areas NE of Portland Thursday afternoon. How far west the precip builds back is still questionable though it shouldn’t get past Portland. This part of the storm will most severely impact the midcoast as the low passes east. Winds will pick up as well as the storm strengthens so watch for even more blowing and drifting Thursday afternoon and evening.

Here is my snow map, uncertainty still exists but I think someone along the midcoast sees a foot maybe a little bit more.

I’ll have another update tomorrow morning.

-Jack

Hello everyone!

Today will feature an extra tricky forecast as a Norlun trough sets up. Bust potential is extraordinarily high here. As with all Norlun trough events, one town may get buried while the next town over may see flurries. Which towns those will end up being are still unknown though we can narrow it down a little bit from last night.

The trough has already set up somewhat offshore and to our south with snow extending from Providence northeastward. Radar shows snow moving ever so slightly westward however westward motion of the trough as a whole will be pretty limited today so while flakes could start falling as early as this morning, steady and heavy snow should hold off until the evening.

Here is my updated snow map. Really tricky forecast. I think the low end for the jackpot zones is 4-8″ but where the heaviest bands set up 12″+ is a distinct possibility.

More snow is in the forecast for the weekend. As for the coastal rain threat you may have heard about regarding this storm, I’m going to need a lot more model support before I buy into the idea that above freezing air makes it very far with a nearly 3 foot snowpack. More details later.

-Jack

Hello everyone!

Special update this evening to cover our next storm threat that is likely to bring snow to the region tomorrow afternoon into tomorrow night. This will be a Norlun trough type event which are notoriously fickle and localized. This is the type of situation not dissimilar to Sunday when York got 21″ while the Portland area picked up between 1 and 3″. Right off the bat, there is bust potential. Don’t be surprised if you get far less snow than expected because the heavy band set up 10 miles away. That being said, let’s dive into the mechanics of this event.

Let’s start by looking at some of the basic players on the field so to speak. A wave of low pressure will develop too far offshore to bring any impact on its own but upper level energy will help to create an inverted, or Norlun, trough extending towards the coast. A Norlun trough is basically an axis of shifting winds, in this case ESE winds
ahead of the trough and NW winds behind the front. The ESE winds bring in the moisture and when they run into the cold NW winds, upward motion is created and thus precip occurs.

Another interesting feature most models are hinting at is the development of a mesolow along the coastal baroclinic zone. This is basically a ‘mini storm’ that forms along the natural frontal boundary between the bitter cold continental airmass and the somewhat less cold marine airmass. What this little ‘mini storm’ does is help to focus precip where it forms which would result in heavier bands of snow wherever it develops. Right now, the area with the best chance for seeing mesolow enhancement is east of Portland.

Another supporter of heavy snow bands comes from the intense upward motion brought on by the mesolow and the wind shift line. The GFS model (shown) suggests the most intense upward motion to be between Portland and Brunswick and inland from there while the NAM has it farther south over York county and points inland.

The NAM shifts the heaviest precip south into York County similar to Sunday’s storm.

The CMC model puts the heaviest precip back into the Midcoast. All these maps are to say: there is bust potential here. As with all Norlun trough events, the location of the heavy band is very hard to predict until right when the snow starts falling. Right now, I think the best threat for being under the heavy band for the longest period of time exists north of Portland. That being said, York County still has the potential to hit the jackpot though their chance is much lower. All areas should see at least some snow with most coastal and inland areas seeing at least some heavier snow. For the mountains, this is mainly a snow shower type event.

The upper air map for Thursday shows several interesting things. First notice the closed upper low (black lines) over Ontario and Upstate NY. This is the trigger for the mountain snow showers. Where there are upper lows, there are snow showers. Second notice the trough is tilted ever so slightly negative (blue line). This helps to turn winds ahead of it southeasterly which draws in Atlantic moisture.

Finally notice the batch of energy over eastern MA (Green circle). This is the trigger for the mesolow. This is the wild card here as how strong that energy is will dictate how powerful the mesolow and the trough will be. Stronger energy would mean more heavy snow while weaker energy would mean lighter snow. Remember the last time the upper level energy was a little too weak? That would be Sunday and it had disastrous consequences.

Here is my thinking as to snowfall amounts. Expect a coating-2″ outside of coastal Maine where the mesolow and trough axis will enhance things. For coastal Maine, the bottom line looks to be 2-5″ but I really want to stress that where the trough sets up will get a decent amount more than that. A 4-8″ event is likely where the trough sets up but where that happens is far too uncertain to pinpoint. Hopefully that becomes more clear in the coming days.

Another storm is looking more and more likely over the weekend, more details to come on that one later on.

-Jack

Hello everyone!

Today will feature continued calm conditions as a storm slides to our south. Snow should make it as far as Portsmouth, NH this morning and south of there light snow is possible with very little accumulation while north of that, just cold and cloudy conditions are on tap for today. Highs will be mainly in the teens with some 20’s along the southern coast. Our next chance for snow arrives tomorrow night into Thursday with a Norlun trough event.

-Jack

Hello everyone!

Temps this morning wouldn’t be too bad on their own, generally in the single digits above or below 0 but a strong NW wind continues to blow this morning making it feel way colder than it actually is. Wind Chill Warnings and Advisories are up this morning to cover that threat. At 6AM this morning, Mt Washington recorded it’s highest wind gust since 2008 reaching 141 MPH.

Despite the cold, the sun is our in full with very few clouds to speak of so at least there is one good thing about today’s weather. All these winds will continue to blow around both yesterday’s new snow and the 24-36″ of powder already on the ground so watch for some patchy reduced visibililties today as well as some slick spots where the drifts may have found their way onto the road.

Our next chance for snow is tomorrow along the coast (snow showers at best), followed by Wednesday night into Thursday (Norlun trough), and then again Sunday. Below normal temps look to continue with no melting in sight.

-Jack

Hello everyone!

I’m sure there was some euphoria and some disappointment this morning after expecting to wake up to a raging blizzard and instead seeing some light snow and a little wind. To be fair, some areas are right on forecast with heavy snow and near zero visibility. A highly localized band of snow set up over Coastal York County who did pretty well for this storm. Eastern MA should do ok as well as 20″ reports are already streaming in from the North Shore.

This post will deal more with the widespread blizzard that wasn’t for Maine and New Hampshire. That being said, high winds will still whip around the snow we already have on the ground and cause reduced visibility and whatever new snow fell last night will add to that. Temps will still be cold and thus wind chills will continue to be a threat.

First Factor: Upper Level Low

Yesterday morning the blizzard forecast was on. Models predicted a strong and strengthening upper low off NYC with tons of energy off of Southern New England. All this energy would translate into a strong and rapidly strengthening storm and thus lots of snow was predicted.

Yesterday evening’s models picked up on the weakness of the upper low and thus the forecast changed drastically. Notice the two weak upper low centers in the image above. This showed a lack of organization and thus prevented moisture from being wrapped in as easily and as quickly. Remember, this disturbance came directly from the Arctic which means lots of cold and no moisture. Basically the entire forecast hinged on the upper low being strong enough to wrap in Atlantic moisture which did not happen. We are now left with a strong surface low that has very little moisture, and thus very little heavy precip,  on the NW side.

Second Factor: Lack Of Energy For Banding

Here is yesterday morning’s GFS showing lots of frontogenesis across the area. Frontogenesis can basically be thought of as fuel for heavy snow bands. Lots of frontogenesis (shown above) creates lots of heavy bands. This was yet another factor that contributed to what was a high confidence forecast for blizzard conditions and lots of snow.

Once again, yesterday’s models changed their mind. Notice the lack of the pinks and reds in yesterday’s evening run. Without as much fuel, heavy bands were confined to very small areas (Boston and York County) while the rest of us saw flurries. Bands down in Boston even caused thundersnow however the tremendous amounts of energy that was used up by those bands came at the expense of other areas of heavy snow that were trying to form last night.

The Result: Less Snow

Now let’s look at the surface map from yesterday’s morning run. notice all the dark greens in the blue circle showing heavy snow. Without upper air support, those couldn’t happen. Yesterday’s evening run finally picked up on that and showed any dark green confined to Eastern MA.

Here is yesterday’s evening run showing the dark green confined to eastern MA which matches what’s happening this morning very well.

Had the storm been about 100/150 miles NW of where it is now, those bands would have been over us and the forecast would have verified.

Regardless of how hard the forecast busted, the storm still looks really cool on the visible satellite this morning. See the eye?

Our next storm threats arrive Wednesday (probably light if anything) and next weekend (still very uncertain).

-Jack

Hello everyone!

We are still expecting a strong winter storm to impact the region tonight and into tomorrow, snow has already begun across much of the area however the storm looks to not pack quite as powerful a punch as earlier forecasts.

Snow

Snowfall forecast – not as much as you may have heard yesterday but still an appreciable storm. Blowing and drifting will make measuring hard and road conditions much worse than what would usually be expected from this amount of snow. There is still bust potential here… the trend in the past 24 hours has been towards less snow so amounts could end up a little lower than the numbers shown here. Localized banding will also help contribute to wildly fluctuating snowfall amounts.

Wind

Wind will be the big concern with this storm as the dry fluffy nature of both the new snow and the old will lead to extensive blowing and drifting of the snow as well as localized whiteout conditions. For this reason, blizzard warnings are up for the coast and adjacent inland areas. While most areas should see blizzard conditions, only the immediate coast should see a full-regulation blizzard with winds 35 mph+ and visibilities at or below 1/4 mile for 3 consecutive hours. Power outages could also be a problem with wind gusts at the coast approaching 50 mph.

Looking ahead, cold conditions look to remain locked in place with storm threats on Wednesday and again next weekend. More details to come on those as they become more clear.

-Jack

Hello everyone!

Temps this morning are very cold, as in very cold. Most areas are in the 10’s below zero with only the very immediate coast seeing temps in the single digits below zero. Winds are light however which will make things slightly more bearable as you start to think about stocking up for the next storm. In other words, bundle up if you’re making room for more snow in your yard or are going out to gather supplies.

Snow will begin later today between the hours of 1 and 4 PM from SW to NE and it will be light until after 6 PM or so. I’ll have a full storm update later this morning or early this afternoon.

-Jack