Frequent updates will be posted below on the heavy snow and wind event affecting the region today and tonight. Radar images are from the Pennsylvania State University e-Wall.
Links: This morning’s forecast | 8-Day Forecast | Twitter | Facebook
Final storm snow totals in NYC:
Central Park – 11.5″ | LaGuardia – 8.1″ | JFK Airport – 7.1″
10:40 PM: Storm To Continue Gradually Ending
As of 10pm, the low pressure is east of eastern North Carolina, extending northeastward. Minimum pressure is near 997 mb, and the low will continue to track northeast as it consolidates and begins to steadily deepen over the next few hours.
Since the previous update, a dry slot showed up on the radar over northern NJ and NYC, with snow rates down to flurries or light snow showers. While the majority of the event has ended, occasional snow showers are expected to continue through 12-2am as some precipitation from the developing low near North Carolina extends into the area. Steady snow is expected to continue over Long Island and coastal CT, however, with current totals so far generally between 9-12 inches. Another several inches are expected through the end of the storm, with the steady snowfall ending by 5am.
Forecast Update: The snow cover from this storm will not be going anywhere in the near future; a prolonged cold pattern will set up through the next 7-9 days with temperatures during this time period remaining below freezing, only approaching 32 degrees on Saturday with a risk of light snow showers but likely falling short for most locations. Lows in the single digits are expected tonight, with wind chills between -5 and -15 degrees, with partly sunny skies on Wednesday and highs in the low-mid 10s inland and mid-upper 10s elsewhere. Highs will remain in the 15-20 degree range through Friday with lows in the 0s for most except for the coast, with another round of cold temperatures expected for next week along with another snow potential towards next Monday.
This is the final storm update for tonight. Another brief update will be posted early on Wednesday morning, followed by an in-depth forecast analysis. Due to delays from this storm, the daily observations for the first half of January will be added tomorrow, and a storm summary for this system will be added either tomorrow or on Thursday.
9:15 PM: Snow Winding Down Over NJ
As of 9pm, the low pressure is near eastern North Carolina, extending northeastward. Minimum pressure is near 997 mb, and the low pressure area will continue to consolidate tonight as it steadily tracks to the northeast.
Over the last hour, the snow band has continued to shift east into west-central Long Island and south central CT, where heavy snow with rates up to 1-2″/hour are being reported. Along with strong northerly winds, this will continue to result in near-blizzard conditions. While the precipitation shield continues to shift east, with northern NJ and SE NY generally down to light snow showers, additional heavy snow is developing over the southeast Mid Atlantic region with the low pressure near North Carolina, which will then continue to track northeast overnight while intensifying. The heaviest snow from this round will stay offshore, but is expected to hold back the precipitation shield enough to support continued moderate snow over most of Long Island and coastal CT through 2-4am, while snow generally tapers off from west to east into NYC by that time and LI/CT by 5-7am. Meanwhile, temperatures will continue to fall into the upper 0s and low 10s, which will lead to wind chills falling into the -5 to -10 degree range by the end of the storm.
7:40 PM: Snow Band Shifting East
As of 7pm, the broad area of low pressure is located east of southeast Virginia. Minimum pressure is near 997 mb. The system will consolidate over the next few hours as the southern low near eastern North Carolina becomes dominant and continues to track northeast as the trough becomes neutrally and later negatively tilted.
Since the last update, the heavy snow band continued to slowly shift east, with reports of 2-3″/hour rates in part due to the high snow to liquid ratios, as high as 20:1 in some locations. 700mb frontogenesis, which was very high over the area earlier this afternoon and aided in the setup of the heavy snow bands, is pivoting along with the precipitation shield while shifting east and shrinking in coverage area, which supports the snow band over NYC slightly but not substantially weakening as it shifts east into Long Island, while precipitation over northern NJ and SE NY gradually decreases in intensity, becoming light to moderate by 8-9pm and ending by 12-3am. Meanwhile, with more favorable dynamics shifting towards the southern low, heavy snow will develop near the coastal Mid Atlantic and track northeast later tonight, but with the heaviest snow staying offshore. At this time, the precipitation shield is expected to set up close enough to allow for continued moderate to locally heavy snow over Long Island and coastal CT through at least 3-4am, with decreasing rates afterwards until snow ends by 5-7am. Totals of at least 10-14 inches are expected over NE NJ, NYC, Long Island and coastal CT, with localized totals over 14″ possible in Long Island.
6:10 PM: Heavy Snow Returns
Some of the heaviest snow of the storm is currently falling over the area as the system slowly continues to pivot, with the heavy snow band over north central NJ and SE NY shifting east into NE NJ and NYC within the next 10-20 minutes. Snow rates approaching 2″/hour have been reported under some of these bands, which will continue over the next 1 or 2 hours over NYC, NE NJ, Rockland/Westchester counties in NY, and Fairfield county in CT. Meanwhile, areas of heavy snow will continue over Long Island.
The next area to make note of is North Carolina, where the radar above shows developing moderate-heavy precipitation while the rain/snow line crashes southwards. As the low pressure begins to intensify at a steadier rate and the broad low pressure system consolidates over the next few hours, the precipitation shield will continue to become slightly more north-south oriented as the snow bands gradually shift east of NYC while weakening as the more favorable dynamics shift south of the area. Consequently, heavy snow will develop along the eastern Mid Atlantic coast, but with the heaviest snow from this round then shifting offshore and east of the area. Regardless, it will help to keep light-moderate snow across most of the area through at least 12am, with the snow then ending from west to east, reaching NYC by 2am and Long Island/CT by 3-5am. Forecast accumulations are unchanged for most, although based on latest reports, more widespread 10″-14″ totals appear likely over northeast NJ and SW CT and into NYC and Long Island.
5:05 PM: Steady Snow Still Falling
As of 5pm, the low pressure is off the coast of SE Virginia. Minimum pressure is near 998 mb, and the low is slowly tracking ENE. The second low near North Carolina is catching up as the trough gains a neutral tilt, and will consolidate later tonight before steadily intensifying.
There are two main bands of heavy snow at this time, one over SW CT into north central NJ and Rockland/Westchester counties, and the other is near Long Island; NYC is currently in between the two snow bands and is seeing slightly lighter snow rates, along with NW NJ which has yet to enter the heavier snow bands. As the system continues to pivot towards a more neutral (south to north) tilt, the snow bands will begin to shift back east after 6-7pm as dynamics begin to weaken over the area, shifting southward into the Mid Atlantic coast where heavy snow is expected to develop. Until then, snow rates near 1-2″/hour will continue under the heavy snow bands before gradually winding down later this evening.
3:30 PM: Snow Intensifies N & W of NYC
As of 3pm, the low pressure is just off the coast of southeast VA. Minimum pressure is near 998 mb, and the low is tracking ENE. As the trough axis becomes neutrally tilted, the extended area of low pressure into North Carolina will catch up with the low near SE VA, giving the impression as if the low is briefly stalling this evening, before consolidating and steadily tracking NE as the low deepens.
The heavy snow band has continued to expand north, and is currently covering NE NJ into Rockland/Westchester counties and southern CT, especially in SW CT. Snow totals up to 3-6 inches have generally been reported so far under the locations that have been under the heavy banding, while NW NJ and SE NY have yet to exceed 1-2 inches based on the latest reports. While precipitation amounts so far are generally below 0.20 to 0.25 inch, conditions are favorable for high snow to liquid ratios, leading to higher snow totals with ratios of at least 15:1 to 20:1 observed so far. The heavy snow is on track to continue over the immediate NYC area, NE NJ, coastal CT and parts of Long Island through 7pm with increasing northerly winds, before dynamics weaken over the area and shift into the Mid Atlantic coast towards the developing low pressure, where heavy snow is expected to develop. As this occurs, snow will begin to weaken across the area and gradually taper off from west to east, ending west of NYC by 12-2am and east of NYC by 3-5am. The updated snow map can be found in the bottom of the post; snow totals of 3-6 inches are expected in NW NJ and interior SE NY, 7-12″ in the immediate NYC area, and 8-12″ across most of Long Island and coastal CT.
2:15 PM: Snow To Continue Expanding North
As of 1pm, the low pressure is positioned near southeast Virginia. Minimum pressure is near 1000 mb, and the low is tracking ENE. The area of low pressure extends southwest towards western North Carolina, and will consolidate later this evening as the low seemingly stalls for a short period of time as the trough axis gains a neutral and later negative tilt while steadily deepening.
Over the last hour, the snow band has continued to slowly make its way north as expected, and is currently covering NYC while expanding into northeast NJ. While snow rates are not as heavy as they were over central NJ, with reports of as much as 6 inches so far under these locations, the heavy snow band will continue to gradually expand northward until settling over northeast NJ, NYC, central-western Long Island and coastal CT by 3pm, continuing through 7pm before weakening as the mid level lifting weakens with the favorable dynamics shifting towards the developing coastal low near the southern Mid Atlantic coast. Based on the latest indications, heavy snow is likely to spread up to Morris and W Bergen counties, Rockland/Westchester in NY, and southern CT, with moderate snow elsewhere across the area; as such, the 8″ and 10″ zones were expanded slightly further inland while the remaining zones were kept intact. Based on current reports under the heavy snow bands, totals of up to 12-16 inches are expected under locations that fall into the heavy banding over the NYC area.
1:00 PM: Heavy Snow Near, South of NYC
As of 12pm, the low pressure is positioned near southeast Virginia. Minimum pressure is near 1002 mb, and the low is steadily tracking ENE. The low will soon emerge off the coast and begin to gain a northerly component, while slowing down late this afternoon as the trough becomes negatively tilted before continuing to track northeast and steadily deepening.
Over the last few hours, a narrow band of heavy snow developed along a Philadelphia-central NJ-Long Island axis, where up to 2-4 inches of snow have already accumulated. Further north, however, the snow has struggled to expand due to subsidence north of the main band of heavy snow, with lighter accumulations generally below 1-2 inches. As the low continues to track northeast and deepen, stronger lifting will expand further north supporting the snow bands shifting to the north as well, but with the northward extent somewhat uncertain. A tight precipitation gradient is likely to set up near the north end of the snow band, which was reflected with this morning’s snow map, but the exact location depends on the northward expansion of the heavy snow band over the next few hours.
So far, the snow band appears generally on track with the short range models, with the placement of the banding likely to shift north and end up centered over NYC, far eastern NE NJ, Long Island and coastal CT by at least 3pm, continuing through 7pm before dynamics start to become less favorable over the area and shift towards the developing low pressure near the Mid Atlantic coast. Northwest of the band, totals of at least 3-6 inches are expected, locally higher, while locations under the banding will see rates of 1-2 inches per hour with the possibility of thundersnow and totals up to 10-15 inches.
Updates will continue on an hourly basis, and an updated snow map will be posted with the 2pm update.