No we aren’t done with snow yet. Sometimes winter likes to linger into late March and even April.

An inverted trough with bands of snow will develop over New England and Long Island tomorrow afternoon and evening. This an elongated area of low pressure that extends from a larger storm developing well offshore. Upper-level shortwave energy enhances lifting and instability along this trough. Often there is narrow band of heavier snowfall associated with these troughs. The exact placement and intensity of the banding with these type of systems, are often difficult models to handle and these solutions vary from run to run. At this time it appears, that there is enough agreement to increase chances for accumulating snow tomorrow afternoon and even more so tomorrow night for parts of Long Island and New England.

The latest run of the 18z GFS, shows a band of moderate to heavy snow falling over Eastern Long Island by tomorrow evening. The GFS sounding over OKX (Brookhaven, NY) shows significant omega values of up to -15 ub/s in snow growth region between 700mb and 800mb. Temperatures early tomorrow afternoon will be middle 30s. So initially some melting will occur, especially the roads and streets. However, after 4pm temperatures will fall into lower 30s and upper 20s as snowfall rates begin to increase and more cold air starts to advect in from the northwest. Snow should start accumulate on most surfaces at this point. At this time, a 1″ – 3″ snowfall looks most likely over Eastern Long Island and Southeast Connecticut. Localized snowfall totals between 3″ to 6″ are possible if heavier banding develops Saturday night. This will continued to be monitored and I will have another update tomorrow morning

Elsewhere over tri-state some snow showers or flurries are possible tomorrow afternoon and early tomorrow evening..  These will not amount to much than some dustings or coating on the grass and colder surfaces. These areas will be too far away from the inverted trough. Some places west of New York City may not even see a flake. Snow will begin to end for Eastern Long Island and Southeast Connecticut, after midnight Saturday night. Sunday will become mostly sunny with high temperatures in upper 30s to lower 40s. As high pressure builds in from the west.

Snow will overspread the area from southwest to northeast later this morning and this afternoon. Latest NAM and RGEM show snow changing to sleet then freezing rain for many areas NYC and south and east this evening. However, warm air advects northward, between 850-925mb, the thermal gradient will be increasing at this level. This could enhance lifting for a period of moderate to heavy snow before this changeover occursover North-Central NJ, New York City and Long Island. If this changeover before 7pm,then 2″ or 3″ is more likely to occur. If the changeover is delayed just an hour or two 4″ or 5″ are more likely. This even more likely over north shore of LI, parts northern parts of five boroughs, and just north and west of Newark, NJ. Further north over Northernmost New Jersey, the Lower Hudson Valley, and Connecticut is still likely to remain snow. Models since yesterday have increased liquid totals for most of the area. More freezing rain also likely parts for the southern half New Jersey,  before a change to rain.  As surface temperatures will be slow to rise to just above freezing. The forecast below has been updated to reflect these changes.

The latest models appear to becoming together on colder and wetter solution for the Tri-state on Sunday afternoon and night. The shortwave trough will cause weak low to from just off the New Jersey or Delaware shores. This will transport more moisture into area and cause the warm front to lift more slowly through region. A strong 700mb-850mb west-southwest jet will also enhance a thermal gradient that will enhancing lifting. At this time, appears most likely over NE NJ, NYC and LI. Models soundings show a warm layer near 900mb that will cause change over to freezing rain for a few hours Sunday evening, in these areas. Before ending as some light snow around daybreak Monday.Just north of this gradient is where precipitation is likely to fall mainly in the form of snow. Although, it’s not of the question some parts of there is brief mix with sleet/freezing rain.

The forecast below a blend of American and Canadian models. Leaning more toward NAM thermal profiles and leaning more towards RGEM/GGEM and GFS liquid forecasts.  So this forecast may be update later tonight, after viewing more guidance:

The storm late Tuesday and Wednesday still appears to track over Ohio Valley and Great Lakes. This will cause any frozen precipitation to quickly changeover to rain in our area. However, latest models are indication that this storm’s cold front may slow down  with more waves forming along it Wednesday night and Thursday. The outcome comes to the placement of the frontal boundary, the timing of waves moving up the front and whether the upper-level trough can take a more neutral or negative tilt. I will keep an eye on it and hopefully have another update later.