- Wintry pattern continues through March
- Light snow and rain Tuesday, main event on Wednesday
- Over 6 inches in Central and Northern New Jersey
- Coastal flooding concerns
Our historic March rages on, with another significant winter storm looking increasingly likely for Tuesday evening into Wednesday. For several days, model guidance has suggested the threat of a mid-week storm system along the coast. That looks to come to fruition in the form of a slow-moving, long duration winter storm. This spells snowfall, coastal flooding, and potentially blizzard conditions for parts of the state.
The parade of winter weather this month is due largely in part to a log jammed upper level flow over the northern and western Atlantic Ocean. In February, most low pressure centers slid to our north and west, bringing rain, or the catch-all “wintry mix.” Since the start of the month, however, the pattern has shunted the tracks for storms to our south and east, keeping New Jersey on the cold side of these systems. The pattern has also has kept areas of high pressure across southeast Canada, which has brought several shots of cold Canadian air to the northern mid-Atlantic. If you’ve been out the door early the last several days, you’ve felt it. It will be interesting to see if 2018 is the second straight year that March has a lower average temperature than February at the climate reporting stations.
The upper level pattern over the eastern half of the country is potent, to say the least. As a mid level trough swings across the Mississippi Valley and deepens Tuesday, several pieces of energy drop in, lighting the fuse for a developing coastal bomb. Model guidance is still struggling to resolve weather or not there will be one wave of low pressure or two. If it’s two separate waves, we will see precipitation spread across New Jersey as early as Tuesday afternoon. If the energy consolidates a bit or one piece of energy is recognized as the lead piece, then this will be more of a Tuesday night into Wednesday event. The difference is whether or not precipitation is falling for 24 or 36 hours, and also at what intensity snow or rain falls. Either way, this is a long duration event from a storm that will move slowly, and lash the state with winter weather.
Wednesday is all but guaranteed to be the worse of the two days. If you have to travel one or the other, Tuesday is the better day. Wednesday is looking increasingly likely to be a very high impact weather day, for most, if not all, of the state. You know the drill at this point — bands of heavy snow with snowfall rates of 1 to 3 inches an hour possible, whiteout conditions and nearly impossible travel. Conditions will be not much unlike what central and northern New Jersey saw in the most recent snow storm if the forecast for Wednesday comes to fruition. It’s a March snow storm working with plenty of moisture, so heavy snow capable of bringing down tree limbs and power lines is once again in the cards. I think the winds will be considerable as well, especially along the coast where blizzard conditions are possible Wednesday. With a long duration of east and northeasterly winds, coastal flooding concerns are present as well.
Being about 48 hours out, there is time for all of that upper-level energy to be resolved differently. There is a plausible scenario that the surface low slips a bit further east and northern parts of the state are relatively unscathed. In that case this would still be a high-impact event for southern New Jersey and the coast. I don’t think we’re going to see the track adjust much further north and west, so precipitation-type issues should remain fairly limited to southern New Jersey and the southern half of the coastline. Even here I think it’s a rain to snow situation.
The potential is there for accumulations to increase as well. This storm is obviously anomalous. It will be astronomical Spring by the time it starts, after all. Climatology says to couch expectations for prolific snowfall this late in the season, but it isn’t unprecedented. I’ll be more comfortable forecasting higher amounts if things look the way that they do, this time tomorrow. Stay tuned.