​Good evening to you from SCW!
 
There’s a lot of buzz out there about a strong coastal storm for Friday into Saturday. While it’s true that there is a significant system shown on a lot of the models, it’s equally true that there is a ton of spread among the models, and it’s still too early to make any definitive claims as to what is going to happen. That said, we can still take a look at the setup and the different possibilities.
 
Wednesday-Thursday
 
The calm leading up to the storm. High pressure remains in control through tomorrow before weak low pressure brings a slight chance of a sprinkle tomorrow night. Mostly sunny skies tomorrow give way to increasing clouds on Thursday, with chances for rain increasing as we head towards Thursday evening. Any precipitation that falls on Thursday will almost certainly be rain; it’s not until later in the storm that we could start to see some wintry weather in the region as temps crash through dynamic cooling.
 
Temps for tomorrow and Thursday should be well above normal, with highs in the 50s both days.
 
Friday-Saturday
 
Main event in the forecast period is a strong, slow moving coastal storm that will impact the region from Thursday night through Friday and possibly into Saturday as well.
 
Broadly speaking, low pressure moves northeast from the Midwest into the lakes, but due to strong NAO blocking to the north of us, instead of cutting into the lakes and bringing us a rainstorm, we see the system shunted southeast until it eventually transfers its energy to a coastal low. The blocking in place means that unlike many of the storms we’ve seen recently, this one won’t be in any hurry to move out, and therefore it will remain offshore or just inland for quite some time before eventually moving out to sea.
 
Large systems are often our most consistent on the model guidance, but that is not the case here. All of the major global models have their own set of solutions, and as of now, we haven’t yet seen a defined trend towards one camp or the other that makes me comfortable endorsing one set over the other. As we go through the models, keep in mind that all of these outcomes are very possible, and equally as possible is some hybrid of these solutions or a totally different one all together. At this point, pretty much all I’m comfortable with saying is that there will be a large storm somewhere on the eastern seaboard this weekend.
 
GFS
 
Here’s an animation of the system from the most recent GFS model.

The GFS is the most northerly of the solutions, but also the strongest. Initially, we’d see heavy precip across the state Thursday night into Friday morning, and the column would be warm at least through the midlevels as the system is far enough north that the midlevel lows pass over us, making precipitation type all rain. However, as the system begins to move out to sea, we see colder air begin to get wrapped in at the higher elevations, and should precipitation rates be strong enough, we could see dynamic cooling take over and flash areas over to a heavy wet snow. As shown verbatim on the model, we don’t flip over to snow until after most of the QPF has already fallen, but as the GFS has a tendency for being warm at the lower levels, it wouldn’t surprise me if we saw a bit more snow in this solution than the model shows at first glance, but that’s not a guarantee by any means.
 
NAM

​The NAM is a similar evolution to the GFS, but the whole system is pushed further south due to a stronger block and so we switch to snow much faster. The result is a significant snowstorm for the whole state; verbatim it’s spitting out some crazy numbers (2’+ in the mountains with snow continuing at the end of the run), but given it’s the NAM which is known to have a wet bias I would be very hesitant to believe those values right now. Nonetheless, in a more wintry situation like the NAM shows, significant snowfall would be a near certainty.
 
Euro
 
Unlike the American guidance, the Euro is much less enthused with the idea of significant precipitation in our area. Stronger blocking and less phasing shunts the whole system south of us, and while we would still see some rain Thursday night into Friday morning, we would see much less QPF than under the previous two scenarios. While we can’t post the full Euro due to copyright issues, these maps should give you a good idea of the difference between the Euro and the GFS. On the left is MSLP on the Euro valid for 7 AM Friday morning, while on the right is the same image from the GFS. Look how much further north the low is on the GFS!

So what does this all mean?

As I said above, I have no idea. Usually, I’d look for trends in the camps of guidance, with one camp making concessions towards another, but we haven’t really seen that yet with this system. Next, I’d look to ensemble guidance, but here the ensembles are similar to their op runs and don’t offer us a lot of help. That leaves us with climatology and intuition. Climo with a strong -NAO is often to develop blocking and push things south, which would argue for the more suppressed solution that the Euro shows, but the storm is extremely impressive and I’m having a hard time believing that it will be pushed east as easily as the Euro shows it happening. Gun to head, I’d expect a mostly rain event for the state, with some snow on the backend (highest amounts at elevation), but the odds of a foot of snow or nothing at all are probably just as high as what I just outlined, so please don’t be surprised if we come back tomorrow with a snowmap for warning snows or an updated forecast for nothing at all J

What we do know is that regardless of what the eventual impact is to the state, there will be a powerful storm in the Atlantic this weekend, and that means that winds will likely be high and coastal flooding is a possibility. Combine that with the peak of a tide cycle this weekend and coastal areas have reason to be concerned; while I think eastern MA will take the brunt of the impact, it is still likely that we will at least see low-end coastal flooding here, with more significant impacts possible depending on the ultimate track of the system.
 
All in all, a complex storm that certainly hasn’t shown us its last cards yet. Stay tuned!
 
Sunday-Wednesday
 
High pressure moves in behind the storm leading to much improved conditions for Sunday into next week. Next chance of precip is midweek with the passage of a cold front, some models have phasing between the two streams which could produce a larger event, but at this lead time just going with a chance of rain and snow for now until we get through the short term as its likely that the track of the next system will be based on the track of this one.
 
The Dailies
 
Wednesday: Mostly sunny, with highs in the mid 50s.
Thursday: A chance of showers, then rain becoming likely late. Highs in the mid 50s. Chance of precipitation is 70%.
Friday: Rain, then rain or snow. Highs in the mid to upper 40s. Chance of precipitation is 95%.
Saturday: A chance of showers, otherwise, mostly cloudy, with highs in the mid 40s. Chance of precipitation is 50%.
Sunday: Mostly sunny, with highs in the upper 30s to lower 40s.
Monday: Mostly sunny, with highs in the lower 40s.
Tuesday: A chance of rain or snow, otherwise, mostly cloudy, with highs in the lower 40s. Chance of precipitation is 40%.
Wednesday: A chance of rain or snow, otherwise, mostly cloudy, with highs in the upper 30s. Chance of precipitation is 40%.
 
We’ll keep you updated as the models continue to hash out this storm system – stay tuned!
-SA

What a change the last 24 hours have brought! 24 hours ago, it was the warmest day ever recorded in February.  Now it is sleeting in the northern half of Connecticut!

Currently: A stationary front extended from Northern VA to the Southern edge of the Delmarva Peninsula.  A weak wave of low pressure had developed on the front over the mountains of WV.  Cold high pressure stretched from the Great Lakes to Northern ME.  This frontal boundary will serve as the focal point of unsettled weather across our area.

Tonight: We need to watch for the potential for some light wintry precipitaiton across interior portions of the state.  The first question, of whether or not it will be cold enough, has already been answered (it will be).  The other questions are how much precipitation will fall and what type it will be.  Fortunately, it looks like sleet should predominate rather than freezing rain, and that is a good thing.  There could even be a burst of snow across the northern and central parts of the state... it wouldn't be totally inconceivable for snow to make it all the way to the coast.  A coating to 2" is possible across the north- generally I 84 and north, with most accumulations restricted to the cold surfaces, and the closer to 2" readings restricted to higher terrain.

As the core of the cold air moves in, it will also allow drier air to slip into the state, which means precipiation should shut off this evening and it should stay dry until tomorrow afternoon.  By then, the thermal profiles aloft clearly support rain, although it wouldn't be a total shock if some sheltered location starts off as a little freezing rain. 

As for tonight's temperatures, they will be cold, and it will be rather a shock to the system.  Lows should be 25 to 30 up north and 30 to 35 in the south, with most of the state, except the far SE, getting to or below freezing.

Tomorrow: The first half of the day should be dry, albeit cloudy, then precipitaiton should return by the 2nd half of the afternoon, as the aforementioned frontal system starts moving back north as a warm front.  For now, based on model temperatures, I'll keep all precipitation as rain.  Thermal profiles aloft definitely support rain.  However, it is not out of the realm of possibility, as I mentioned, to see some freezing rain at the start in the usually coldest spots.  We'll have to keep an eye on that! As for temperatures, most of the state will stay in the 30s, which is why we need to watch for areas of freezing rain.

Tomorrow Night/Sat: As the warm front approaches, we'll see a period of rain tomorrow evening.  Temperatures should then stay steady or slowly rise tomorrow night.  Saturday's temperatures should rise to 50-55, with the warm front by then very close to the region.  Most of the time later tomorrow night and Saturday should not see rain, although there will be areas of drizzle and fog.  Rain should develop later in the day Saturday and Saturday night as the front sags back south into New Jersey.  A wave of low pressure will move along the front, as well, enhancing lift across the state.

Long Term: To start the long term, Sunday is basically a wash out.  With a stationary front stalled south of the state and waves of low pressure moving along it, that is a good recipe for overunning rains to continue all day.  In addition, temperatures should be a good 5 degrees (or maybe more) cooler than on Saturday.  So look for a chilly, raw, rainy Sunday.

Then Monday through Wednesday will feature much nicer weather.  Monday is most likely the pick of the week, but that isn't saying that Tuesday or Wednesday will be bad.  Highs should be generally 50-55 through the period, with the coolest day possibly being Tuesday.

Models then hint at a cold high building back in over Canada for Thursday and Friday, while a coastal storm forms offshore along an old frontal boundary.  That would likely spell a rain changing to a wind driven snow event for much of the state, with colder air building in behind the storm- although by then we're way far out, so details have yet to be ironed out.

In the long range, the overall pattern will shift dramatically to one that features a very strong -NAO.  We have not seen a truly negative NAO of that magnitude in quite some time.  While details as to when and what types of storms we get are too far out to say much about, these types of scenarios generally spell cold and stormy weather across our area.

Now, let's take a look at our weather in graphical form.  We'll highlight the storm for Sunday, because I really want to post the GFS Ensemble map regarding our coming negative NAO.

If I had to draw fronts on that map, the cold front would be over Western Pennsylvania, with the warm front arced from Rhinelander to Atlantic City.  So Connecticut is stuck in a cold rain.  Now, let's take a quick look at the GFS ensemble map valid 11 days from now..

​

That's basically the most classic negative NAO one can expect.  Of course, timing and track would be everything, but verbatim, that is a very stormy, and somewhat cold, look, in this area.

Anyway, I'll leave it at that for now, and we'll see where that goes... see you next week!

​-GP!

Good evening from Southern Connecticut Weather.
 
After a bit of a reprieve from winter, it’s coming back. At least for a day. In the last day or so, we’ve been watching the potential for an area of low pressure to develop and ride toward our region, bringing the potential for precipitation. As we’ve gotten closer toward the period of interest, our confidence has increased in the potential of a moderate winter storm impacting our area this weekend. We are still a little more than two days out from showtime, so this is a forecast that is worth watching closely in case things trend one way or the other—as they have in a number of systems we’ve seen this season.
 
Overall Setup
We’ve been missing well timed cold for much of the last month, resulting in a series of rain events where we have plenty of precip but no cold. Now, we’re in a setup where a high pressure to our north will be in place to deliver cold enough air for most. However, this high pressure will be scooting to the east and away from us as an area of low pressure develops off the Mid-Atlantic coast on Saturday. As a result, there are questions that remain about the overall track of the storm, and how much warmth is able to get punched into the column as precipitation is falling.
 
Currently, much of the guidance suggests that we see an area of low pressure that is just right, both in strength and track. Too strong and we could see mixing in southern Connecticut that cuts down on snowfall. Too weak and we see a much less impressive system, even if it is all snow for everyone. We take the middle ground here expecting an Advisory to Warning level event bringing 3-6 inches of snow across the state.
 
Beware, southern folks. We’ve danced this dance before. Should we see the stronger solutions verify, you're in line for a 6"+ event, but if it gets too strong, we could see rain mix in, and if it's too weak, only an inch or two of snow will be the end result. It's a fine line - stay tuned...

Here's our snowmap for this event.

Timing
The overall timing seems to be coming into better agreement. Our aforementioned low pressure develops off the Mid-Atlantic coast on Saturday and begins making a run northeast. With high pressure still in place, we expect much of Saturday to be ok. Right now, if you have plans during the day, they look fine. By the evening hours however, you should expect some light snow to begin breaking out from southwest CT to northeast areas over the evening and overnight hours. This far out, timing can change by a few hours in either direction, even with models in solid agreement, so keep an eye out for that.
 
We expect snow to fall from Saturday evening through the early morning hours of Sunday. This is a fast mover. In fact, we expect the bulk of accumulating snow to fall in a relative short period of a few hours. 

Snow Accumulation
​
As our map above shows, we’re starting out by going with 3-6 inches of snow, with more likely in central Connecticut and less near the shoreline. This accounts for the potential of mixing, which is possible if there is a last minute shift of the storm track north. If we get a track that is closer to the benchmark (70/40) or just south, we will likely see virtually the entire state stay snow and that will increase totals, especially near the shore. On the contrary, a more suppressed solution like the GFS, shown below, will result in just a couple of inches of snow at the maximum.

For snow lovers, the GFS is an unfavorable scenario. The last few GFS runs have given less snow verbatim, with a mix line that punches pretty far deep into Connecticut. This is an outlier right now is not being given much weight. The Euro on the other hand brings in a more solid thump of snow during the overnight hours of Saturday/early Sunday morning with a mix line precariously close to the shoreline, but far enough offshore to bring a significant event.

In the end, this solution would bring warning-level snows to the majority of the state, compared to the GFS which brings only a couple of inches. ​There is a definite split in the guidance, and so we’re going to have to keep watching the short term trend. 
 
Impact
Overall, we think this has the potential to be a moderate event. We lean toward a moderate event at this point for a few reasons.  First, although this will be a fast moving low, it looks like there will be very good dynamics with this system. Like our last few rain storms, there will be a significant amount of moisture available. That increases the potential of significant snowfall if the column cooperates. In addition, some of the soundings and other factors we look at on the guidance show good snow growth, which would maximize snowfall potential.
 
With those factors at play, we expect a period of moderate to heavy snow that will make roads difficult to pass during the overnight hours. In addition, with the rain/snow line likely to be close to the shoreline, we should see heavier and wetter snow especially along the shore, which could cause problems of its own. We’ll see these factors come in greater focus the closer we get.
 
As always, please like, share, and interact with us on our social media--on Facebook to share our discussions, and follow us on Twitter @southernctwx to retweet our posts. Hit the buttons below to join.
 
Thank you for reading SCW. 
 
-SA & DB

​Good evening to you from SCW!
 
A pleasant evening is on tap for your Valentines Day with clear skies and warm temperatures in the mid 40s across the state, although we may see some showers roll in after midnight in some areas. Enjoy the calm while it lasts though as the extended looks volatile both in terms of storminess and temperatures.
 
Thursday
 
Well above normal temps will be the story of the day tomorrow, with highs in the mid to upper 50s expected. Should remain dry for most of the day, but some showers could start to work into the western portion of the state towards the end of the evening commute and especially later in the evening into the overnight hours.
 
Friday
 
Cold front passes through the state overnight Thursday into Friday morning and brings a round of showers with it. Precipitation amounts should be relatively light as heavier QPF remains well to our west, but still can’t rule out a couple of isolated heavier cells developing. Otherwise, expect showers ending by mid-morning and another day of warmer temps with highs in the lower 50s.
 
Saturday
 
Much more seasonable weather is on tap to start off your long weekend – highs in the mid to upper 30s and mostly sunny skies expected. Should be an awesome day to be outdoors – great day for skiing, hiking, skating, or any and all outdoor activities!
 
Saturday Night-Sunday
 
The second and more interesting system in this forecast arrives Saturday evening as quick moving Arctic energy tracks south of the coastline Saturday evening into early Sunday morning. In a large-scale sense, the eventual storm track will depend on the interactions between and timing of two features; high pressure to our north that’s sliding east and energy coming up from our southwest that will then track nearly due east and out to sea. How far northeast the energy can make it before it begins to slide out to sea will depend on both the amplification of the system(and the amplitude of the trough enabling it to come up the coastline) and the positioning of the high.

One thing that’s tricky about this system is the speed with which it’s moving. Our shortwave of interest won’t come ashore until tomorrow night, and given the frequency which we’ve seen late-stage shifts in the guidance this season, I wouldn’t be comfortable starting to nail anything down until Friday morning when we have a model suite with full sampling and can get a better idea of what we’re working with. As of now, it appears likely that there will be some sort of storm over our area Saturday night, but a range of outcomes ranging from a miss to a snowstorm to a rainstorm are all on the table. We’ll continue to keep an eye on the guidance and keep you updated!
 
To show the spread in the model solutions, here’s a look at the 18z NAM, GFS and ICON for 1 AM Sunday. 

​The NAM is a moderate snowstorm over the area, the GFS is weaker with the energy and is thus suppressed to our south, and the ICON is the strongest of the bunch and would result in a warning-level snowstorm for much of the area. As the models keep flipping back and forth, it’s hard to say with any confidence which solution is correct as of right now, so we’ll keep all options on the table and hopefully start to see some more solid trending emerge soon.
 
One thing that is certain is that this system is moving very quickly as it is extremely progressive; snow should be out of the state by early Sunday morning and so overall impacts will be comparatively minimal given the duration and timing.
 
For the rest of Sunday, expect clearing skies and warming temps; highs in the low to mid 40s seem reasonable. There’s a very real chance that most of the snow we see on Saturday could melt away on Sunday, so enjoy it while it lasts!

Monday-Tuesday
 
Next week looks to be dominated by a strong Southeast Ridge which will bring warm air up into the region. The guidance differs somewhat on the magnitude of it, with the GFS keeping temps limited to merely well above normal while the Euro brings a blowtorch into the area with highs potentially approaching the 70 degree mark midweek. For now, will lean towards the less-extreme solutions, but the Euro does have plenty of ensemble support and in a fast pattern with no blocking, we’ve seen some crazy numbers thrown up in the past. As far as precipitation goes, with the Euro solution we would be soundly warm-sectored and thus warm and dry, while the GFS would keep us in the storm track and bring some chances of rain into the forecast. At this lead time, will go with chance pops for rain on Tuesday as a result, but stay tuned for more details…

Here's a look at high temps on the GGEM for Tuesday - the Euro is even warmer!

​The Dailies
 
Thursday: A chance of showers in the morning, then cloudy, with highs in the mid to upper 50s. Chance of precipitation is 50%/
Friday: A chance of showers in the morning, then cloudy, with highs in the low 50s. Chance of precipitation is 60%.
Saturday: A chance of snow late, otherwise, mostly sunny, with highs in the mid to upper 30s. Chance of precipitation is 50%.
Saturday night: Snow likely. Chance of precipitation is 70%.
Sunday: A chance of snow early, then clearing, with highs in the low to mid 40s. Chance of precipitation is 40%.
Monday: Partly sunny, with highs in the low to mid 40s.
Tuesday: A chance of rain, otherwise, warm, with highs in the upper 50s to lower 60s. Chance of precipitation is 40%.
Wednesday: Partly cloudy and hot, with highs in the 60s.
 
We’ll keep you updated on the snow potential for this weekend as we know more, until then, Happy Valentines Day from SCW!
-SA

Good afternoon from Southern Connecticut Weather! 

As expected, rain is falling across the state today, as our large area of disturbed weather continues to traverse the region. Expect more rain, heavy at times, over the rest of the day. It should begin to diminish during the overnight hours as a cold front pushes through the region and finally clears us out. 

Monday 
Tomorrow starts out mostly cloudy, but as the cold front continues to push off the coast we'll see clearing conditions. Expect seasonable temperatures (remember that our average high temperature is now rising the further into the month we go) and clearing skies over the course of the day. 

Tuesday-Wednesday
Colder conditions are expected on Tuesday, as high pressure dominates through midweek. That should give us mostly quiet and sunny conditions. Highs on Tuesday look seasonably cold, with many in the 30s, especially inland. Tuesday night or early Wednesday morning, we could see another very weak area of disturbed weather reach the area. With colder conditions, there's a slight chance of snow showers. I do not think we see anything significant precipitation wise through mid-week however. 

Thursday-Friday
Things begin to look warmer and unsettled by Thursday, as the high pressure that brings clear and dry conditions fades away to a series of waves that may materialize and bring us precip. The best chance of precipitation looks to be during this time period, as we see another cold front attempt to push through and a weak wave ride along it. If that is the case, depending on the timing, we could see rain showers changing to snow showers in this time range.

​At this time, I don't really want to put too much stock in any model for the period, but the overall look does show a signal for some potential precip. 

The Weekend
At first glance, the coming holiday weekend looks nice. High pressure looks to assert itself again, and we are currently looking at seasonably cold and dry conditions that moderate by Sunday. Of course, with a boundary that may hang around it is too soon to lock this in, but at least right now, President's Day weekend looks solid. 

Is Winter Over?
Finally, we've gotten a fair amount of questions like this the last week. The short answer is no. Winter is not "over".

For winter (read: snow) lovers, we've been in a rough stretch after a strong start to the season. The March 1st start to Meteorological spring may be just a few weeks away, but despite this current overall pattern which does not favor significant snow events, March tends to be a month, especially recently, capable of producing snow events.

I don't see anything major in the foreseeable future, but in this region, it's hard to close the book on winter at this point in the season.

Closing the shades for a while until the pattern changes? Maybe.

Declaring an end to winter? Not yet. 

The Dailies
Monday: Mostly cloudy early with clearing skies over the course of the day. Breezy. Highs in the upper 30s to low 40s. 

Tuesday: Mostly sunny with seasonably cold conditions. Highs in the low to mid 30s. Chance of snow showers late 10%. 

Wednesday: Mostly sunny and warmer. Highs in the mid to upper 40s. 

Thursday: Partly cloudy with a chance of showers. Highs in the low to mid 50s. Chance of showers 40%. 

Friday: Mostly cloudy with a chance of rain and snow showers. Highs in the low 40s but dropping during the day. Chance of precipitation 40%. 

Saturday: Mostly sunny and seasonably cold. Highs in the low to mid 30s. 

Sunday: Mostly sunny. Highs in the low to mid 40s. 

As always, please like, share, and interact with us on our social media--on Facebook to share our discussions, and follow us on Twitter @southernctwx to retweet our posts. Hit the buttons below to join.

​Thank you for reading SCW. 
​
-DB