Have a good evening everyone! Stay warm this evening, and stay with us throughout the storm, we will post updates as needed. Thank you for reading, and continuing to support SCW!- GP

Good afternoon from Southern Connecticut Weather!

Currently we have clouds building in from the west in association with a clipper system. This clipper system, as with most fast movers in a progressive patter, will serve as more of whitening of the snowpack and nuisance for early Friday morning travel. The system does not look to be here for very long, and possibly will be in and out before the mid morning hours. As of right now, the beginning of the morning commute does look to be snowy though, so please be careful if you need to travel especially between 5 and 9 am.

Right now with the cloudy skies, we have temperatures statewide hovering in the upper 20s and low 30s. These Temperatures don't look to budge much as the clouds will work as an insulator, but overnight temps look to be well below freezing and prime for snowy conditions. Snow should begin to move in statewide between 12 and 2 am, and continue through most of the morning with varying intensities. All said and done, we expect 2-4 inches to fall in the northern tier of the state, while 1-3 is expected to fall elsewhere except the far southeastern portion of the state where a general coating to 2 inches is expected. Our map has changed since yesterday, bringing the higher totals to the northern part of the state, with less falling in the southeastern portion of the state as current conditions and models have trended the disturbance north, as is quite common with clipper systems. Not expected to be major storm, but could throw a wrench into the morning commute.

After the clipper departs, an Arctic cold front will swing through the state leaving Connecticut in the ice box for much of the weekend. Temps on Friday night look to dip into the single digits toward 0. Temperatures for the day on Saturday do not look to make it much higher than the middle teens. Along with the cold temps, windy conditions will be prevalent across the state from Friday afternoon through Saturday, driving wind chills into the negative numbers, especially later Friday night through. The only caveat to all of this is conditions will be mostly clear during the coldest times, so no wintry precipitation to worry about, until possibly Sunday where we are closely watching the possibility of a potent coastal storm which looks to effect the latter half of the weekend through the early part of next work week. We will have more on this potential storm over the next few days, right now it is too early to speculate about storm track, accumulations and the like. Stay tuned for a future discussion on this disturbance.

Have a good rest of your afternoon and evening everyone! Stay tuned for all the latest from Southern Connecticut Weather!- Tim

A very cold weekend is anticipated and as many Americans are watching football, there may be many meteorologists watching our next coastal snow threat, depending on exactly where the next coastal low tracks. First, for Saturday, a very cold, but sunny day is anticipated. Low temperatures should actually be fairly uniform across the state, because the areas that typically get colder at night will likely see more cloud cover. Thus, lows statewide should pretty much be in the upper single digits above zero. For highs on Saturday, there should just be the usual differences, from mid to upper 20s statewide. Wind gusts to 35-40 MPH will make it feel colder.

For Sunday into Monday: Clouds will increase on Sunday, especially in the south, ahead of the next coastal system. Snow should develop late Sunday night across at least the Southern portion of the state. Yesterday’s models were much further north with this system- in fact, so far north that the southern areas would definitely have to worry about precipitation type issues. However, today’s models have largely shifted south, so much so that the northern half of the state is definitely precipitation-free and some light precipitation makes it only to the south coast, if at all. Under this scenario, the precipitation type would definitely be all snow, but precipitation would be a lot lighter. This storm should be easier to forecast than the last one, since it is not a redeveloping storm, and it’s going to be tracking across the United States. However, it is still important to note that this storm system will not be moving into the Southwestern United States until Friday afternoon, and that is when more reliable data would become available. So until that point, we won’t have too much confidence in the ultimate track of the system. Therefore, for forecasting purposes, will go with a chance of snow and layer pops 50 south to 30 north, for the Sunday night into Monday time frame, and keep precipitation all snow for now, as the colder solutions seem to be preferred. As far as temperatures on Sunday, lows should be 10-15 statewide with some high clouds moving in and still breezy conditions limiting radiational cooling. Highs should be pretty uniform as well, pretty close to freezing, due to cloud cover, which will likely be thickest in the south. For Monday’s temperatures, lows will be from the low to mid teens in the north, to the upper teens in the south. Highs will not be a lot warmer than the lows, as cold air filters in. Highs should generally be in the upper teens north, to maybe a degree or so above 20 in the south. Here's a look at highs from Saturday from the GFS model.

For Tuesday and Wednesday, bitterly cold air infiltrates the state on Tuesday, with a little moderation for Wednesday. Generally fair weather is expected these two days. Depending on the track of the coastal low, Tuesday could be quite windy, which would only add to the chill. Tuesday’s low temperatures could very well be the coldest of the season for many areas, with low temperatures a few degrees below zero in the cold spots to only a few degrees above zero in the warm spots. Temperatures may recover pretty well on Tuesday, as we’ll have full sun, and winds backing around to the Southwest during the day. Highs should make it into the mid and upper 20s. On Wednesday, low temperatures will feature a larger range, mainly because Tuesday night may be a very good radiational cooling night. Temperatures could get into the upper single digits above zero in the cold spots, but only upper teens along the south coast. High Wednesday should be in the low to mid 30s. Yet another coastal storm is possible for Thursday, but more on that later!

FORECAST FOR ALL OF CONNECTICUT:

Tonight… Clear and cold. Lows ranging from a few degrees below zero in the cold spots to the upper single digits on the south coast.

Tomorrow… Increasing cloudiness. Highs within a few degrees of 30..

Tomorrow night… Light snow developing after midnight. Lows in the mid to upper 20s. POP 90.

Friday… Snow ending by dawn in the southwest, tapering down in the afternoon in the Northeast. Snow accumulations: 1-2” West to 2-4” East. Becoming windy late in the day. Early highs in the mid to upper 30s, then temperatures falling rapidly.

Saturday: Sunny, windy, and cold. Lows in the mid to upper single digits. Highs in the mid to upper 20s.

Sunday: Increasing clouds. Lows in the low teens. Highs around freezing.

Monday: A chance of snow, especially along the south coast. Cold. Lows in the mid to upper teens. Nearly Steady temperatures through the day. POP ranging from 50 along the south coast to 30 north.

Tuesday: Clearing, windy, and very cold. Lows 5 below to 5 above. Highs in the mid 20s.

Wednesday: Increasing clouds. Lows 10 to 20. Highs 30-35.
GP

Good afternoon from Southern Connecticut Weather!

Currently we are watching for a potentially historic snowstorm to impact the region from Monday through Wednesday, but first we will have a calm before the storm, today will feature sunny skies and seasonable temperatures in the mid to upper 30s, perfect for cleaning up from yesterday's storm. As we head through this evening, mostly clear skies will become mostly cloudy skies, especially after midnight. Temperatures will be in the low to mid 20s.

Looking ahead to Monday morning, skies will be overcast with a chance of scattered flurries and snow showers, especially as we head toward the latter part of the morning. Snow intensity will become steadier during the mid to late afternoon,  just in time to impact evening rush hour. Light to moderate snow becomes heavy snow during the latter part of Monday night through Tuesday morning. Along with the increasing snow intensity, winds will pick up dramatically as well, at times creating blizzard conditions, especially in the eastern and southern portions of the state. Shoreline cities and towns will not only have to deal with buffeting 50-60 mph wind gusts, but coastal flooding, as the rapidly strengthening low pressure area piles water into Long Island Sound.

During the day on Tuesday, heavy snow and high winds will persist, especially in eastern areas. Models are hinting at strong bands of snow setting up in the western part of the state, as well as the eastern part of the state, with consistently moderate snows for central Connecticut. Heavy snows look to continue through Tuesday afternoon, with the heaviest ending by Tuesday evening. On Tuesday night, light to moderate snow will continue to fall,  and the 12z model runs hint at snow continuing through the morning hours of Wednesday, before clearing takes place Wednesday afternoon. I do expect that the majority of accumulating snow occurs late Monday night through Tuesday afternoon as the clipper system rapidly intensifies just off the coast. As the low pressure area sits nearly stationary just off the coast and rots, bands of varying intensities will rotate through the area, thus accumulation could differ greatly from town to town, and even within a mile of any given spot.

Currently our thoughts on accumulations are, 16-24 inches west of I91, and 18-30 inches east of I91. The "lower" end of these totals looks to be dead in the center of the state, as current modeling depicts less in these areas, and the heaviest of the banding will just miss to either the east or west. That said, 16-18 inches of snow is nothing to sneeze at, and with winds whipping to nearly 60 mph, great caution must be taken.  Even during a "lull" in snowfall, winds will still kick up loose snow, creating white out conditions and high drifts in place susceptible to such conditions. So even if you do see a drop off in intensity, don't be caught off guard, conditions outdoors could still be quite dangerous.

As far as temperatures go, statewide, temperatures will be well below freezing. Winds will create windchills ranging from 0-10 above. If you do need to be outside, please dress in layers, keeping all extremities and skin covered. Just a few minutes outside in these conditions could cause frostbite. Driving is not encouraged from Monday night through Tuesday night, but if you do need to drive, please be sure to have a winter survival kit in your car (water, extra food, phone charger, clothing, shovels, etc) in case you are stranded. 

Currently, Blizzard watches are in effect for Fairfield, New Haven, Middlesex, and New London counties with Winter Storm Watches in effect for the northern counties of the state. By this evening, I do believe the entire state will be in some kind of warning, meaning blizzard or winter storm conditions are imminent by tomorrow morning.


To sum up, today is the quiet before the storm, with temperatures being quite seasonable, ranging from the mid to upper 30s statewide with sunny conditions. Temperatures fall back into the 20s this evening and clouds increase.  An Alberta Clipper drops in from Canada and tracks through the Mid Atlantic then eventually off the mid Atlantic coast where it eventually start to phase and intensify into a strong low pressure system or "Miller B"  and begins to track north and eastward where it eventually becomes nearly stationary at the 40/70 coordinate, or "benchmark". This low will be trapped between Atlantic blocking to the east and a strong higher pressure system to the north. The system will finally begin to dissipate later on Tuesday, basically just off of the Massachusetts coast. Snow could begin to fall as soon as late morning Monday, and become steadier and heavier toward dinnertime. The height of the snowfall looks to be late Monday night through early Tuesday afternoon, with additional accumulating snowfall impacting the area through lunchtime on Wednesday, where totals statewide look to be 16-24 inches with isolated higher totals.  Main impacts from the storm, will be of course heavy, blinding snow which will make roads very treacherous or not drivable period. Wind, which not only has the ability to cause damage to trees and buildings etc, will cause blizzard conditions and dangerous wind chills. As with most nor'easters, the shoreline looks to be in danger of some coastal flooding as the rapidly intensifying low pressure system piles water into the Sound. Please heed all warnings from local media and National Weather Service about such impacts.

Have a good rest of your day everyone! As always, thank you for reading, and stay tuned for further updates...- Tim

Good evening from Southern Connecticut Weather!

Tonight’s update focuses on the setup, model analysis, timeline and impacts from a snowstorm that is modeled to impact the area from Monday night into Wednesday morning.  Considering the short lead time from which this storm has developed, we would be grateful if you would share with friends and family to raise awareness of this potentially major event. Enjoy the discussion! –Greg and Spencer

Overall pattern and setup overview:

An anomalously strong Alberta Clipper system will dive down from Canada then track into Appalachia, before redeveloping off the east coast.  As it does so, it is expected to ingest energy from the Southern jet stream.  This should aid in strengthening the low pressure system and also in developing very heavy precipitation near the storm center.  The biggest question at this point is not precipitation type- it looks cold enough for snow in all areas, but where the low pressure system begins developing and where it will ultimately stall or drift to the west.  There also doesn’t seem to be much question as to whether or not the storm will be strong- all computer model solutions currently show a strong low pressure system offshore of the Northeastern United States.  So, for now, I have included a preliminary model discussion, breaking down each model and discussing what each model shows.

Preliminary model discussion regarding the upcoming Monday/Tuesday storm..    

As you know, there are several operational computer models that meteorologists and forecasters use to aid them in forecasting the weather.  This discussion will provide information as to what each model shows and what it could potentially mean for weather here in Connecticut.

GFS: The American medium range forecasting model, or the GFS, shows the Alberta Clipper racing through, without much interaction of the two jet streams, until the Clipper system is pretty far offshore.  This would result in accumulating snow for everyone from the clipper, but the coastal low (which would be capable of producing the biggest accumulations), would be too far offshore to really bring significant accumulations to anyone except far Eastern Connecticut.

ECMWF: The European model, which is the medium-range computer model produced in England, shows a massive blizzard for basically the entire Northeastern United States.  The low pressure system develops much earlier and further SW, then stalls.  This rotates in several bands of very heavy snow, accompanied by very strong winds.  If this model solution verifies literally, there would be a historic East Coast Blizzard from Delaware to Maine.  

UKMET: The UKMET model, as the name implies, is produced by the same agency as the ECMWF.  It’s basically a shorter-range model.  Its solution is similar in evolution to the ECMWF, but not as extreme, resulting in a solution between the ECMWF and GFS. 

GGEM: GGEM is a model produced in Canada by Environment Canada.  This model produces a solution sort of in between the GFS and UKMET- which is more aggressive than the GFS, but nowhere near as aggressive as the ECMWF.

ECMWF ENSEMBLES:  For those who don’t know, ensembles are runs of the same model run with slight alterations to their equations.  You may wonder why this is done.  The reason it’s done is to provide a check with the operational, or main, run of the model.  In other words, if an operational model shows something, and the ensembles look vastly different, or are skewed one direction or another, it gives us a clue that the operational model is not correct and that the forecast should take that into consideration.  However, the ECMWF ensembles looked very much like the operational ECMWF! This would generally increase confidence that the operational model is correct.  Also, keep in mind, that an ensemble mean is an average of all the “members” of an ensemble package, of which there are many.  So, as you might expect, to get an average to show something big is significant.  Because there are almost always a few members that show next to nothing.

 

UPDATE: The newer GFS has just arrived and looks very similar to the ECMWF… therefore, potential impacts from the new GFS are obviously much higher.

As far as what to do as far as potential impacts to our area, preliminary ideas would be to let everyone know that yes, there is a potential for a very high-impact event.  However, with this event still being a bit out in time, and some of the crucial data just coming ashore, we will use caution and not go as extreme as the ECMWF, especially considering that models are just coming into agreement on this solution.  However, it is important to note that confidence is definitely increasing on a major event for most, if not all, of Connecticut.  If current trends continue, tomorrow morning’s update will go with a significantly higher-impact event for most, if not all, of the area.  Stay tuned!

-Greg

Progression Overview

Light snow would move into the area Monday night, perhaps clipping the tail end of the evening rush but not causing any major issues there. Precipitation would be light throughout much of the evening and overnight hours, but don’t get too comfortable with that, because it wouldn’t last. Towards the morning hours, the low would begin to bomb and strengthen, promoting the development of what is known as a CCB(Cold conveyor belt, or a large band of intense precipitation) on the west side of the low. While it remains unclear where in the state has the best chance to be hit with the brunt this CCB, model guidance generally favors eastern areas for the heaviest snows. However, the entire state should see rates increase, and areas that see the best banding could see rates of 1-2” per hour!

 What happens next depends on where the low stalls out. All guidance stalls the low somewhere off the New England coastline and allows bands of precipitation to rotate around it, but exactly where it stalls will be critical to who sees the highest totals. A stall further to the east would benefit eastern areas while western areas are mainly dry or seeing light snow, while a stall closer to the coast would allow for the entire state to get into the heavy banding and for western areas to have the highest totals. This portion of the storm will have the heaviest snow rates for whoever gets under the strongest bands, and it’s possible that we could see rates of over two inches per hour. The precipitation shield will be more banded though, because the strong bands create subsidence zones on either side of them and the result is the areas outside the bands see only light precipitation instead of a more widespread precipitation shield. Where exactly these bands set up will determine who jackpots for this event, and that’s not something we will know until much closer to the event.

We’ll see the low continue to be stalled and slowly rotting right through Tuesday evening, before moving out overnight Tuesday. Some lingering snow showers are possible right through the morning rush on Wednesday.

In terms of snow totals, the answer right now is really who knows? All guidance is in good agreement on at least warning level snowfall for most of the state(6”), so that’s probably a good baseline to start with on the low end except for far western areas which could see a bit less if a far eastern track was to verify. On the high end though, the numbers are potentially staggering. Both the 18z GFS and 12z EURO print out two feet or more of snow for parts of the region, and quite frankly, with the setup, we don’t think this is unreasonable. However, the question of where we would see those amounts is still very much up in the air, and we won’t know where that is until go time really when the bands begin to form. For this reason, the snowfall map will have very wide ranges and be a very low confidence forecast. We’ll have it out tomorrow morning after we see another round of data. Most likely, the majority of the state will be in the range of 8-16”, but if the 0z models continue to trend stronger, all bets are off. Of course, it could go back to a complete whiff, but I’m not buying that.

Impacts

·      Warning level snows

Widespread significant accumulations are expected from this system. Thankfully, this will be a lighter snow than what we saw today which will make it easier to remove.

·      School/Job closures

There is the potential for a snow day on Tuesday for the entire state, and quite possibly on Wednesday as well for the areas that are hit the hardest.

·      Power outages

Heavy snow along with strong winds will lead to potential power outages

·      Coastal Flooding

Strong winds will result in potential coastal flooding at times of high tids.

·      Potentially extreme travel conditions from Monday night to Wednesday morning

Rapidly accumulating snow combined with cold temps will allow for instant accumulations on roads, causing a major snafu.

Bust Potential

Lots of it in every possible direction. That about sums that one up.
Next steps from SCW

·      First call map and discussion: No later than 3 PM tomorrow afternoon

·      Second call map and discussion (Potentially): Monday morning, may skip directly to final call if no major changes.

·      Final call map and discussion: No later than 7 PM Monday night

·      Live updates: Every 2-3 hours through the event. We have a forecaster scheduled to be on duty from 7 PM Monday night until noon on Wednesday to bring you up to the minute coverage.

Considering the rapid nature of which this storm came into our viewfinder, please share with friends and family to get the word out! We’ll see you tomorrow afternoon, and as always, thanks for reading SCW!

-Spencer