Jan 23, 2014: Cold Continues, Some Snow Upcoming

Forecast Highlights:

gfs_namer_078_500_vort_htA prolonged cold spell began with Tuesday’s storm, with temperatures over the last two days generally in the 10s and single digits. Similar temperatures will continue today and tomorrow, before warming up on Saturday ahead of a cold front with snow showers producing up to 1″ of snow or locally higher. Another round of even colder temperatures is likely by the middle of next week before the potential for late week snow (Image credit: NCEP MAG).

 


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Wednesday, January 22 Observations:

1.22.14As Tuesday’s storm departed the region, temperatures gradually fell into the single digits across most of the area by the morning hours, with strong northerly winds leading to wind chill values between -5 and -15 degrees. More sunshine returned later in the day as temperatures warmed up into the low to mid 10s inland and mid to upper 10s elsewhere, marking the second day this winter where almost the entire area stayed below 20 degrees.

The highest temperature was 20 degrees in Montauk, NY, and the coolest high temperature was 10 degrees in Danbury, CT.

 


 

Today – Saturday: Cold Continues, Snow Expected for Saturday

A cold air mass remains situated over the region at this time, with 850mb temperatures generally between -15C and -20C. The trough axis will swing through the region tonight into tomorrow, bringing the coldest temperatures aloft into the region before departing by Friday night, supporting a continuation of well below normal temperatures through Friday. Partly to mostly cloudy skies are expected today with highs in the upper 10s to low 20s, with lows falling overnight into the single digits to low 10s again while highs on Friday climb into the upper 10s for most of the area and the mid 10s inland.

6z run of the high resolution 4k NAM at hour 60, depicting light to locally moderate snow moving through the area early Saturday afternoon. Despite a strong southwesterly flow, this will fall as snow (Image credit: PSU e-Wall).

rad60More changes will occur in the upper level flow on Saturday as a strong piece of the polar vortex dives southward through the Hudson Bay, with a low pressure developing and steadily deepening over southern Canada. As it does so, a strong southwesterly flow will set up over the region with winds near 10-20 mph, which will remove most of the cold air from the region, while light precipitation spreads into the region ahead of the cold front in the evening hours. Given the initial strong cold over the region, however, enough cold air will remain in place that despite the low pressure well to the north, along with a strong southwesterly flow, precipitation type will fall as snow across most of the area as temperatures only rise into the mid 20s to low 30s, an unusual scenario for the area involving both snow and strong southwesterly winds. Enough moisture is likely for at least light to locally moderate snow, mainly between 10am and 5pm, with up to an inch of snow expected with locally higher totals possible.

 

Saturday Night – Next Week: Cold Continues

The strong upper level low over Canada will remain just north of the US/Canada border, with lower heights aloft quickly swinging through the region on Sunday before slightly rising as a strong shortwave trough dives into the Midwest from western Canada. This will bring cold temperatures back for Sunday, with partly sunny skies and highs in the low-mid 20s for most locations. The aforementioned shortwave trough will then quickly move through the region with a surface low pressure tracking through the Northeast, producing a swath of light to moderate snow; as of yesterday’s update, the GFS was among the southern models supporting moderate snow for the area while the ECM and CMC kept the snow mostly north of the area, but since then the GFS has trended north as well. The upper level setup, including the positioning of the upper level low, is less favorable for a significant snowstorm than it was on Tuesday, and some changes in the anticipated setup from earlier runs make a south trend appear less likely as the system interacts with the upper level low, pulling it northwards while keeping most of the snow north of the area. A factor to keep in mind is that shortwaves emerging from Canada have often been underestimated with the current pattern, and some changes are still expected, although at this time it does not appear to be enough to support the moderate snow potential being centered over the area.

6z GFS at hour 102, depicting the clipper system over New England with snow mostly north of the area. The southward surge of anomalously cold temperatures can be seen over the Midwest (Image credit: PSU e-Wall).

f102The latest outlook is for a chance of snow showers on Sunday night, mainly north of NYC; despite the low pressure tracking well north of NYC, enough cold will remain in place for precipitation to fall as snow, with temperatures likely to briefly touch the low 30s on Monday morning before falling again. Behind the clipper system, the back end of the trough will enter the Midwest US, allowing for another southward surge of very cold temperatures into that region with temperatures well below zero degrees. Unlike early January, however, the westerly flow will not be as strong, and the trough is expected to generally remain positively tilted which supports a slowing down of the cold air mass as it approaches the Ohio Valley; even so, this is still expected to support well below average temperatures in the area, with highs likely in the 10s and lows in the single digits for most and below zero inland.

The next time frame to watch is late next week, with the trough shifting towards the area. The latest models keep the area dry with no precipitation nearby; further east, however, a wave of low pressure is modeled to develop well off the coast, which given the uncertainty in the upper level flow will continue to be monitored for potential changes over the next few days for the potential for a stronger low closer to the coast.

2 thoughts on “Jan 23, 2014: Cold Continues, Some Snow Upcoming

  1. Guy Reply

    So you know what the big question is… February 2nd… Super Bowl. What are the odds?

    • NYC Area Weather Post authorReply

      As the Super Bowl is still about 10 days away, it is too early for a high confidence outlook; looking at the general pattern, however, chilly temperatures appear likely in general but not to the magnitude of the current cold, with precipitation chances uncertain at this time. Once the date enters a closer time range within a week, more forecast details will be posted.

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