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Inland Runner To Bring A Mix Of Precip Tonight Through Thursday

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Hello everyone!

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

5:00PM Observations Showing The Setup Tonight/Tomorrow Morning. Image Credit: COD
5:00PM Observations Showing The Setup Tonight/Tomorrow Morning. Image Credit: COD

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.

2-23 Graphic 5

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

18Z NAM Sounding Showing Freezing Rain Potential Tomorrow Morning. Image Credit; Twisterdata.com
18Z NAM Sounding Showing Freezing Rain Potential Tomorrow Morning. Image Credit; Twisterdata.com

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.

2-23 Graphic 6

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

12Z Hi-Res NAM Showing Heavy Rain Thursday Morning. Image Credit: Weatherbell
12Z Hi-Res NAM Showing Heavy Rain Thursday Morning. Image Credit: Weatherbell

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

18Z NAM Showing A Strong But Not Ridiculous Low Level Jet Thursday Morning. Image Credit: Weatherbell
18Z NAM Showing A Strong But Not Ridiculous Low Level Jet Thursday Morning. Image Credit: Weatherbell

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.

Another update tomorrow morning.

-Jack

Another Inland Cutter This Week

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Hello everyone!

The forecast for Wednesday into Thursday remains on track this evening. As it is drawing nearer, I’ll elaborate a little on the expected impacts which include snow, sleet, freezing rain/ice, heavy rain, and wind. I’ll do a quick rundown of each threat. All in all, this will be a fairly typical inland runner and nothing out of the ordinary is expected for Maine. One wave of precip will arrive during the day Wednesday into Wednesday night while the second will arrive Thursday morning and continue through Thursday afternoon. A third wave is likely following that which will last into early Friday morning.

Wave One: Snow

12Z GFS Showing The Setup For Snow Wednesday Morning. Image Credit: Accuweather
12Z GFS Showing The Setup For Snow Wednesday Morning. Image Credit: Accuweather

Ahead of the storm, we have fairly cold air (step outside if you don’t believe me). As per usual, cold air leaves when it pleases and as warm air begins to move north, the first phase of the fight will feature snow Wednesday morning. A general 1-3″ is expected before warm air aloft moves in to turn things over to sleet and freezing rain. A bit more is expected in the mountains where I could see 2-4″. I also wouldn’t be surprised if coastal areas only saw a coating. This will fall overnight tomorrow into the early morning hours Wednesday. As dawn breaks Wednesday, warm air aloft will be gradually changing things over to sleet and freezing rain from south to north.

Wave One: Mix

12Z GFS Showing The Cold Air Damming Setup At The Surface Wednesday Night. Image Credit: Accuweather
12Z GFS Showing The Cold Air Damming Setup At The Surface Wednesday Night. Image Credit: Accuweather

While warm air will stream in unopposed aloft, the cold will put up a good fight at the surface. High pressure will be slowly sliding east across the Canadian Maritimes and I expect low level cold to hang on for a good long time. The map at left shows winds at the surface Wednesday evening. Notice NE winds still locking in cold air at the surface Wednesday night. The development of weak low pressure offshore will aid in this process. This wind will continue to cause problems even into the beginning of wave two which arrives Thursday morning just as this is beginning to erode. Several tenths of an inch of ice are possible and could lead to power outages especially if it doesn’t get a change to melt before the high winds associated with the cold front arrives.

Wave Two: Rain

12Z GFS Showing Heavy Rain Moving In Thursday. Image Credit: Weatherbell
12Z GFS Showing Heavy Rain Moving In Thursday. Image Credit: Weatherbell

Eventually, the cold air will be swept out of the way as SE winds pick up. A cold front will be approaching and ahead of it will be a line of heavy showers with some embedded thunder possible. A general inch to two inches of rain is likely which could lead to minor drainage/urban flooding. Despite that, no major issues are expected as we hardly have any snowpack to melt away.

Wave Two: Wind

12Z GFS Showing High Winds Once Again Lurking Above The Surface. Image Credit: Accuweather
12Z GFS Showing High Winds Once Again Lurking Above The Surface. Image Credit: Accuweather

As is usually the case with these storms, a band of strong winds will cross the area around the time of the heavy rain. The heavy rain will help mix some of those winds to the surface which could lead to scattered power outages. Notice the lack of bright pinks and purples in this map where we had them covering the entire region last week. Winds this week will be slightly weaker with 40-50 mph gusts most likely (last week we had 50-60 mph winds).

Wave Three: Light Mountain Rain/Snow

12Z GFS Showing Light Rain And Snow Moving Back In Friday Morning As Cold Air Pours Back In. Image Credit: Weatherbell
12Z GFS Showing Light Rain And Snow Moving Back In Friday Morning As Cold Air Pours Back In. Image Credit: Weatherbell

As cold air pours back into the area Thursday evening, an upper disturbance will pass overhead which will cause another batch of precip to move through. This will be most widespread in the mountains but everyone has a shot at a quick coating-2″ of snow as westerly winds bring the cold back in. This should move in late in the evening Thursday and should be out of here by dawn Friday.

More updates in the coming days.

-Jack

Next Week Looks Stormy, Details Remain Uncertain

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Hello everyone!

Our storm this upcoming week is still on track but just because we’re getting closer to the event doesn’t mean we’re all that much closer to deciphering what will happen. The trend in guidance over the past 24 hours has been towards a warmer solution with brief snow quickly going over to rain. While this remains very much a viable solution, I’m not ready to bite just yet. I want to wait for a few more rounds of guidance with better sampling of the disturbances that will eventually form the storm before I pull the trigger on a rainy solution. Due to that, my thoughts haven’t changed much. A cold front will move through tomorrow night and colder air will follow for Monday. Low pressure will then move NE from the Gulf of Mexico. Its exact track will determine what falls from the sky. We should have a better idea Monday afternoon as the disturbances that will form the storm begin to join together over Texas.

12Z GEFS Showing Uncertainty In The Forecast For Next Week. Image Credit; Weatherbell
12Z GEFS Showing Uncertainty In The Forecast For Next Week. Image Credit; Weatherbell

Here are the GFS ensembles for the storm. While there is still a large spread in ideas as to where the storm will track, guidance is converging on an inland track. Notice the lack of a large high to the NE to feed cold air into the region. Our cold high from Monday has already been swept off to the Azores which leaves warm air free to flood northward. While I’m still not completely convinced, this is the solution I’m leaning towards based on the pattern and what I’m seeing in terms of guidance.

Following this storm, colder air moves in for the weekend and we have another shot at snow around that time as well.

-Jack

A Progressively More Active Week

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Hello everyone!

Our pattern slowly becomes more active over the coming week beginning with light snow tonight and ending with what could be a large storm next week. We still have three storm threats but I don’t think Northern New England gets much of anything with the Monday storm threat I talked about a couple of nights ago. However, that storm still plays an important part in the lead up to what has the potential to be a large storm next week. For now, let’s look at tonight and the storm expected to drop light snow in the next 12-18 hours.

Radar/Surface Obs Composite From ~5:00PM This Evening. Image Credit: COD
Radar/Surface Obs Composite From ~5:00PM This Evening. Image Credit: COD

Light precip is falling over NY currently and this will move east into our area tonight. The low pressure responsible is tracking to the north and thus is dragging warm air up into the region on southerly winds. This will be enough to result in a wet snow for the mountains and foothills and wet snow mixing with rain along the coast. Snow will fall predominantly tonight into tomorrow morning and will be largely in the form of snow showers with on and off precip. Little accumulation is expected and my original thinking of 2-4″ for the mountains, 1-3″ for the foothills, and a coating-2″ for the coast/coastal plain looks good. Warmer air will flood into the region behind this storm on westerly winds setting up spring like temps this weekend. Highs tomorrow will be in the 30’s and 40’s following precip clearing out in the morning. Highs Sunday will get close to 50 in the south with 40’s for most.

18Z NAM Showing The Setup Monday As Cold Air Builds. Image Credit: Accuweather
18Z NAM Showing The Setup Monday As Cold Air Builds. Image Credit: Accuweather

A cold front sweeps the warmth offshore Sunday night and low pressure develops along the front Monday. This will remain largely to our south though more clouds are likely for all with a flurry possible in the south. The big impact though will be the cold building in with a fresh Canadian airmass sweeping SE. By the time Tuesday rolls around, we will have a stalwart 1030mb+ high that won’t be in a hurry to move. This sets up our midweek storm threat.

12Z GFS Showing The Complex Storm Threat Midweek. Image Credit: Accuweather
12Z GFS Showing The Complex Storm Threat Midweek. Image Credit: Accuweather

By the time next week arrives, a large and fairly deep trough will be carved out across the east with a ridge in the west. Tons of disturbances will be zooming around the east and the exact track of the storm(s) will depend on the exact strength/placement of each and every one of the disturbances I circled in blue (along with others not visible in this image). This is why this forecast is so darn complicated. Despite that, I think we can begin to make some sort of sense out of at least the basics. It is far too early to talk precip type or exact timing but I think the storm works in two parts. The first arrives at some point Tuesday or Wednesday and remains moderate or weak in strength. It looks to deliver moderate to light precip of some sort depending on the track. Remember, we have fresh cold in place so my inclination would be to lean towards less, colder precip as the low slides south. The second part of the storm arrives later in the week, Wednesday into Thursday and is much stronger.  It could deliver much more precip depending on the track. Of what nature the precip is and exactly when it comes and goes is anyone’s guess at this point but the takeaway is that it could be much stronger.

All in all, a more active pattern is shaping up for our area heading into next week. While the exact details are TBD, it does look like we have a good chance at seeing significant precip. Could it be mainly rain? Sure. Could it go out to sea? Possibly. Could it deliver significant frozen precip? Absolutely it could. Stay informed with the latest forecasts through your favorite source (NWS, local media, people like me) and remember that this is still very far away. Don’t panic, stay informed.

-Jack

A Wintry Mess Midweek Next Week

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Hello everyone!

With today’s Norlun trough fizzling out over the Midcoast and cold air pouring in as forecast, attention can now turn to a mid-week mess due to arrive Tuesday across the area as low pressure passes over the region. Because the low will be passing over us and not to our east, this will be a mix event with a medley of precipitation types including but not limited to rain, snow, sleet, and freezing rain. I’ve covered tonight and tomorrow’s bitter cold several times in the last few days so refer to last night’s blog post for the most recent info on that. Nothing has changed since then. With that said, let’s dig into the Tuesday storm.

12Z GFS Showing The Setup For Tuesday. Image Credit: Weatherbell
12Z GFS Showing The Setup For Tuesday. Image Credit: Weatherbell

The Arctic high pressure containing the bitter cold we feel tonight and tomorrow moves offshore Monday bringing behind it warm SW winds. Temps will rise on Monday but keep in mind, they have a lot to rise as temps Sunday remain largely below 10 degrees. The airmass ahead of the storm is also extremely dry so there will be room for evaporational cooling at the onset of precip. I think we get a good burst of snow at the start of the storm across the area before warm air intrudes from south to north (this looks like a solid front end thump event for those familiar with New England weather terminology). How far north that warm air makes it and how fast it makes it there will determine precip type and thus what accumulations will end up being.

12Z GFS Showing The Arctic High Moving Offshore Monday Evening Leaving In Its Wake Warm Southerly Winds. Image Credit: Accuweather
12Z GFS Showing The Arctic High Moving Offshore Monday Evening Leaving In Its Wake Warm Southerly Winds. Image Credit: Accuweather

How do we go from 20 below zero to rain in a matter of days? The answer lies in the placement of the Arctic high pressure. Notice how the high has departed to the east on Monday and behind it, warm southerly winds are already eroding the cold in place long before the storm gets to us. This is why I’m not super bullish on cold air remaining locked in. That being said, I’ve learned over my time forecasting in Maine that cold air has tremendous sticking power and is not easily moved. This is why I think the mountains stay mainly snow while the rest of the area only briefly sees rain with the exception of the coast where there will be more rain.

12Z GFS Highlighting A Rough Idea For Dominant Precip Type Tuesday Afternoon. Image Credit: Accuweather
12Z GFS Highlighting A Rough Idea For Dominant Precip Type Tuesday Afternoon. Image Credit: Accuweather

In terms of what sort of precip will fall from the sky, the short answer is too early to tell exactly. However, I do feel comfortable roughly outlining my thoughts for general precip type. I think the mountains is mostly snow as the low passes over the coastal plain. They look to remain on the cool side of the low and even if the low passes over the mountains, I think you’d be hard pressed to get enough warm air that far north-west to allow for an extended period of rain. I do think though that the mountains mix with some sort of sleet/freezing rain at some point. The coast is the other higher confidence forecast (relative to the storm in general, confidence is medium at best with any aspect of the storm). The low would have to track significantly farther south than forecast for cold air to remain in place throughout the storm. For coastal areas, look for snow changing to a mix then changing to rain with briefly heavy rain possible. For inland areas, expect some sort of a mix with snow at the onset and rain to finish. What happens in between is anyone’s guess. Confidence will increase in the coming days so stay updated for the latest info.

I’ll try to have an initial guess at accumulations tomorrow evening in my next update on the storm. I’ll have tomorrow’s forecast as usual tomorrow morning.

-Jack

 

Midcoast Snow Tomorrow, Cold For All Sunday

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Hello everyone!

Cold air is firmly entrenched today but even colder air is on the way. Look for a cold front to smash SE tonight bringing behind it the coldest air all season and the first truly Arctic air we’ve seen all season. As the cold air moves in, an upper low diving to our south will set the stage for a Norlun trough event along the midcoast tomorrow. Beyond that, bitter and dangerous cold arrives Sunday followed by a messy storm midweek next week.

Saturday Norlun Trough

12Z GFS Showing The Setup For Tomorrow. Image Credit: Weatherbell
12Z GFS Showing The Setup For Tomorrow. Image Credit: Weatherbell

The front gets hung up along the midcoast as the upper low slides to our south. Winds out ahead of the 500mb trough will turn southeasterly and eventually easterly which will provide a mechanism for moisture to be transported into the region. Also, with southeasterly winds aloft, there will be nothing to move the trough once it sets up. Most of us will see the moisture transport aloft in the form of light snow/snow showers during the day tomorrow with light accumulations. The midcoast will be the only area to really capitalize on that. To understand why, read the next paragraph about how Norlun troughs work. If you’re more interested in the forecast, skip on down to the next picture and read about the cold coming Sunday.

A Look Behind The Scenes At Norlun Troughs

Here is a graphical explaination of a Norlun trough I did for UpPortland. Notice that tomorrow the trough will be over the Midcoast rather than Portland. All poor image design credit goes to me (and Frontpainter for the map)
Here is a graphical explanation of a Norlun trough I did for UpPortland. Notice that tomorrow the trough will be over the Midcoast rather than Portland. All rough image design credit goes to me (and Frontpainter for the map)

Because it’s been so warm recently, the ocean is still quite toasty. This sets up a very large difference in temperature between the warm ocean and the cold air. The warm water will heat the lowest level of the atmosphere creating warm air which wants to rise. Above this very shallow layer of relative warmth lies an entire atmosphere of very cold air which wants to sink. Somewhere in the impenetrable fortress of cold, there will be a weakness. The warm air will rush upwards through this weakness generating tremendous upward motion and leading to warm moist air crashing into cold dry air. This violent collision will produce snow.

2016-02-12_17-30-17
A Cross Section Of The Atmosphere Showing The Dynamics Involved With The Trough. More Rough Image Design By Me.

As the new trough takes up the energy immediately near it, warm air trapped under the cold air all across the Gulf of Maine will rush in to take its place so it too can rush upwards and cool. As the trough is using up the existing warm air, new warm air will keep being created as the water continues to warm the lowest levels. This warm air will rush to the weakness in the cold and rise up, depositing its moisture along the way. This is what we call a Norlun trough.

One of those will form over the midcoast and deposit heavy snow tomorrow. Totals are likely to come it at around a foot in the core of the trough but it remains to be seen exactly where that sets up. These events are notoriously fickle and can set up wherever they please or not at all. One good example happened just last night when a weak Norlun formed over Portland out of left field causing major issues. Bottom line: expect the unexpected.

Expected Snowfall. Notice The Sharp Cutoff Which Leads To High Uncertainty From Brunswick On East To Rockport.
Expected Snowfall. Notice The Sharp Cutoff Which Leads To High Uncertainty From Brunswick On East To Rockport.

Expected snowfall for tomorrow. Upslope snow showers in the mountains are likely to produce 1-3″ in the usual spots. Farther south, a dusting to as much as 2″ is possible with isolated snow showers/flurries. In the core of the Norlun, thundersnow is possible as there will be a solid amount of instability associated with the temperature falling dramatically with height from the warm ocean to the bitter cold air moving in aloft (technical: lapse rates will be very impressive).

NW winds will be howling tomorrow beginning in the afternoon. While blowing and drifting snow will initially not be an issue, by Saturday night, those who saw snow will also see it blowing around leading to more slick spots and reduced visibility. It will also add an extra sting to the air if you happen to be out and about Saturday night.

Dangerous Cold Sunday

18Z GFS Showing Dangerous Cold Sunday Morning. Credit: Weatherbell
18Z GFS From Yesterday Showing Dangerous Wind Chills Sunday Morning. Credit: Weatherbell

Very cold air is still on track to come into the area behind the storm on Sunday. Actual temps will drop well below zero and as NW winds howl at over 25 mph, wind chills will drop even lower. This is the image I used for last night’s post and it still applies as wind chills approach -40 to -50 in the north with -20 to -30 degree wind chills in the south. Bundle up for the Valentines Day dates both Saturday and Sunday nights. Thankfully, the extreme cold is out on Monday.

Messy Midweek Storm

12Z GEFS Showing The Range Of Possible Outcomes And The Lack Of Confidence Regarding The Forecast At This Point. Image Credit: Weatherbell
12Z GEFS Showing The Range Of Possible Outcomes And The Lack Of Confidence Regarding The Forecast At This Point. Image Credit: Weatherbell

As the cold retreats, we have another storm threat. We are virtually certain to see precip the question is of what variety. Right now, it looks like a mess with all precip types possible for everyone. It is far too early to nail down exact impacts or amounts but total accumulation of whatever falls could be significant. My thinking from yesterday still applies in that uncertainty remains large here. One group of forecast models leans towards a colder, farther east solution with more snow than mix while another camp of models leans towards more rain and mix than snow.

Another storm is on the horizon late next week but we have to get the first two resolved before we can dig into that one. Just know that there is the potential for a storm and as always, ignore any hype you may see.

I’ll have more updates in the coming days as the midweek storm becomes clearer. I’ll also be on Twitter watching the Norlun trough evolve tomorrow @JackSillin.

-Jack

A Cold And Unsettled Week Ahead

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Hello everyone!

I thought I’d take a minute this evening to go over the next week or so of weather taking a quick look at what to expect. This will be a tale of a classic New England winter with snow, bitter cold, and the potential for a sizeable storm. Let’s start with the light snow which arrives tomorrow.

Light Snow Tomorrow 

12Z GFS Outlining The Light Snow Threat Tomorrow. Image Credit: Weatherbell
12Z GFS Outlining The Light Snow Threat Tomorrow. Image Credit: Weatherbell

A storm will pass well offshore tomorrow but an upper low still lurks to our west. Much like with our last storm, there will be a moisture transfer between the two storms. However, both storms will be weaker this time around especially the offshore storm (weak wave compared to powerful bomb). Therefore, the same concept applies but with less snow. Spotty snow showers will impact most but they will be hit or miss. The midcoast could get brushed with a bit of steadier light snow. A coating-2″ is forecast for everyone but 3″ is possible in the mountains and along the midcoast.

Bitter Cold For Valentines Day

12Z GFS Showing VERY Cold Air Over The Region Sunday. Credit: Weatherbell
12Z GFS Showing VERY Cold Air Over The Region Sunday. Credit: Weatherbell

An Arctic front blasts south Saturday and frigid winds bring in very cold air behind it. Lows Sunday morning are likely to drop well below zero into the 20’s below up north and the 10’s below in the south. The map shows temps at 5,000 feet so don’t panic with the -30C temps across Maine but do realize this is the real deal with dangerous cold on Sunday. Highs on Sunday will struggle to get above zero across Maine and New Hampshire and probably won’t in the mountains. The coldest air arrives just in time for Valentines Day so plan accordingly. Thankfully, the brutal cold moves on heading into next week though it does leave us a parting gift in the form of a storm threat.

Snow Threat Returns Next Week

12Z GEFS Showing The Threat For A Snow Event Next Week
12Z GEFS Showing The Threat For A Snow Event Next Week

As the bitter cold retreats, a storm will likely try to form somewhere. At this point, all solutions are on the table from Rain to OTS though the general consensus is for some type of snow event. This is too far out for specifics but just know that at some point in the middle of next week, there could be a snow event.

I’ll have more updates tomorrow.

-Jack

Snow Continues Tonight, Departs Tomorrow

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Hello everyone!

Snow is currently falling across the region with light to moderate being the dominant intensity. Look for this to continue through the night along with high winds that will blow the snow into a low visibility, drift inducing frenzy. Amounts in your front yard will range from 0-24″ when drifts are included. The actual amount of snow that will fall from the sky is likely to be in the 4-8″ range along the coast and in the 2-4″ range inland though with drifts, amounts will be far different when you look outside tomorrow morning.

HRRR Model Showing The Evolution Of Light Snow Tonight Through Early Tomorrow Morning. Credit: Weatherbell.
HRRR Model Showing The Evolution Of Light Snow Tonight Through Early Tomorrow Morning. Credit: Weatherbell.

Here is the HRRR model with a general idea on the evolution of the snow through tomorrow morning. I suspect it may be a little quick to shut off the snow as the upper low to our west will be eager to continue pulling in moisture. I think mid to late morning is a more reasonable stop time with drying from SW to NE.

Snowfall amounts from last night still look good with 4-8″ for most, 2-4″ in the mountains.

Check out last night’s post and this morning’s post for more info. That information still applies as the storm is progressing as forecast.

Snow showers are possible throughout the week as waves of low pressure develop well offshore. Another chance for respectable snow arrives early in the weekend next weekend followed by a blast of truly Arctic air early next week.

-Jack

Prolonged Light Snow On Track Today

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Hello everyone!

Everything is lining up as forecast and a long duration light snow event is likely today. Snow looks to arrive around noon here in Maine, a little earlier along the coast, and a little later inland towards the mountains. Not much has changed since yesterday in terms of expected snowfall. I still think the coast has the best shot at hefty snowfall amounts. Keep in mind, snow will be able to accumulate quite efficiently despite snow never falling that heavily. The good news with the light snow is that it will be easily moved by your shovel. The bad news is that it will be equally easily moved by the strong winds today that will gust along the coast to near or over 30mph. As a result, expect blowing and drifting of the snow not only that is just falling, but also of the 6″+ of snowpack most coastal areas have left over from Friday’s storm. This is likely to cause visibility issues especially for the evening commute.

HRRR Model Showing Heavy Snow Remaining South But Light Snow Impacting Maine Today. Credit: Weatherbell
HRRR Model Showing Heavy Snow Remaining South But Light Snow Impacting Maine Today. Credit: Weatherbell

Here is the HRRR model just to give you an idea of how the storm plays out in general. Don’t take it word for word in terms of individual bands or timing down to 15 minutes but look at it to get the general idea of the heavy stuff remaining south and the light stuff sitting over us for a while.

Temps today will be in the 10’s and 20’s.

Snow winds down tomorrow afternoon though snow showers will continue through Thursday as various pieces of energy rotate around an upper trough to our west.

-Jack

Long Duration Light Snow Event Arrives Tomorrow

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Hello everyone!

A powerful storm is bombing out over the ocean near the Carolinas this evening and we will be on the far western edge. At the same time, a complex upper low is diving SE across the upper Midwest. They will form a connection of sorts that will transport warm moist air over the cold air moving in tonight following today’s cold front.

12Z GFS Showing Mositure Connection Between Clipper And Coastal Storm. Image Credit: Accuweather
12Z GFS Showing Mositure Connection Between Clipper And Coastal Storm. Image Credit: Accuweather

The coastal monster will stay mainly offshore but it will throw a ton of moisture back to the NW. There is a clipper to the NW which is ready to receive this moisture and will help draw it back NW. Bottom line: there will be a feed of moisture over the area tomorrow as moisture from the coastal low gets pulled back into the clipper. If you watched my video discussing the Friday storm, you know that we need three things for snow: moisture, cold, and lift. We got the cold today with that Arctic front and above is the moisture. The problem though is the lift.

GFS Model Showing Broad But Light Lift Tomorrow Evening
12Z GFS Model Showing Broad But Light Lift Tomorrow Evening. Image Credit: Accuweather

As the warm air providing the moisture rises up and over the cold air at the surface we got today, it will rise, cool, and condense into precip. Sometimes, this mechanism for forcing (getting air to rise) can be quite effective in producing heavy precip. Not so much this time. If you’ve followed along for a while, you’ll know that I use Vertical Velocity to show how much air is rising and thus how heavy precip will be. In the big storms, you’ll often see bright purples and reds (notice scale on right of image). This time, we see yellows and oranges. This is indication that there will be less mesoscale banding and more broad lighter precip. Therefore, look for lighter snow though it will last long enough for fairly heavy accumulations.

12Z GFS Showing Gusty Winds Tomorrow Afternoon. Credit: Accuweather
12Z GFS Showing Gusty Winds Tomorrow Afternoon. Credit: Accuweather

This snow will be light and dry which is nice for shoveling but will be unfortunate because the gusty winds will have no problem blowing around the light, fluffy snow. For this reason, expect blowing and drifting snow to cause visibility issues especially tomorrow afternoon (map valid 1PM tomorrow). Winds are likely to range from near calm in the mountains to over 30mph at the coast.

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Here’s what I expect in terms of total snowfall. Keep in mind, this falls over a near 30 hour period from late morning tomorrow through Tuesday afternoon. Slow and steady is the name of the game for this one.

I’ll have more updates tomorrow.

-Jack