All posts by Lei Zhao

NYC Weekend Weather – Dec 8, 2017

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The weather headline for this weekend will be our first accumulating snow of the season! Aside from this, below average and cold temperatures will be in place throughout the weekend and well into next week. This persistent cold spell has a direct link to high pressure over the western US that has resulted in fires in California. Another chance for additional accumulating snow is possible early next week.

Rest of today – high temperatures in the low-40s with mostly cloudy skies. Snow beginning in the overnight hours into tomorrow.

Saturday – snow throughout the day, accumulations of largely between 2-4″ during the day expected in the city, but with higher totals moving east, in the 4-6″ range for parts of Queens, and Brooklyn. High temperatures in the low-30s.

A coastal storm will develop and strengthen off the Southeast coast as an upper level shortwave and a jet streak work to enhance it. The jet streak in particular will provide strong lift for the development of snow showers. Thermal profiles throughout the atmosphere in our region will support all snow. Model trends seem to continue nudging the track westward over the past couple of days. Further shifts west would result in higher snowfall totals, which are suggested by the GEFs plumes in the last image in this section that point a range of 6-8″ of snow for LGA.

Weather Prediction Center surface low tracks and clusters. Focus on the coastal low track. The mean track takes this storm very close to the 40°N 70°W benchmark, a location for coastal low centers that generally translates to robust snowfall for winter storms.

Sunday – an additional accumulation of an inch or so is forecast overnight Saturday as snow begins tapering off going into Sunday. As the low pulls away, winds will turn to the west and strengthen. High temperatures will actually be somewhat warmer in the upper-30s with mostly sunny skies.

Monday – mostly sunny skies again with high temperatures around 40°F.

NYC Weather Update – Dec 4, 2017

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The biggest weather headline for the beginning to mid-week period will be the passage of a warm front and then a robust cold front. This will bring us a dramatic swing in temperatures along with moderate to heavy rain overnight Tuesday. Late in the week, our eyes turn towards a developing coastal low, with temperatures well within the range to support snow, there’s a chance for us to see our first accumulating snows of the season this weekend.

Rest of today – mostly sunny with high temperatures around 50°F. High pressure remains in control during the day while it moves offshore.

Tuesday – cloudy with much warmer high temperatures nearing 60°F behind the passage of a warm front in the early morning hours. We’ll be in the warm sector of a low that will be centered well north of us in Ontario, and warm air will flow in from the southwest ahead of a cold front. Rain chances increasing during the day, with the best chances for rain starting in the afternoon. Rain continues overnight, moderate to heavy at times.

Wednesday – rain chances continue into the morning. Clearing conditions, with winds turning to the winds once the cold front clears our area. High temperatures peak at around 50°F but fall during the day.

Thursday – noticeably colder, with overnight lows in the low-30s. High temperatures in the mid-40s, a couple degrees cooler than normal for this time of year.

 

Weekend Snow?

Model runs over the past couple days suggest the possibility for multiple storm systems that could bring snow over the weekend. The more significant of these would be a possible coastal storm. However, the latest model runs suggest this storm would take a track too far offshore to affect us with significant precipitation. A second, weaker disturbance could move through Sunday as well. Temperatures will definitely be cold enough to support snow, especially during overnight hours. Later in the week, we should see clearer signals about whether we’ll get our first accumulating snow this season during the weekend.

NYC Weather Update – Nov 27, 2017

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The last week of November will actually see fairly mild weather. Sunny conditions will prevail along with a warming trend as southwesterly winds circulating around an area of high pressure sets up over the Southeast.

Rest of today – high temperatures around 50°F with sunny skies. Northwest winds between 15-20 mph with occasional gusts nearing 30 mph.

Tuesday – cold start to the day with low temperatures overnight in the upper-30s. Despite this, high temperatures should warm into the low-50s with the winds shifting to the south.

Wednesday – warmer still with high temperatures in the mid-upper 50s. We could even hit 60°F in a couple places. Winds will be blowing from the southwest eventually shifting to the northwest.

Thursday – temperatures will cool off significantly overnight, daytime temperatures will be cooler around 50°F. Increasingly cloudy with a cold front advancing and forecast to pass through the city overnight into Friday.

NYC Weekend Weather – Nov 24, 2017

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Temperatures this weekend will be largely around normal levels for this time of year, with the exception of Saturday. Warm advection will precede the passage of cold front. This frontal boundary does not look like it will have much moisture to work with. Travel conditions are expected to be trouble-free for those returning from the Thanksgiving break.

Rest of today – sunny with high temperatures around 50°F. Light winds shifting from west to south.

Saturday – temperatures warming into the upper-50s as a result of continuing warm winds from the southwest. Increasing clouds with the approach of a cold front. The best chance for precipitation with this front will be late in the day or in the overnight hours. Limited moisture will mean that this is not a washout.

Sunday – behind the cold front, winds once again shift back to the northwest, resulting in cooler temperatures in the 50°F. Sunny and breezy otherwise.

Monday – on the cool side again with high temperatures in the upper-40s and mostly sunny skies.

NYC Weather Update, Thanksgiving – Nov 20, 2017

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The weather looks to cooperate most of Thanksgiving week, aside from Tuesday night into Wednesday with a chance of rain as a cold front passes through. Travel impacts should be minimal. Thanksgiving Day itself should be pleasant, though on the cool side with below average temperatures.

Rest of today – earlier this morning, some areas in and around the city got the first few snowflakes of the season. There won’t be any more flurries today, but temperatures will be below normal with a stiff wind blowing from the west at 20 mph and gusts in the 30 mph range. Highs will probably only reach into the upper-40s as a result, even though we do anticipate skies clearing up in the afternoon.

Tuesday – winds turn to the southwest overnight into Tuesday as a high pressure center south of us today moves east, bringing us a shot of warm advection, and much warmer temperatures. Warmer than average highs in the upper-50s to near 60°F are forecast with sunny skies.

Wednesday – overnight Tuesday into Wednesday, rain chances increase as a cold front approaches the region. Rain showers may continue impacting the area into the AM rush. Once the cold front pushes through, winds shift back to the west and northwest, with gradual clearing conditions. High temperatures should be in the low-50s.

Thursday (Thanksgiving Day) – the passage of the cold front on Wednesday sets the stage for much cooler temperatures for the Thanksgiving Day Parade. Cold advection will bring temperatures into the mid-30s overnight, and temperatures at the start of the parade will probably only be in the upper-30s. Fortunately, there should be no other adverse weather impacts on this annual festivity. High temperatures should top out in the low-mid 40s with mostly sunny skies.

NYC Weekend Weather – Nov 17, 2017

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A cool Friday and Friday night yields to a rainy, though milder weekend. A return to largely below normal temperatures to start the week. Looking ahead into next week, weather conditions should be fair and without disruptions for the busy travel days around Thanksgiving.

Rest of today – sunny, cool and windy with high temperatures in the upper-40s. Northwest winds 15-20 mph with higher gusts though diminishing as the day progresses.

Saturday – increasing clouds as a warm front attached to a low pressure center over the Great Lakes approaches the area. Increasing clouds as winds shift to a warmer and wetter southerly direction. Chances for rain increasing through the day, with mostly cloudy skies otherwise and high temperatures in the upper-50s.

Sunday – rain chances are highest overnight from Saturday into Sunday. Low temperatures should be on the warm side near 50°F. Rain continues into Sunday morning prior to the passage of the cold front pictured above. Once that cold front pushes through, clouds should gradually break. High temperatures are anticipated to reach in the mid-50s again. However, on the back side of the cold front, we’ll see fairly strong winds returning from the northwest with a large pressure gradient. This will lead to temperatures dropping back into the 40s by the evening.

Monday – sunny skies but much cooler again with high temperatures in the mid-40s.

NYC Weekend Weather – Nov 10, 2017

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Get ready for record-breaking cold and a blast of deep winter tonight. The cold spell slowly abates over the course of the weekend, but even by Monday, high temperatures are still anticipated to be below normal for this time of year. There is a chance for precipitation on Sunday night with the passage of a weak disturbance.

Rest of today – we’ve already reached today’s daytime high of about 40°F and temperatures will be falling throughout the rest of the day. An arctic front is passing over us now, in its wake, strong cold advection (transport) is ongoing as a continental polar airmass from northern Canada dives down into the area. A high pressure center over Minnesota is also creating a fairly strong pressure gradient with a low pressure system in central Quebec. This will result in breezy conditions with winds from the northwest at around 25 mph and gusts over 40 mph. Wind chill values will fall from the 30s into the 20s.

Strong cold advection is ongoing behind the arctic front. Temperatures are dropping by as much as 2.5-3°F per hour in the Northeast.

Saturday (Veterans Day) – overnight lows going into Saturday are forecast to plummet to record-breaking levels in the low-20s. The high pressure pictured above will be moving closer to us, decreasing the pressure gradient and reducing the winds here. Temperatures should top out around 40°F with lots of sun. It will be a chilly, but sunny day for the Veterans Day Parade.

Sunday – temperatures continue to warm into the upper-40 with increasing clouds.

Monday – some uncertainty exists about the possibility of precipitation overnight into Monday. High temperatures will finally be approaching normal for this time of year with highs in the low-50s and mostly cloudy skies.

NYC Weather Update – Nov 6, 2017

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After a brief warm spell, we are looking at a full week ahead of average to below average temperatures. A distinct fall feel has come just as we ended Daylight Saving Time. The best chances for rain are at the beginning of the week.

Rest of today – high temperatures into the mid-60s ahead of an advancing cold front. This cold front will carry with it the chance for some showers later today. Mostly cloudy otherwise.

Tuesday – once the cold front passes us, winds will turn rather quickly northwest, bringing much cooler air into the region. High temperatures will likely be in the low-50s with partly sunny skies.

Wednesday – this frontal boundary from early in the week will stall out south of us. This will allow multiple shortwaves to ride up the frontal boundary, giving us a slight chance of rain overnight Tuesday into Wednesday. High temperatures will again be on the cool side, only in the low-50s with mostly cloudy skies.

Thrusday – a tad bit warmer, with a mix of clouds and sun and high temperatures in the mid-50s.

NYC Weekend Weather – Nov 3, 2017

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This weekend’s weather will be a tale of contrasting temperatures and airmasses. The week ends with warm temperatures more than 10°F above normal. A cold front sweeps through and fall returns for the weekend itself, but another warm up takes place leading into Monday. Also, Daylight Saving Time ends at 2AM Sunday.

Rest of today – increasing clouds for the day. Warm with high temperatures in the mid-70s. Yesterday, a warm front pushed through, putting us in the warm sector associated with a low pressure now over northeastern Quebec.

Saturday – quite a different feel tomorrow once this cold front below moves through the area. Winds will become onshore from the east, bring much cooler air. High temperatures are expected to top out only in the upper-50s with sunny skies (around normal for this time of year).

Sunday – there’s a chance of showers overnight Saturday into Sunday associated with the next storm system to impact the area. An advancing warm front is expected to bring light, stratiform rain ahead of it. Temperatures will be warmer, in the mid-60s with mostly cloudy skies.

Monday – the familiar pattern of warm front followed by cold front continues Monday. We’ll again be in the warm sector with temperatures peaking at about 70°F. Rain should accompany the passage of this cold front.

NYC Weather Update – Oct 30, 2017

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Crisp fall weather is in place for the start of this work week on the heels of yesterday’s strong storm. Winds abate today but temperatures turn noticeably colder tomorrow. A gradual warming trend is anticipated later this week with highs pushing back towards 70°F.

Rest of today – as the low pressure responsible for yesterday’s storm continues to pull away from us to the north-northeast, the pressure gradient will relax and result in lower wind speeds. These winds will bring with them a much cooler Canadian airmass (via cold advection) and high temperatures should be in the mid-50s.

Map of analyzed values of cold advection (transfer of heat, or in this case, lack of heat). The blues and purples indicate areas of increasing intensity of cold advection, where temperatures are falling by as much as 2ºF an hour. The causative agent of the cold advection in the Northeast are the winds associated the departing storm.

Tuesday – sunny skies, a sparkling fall day with high temperatures in the mid-50s again.

Wednesday – partly sunny with high temperatures in the mid-50s.

Thursday – a return to warmer temperatures in the mid-60s with us in the warm sector between a retreating warm and advancing cold front.