Tag Archives: high pressure

NYC Weekend Weather – Mar 16, 2018

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An uneventful, though kind of cold weekend is in store for the NYC area. Great news for those of you going out for St. Patrick’s Day festivities. Looking ahead into mid-week next week, we have the potential for yet another nor’easter impacting the region with, you guessed it, the possibility for more snow.

Rest of today – partly sunny to mostly cloudy skies with a high near 40°F.

Saturday (St. Patrick’s Day) – warmer, sunny, with a high in the mid-40s, pretty much ideal conditions for the parade.

Sunday – sunny, high in the low-40s. High pressure will be in control of the area.

Monday – mostly sunny with highs in the mid-40s.

Why Seemingly Unending Conveyor Belt of Nor’easters?

The simple answer: The Greenland Block. You may have heard the term “blocking high” mentioned in regards to the anomalously active and cold weather pattern over the Northeast this month. In essence, what’s happened is that a strong ridge of persistent high pressure has formed over Greenland this month. Very cold air over snow-covered landmasses like Greenland is often quite stable. Colder, denser air, also increases surface pressures.

Cyclonic flow around such an area of strong high pressure can wreak havoc with the polar jet stream – diverting its normal flow around the high. This can (and has in our case) lead to the polar jet diving far to the south, allowing large intrusions of Arctic air into the Eastern US. Jet streams can also enhance storms via upper level divergence, lowering surface pressures. Lastly, the blocking high can slow the normal eastward progression of storm systems, causing storms to linger over areas and extended periods of precipitation and coastal impacts in the case of nor’easters.

The Greenland Block is correlated with an index called the North Atlantic Oscillation. When values of this index are negative, it’s more likely that such a blocking pattern arises. Lucky for us, it appears that we may finally get a break in this pattern towards the end of the month.

 

 

NYC Weather Update – Feb 26, 2018

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A wet and windy Sunday gives way to a week of mild and drier conditions. Temperatures this week will range about 10F above normal. While not remotely close to the record-breaking highs set last week, this should still result in pleasant conditions. Dry weather should hold up until late in the week when our next chance for rain arrives.

Rest of today – decreasing clouds with high temperatures in the mid-50s.

Tuesday – sunny, high temperatures again in the mid-50s after a colder start to they day.

Wednesday – mostly sunny with high temperatures in the mid-50s as an area of high pressure continues to dictate sensible weather in the area.

Thursday – as this high pressure moves off to the east, increasing clouds will build ahead of the next storm system. Chances for rain will increase through the day with cooler temperatures in the upper-40s.

 

NYC Weather Update – Feb 12, 2018

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After a soaking rain this weekend, we start the week off with cooler, drier conditions. Temperatures ramp up going into mid-week before the next chance for precipitation hits us Thursday.

Rest of today – decreasing clouds as high pressure builds behind the cold front that passed through earlier today. High temperatures in the low-40s dropping through the course of the day.

Tuesday – mostly sunny with high temperatures in the mid-30s.

Wednesday – milder with high temperatures in the upper-40s and increasing clouds late in the day.

Thursday – a surge of warm air ahead of the next cold front to hit the area will raise temperatures well into the 50s, possibly as high as 60°F but with a chance for showers and mostly cloudy skies.

NYC Weather Update – Jan 8, 2018

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We have a week ahead where we should see temperatures warming into the normal range through mid-week near the 40°F mark. A even more pronounced warm up takes place towards the end of the week with rain expected.

Rest of today – overcast with temperatures at or just above the freezing mark. A frontal boundary passes through later today bringing the chance for snow showers. Some mixing with sleet and freezing rain could occur at the coast with temperatures slightly above freezing. Timing of precipitation will be late afternoon potentially disrupting the evening commute.

Tuesday – a great day with mostly sunny skies and high temperatures at or above 40°F.

Wednesday – partly sunny with high temperatures in the upper-30s.

Thursday – an approaching frontal boundary and high pressure forming over the Atlantic will lead to strong warm advection and warm winds flowing from the southwest. In response, temperatures will surge into the upper-40s and maybe touch 50°F! Quite a difference from last week.

 

 

 

 

 

 

 

 

 

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 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 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 Weekend Weather – Oct 20, 2017

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High pressure continues to exert its influence over the region through the weekend and into the beginning of next week. Temperatures will be quite mild and about 10°F above normal for this time of year. Ideal viewing conditions exist for the Orionid meteor showers.

Rest of today – sunny and mild with highs in the low-mid 70s despite northwest winds.

Saturday – similar setup as today. Sunny with highs in the low-mid 70s. Winds shift to the south as high pressure moves east and offshore.

Thanks to this persistent area of high pressure over the eastern US, we’ve a long bout of sunny and dry weather that continues through the weekend.

Sunday – mild and mostly sunny with high temperatures again in the low-mid 70s.

Monday – increasing clouds and slightly warmer with highs in the mid-70s. We’ll be in the warm sector ahead of an advancing, slow-moving frontal boundary. This feature will bring our next and much needed chance at precipitation into Tuesday.

Orionid meteor showers
These will be peaking over the weekend. Look towards the constellation Orion during the overnight hours with best conditions at around 2AM. Astronomers are expecting a peak of 15-20 meteors per minute radiating from this constellation. The meteors are actually fragments of Halley’s comet, which approaches perihelion (closest pass to the sun) next in 2061. If you’re lucky enough to get away from light pollution, you won’t have any moonlight to contend with either. Sky conditions will be ideal this weekend.

NYC Weather Update – Oct 2, 2017

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October gets started with a decidedly fall feel, but temperatures do warm up later in the week before returning back to normal over the weekend. High pressure is in control for basically the entire forecast period, resulting in sunny conditions each day.

Rest of today – sunny with high temperatures around normal about 70ºF.

Tuesday – a touch warmer, high temperatures in the low-mid 70s and sunny.

Wednesday – warming trend continues with high temperatures rising into the upper-70s as high pressure moves to the southeast. Sunny skies.

Thursday – summer returns briefly with high temperatures well into the 80s and sunny conditions again.