Light Snow Likely Overnight; Highest Accumulations Near Coast

Below we share our official forecast for the light snow expected overnight into tomorrow morning.  Premium members have been receiving updates for the past 24 hours, and just received the updated percent chances of delays/snow days for schools across the SWCT/NY region.  They will receive additional updates through the day as to the chances of snow impacts, while any changes to the accumulation forecast will also be posted here.  To view the current chances of delays/closings and to receive all future changes by email, sign up here.  Otherwise, the latest forecast is attached below:

Partly cloudy skies early this afternoon become mostly cloudy by the evening as moisture approaches from the west.  Light snow showers between to move in betwen 9 PM and midnight tonight.  Steadiest snow is then expected between 1 and 5 AM (UPDATED), moving from west to east.  Between 6 and 9 AM we rapidly clear out, with the entire region dry by 9 AM as the sun attempts to come out by late morning.

Current snowfall estimates are for 1-3 inches of snow along coastal and inland regions and a coating-2 inches far inland around/north of I-84.  Model guidance is relatively consistent with the most steady snowfall occurring along coastal areas.  There remain some differences in guidance; short-range HRRR guidance shows only about a tenth of an inch of QPF, as do the short-range ARW/NMMM, but other guidance like the NAM and RAP show the potential for .15 to .2 inches of liquid by the coast which could easily become 3 inches of snow.  All snow will be quite light and fluffy, resulting in snowfall ratios of 1:15 to even 1:20 across the region.  Accordingly, even just .05 inches of liquid could become an inch of snow, which is why I am very confident that at least an inch of snow will fall along the coast.

Travel impacts tomorrow morning are likely for the Friday morning commute.  Of course, snow will be light, so impacts will be minimal, but slippery travel looks most likely between 3 and 7 AM.  Snow will stick instantly on roadways with cold temperatures, and though it may not be too icy and snow will not be heavy it may be hard for any sand/salt to melt much of the snow, so we could see slushy/snow-covered roads into around 7 or 8 AM.  Temperatures struggle to rise above freezing, so some snow could linger on back roads later into the morning.  Accordingly, just be slow to take it slow tomorrow morning, especially if you are out before 7 AM.

Tomorrow’s Storm Mostly Wet For Region

All week we have been updating Premium subscribers on a storm system moving through tomorrow.  We had been downplaying expectations as it had been clear that the setup was not conducive for significant snowfall accumulations, especially down at the coast, and recently weather modeling guidance has moved in that direction.  Today we issued an updated forecast for them, along with a travel impact highlight and forecast through the next 2 weeks as to when we could see the next major winter weather event.  To view the full forecast for the upcoming storm and to get email updates around all weather events, subscribe here.  Otherwise, below we have attached the summary of our forecast for tomorrow:

A rapidly strengthening storm system will move even closer to the region than expected tomorrow.  Model forecasts shifted a bit further northwest with the storm system and take slightly longer to develop the independent low pressure center that was supposed to lock in colder weather, so accordingly we are going to see more rain than any type of wintry precipitation across the region.  Light snow showers start between 7 and 10 AM across the region, quickly mixing with rain by 10 AM.  After 10 AM the entire region quickly turns over to heavy rain.  In the heaviest bursts of precipitation some wet snowflakes could mix in through the afternoon, but with temperatures in the upper 30s/lower 40s it will be very difficult for any snow to stick at all.  Rain lingers into the evening, potentially mixing with some snow on the back end as precipitation winds down by 9 PM.  We then dry out overnight with low temperatures in the low 30s/upper 20s.  As the storm rapidly strengthens to our northeast we should see gusty winds overnight with gusts into the low 30 mph range.

Accumulation forecasts are much more high confidence now as the entire storm is expected to be rain at the coast and even some inland regions.  Only far inland is there a threat for some wintry accumulations.  At coastal regions, a slushy coating is possible with the original round of snow showers before the rapid turn to rain.  Only on grassy surfaces will any coating be possible and just that seems unlikely; any coating will begin melting rapidly by 10 or 11 AM.  Inland further from the coast we could see a coating to 1 inch of snow in the first round through 10 or 11 AM, again mainly on grassy surfaces.  At the height of the storm, especially on the back end, some heavier banding of precipitation could see some snow reach the surface further inland, but recent models are showing even that be a bit unlikely.  Far inland, a coating to 2 inches is possible.  In the colder scenarios either at the front or back end of the storm we could have a quick thump of snow, but even far inland (north of I-84) almost all of the storm will be rain, limiting accumulations dramatically.

Snow Turns To Freezing Rain Tomorrow Morning

A moderate impact winter weather event is expected late tonight into tomorrow, with impacts winding down by early tomorrow afternoon.  Premium subscribers just received a detailed breakdown of when the worst travel conditions are likely to be, where confidence is highest/lowest in the forecast, and what is likely to change from here.  Attached below is our expected timing of precipitation and accumulation expectations across the region.  As it is early in the season, we attached a piece of our travel impact forecast as well.  To get more detailed updates emailed directly to you in real-time, be sure to subscribe here.

Snow breaks out across the region between 1 and 3 AM, generally from west to east.  The heaviest snow is expected between 6 and 10 AM across the region, when snowfall intensity of up to an inch or more may be possible.  By 8 AM we may begin to see sleet and freezing rain mix in across far southern areas.  By 9 AM we expect coastal areas will be turning to a mix of sleet and freezing rain, though temperatures are likely still below average.  The entire region goes over to freezing rain by around 10 AM as surface temperatures only gradually warm.  By 11 AM temperatures at the coast barely get above freezing, but some icy patches may linger while inland areas are almost all below freezing.  By noon precipitation dies down as a mix of freezing rain/rain across the region, and we dry out through the afternoon.

As for accumulations, right now a broad 3-6 inches of snow can be expected across the region.  However, a more precise forecast would be 2-5 inches of snow/sleet in coastal areas and 3-6 inches inland, as inland areas see about an hour more intense snow that could allow for accumulations to be a bit higher than coastal areas which mix sooner.  Additionally, the entire region could see up to a tenth of an inch of ice, which would actually make travel even more dangerous than just the snow.  There is the potential for the period of freezing rain and especially rain to compact the snow, especially as the first part of the snowfall will be rather fluffy, so we could see widely varying accumulation amounts (anywhere inside these ranges) but these amounts are for what is forecast to fall before any turn to freezing rain/rain.

In terms of travel impacts, we begin to see roads become slippery with light snow falling between 2 adn 4 AM.  The worst travel conditions look to be between 6 and 11 AM at the coast and 6 AM and 12 PM inland.  Even into the afternoon there look to be some lingering icy patches, so through 3 or 4 PM inland some areas in valleys could see enough cold air trapped for lingering icy patches causing delays and travel troubles.  By tomorrow evening concerns should ease, and overnight temperatures rise relatively quickly so that there will be no overnight travel concerns, but into the late morning at the coast and early afternoon inland look to be quite slippery.

Overnight tomorrow night we see some drizzle with low temperatures rising from the low to the mid 40s through the night.  Into early Sunday more steady rain can be expected across the region as temperatures rise, quickly melting any lingering snow.

Snow Quickly Turns To Rain Overnight

Below is our forecast for the winter weather event overnight tonight.  For more details on expected travel and any potential school impacts, you can sign up for our Premium service here and have all updates emailed directly to you with outlined travel and school impacts.

Snow showers are popping up across the region. They will gradually become more steady over the next few hours, and through 8 PM a coating to maybe half an inch of snow can be expected. A few isolated areas could approach an inch, but generally just about half an inch is expected. By 9 or 10 PM any snow showers wind down from this first round of snow.

There is a pause in precipitation between 9/10 PM and 1/2 AM. Then between 1 and 2 AM light precipitation overspreads the region, gradually getting steady by 3 AM. Though precipitation may initially be a burst of snow at the coast, it quickly turns over to rain by 2 or 3 AM. Inland we begin to turn to rain and freezing rain by 3 or 4 AM, and snow is enirely out of the region by 5 AM. We may see a couple hours of icing between 3 and 6 AM inland, but by 6 AM most of the region should see temperatures above freezing with only patchy icing very far inland. Rain showers will continue through the morning but should wind down by noon.

Accumulations overall will be quite limited. A coating to an inch of snow is expected at the coast, with most of that falling through 9 PM. Inland I expect a coating to 2 inches, with amounts less than an inch likely just north of the Merritt but accumulations approaching 2 inches possible near areas like Danbury before a turn to freezing rain and rain. Up to a tenth of an inch of ice could be possible in patchy areas inland as well, potentially necessitating Winter Weather Advisories. Far inland, 1-3 inches of snow is likely before a turn to rain, with up to a tenth of an inch of ice also possible. It is highly unlikely anywhere sees more than 2-3 inches of snow, even very far inland, and it is possible amounts are capped below 2 inches across the entire region.

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Light Snow Expected Overnight

With light snow expected overnight that could bring impacts tomorrow, we have been updating Premium subscribers with potential school and travel impacts.  Below we outline the forecast for the region:

Overnight we should see increasing clouds through the night.  Low temperatures get down to the low/mid 30s at the coast and maybe hit 30 further inland.  Temperatures gradually begin to warm overnight with a weak southerly flow.  Light snow showers break out between 1 and 4 AM across the region from west to east.  Between 4 and 8 AM precipiaion could briefly become moderate, cooling surface temperatures a bit.  Between 4 and 6 AM snow turns over to rain at the coast, with that same transition happening inland bewteen 4 and 7 AM.  Rain showers then continue through around 10 AM and we dry out from there.    Some models even show rain dominating the entire time at the coast, but at this point I favor some snow down to the coast thanks to a cold column it will just struggle to stick with relatively warm surface temperatures.

Accumulations are expected to be very minimal.  Most coastal areas likely see snow struggle to stick on roadways and other surfaces, especially across western Fairfield and all of Westchester counties where warmer weather is expected.  Still, coastal accumulations of up to around a half inch, primarily on grassy surfaces, are possible.  Further inland, accumulations of up to an inch are possible, mainly in elevated regions. North of I-84 isolated amounts a bit higher than an inch are possible as well, though widespread amounts of over an inch look unlikely thanks to relatively marginal surface temperatures.  Most accumulations are likely to occur between 4 and 7/8 AM before surface temperatures warm significantly.

At this time, travel looks to be potentially slippery in coastal areas between 3 and 6 AM and inland areas between 3 and 7/8 AM Minor impacts are possible, as snow may be able to stick on roads further inland with surface temperatures just slightly above freezing.  Any more intense bursts of snow would quickly stick and cover roads with margial inland surface temperatures.  At the coast, south of the Merritt, we will still struggle to see temperatures consistently below average that would allow any real sticking of snow on the roads.  Though patchy slick spots could exist, no widespread impacts are expected even if there are some accumulations on grassy surfaces.

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