March 21: Morning Winter Storm Update

Jonathan Carr
By March 21, 2018 11:10

March 21: Morning Winter Storm Update

Discussion: We have a snow/sleet/rain line/situation currently near the I-95 corridor. I expect this to advance to the SE between now and afternoon hours (possibly earlier) as the low-mid level temperatures crash. Precipitation should then bring this colder air down to the surface and allow for the late-March stickage. Since SENJ will be the last to changeover to snow, SENJ should expect the least accumulations from this winter storm. By 4pm the entire state should be all snow and we’ll stay that way through evening and possibly overnight hours. The latest short-range model guidance has snow tapering off between 3-4AM Thursday morning.

Based on the relationship between the departing wave (yesterday’s event), the approaching upper-level low and the new coastal low forming off Delmarva, we have a slight tweak to make. The ULL is a little bit further S and W than it should be and the coastal low is a little more organized as a singular low. We think this could possibly open up the jackpot about 25 miles to the NW of where it was. This would mean slightly higher snow amounts for NWNJ and slightly less for areas just SE of the I-95 corridor. No changes for most of SENJ.

Winds are gusting from 38-44mph (from Atlantic City down through Cape May). Points N of that on the ENJ coast are seeing gusts in the 30s. Areas away from the ocean are seeing lesser wind values. Winds should ramp up over the next 6 hours with the singular coastal low development and sustain higher values well into Thursday. The good news is that coastal flooding risk has likely been reduced. I’m fairly confident we can take major criteria off the table given the more organized low—leading to more of a N/NE storm surge direction (more perpendicular to our inlets). I would still however expect moderate-to-major coastal flooding, especially for the SENJ coast.

In English: The storm is just getting started. Areas still seeing rain should soon transition to sleet or possibly just go right to snow. No one along or SE of I-95 should be surprised by the rainy/mixed start this morning. It was well advertised, timing is right on track and we’re about to thump through early tomorrow morning. We now think more of NWNJ could see higher snowfall accumulations (like NENJ and CNJ) with a small reduction just SE of the I-95 corridor. No changes for most of SENJ. We’re talking a couple of inches either way here so nothing drastic. All warranted hazards remain.  Winds should continue intensifying along the coast throughout today but the coastal flooding risk has likely been reduced (good news) from the moderate-to-major category down to the minor-to-moderate category. Areas away from the ocean should also notice winds picking up soon but not as bad as the coast. I hope everyone is warm and well-prepared. Be safe! JC

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Jonathan Carr
By March 21, 2018 11:10