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A winter storm warning has been issued for Sussex, Hunterdon, Somerset, Warren, Morris, Mercer, Middlesex, Passaic, Essex, Union, Hudson, and Bergen Counties. This is for both part one and part two of the storm.
A winter storm watch has been issued for Burlington, Camden, Gloucester, Salem, Ocean, and Monmouth Counties. This is for part two of the storm only.
A winter weather advisory has been issued for Atlantic, Burlington, Camden, Gloucester, Salem, Ocean, Cape May, and Cumberland Counties. This is for part one of the storm only.
Criterion:
A winter storm warning means four inches or more of snow or sleet and/or 0.25” or greater of ice accretion is imminent or occurring. North of Interstate 195, the criteria for snow is six inches.
A winter storm watch means four inches or more of snow or sleet and/or 0.25” or greater of ice accretion is possible. North of Interstate 195, the criteria for snow is six inches.
A winter weather advisory means two inches of snow or sleet/and or 0.01” to 0.24” of ice accretion is imminent or occurring. North of Interstate 195, the criteria for snow is three inches.
A serious and very dangerous winter storm is about to impact New Jersey. This storm will bring different weather elements to different parts of the state. From surveying members of the public today, they are very confused about what to expect. There simply is not enough time to explain all the details for each part of the state on television or radio. So I will try to break things down here the best I can.
I am expecting snow to break out across much of our region late tonight into Tuesday Morning. The snow is the result of warmer air riding over colder air. This is called overrunning induced precipitation in meteorology. Eventually, the warmer air will cause the air aloft to rise above freezing and this will begin to melt the snowflakes. However, cold air will hang tough at the surface and below freezing temperatures will remain stubborn in the interior. Therefore, freezing rain can be expected. The layer of below freezing temperatures at the surface at first may be large enough for the raindrops to refreeze before hitting the surface. This is sleet. Otherwise, raindrops will freeze when they make contact with a below freezing surface making it freezing rain. As the warmer air makes inroads aloft, the precipitation intensity will lighten and shift northward. Therefore, Central and Southern New Jersey may only experience freezing drizzle into the evening. The precipitation should remain snow for much of Tuesday in the higher terrain and this is where the heaviest available liquid is expected to be. Therefore, I still expect four to eight inches of snow in this area. My snowfall map remains unchanged. Some portions of New Jersey below Interstate 195 could rise a degree or two above freezing as the precipitation intensity lightens. However, temperatures will drop as the sun begins to set slightly and this will mean temperatures falling down below or at freezing in time for part two. The more mixing we see, the less snowfall we will get. This makes for a tricky forecast for snowfall totals.
The second part of the storm is an inland coastal low pressure area. This will be passing to our west and then over/just north of the region on Tuesday Night into Wednesday. The position of the low pressure area places New Jersey on what is considered the “warm side” of the storm. This will take a warm front and try to lift it up through the state from the southeast. However, how far inland and how fast that warm front moves through the state is in question. I have a feeling that this front will have difficulty lifting up through the area. We could have 20 degree difference in temperature from northwest to southeast. The shore could see some 50's on Wednesday with t-storms. The snowpack and an area of high pressure hanging tight to our north initially will continue to make it difficult for the temperatures to warm at the surface in the interior. This is especially true for areas with a northeast wind. This is what we call cold air damming. Therefore, more freezing rain can be expected. I expect this to give way at some point South and East of Trenton, but even along Routes 70, 73, 206, and 130…this may take several hours. The beginning of the second part may have some fairly good available liquid, so even here one-quarter of an inch of ice or more could accumulate before a change to plain rain. Any plain rain that occurs on Wednesday Afternoon could be very heavy and combine with the snow and ice to cause flooding problems. Meanwhile, areas that do not see a change to rain will see a crippling ice storm.
For the flooding potential, the greatest amount of plain rain will be in areas with the least snowfall and the sandy soil. However, should heavy rain impact areas around the Delaware and Raritan Basins, more significant stream, creek, and river flooding would be likely. I think the greatest flooding issue will be poor drainage flooding as the ground is frozen and covered in snow and many roadway drains are blocked by the snow and ice.
Winds could become gusty for a time on Wednesday, especially as the warm front lifts through. Wind gusts could approach or exceed 40 MPH along the coastline. The wind will be gusty inland as well. For areas with ice, wind and ice will make for a bad combination. It takes 0.25” of ice to begin to down trees and wires. The more widespread outages come with 0.50” or greater of freezing rain.
If we do see over 3 inches of wet snow on trees in parts of New Jersey and add the expected ice I am forecast….power outages could be severe in Northwest and Western-Central New Jersey. By the way, the new NAM shows over 1.00” of liquid in just a six hour span…so 1.75” of ice in some areas looks reasonable. That amount of ice has the potential to devastate and destroy. Please see the map to see which area I have highlighted. Keep in mind we have set just about every record, so setting records with icing will not be a shock.
The extended forecast calls for temperatures to drop quickly behind the winter storm on Wednesday Night. For areas that see rain Wednesday Afternoon, roadways may freeze up quickly by nighttime. We should see some snow showers as the storm departs very early on Thursday Morning. Temperatures on Thursday will struggle to rise above freezing.
Friday is the calm before another storm on Saturday. This storm could bring snow inland and a wintry mix in Southeastern New Jersey. Right now, an accumulating snow is expected in the interior. Whether or not this system will bring a more significant snow is in doubt, but I believe it has a potential to do so.
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