Unsettled Conditions (Jan 1-3)

Jonathan Carr
By December 31, 2020 15:17

Unsettled Conditions (Jan 1-3)

Discussion: Precip should slowly clear from W to E this evening. It’s possible some snow/sleet mixes in but nothing crazy. The S side of passing high pressure should then improve conditions overnight into Friday morning. Clouds and rain should then move in from the SW between Friday afternoon and evening hours. NNJ/NWNJ should keep an eye on surface temperatures Friday PM as some icing could occur before everything changes to rain for early Saturday AM hours. Conditions should improve and become mild for Saturday daytime hours. Temps should then fall below freezing for at least NWNJ Saturday night as more precip moves in by late Sunday morning. That brings us to the Jan 3-4 synoptic signal I’ve been mentioning for a few articles now. We have a weak low passing just SE of NJ. That should provide E flow and keep the lower 2/3 of NJ warm and wet. NWNJ, possibly some of NENJ, are expected to cool enough Saturday night to potentially start out as snow Sunday morning. Then as the low tracks a little more NE, the flow will become northerly for most of NJ. The snow/rain line should then move S and bring more of NJ into snowfall before precip wraps up by Sunday night. SNJ would have the smallest chance of ending as snow but NENJ and CNJ could possibly cash in a bit. We’ll see. I’ll be watching the short-range model guidance and live obs evolve over the weekend and will report accordingly. After Jan-3-4, the next synoptic storm signal would be for next weekend (~Sat Jan 9). Between this Sunday and next Saturday, a relatively uneventful Monday-Friday. Slightly colder conditions Monday-Tuesday behind the low’s N fetch then moderation for Wednesday-Friday. Some longer-range model guidance is suggesting a warmer period in the Jan 8-15 period. While it’s typical for the “January thaw” to occur each year, I think the extent and intensity of Jan 8-15 is overblown. The AO (available Arctic cold), NAO (high-latitude Atlantic blocking) are continuing to project negative as far as I can see in January. The PNA (W North America ridging) is showing signs of positive phase with a reciprocal falling EPO (E Pacific troughing reinforcing the W US ridging). This oscillation-based forecast would suggest a W US ridge/E US trough pattern during the time frame that the physics-based long-range models are suggesting warmer surface temperatures. Also, the Euro just laid out a snow event Jan 9 for the next signal. With that said, I think we’re going to see some wild swings in long-term modeled temperature conditions.

Note: Unless specifically mentioned by location (Example: NNJ elevations, SENJ immediate coast, Interior CNJ/SNJ, etc.) assume the following forecast language is statewide for New Jersey. When I say “from elevations to sea” I mean from NWNJ mountains spreading down to immediate ECNJ/SNJ coastal areas. Directions are shortened (N = North, S = South, W/SW = West/SouthWest, etc.).

Friday (Jan 1) high temperatures should reach the low-to-mid 40s for most areas. NWNJ elevations might hang in the upper-30s. Skies should be mostly cloudy with periods of rain likely moving for PM hours. Winds should be light out of the E, breezier along the immediate ECNJ/SENJ coast. Overnight lows should range from near-30 to near-40 from elevations to sea. Precipitation could mix with snow for NWNJ but with little-to-no expected accumulations.

Saturday (Jan 2) high temperatures should reach well into the 50s, possibly near-60 for interior CNJ/SNJ. After some possible AM rain lingering, skies should improve for the rest of the day. Winds should be light out of the W. Overnight lows should range from near-30 to near-40 from elevations to sea.

Sunday (Jan 3) high temperatures should range from near-40 to near-50 from elevations to sea. Skies should be mostly cloudy with periods of rain likely. Winds should be light-t0-breezy out of the NE. Overnight lows should range from 20s to 30s from elevations to sea. As of right now, precipitation is expected to change over to at least a wintry mix for parts of NNJ Sunday night into Monday. I’ll be watching that over the weekend in case more parts of NJ are brought into the cold game.

An early look at next week indicates rather uneventful conditions Monday-Friday. Monday-Tuesday colder than Wednesday-Friday. After whatever happens for NNJ Sunday PM into Monday AM, the next synoptic signal is then ~Saturday, Jan 9. I’ll be tracking. Have a great weekend and a happy new year! Be safe! JC

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Jonathan Carr
By December 31, 2020 15:17