WEATHER

Arctic Chill Today, First Widespread Snow Friday Night

20161215_snowmap_squareBy John Cifelli
NJTV News Meteorologist

– Teens and single digit cold tonight

– Wind chill below zero in places tomorrow morning

– Snow begins late Friday night, ends as rain on Saturday

– More rain Sunday, possibly ending as snow

Winter has dabbled its toe in the waters of New Jersey the last few weeks, with some light accumulating snows for the north, and a few blustery cold days. There’s no indecisiveness to the chill today however, as the first real Arctic intrusion is being felt across the state. As cold winds blow from the northwest, we’ve already seen the daytime high temperatures, which generally came in the upper teens and low 20s around 11 a.m. Temperatures will continue to slowly fall throughout the afternoon, until the bottom falls out of the thermometer with nightfall. Low temperatures tonight will fall to the single digits in some places, and the winds will whip wild enough to drop windchill values below zero. If you are out tonight, bundle up. It’s dangerous cold!

The high pressure center driving this cold is transient, and it will slide east across the state on Friday. The next storm system approaches shortly thereafter. Although the low pressure center affecting our weather will still be in the Midwest Friday and Friday night, the air flow ahead of its approach will spread moisture over the strong dome of cold air settled in the northern mid-Atlantic. Tapping into Gulf of Mexico moisture, snow breaks out in response late Friday night, well after dark. The caveat here is that it will be dark and road surfaces too cold for brine or salt treatments to do much at first, so snow will stick right away. Also, these kinds of snow events where moisture overruns cold air at the surface tend to start a little earlier than model guidance suggests. If you’re out for a holiday party Friday night, keep your eye on the radar during your yuletide revelry.

The cold surface high is sliding east, not northeast, which will allow for surface winds to switch and strengthen from the south as the storm approaches Saturday morning. Temperatures will moderate accordingly, and snow yields to a wintry mix and then rain, from south to north through the morning. By early afternoon, whatever is still falling will be wet, not white. We might even see a break in the clouds in the afternoon, as temperatures rise into the 40s. The afternoon probably won’t be too shabby weather-wise, certainly the best chance over the weekend to wrap up some holiday shopping, or grab your tree if you’ve been delinquent in decorating.

Sunday, the surface low slides to our north, dragging a cold front across the state. We will see another round of rain, possibly heavy, as the front slowly passes across the state. Colder air filters back across New Jersey in its wake, which could turn the rain to a brief period of snow on the back side of the front. This could whiten the ground and lay down a coating, but I don’t think any substantial accumulation is likely. We’re back in the ice box thereafter, with high temperatures in the low 30s Monday and Tuesday statewide, before moderating mid-week.