Happy New Year’s Eve from Southern Connecticut Weather!
 
With a wild 2016 winding down I’m expecting one more shot of precipitation for your festivities tonight. The week ahead is uncertain, with a bit of a roller coaster ride in terms of temperatures and conditions and yes, we are watching the potential of a winter storm by the end of the week.
 
New Year’s Eve

​RGEM depiction of this evening and overnight. This model, along with other high resolution and short term models, show the potential for light accumulations in the northwest and northeast part of the state tonight.
 
My main “concern” this week is for tonight, as a clipper crosses northern New England. With that track, we have a mixed bag scenario likely to unfold, with rain at the shore, a mix in the valleys, and snow possible in the elevation spots in northwest and northeast Connecticut.
 
Timing
I expect light rain/snow showers to arrive between 7pm and midnight, lasting through the early morning hours. I expect the precipitation to remain mostly light and to be gone by sunrise. I wouldn’t cancel plans, but the timing and temperatures hovering around freezing require everyone to take it easy on the roads and sidewalks tonight.
 
Accumulations
Generally, I think we’re talking about a coating to maybe an inch in the elevation spots, but the high-resolution guidance has had upwards of two inches of snow falling tonight. I think that’s overdone—these systems are usually moisture starved and I’m not sure we get good enough lift to squeeze out an overperformer, but be aware of the (low) potential. Regardless, I expect slick conditions on the road tonight virtually everywhere, so drive safely! 
 
New Year’s Day
Tomorrow looks like a great day, after the precipitation clears late tonight I expect seasonable temperatures and clear conditions tomorrow.
 
Monday/Tuesday
The early part of next week is active as—stop me if you’ve heard this before—a storm cuts to our west. With it, temperatures from Monday to Tuesday rise quite a bit, with temperatures on Tuesday rising above normal for this time of year. Monday could be a mostly dry day, with some rain showers or even some brief light mixed precipitation in colder spots, but by Tuesday and early Wednesday we are in the rain. It could be a decent rainmaker, which is important as we are still locked in the grip of a drought.

GFS depiction of early next week. There has been a strong signal for a rainer on the guidance for the last few days.
 
Wednesday/Thursday
The middle of the week looks quiet in terms of sensible weather, with no precipitation expected. However, the temperatures will seesaw, with warmer conditions Wednesday giving way to northwest flow and colder and near to below normal temps by Thursday.
 
Friday/Saturday
As I mentioned at the start of this post, I am watching the potential next weekend of a storm. However, the usual caveats apply. We’re forever away as this is at least a week out and the recent trend has been a total 180, from a potential significant winter weather event toward a total nonevent. Suppression depression. Right now, this period is barely worth casual attention, but I’ll be watching in case things change.
 
Thanks for reading. I’ll have the next installment of the SCW two-week outlook out tomorrow!
 
The dailies
New Year’s Eve: Increasing clouds with rain and snow showers by the evening and overnight hours. Highs in the mid to upper 30s. Chance of precipitation 50%.

New Year’s Day: Rain/snow showers ending early. Breezy early but turning nicer as the day progresses. Highs in the upper 30s to low 40s. Chance of precipitation early 50%.

Monday: Increasing clouds with rain showers by afternoon. Highs in the mid 30s to lower 40s at the shore. Chance of rain 70%.

Tuesday: Rain. Highs in the upper 40s to low 50s. Chance of rain 90%.

Wednesday: Rain ending early. Highs in the mid to upper 40s. Chance of rain early 40%.

Thursday: Sunny and colder. Highs in the upper 20s to low 30s.

Friday: Sunny and seasonably cold. Highs in the upper 20s to low 30s.

​Saturday: Partly sunny and seasonably cold. Highs in the mid to upper 20s. Chance of snow 10%.
 
-DB

Good afternoon from Southern Connecticut Weather!
​
   Today was cloudy in some parts of the state, with sun breaking out in others and cool conditions. Temperatures around the state ranged from the low to mid 30s inland, to upper 30s and lower 40s at the shore. A few snow showers did make it to the area in association with some lake effect snow streamers from Lake Ontario. As we head through this evening, skies should remain partly cloudy until about midnight with clouds moving in toward dawn. Temperatures will be in the mid 20s inland to the lower 30s at the shore, temperatures will stay steady and rise slightly as we head toward morning. I mentioned clouds will move in later this evening, and that is in advance of the next weather maker we have been talking about for a few days now.

​   Last night we had issued our first call snowfall map and discussion for the 12/29 system, and much has changed since we published it.  Timing still looks pretty much on par for this storm, early Thursday morning through Thursday evening, as well as the shoreline getting basically no snow from this storm.  Dynamics have trended in a warmer direction with this storm, as it looks to intensify earlier and track closer to the coast, thus snowfall totals will need to be brought down quite considerably in all areas, especially northeastern Connecticut. We had a 4-8 inch snowfall zone in northern Tolland and Windham counties on thoughts that these places would have just enough elevation as well as close proximity to the rapidly developing, or bombing low pressure system. Our thinking was these areas would ‘cash’ in on the best dynamics, and this does no longer looks to be the case. Models have basically “caved” to an idea that the storm will intensify very rapidly, thus bringing the low center very close to Connecticut and warmer at the 925 through the surface level of the atmosphere to above freezing in most of Connecticut, especially in southern and eastern Connecticut. What this translates to is less emphasis on frozen precipitation, and more on liquid precipitation. All areas should start off as snow, most areas should rapidly change to rain as the area of low pressure intensifies just south and east of Long Island Sound. Temps should rise steadily into the upper 30s and 40s at the shore, and to the mid 30s inland, coupled with temperatures at the 925 level of the atmosphere, that spells rain for most of Connecticut. I'm looking at the possibility of some backside snows as the storm pulls away on Thursday night, but I’m not expecting much, if any, additional accumulations.

​As seen on the map, snow totals go from 0 at the shore in southeastern Connecticut, to about 4 and some spot 5 inch totals in far northwestern Connecticut. Yes, again, the Litchfield Hills are the “jackpot” area for the state, as they will hold the cold air the longest from the surface to the mid-levels. For the rest of the state, this looks to be nothing more than a nuisance event, but even a trace of snow on the roads can lead to some problems, so still be careful driving in these areas. As far as other hazards are concerned, rain may be the biggest issue over most of the state, looks like a solid half to 3/4s of an inch of rain will fall when all is said and done. Rain could be quite heavy at times especially during Thursday afternoon in eastern and southeastern Connecticut. As far as wind goes, it could get breezy on Thursday night as winds shift back to being out of the north and northwest. Expect winds of around 20- 30 mph during this period. 

​Looking to Friday and beyond, a frontal passage comes through on the back side of the departing low pressure system. Winds stay gusty during the day on Friday due to the pressure gradient and temps will again drop statewide, with the chance of an isolated snow shower. Over the weekend, we are watching for a weak “clipper” type system to influence the weather on New Years Day. It looks to be some snow and rain showers, and at this time does not look major. Also being watched is the potential for another system for later next Monday, and currently this event looks more wet than white.  In the longer term, we are watching for a pattern change to a stormier, snowier period, which looks to take place by around the week of the 9th. We will have more in depth analysis on this period in future discussions.

​As always, thank you for taking the time to read this discussion! There will be periodical updates during the day on Thursday to keep you abreast of all happenings with this storm system.  We at Southern Connecticut Weather appreciate being your trusted source for all things Connecticut weather. Stay tuned on Facebook and Twitter @SouthernCTWX!- TW

A very active and stormy weather pattern is setting up this week. We have several events to deal with- first, a snow threat Thursday, snow squalls Friday, snow showers for NY EVE Night, and then maybe ice Monday? A map is being issued for the upcoming Thursday threat. After coordination with TW and DB... more details below.

Currently: The cold front has now cleared the entire state. A secondary push of cold air, which will set the stage for a winter storm threat, is over Central Ontario and Quebec, will move through tomorrow.  Just a wind shift is associated with this cold front, so its passage should be dry.

Tonight: Cooler air begins to seap in, and temperatures won't be so warm as they've been.  Look for low temperatures within a few degrees of 30.

Tomorrow: Generally sunny, with highs 40 to 45.  Quiet and nice day for the time of year.  Clouds increase tomorrow night ahead of the storm, with lows generally from the low 20s to low 30s.  I think clouds will increase late enough to allow for radiational cooling.

Now for the storm potential for Thursday:
The various model solutions are as follows. The ECMWF suite, which includes the UKMET, very aggressively develops a strong low pressure system way down by the VA Capes and explodes it near the coast.  This would almost always favor significant snow for most, if not all, of the area.  However, most other models, including the newest NAM, GFS, and GGEM models show the low develop much further north and weaker.  This would result in less precipitation and less cold air.

Years ago, I would have been inclined to just ride the ECMWF and wait for other models to come to it. However, the ECMWF's performance has struggled lately, while the GFS has gotten much better.

There isn't a lot of cold air available at the surface.  If there were more, it would be a question of more snow vs. less snow.  However, with a VERY marginal surface air mass, we would need very heavy precipitaiton to pull down colder air from aloft and cool the column- a process known as evaporational cooling.

Because of the lack of cold air available, if any "fluke" heavy bands of snow set up, one area could get signifcantly more snow than another, even if it's an area that shouldn't be "snowier".  If a band like that sets up, there's often another area that gets much less precipitation near the heavy band.  That area would then receive much less snow as a result.  It is impossible to speculate where such bands will or will not be.  Therefore, this forecast is of much lower confidence than normal.

Here's a look at our first call snow map for this event

We're expecting little if any, snow accumulations along the south coast, 1-3" in the central portion of the state, and 4-6" in the northern part of the state.  For now, it looks like the Windham hills will be the big winner, as they'll have both elevation and be further east and closer to the storm.  6-8" could fall in those areas.  Of course, as always, this is subject to change up until the storm, and we'll have a final call map out tomorrow evening.  Some areas could see large "parachute" snow flakes falling, but not really accumulating, if the surface is in the mid 30s and the upper levels are cooler.  For now, I'll call for highs mostly in the upper 30s on Thursday.

​As far as the timing goes, I expect snow to move into the state on Thursday morning before mixing with and changing to rain from south to north across the state. Rain may flash back to snow across the state later in the evening as colder air works in from the deepening system. Best chance for that is in the NE hills, contributing to the higher snow totals there.

After a cold frontal passage, as a secondary cold front approaches Friday, aided by lake effect streamers, a band of snow squalls could move through during the afternoon.  As is always the case with snow squalls, accumulations would be limited to areas that get heavier squalls.  The Litchifeld hills would be the favored areas, but any area could get a rogue squall.  High temperatures on Friday should again be in the upper 30s.

An Alberta Clipper system will pass to the north New Year's Eve.  A band of snow showers will accompnay this feature.  Minor accumulations may accompany this feature, since it will be passing through at night. Look for highs on Saturday to also be in the upper 30s.

New Year's Day should feature fair weather and warmer temperatures in the mid 40s.  Then on Monday, a new system will track to our west and spread overrunning moisture ahead of it.  Models tend to underestimate low level cold air at this range, and there is a very strong high pressure system over New Brunswick province. This is a recipe for light freezing rain or freezing drizzle and a potentially very treacherous day.  Fortunately, it is a federal holiday and many do not have work.  Monday's highs should be in the upper 30s, but those highs may occur very late at night.

Beyond that, as the storm tracks to our west, much warmer air will move in for Tuesday, with high temperatures getting into the mid 40s.  After that storm pulls out, the pattern will gradually realign and a large ridge over Alaska will help transport more cold air into the region.  In fact, the overall pattern could be quite interesting, as the Southeast Ridge will still be present, which could set up a battleground and create a rather stormy pattern for our area.

Now, let's take a look at some of our weather in graphical format.  First, let's look at something different. These are analog composite snowfalls for storms that had similar upper air patterns leading up to the Thursday system. This doesn't mean it will happen exactly this way, but it looks fairly similar in distribution to our map and is a good check tool to use to see if your forecast makes sense.

You can see the accumulation distribution, ranging from 1-2" along the south coast, to 6-8" in the far north- not all that different from our map!

Finally, let's look at the setup for Monday.  

You can see the high pressure near Caribou, Maine, holding in cold air.  In fact, that new high out near Manitoba may suppress the other low further south, so as to keep Tuesday colder! We'll see, as that's a long way out and not included in our discussion yet!

Please like us on Facebook, retweet our map/disco on Twitter @SouthernCTWX and ask questions! We're here for you!

-GP!

Good afternoon from Southern Connecticut Weather,
 
This week, we’ll be dealing with a bit of a roller coaster ride in terms of sensible weather. Today, we’re dealing with seasonably cool conditions with the potential of some light freezing rain in spots. Tomorrow we warm up for a bit, and by Thursday we are watching the growing potential for what I think is our first nor’easter of the season. This’ll be a brief post covering the next few days.
 
Today
Temperatures are holding near freezing across much of northern Connecticut, and with precipitation approaching from the west, the National Weather Service has freezing rain advisories up for Litchfield and Hartford Counties from 3pm to 11pm in Hartford County and 1 to 10 in Litchfield. Looking at afternoon temperatures, I think this is a nonevent for most. However, it only takes a little bit of ice to cause significant problems, so use extra caution out on the roads. As temperatures warm more this afternoon, the freezing rain/drizzle threat diminishes. 

Current advisories and temperatures across Connecticut as of 1pm. 

The latest radar image showing precipitation pushing toward the state. I expect off and on showers through the state during much of the day and evening, with freezing rain/drizzle in some of our coldest spots. 

Wednesday should be a nice and (mostly) warm day, with temperatures pushing the 50s very early in the morning and dropping temperatures through the day as we get another shot of cooler weather moving in. This sets the stage for Thursday.
 
Thursday
So far this season, the pattern has been most conducive for cutters—storms that develop and cut to our west, bringing periods of mixed precipitation because of marginal airmasses in place that quickly turn to rain as the mid level and surface temperatures warm off a southerly wind.
 
When you hear the term nor’easter, you most likely think of “cold powder” snowstorms, with temperatures more than cold enough for snow all the way to the shore (except southeastern Connecticut, sorry folks), however, not all nor’easters are pure snowstorms, and the coming event looks to be the same at this time.
 
Although we’re talking about the Thursday timeframe, there is enough uncertainty to hold off on doing a map and going into great detail. Here is what we know right now:

• The chances have increased for the development of a nor’easter during the Thursday-early Friday timeframe.
• The lack of a deep cold source and blocking and potential track of this coastal storm make it unlikely for this to be an all snow event.
• Currently we expect a mix of rain and snow, with the potential for significant snowfall accumulations in the northern tier of Connecticut.  

 
The setup is fairly simple. An area of low pressure will traverse across Canada as a shortwave drops from the Great Lakes region and develops rapidly off the coast. The faster and further south the low develops the better for snow chances. In the last few model suites, the trend has been toward colder and more snow for our part of the world. That said, every model has a mix of rain and snow, as marginal temperatures and a lack of locked in cold (due to a lack of a high in eastern Canada) makes it hard for us to keep it cold enough for an all snow event. In addition, there are questions over the eventual track of the low, which has an impact on what we eventually end up with. 

Latest GFS depiction, showing a rapidly intensifying low pressure of the New England coast, but with temperatures marginal and no cold locked in place, there isn't a mechanism to keep this an all snow event--at least based on the current depiction. 

Here is the Canadian model depiction of the surface over the next few days. Similar to the GFS, but is a bit colder which results in more snowfall in northern Connecticut. Of course, this will change over the next few days so do not take this verbatim. 

What you cannot see here is the European model, which has been trending colder tick by tick recently. To be clear, that doesn’t mean that a trend cannot reverse, but the euro trending colder is a red flag for the potential for a more impactful event away from the coast. Overall, I have moderate confidence in a moderate to significant precipitation event in Connecticut on Thursday, with low but growing confidence in accumulating snow in northern Connecticut. This will change as we get closer to the event, so stay tuned for additional updates.
 
Please like us on Facebook and follow us on Twitter @SouthernCTWX, share, and ask questions as always. Thank you for reading SCW.
 
-DB

Good evening from Southern Connecticut Weather!
​
   Quiet but seasonable weather continued for today. Temperatures made it mainly into the upper 30s and 40s statewide under partly to mostly cloudy skies, with even a stray snow shower in far NW CT. Tonight skies clear and temps dip back through the 30s and into the 20s inland under mostly clear skies. So watch for some slick spots on the roads from refreezing of melted snow. As we look ahead to tomorrow, looks like another quiet day with temperatures in the mid to upper 30s inland to the low and mid 40s at the shore with mostly cloudy skies and light winds. Clear and calm conditions continue through Friday night with temps again dipping back into the mid and upper 20s inland with lower 30s at the shore. 

​   If you are looking for some snow to add to the holiday spirit, outside of far northwestern Connecticut, you will most likely be disappointed as we head into Christmas Eve. Clouds will be on the increase Saturday morning with precipitation moving in for the early afternoon from west to east. There could be just enough cold locked in place for Litchfield county that this precipitation could start as a little snow but looks to quickly change to sleet and freezing rain and then plain rain. Reasoning for this event being mainly rain, the stale cold airmass will be rapidly eroded by southwest winds promoting warming. Mid levels will already be above freezing by the time the precipitation moves in, so no help there in terms of frozen precipitation. Rain could locally be quite heavy on Saturday afternoon, take it easy as you do some last minute shopping (or in some cases start and finish shopping). Temps early in the day will move from the upper 20s and low 30s to the mid and upper 30s inland to low 40s at the shore, so freezing rain does not look like it will be an issue throughout much of Saturday's weather maker. Later on Saturday night, skies will clear and temps will again dip below freezing, so please be careful as you head to and from holiday celebrations with black ice on roads being likely.

​   For the all important Christmas forecast, it looks as if conditions will be mostly tranquil with temps early on Sunday morning being in the upper 20s inland and low to mid 30s at the shore, so make sure you throw on a jacket as young and old go outside to try their new toys. Temps will rise into the mid and upper 30s for highs inland and low to mid 40s at the shore, conditions should stay mostly clear as you head out to gatherings. Christmas night, temperatures again drop back through into the mid to upper 20s inland and low 30s at the shore. Conditions again look to be dry.

​   Early next week we start off with temperatures about average to slightly above. With a storm system moving through the upper mid west, winds will swing to out of the southwest and heights will rise promoting warmer temps for Monday into Tuesday. This storm looks to "cut" so far west of us that the only initial impacts look to be warming temps before a cold front bringing rain showers comes through early Tuesday morning. Temps will again drop to slightly below average for Wednesday. Looking even further ahead, I am watching later next week for another system to impact the state possibly next Thursday. At this point, it looks like mainly rain for us, but we are definitely watching it.

​   A brief look at long term shows that the pattern looks to become colder and more favorable for coastal storms, instead of the Great Lakes "cutters" that seem to have taken over the weather pattern. This change looks to occur sometime after the new year, and most likely by the middle of January. Remember, it is only December 22nd, there is alot of winter left. 

​   As always, thank you for continuing to make Southern Connecticut Weather for you trusted source on all things Connecticut weather. Have a great night!-  TW