Mixed Weather Expected (Dec 27-30)

Jonathan Carr
By December 26, 2016 22:27

Mixed Weather Expected (Dec 27-30)

More mixed weather is expected to close out 2016. Let’s break it down…

Meteorological Disco:  As far as this week goes, we’re looking at more gloomy, foggy and rainy conditions overnight into tomorrow. Be careful traveling in the fog! Once the cold front is through (by tomorrow afternoon), conditions should dry out into evening/overnight hours. High pressure then has control through Wednesday. We’re then looking at a light (wintry for some) disturbance this Thursday followed by a cold shot Friday through Saturday (New Years Eve). New years day through about the 4th then looks milder as we’ll be in the warm sector of another lakes-cutting system.

From about January 5th-on we then need to start paying attention. We’ll be heading into an active pattern with the return of colder temperatures. We’re finally seeing some changes in the Northern Pacific Ocean. By the end of the first week of January, the jet stream is likely going to buckle northwards and form ridging in two locations—one being the Alaska/Aleutian Islands area and the other over Greenland. This will produce negatives phases of the Eastern Pacific and North Atlantic Oscillations (EPO and NAO). Therefore, colder Arctic air has nowhere to go/spill but southwards into the US from Canada. This correlates with the modeled (at 10mb and 70mb) elongation and slight descent of the polar vortex into said area. Right now I’m seeing the core of this cold favor the Western US over the Eastern US. Therefore, the coldest air would theoretically plunge into the Northern Rockies and propagate eastward with the natural mid-latitude flow. There is no doubt that this air would still be cold enough for snow by the time it reaches New Jersey. However, it will come face-to-face with a warmer ridge off the SE US. Typically a -NAO means the cold air overpowers the SE ridge. I’m slightly skeptical of this given the lack of positive-phased Pacific North American (PNA) oscillation. On the other hand, extra-tropical cyclones are enhanced by the clashing of air masses so this could go one of two ways, should a favorable-tracking surface low form. The SE ridge could either over-power us with warmer temperatures, yielding more “snow for elevations/rain for lower 2/3 of NJ” or set up something big and wintry for the entire coastal plain. I can’t tell you if or when exactly this would happen, only that the ingredients are there pattern-wise from the 5th-forward. 

In English: After New Years we’re heading into January with a much more favorable pattern modeled for snow than these past few weeks. In the meantime, expect more alternating transient periods of slightly above average and below-average temperatures.

Tuesday (Dec 27) high temperatures should reach well into the 50s statewide. Skies should start out cloudy and rain but eventually give way to clearing by afternoon. Winds could be breezy at times out of the W. Overnight lows should fall into the 20s for NNJ elevations and 30s for the rest of NJ.

Wednesday (Dec 28) high temperatures should reach the upper-30s/lower-40s statewide. Skies should be partly-to-mostly sunny. Winds should be light out of the W/NW. Overnight lows should fall into the 20s for most and possibly the teens for NNJ elevations.

Thursday (Dec 29) high temperatures should reach the upper-30s/lower-40s statewide but that high might occur earlier in the day than peak afternoon. Temperatures will then fall as precipitation moves through and low pressure transfers to the ocean. Right now we’re tentatively looking at another “snow for NNJ/rain for SNJ” event but nothing major. I’ll be posting updates and impact maps starting tomorrow evening. Thursday winds should be light/breezy out of the S (ahead of precipitation earlier in the day) and then breezy/gusty out of the NW behind it into overnight hours. Assuming precipitation ends by or before midnight, overnight lows should then fall into the 20s for most.

Friday (Dec 30) high temperatures should have trouble escaping the 30s statewide. Skies should feature mixed sun and clouds with lake-effect snow flurries/showers possible. Winds should be breezy to gusty out of the W/NW. Overnight lows should fall into the 20s for most. NNJ elevations could fall into the teens.

An early look at the weekend indicates a colder and drier Saturday (New Years Eve) followed by a warmer and possibly unsettled Sunday (New Years Day).

Jonathan Carr
By December 26, 2016 22:27