Good evening from SCW!

As Don mentioned on Sunday, we’re tracking a clipper system for tomorrow evening into early Thursday morning that will bring some light snow to the state. In this discussion, we’ll take a closer look at that system and issue a first call snowmap.

Models and Trends

Guidance is in good agreement on swinging an Alberta Clipper system through the state on a nearly due east trajectory. While some runs earlier in the week were showing a more amplified system and possibly some coastal redevelopment, which would have bumped up QPF while also increasing the chance for mixed precip, the past several model cycles have been in good agreement that this will be a weaker and colder event, meaning all snow. There is still some disagreement among the guidance as to how much QPF will be able to work into the region, with the global models (GFS and Euro) supporting an advisory level event across the region while the mesoscale models (NAM/RGEM) are much weaker and only bring an inch or so of snow to the state. There is good agreement between the guidance that areas to the north and east will see the higher amounts, while southern and western areas will see lighter precip as they miss out on any coastal enhancement that does take place as the storm hits open water. I could imagine a solution where Windham County ends up with 3-5” and Fairfield County only a coating to an inch, but think that’s a little too extreme a gradient for right now.

​The trend has generally been relatively constant over the past few cycles, with the divide between the globals and the mesos remaining present and relatively constant. While the longer term trend has been to weaken the system, over the last few cycles we’ve seen things stabilize and so I wouldn’t necessarily expect that to continue.

Here’s a look at total QPF from the GFS and the NAM through Thursday evening. The GFS generally advertises a quarter to a third of an inch of liquid across the state, with some isolated spots of up to four tenths of an inch or so. That’s good for 2-4” of snow for most, with far southwest areas being the exception and only seeing an inch or two. Meanwhile, on the NAM, most of the state sees only around a tenth of an inch or so of QPF, with some areas even lower. A coating to an inch would be the result of that solution, if that.

Forecast and Timing
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Here’s our forecast snowmap for this event.

I considered splitting the state in two different ways, the first way being to put a zone of lower totals in the SW corner while leaving everywhere else the same and the second way being to put a zone of higher totals in the NE corner while leaving everywhere else the same. However, given that we still have somewhat of a disagreement between the mesoscale models and the global models, and the magnitude of that disagreement is larger than the likely differences from one corner to another under the same solution, I decided to just stick with a broad brushed 1-3” for now, with the caveat that we’ll likely split that up into two zones tomorrow once we have a better understanding of which solution is going to win out.

As far as timing goes, generally expecting precip to hold off until after dark tomorrow (Wednesday) evening, although it wouldn’t surprise me to see some light snow towards the tail end of the evening commute, especially in western and southern areas. Similarly, I expect snow to be mostly out of the state by the start of the morning commute on Thursday, but could see some residual snow showers linger throughout the morning.

Impacts

Overall expecting a relatively low impact event. Here are the details:

• Snow Accumulation: Low to Moderate
• Snowfall Rates: Low to Moderate
• Wind: Low
• Power Outages: Low
• Timing: Low to Moderate
• Road Conditions: Low to Moderate

Winter Weather Advisories are in effect from the NWS for the entire state excluding the immediate shoreline.

​We’ll be back tomorrow with an updated map, until then, enjoy the rest of your evening and thank you for reading SCW!
-SA

Good evening from SCW. 

The last week of February has arrived, and we kick things off with what may be a high end wind event. Let's dive right in. 

Monday
As I mentioned earlier on Facebook, a High Wind Warning is in effect for the entire state between now and 7pm tomorrow. This is the result of a powerful storm developing to our north (of course, given this winter) and a strong high pressure that is taking shape in the Midwest. The resulting pressure gradient and cold air advection in the wake of the cold front passing through will bring us strong winds tomorrow. 

Above is the the latest GFS showing winds *at 850mb* tomorrow. We will not see these kinds of wind sustained at the surface, but with effective mixing, we could see damaging wind gusts on the order of 50-65 mph. With high winds and saturated soil, I expect scattered power outages that could be more widespread statewide should we get some of the higher end gusts. If you are in an area that loses power easily, be prepared to lose it tomorrow. 

The highest wind gusts are likely to occur tomorrow afternoon, between 1-4pm. The wind should begin to diminish Monday evening, but will remain strong into early Tuesday. 

Tuesday-Wednesday
Both days look sunny and cold, as high pressure settles in. We should see dry days with Tuesday below freezing for most and Wednesday perhaps a bit warmer. By late Wednesday we're watching the potential for a weak low to pass to our south, which may bring a period of wintry precipitation. 

Thursday-Friday
The weak low that I mentioned above looks like it may impact the area early Thursday as well. With cold air in place, it seems at this point that this could be a mostly light snow event. I'm not going to lie to you though: I've written that sentence only to be burned enough to tell you that any kind of "all snow" event given the overall pattern isn't something I'm willing to bet anything on. Let's see where things stand on Wednesday morning...

At any rate, the system looks like a quick mover and becomes the first of what could be a series of lows bringing unsettled weather the latter half of the week. Friday looks like it could be unsettled as well with some rain possible. 

The Weekend
Unfortunately, the first weekend of March isn't looking too great. There is a signal for another storm, but--stop me if you heard this before--it looks like a mixed bag to rain event currently. We're still pretty far away so things can obviously change, but for now, it looks like a storm that cuts to our west, bringing us wintry precipitation that changes to rain, followed by cold in its wake. What a winter. 

The Dailies
Monday: Mostly sunny and very windy. Maximum wind gusts of 50-65mph statewide. Daytime highs in the upper 20s to low 30s. Chance of snow showers 10%. 

Tuesday: Mostly sunny, breezy, and cold. Highs in the mid to upper 20s. 

Wednesday: Partly cloudy with increasing clouds. Chance of snow by evening. Highs in the low to mid 20s. Chance of snow 40%. 

Thursday: Snow early with gradual clearing. Highs in the low to mid 30s. Chance of snow 50%. 

Friday: Mostly cloudy with a chance of showers. Highs in the mid to upper 30s. Chance of precipitation 20%.

Saturday: Chance of mixed precipitation changing to rain. Highs in the low to mid 40s. Chance of precipitation 50%. 

Sunday: Chance of rain showers, otherwise mostly cloudy and colder. Highs in the mid 30s. Chance of precipitation 30%. 

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 and trusting SCW. 

-DB​

Good evening from Southern Connecticut Weather. 

It has been a rare sight to see an all snow winter weather event this season, and this just may be the closest we get to that since November. 

A Winter Weather Advisory has been issued for the entire state as an area of low pressure approaches from the west. It will will redevelop to our south tomorrow. With cold air in place, we are expecting a light to moderate snow event. Because of banding and the potential of mixing in parts of southern Connecticut, we are making some adjustments to our snow map. 

After an initial map that showed 2-5 inches of snow statewide, it's time to be a bit more precise. I am taking the numbers up for central and northern Connecticut slightly, and adjusting the snow forecast for the shoreline, where some mixing is possible. Because of some microphysics in the atmosphere, there may be some freezing drizzle further inland tomorrow as well. However, I do not think that will significantly impact snow totals, and I think the lowest totals will be confined to areas right near the shore. 

Snow will break out over the state in the next 3-4 hours. It will become moderate to heavy at times. The majority of snow falls overnight, and we likely see periods of light snow through tomorrow with some possible mixing in southern areas. Things clear by tomorrow night. 

Pictured above: 3km NAM showing a period of snow early on followed by lighter snow during much of Monday. 
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Impacts

Overall this looks to be a low to moderate impact event. 

• Snow Accumulation: Low to Moderate
• Snowfall Rates: Moderate (overnight especially) 
• Wind: Low
• Power Outages: Low
• Timing: Low (given the holiday and that most is likely to fall overnight, the timing actually looks good here) 
• Road Conditions: Moderate

I don't expect delays on Tuesday, as thing should have cleared by then. 

Tuesday-Thursday
Tuesday looks like a great day, with chilly conditions as we watch the next weather maker approach from the south. Wednesday starts off fine, but we will see increasing clouds as we return to the mixed bag storms we've grown accustomed to seeing this season. Things will start off as snow, and change to mixed precipitation and then rain as we head into Thursday. It's still too early to hone in on the details for this one but stay tuned as there could be significant delays late Wednesday into early Thursday. ​

Friday-Sunday
Not much needs to be said about this period yet. As the storm clears on Thursday, Friday and early Saturday look fine. There is some signal however that we may see another mixed bag system Saturday into Sunday. 

The Dailies
Monday: Snow. Highs in the upper 20s to low 30s. Chance of snow 100%. 

Tuesday: Partly cloudy and cool. Highs in the low to mid 30s. 

Wednesday: Increasing clouds with snow and mixed precipitation late. Highs in the mid to upper 30s. Chance of precipitation 60%. 

Thursday: Mixed precipitation and rain. Highs in the mid to upper 40s. Chance of precipitation 80%. 

Friday: Partly cloudy. Highs in the low to mid 40s. 

Saturday: Increasing clouds with snow and mixed precipitation late. Chance of precipitation 30%. 

Sunday: Mixed precipitation and rain. Chance of precipitation 30%. 

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 and trusting SCW. 

-DB​

Good afternoon from SCW! This discussion will include our first call snowmap and discussion for late tomorrow night into Monday.

Models and Trends
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We’ve got an interesting little model battle shaping up here with the system for tomorrow night into Monday. The bulk of the guidance has trended wetter and further north with the system to match the GFS depiction from yesterday, and now advertises a solid advisory snow event for the entire state. The Euro, on the other hand, has come part of the way there. It now brings a good band of snow into the southern portion of the state, enough for advisory level amounts in roughly the four southern counties, but in the northern portion of the state there is a sharp cutoff to just an inch or so of snow.
​
Here’s a look at the total QPF from the Euro (left) and GFS (right). The Euro has a sharp spread between about a tenth of an inch of QPF in the north to about a third in the south, while the GFS has about a third in the north and close to a half in the south. Not a huge spread in the grand scheme of things, but the difference between a nuisance 1-3” event and a plowable 3-5” event. 

While it’s hard to ignore the Euro as it’s our most reliable guidance, it’s not a model that likes to make big moves, and so the fact that it’s consistently ticking further north with the system while the other guidance has held relatively steady suggests to me that the northern consensus should be favored. While I’m not going to completely toss the Euro, even a 50/50 blend of the Euro/GFS would verify a low end advisory snow for the northern portion of the state, and even if the Euro were to verify completely we’d still see advisory level snow in the southern four counties. As such, I am confident with a general 2-5” of snow for the state, with higher amounts more likely in southern areas, with the caveat that if a complete capitulation to the Euro occurs we’ll need to knock amounts down an inch or two in the northern counties.

Temps have also ticked slightly warmer across the board with the progression further north, but I think we’ll be just cold enough to remain all snow across the board. It wouldn’t totally shock me to see a brief mix with sleet or rain on the south coast, but as of now I think that’s unlikely.

Forecast and Timing

Here's our first call snowmap for this event.

As discussed, we’re going to favor the wetter consensus for the first call, and go for a general 2-5” of snow across the board. I would expect most amounts to be in the 2-4” range, but leaving a little room on the top end in case we get some isolated bands of heavy snow or the system continues to tick wetter. Conversely, if the Euro solution wins out, northern areas will be closer to 1”, but confidence in at least 2” is fairly high right now.

The timing of the system hasn’t changed much, with snow moving in late Sunday evening (around midnight Monday morning) and continuing through early Monday afternoon. I don’t expect snow to be all that heavy, but the best chance for heavier snow will be Monday morning. If you have to commute Monday, plan to leave some extra time.
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Here’s an animation of the system from the RGEM.

Impacts

Still missing the SCW impact scale (I’m flying home tonight I’ll have it back soon!) but here’s what we’re expecting:

• Snow Accumulation: Low to Moderate
• Snowfall Rates: Low to Moderate
• Wind: Low
• Power Outages: Low
• Timing: Moderate
• Road Conditions: Moderate

Schools are off Monday for Presidents Day so we don’t have to worry about any snow days, and I don’t think snow will be heavy enough to close workplaces, but do leave some extra time for your commute Monday if you need to work.
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We’ll be back with a final call tomorrow afternoon, until then, if you liked what you read, please consider sharing on your social media platforms and joining our family on ours. 
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Thanks for reading!
-SA

Good evening from SCW!

After another mixed mess earlier in the week and warmer temps, we’re heading back towards the colder side of things as the pattern once again becomes active next week. We’re tracking two systems, one for Monday and one for Wednesday into Thursday, and both have the potential to bring wintry weather to the state. Apologies in advance for the lack of images in this discussion - I'm in the middle of nowhere Canada for a ski trip and the internet is borderline unusable. 

Saturday-Sunday

Sunny with seasonable temps as high pressure prevails over the northeast. Could see clouds to start to build Sunday afternoon, but expect any precipitation to hold off until the overnight hours. High temps should be slightly above normal, translating to the upper 30s to lower 40s, with Sunday being a tick cooler than Saturday. A great weekend to go enjoy all of the new snow that has fallen to our north – ski country did very well this week and conditions should be quite nice!

Monday
​
Weak area of low pressure passes to our south, putting us on the cold side of the system and setting us up for an all snow event. Guidance differs here on the amount of moisture the low carries with it, with the Euro only having a tenth of an inch or so of QPF (equal to about an inch of snow) while the GFS is quite a bit more amped up with around a third to a half of an inch of QPF, enough for 3-5” of snow. As always, something in between the two solutions is probably the eventual outcome, although I would lean slightly towards the GFS solution as it has been steadfast in being more aggressive while the Euro has gradually trended wetter. Either way, not expecting a major storm, but a slower commute on Monday morning (for those who don’t have the day off) appears likely. Snow should start late Sunday night and go through about mid-day Monday on the GFS solution, the Euro solution is more compressed on both ends.
​
Here’s a look at total snow from the GFS (left) and CMC (right). The CMC solution is similar to the Euro, with the heavier totals being in southern areas on both models as they are closer to the low center. Should we see a trend even further north, we’d shift the heavier totals into northern areas and southern areas would see a mix with rain, but I don’t think that’s likely right now.

Tuesday
Transition day between two systems as we’re under a brief ridge. Clear and sunny, highs a bit below normal in the mid 30s.
Wednesday-Thursday
A larger, more complex system is on the guidance towards the end of the forecast period. All models agree that the ridging from Tuesday moves up into the classic position to provide cold air damming (and maybe some blocking) for the state, while a stronger system simultaneously moves into the lakes before ultimately developing a secondary low offshore. We’ve seen this story before this winter. While it’s way too early to begin to speculate on amounts, this system does appear to be redeveloping a bit further south than the others have (at least if you believe the guidance) which makes the likelihood for higher snow totals a bit larger than in some of the other systems to date. That said, when you’ve got a low going into the lakes the midlevels naturally want to warm, so under the current guidance depiction this looks like another messy wintry mix event. We’re still quite a ways out from this one though so stay tuned.

Friday

Calm and quiet behind the system with near normal temps.

The Dailies

Saturday: Sunny, with highs in the upper 30s to lower 40s.

Sunday: Mostly sunny, with highs in the upper 30s to lower 40s.

Monday: Snow likely, otherwise, mostly cloudy, with highs in the low to mid 30s. Chance of precipitation is 80%.

Tuesday: Mostly sunny, with highs in the upper 20s to lower 30s.

Wednesday: A chance of snow, otherwise, mostly cloudy, with highs in the upper 20s to lower 30s. Chance of precipitation is 50%.

Thursday: A chance of snow, sleet, freezing rain, and rain, otherwise, mostly cloudy, with highs in the low to mid 30s. Chance of precipitation is 50%.

Friday: Partly sunny, with highs in the mid 30s.

We’ll be back tomorrow evening with a first call map for Monday if needed (and with more images and a better internet connection :) ), until then have a great weekend and thanks for reading SCW!
-SA