Anomalous cold’s swan song, moderation lies ahead

Welcome to Five Minute Drill, our new segment where we discuss the weather without bias or favoritism on a local, regional, and national scale as the weather suggests. In the week ahead, we’re discussing the movement of bitter cold away from the Northeast states, but the prevalence of a few weak atmospheric disturbances that may lead to wintry precipitation on Monday evening. We touch on where we’ve been over the past few days, why things are changing, and briefly discuss a Northern Plains winter storm later in the week.

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Brutal Cold Grips Northeast, Changes Are Coming Next Week

Good Evening! 

Yesterday we saw an extremely impressive Nor’easter impact much of the Northeast with heavy snow, highs winds, and extremely dangerous coastal flooding for the majority of the day. Snow totals varied quite a bit from west to east, but the highest totals for the region occurred from portions of eastern New Jersey, Long Island, Connecticut, and into New England, where amounts in the 10-20″ range were common. Totals over central and western New Jersey were lower, with numbers generally in the T-8″ range, as was common in PA and SNY. Overall, this was a very impressive and possibly historic storm due to its ferocity and sheer amount of power. Conditions came together in the atmosphere in just the right way to let this storm go from a rather weak 1010mb system off of Florida, to a monster 951mb blizzard off of the Delmarva coast. This extreme pressure drop contributed to the very strong winds we saw over the entire east coast and continue to see today and this evening.

As the storm pulled away last night, a deep Arctic airmass dove down from northern Canada and has caused temperatures to once again drop into the lower to middle teens across much of the tri-state area. Much colder reading were seen over portions of New England, with some locations staying 10-12 degrees below zero! A strong pressure gradient will continue to exist between the Arctic area of high pressure over southern Canada and our blizzard that continues to move over portions of southeast Canada. Winds tonight will continue to gust into the 15-30 mph range and when coupled with lows in the only a few degrees above zero in the immediate NYC metro area, wind chills will become very dangerous. Wind chills will likely drop into the -15 to -25 range for NYC and the immediate north/west suburbs and -20 to -30 for locations in Southern New York and Northeastern PA. These kinds of readings can cause frostbite within 20-30 minutes of exposure, so please use caution if you must go outside late tonight and into the overnight hours and make sure to layer-up!

Animation showing the progression of tonight's expected wind chills from the HRRR model. Readings will be at their lowest around 6-8am Saturday

Animation showing the progression of tonight’s expected wind chills from the HRRR model. Readings will be at their lowest around 6-8am Saturday

This Weekend 

Saturday looks to be yet another brutally cold and well-below normal day across the Northeast as Arctic high pressure builds into the region. Conditions should start off very cold and cool as mid-low level dry air takes over and limits any potential for any clouds besides upper-level cirrus. Winds may attempt to subside a bit during the day, but will likely still gust into the 20’s, which will still bring brutal wind chills in the -20 to -10 range during the early morning and afternoon hours. Highs across the NYC metro area will likely struggle to get out of the single-digits, with lower to middle teens expected to the south over portions of Pennsylvania and New Jersey. Frigid and dry conditions will last into the evening and overnight hours as we see lows drop off once again in the 5 to -10 range. Winds will continue to diminish, but wind chills will still be able to stay in the -10 to -20 range pretty much area-wide. Again, take the necessary precautions if you have to head outside tonight and Saturday night.

Sunday will be another cold and dry day across the Northeast as the Arctic high pressure system is directly overhead. Mid level dry air should ensure that conditions stay mostly sunny, with only a few passing high clouds expected. Despite the Arctic high being overhead, mid level flow will begin to modify ahead of a developing system in the Plains. This should cause temperatures to not be as brutally cold, with highs in the upper teens to middle 20’s expected across the entire area. Lows will likely not fall all that much as the high pressure system begins to exit off the Mid Atlantic coast and the entire region sees return flow from the south.

Animation showing the last of the brutal cold moving through the Northeast tonight and Saturday

Animation showing the last of the brutal cold moving through the Northeast tonight and Saturday

Major Changes Likely By Next Week

After one of the most impressive and longest cold-spells in recent memory for the Northeast, one would think that things would eventually have to break down. Last week I asked this same question, but now it seems like the brutal cold will indeed gradually fade to relatively warmer conditions across the east. After the Arctic high pressure system exits the country by Sunday night, the upper level flow will become more east to west based, which is a strong departure from the highly amplified pattern we have been accustomed to over the previous 10 days. This pattern should allow for multiple shots of warmer air from the south and west to overtake the Northeast, with highs in the 30’s and 40’s likely to make a return. As of right now, there does seem to be a chance that we could get temperatures into the upper 40’s and possibly lower 50’s, but this is around a week away and will likely need to be revisited next week. Regardless, while we may see slightly above-normal temperatures at times, we do have to keep in mind that this is still January and the potential for snow will always remain present. Would could see a rather active period with above normal precipitation through the middle of January as deep tropical moisture may occasionally try to nose its way into the country. We will be watching this potentially warmer and wet period closely over the next couple of days and will provide updates when they are available!

This afternoons ECMWF ensembles showing the potential for above-normal temperatures next week across the central and eastern US

This afternoons ECMWF ensembles showing the potential for above-normal temperatures next week across the central and eastern US

Have a great weekend!

-Steve Copertino 

UPDATE: Significant Winter Storm Aimed At The East Coast, Dangerous Cold Friday & Saturday

Good evening! 

Today has been yet another in an impressive stretch of days below-freezing across the majority of the Northeast! Conditions were mainly calm, with patches of mid to high level clouds racing from southwest to northeast due to a strong/developing jet stream over the Northeast. An area of high pressure has been quickly moving offshore, which has shifted winds to the south over portions of the Mid Atlantic and southern New England. This subtle change was enough to bring in temperatures in the middle to upper 20’s for most of the NYC metro area, with 30’s further to the south. As we head into the night, we expect cloud cover to gradually increase as the large area of low pressure over the western Atlantic Ocean begins to expand substantially to the west and ushers in some mid-lower level clouds. Southerly low level flow will keep conditions a bit warmer than the past few nights, but expect lows to stay in the lower to middle 20’s over the immediate NYC metro, with upper teens likely to the north and west. Things should stay dry for most of the area up until midnight, when some initial light to moderate snow may begin to nose into the southern portions of New Jersey and Pennsylvania.

QUICK LINKS: Latest Snowfall Forecast | Latest Video Discussion

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Video Analysis: Trends and Intricacies of Upcoming Powerful Winter Storm

Good evening! It has become apparent now that a large and powerful storm system is on the way for late Wednesday night and Thursday, but this forecast is more complicated than usual. With the storm growing powerful so quickly, at a far south latitude and with a plethora of convection, we will be in uncharted territory as far as forecasting goes – in other words, common meteorology assumptions will need to be more closely analyzed and thought through.

Our latest video analyzes all of the intricacies regarding this storm, including the multiple pieces of energy involved, how a more powerful southern stream wave can change the entire forecast, how a further west track does not necessarily mean heavier snow for the area, yet a few small westward ticks could mean parts of the area receives a major blizzard. The trends in the modeling regarding the strength and interaction of these pieces of energy is also quite fascinating to watch unfold, and it’s why the GFS model made a rapid shift towards a snowier solution.

Any solution from a minor graze to a significant to major snowstorm is still very much on the table, and while a moderate “blend” may be the way to go with the forecast, it is very important to communicate all of the possibilities and how because of these complex intricacies, it’s harder to communicate them than usual.