Tag Archives: pressure gradient

NYC Weather Update – Oct 6, 2020

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This week, we see slightly above normal temperatures in the low-70s to start off, dropping to below normal temperatures in low-60s later in the week following the passage of a cold front mid-week. Overall sunny conditions punctuated by this frontal boundary tomorrow. Gusty winds and a stray thunderstorm could accompany this front as its parent low deepens over the Canadian Maritimes.

Rest of today – mostly sunny with high pressure exiting to our south, yielding light southwesterly flow and high temperatures in the low-70s. Overnight lows in the upper-50s.

Weather Prediction Center surface forecast for 8AM Wednesday

Wednesday – slightly warmer with warm southwesterly flow ahead of the cold front, highs in the mid-70s. Overnight lows in the mid-50s behind this front, which could bring isolated showers and thunderstorms to the area. Gusty winds could also accompany this front due to the large pressure gradient between us and its parent low moving over the Canadian Maritimes.

GFS model surface pressure and 10 meter above ground winds for Wednesday at 8PM

Thursday – Canadian high pressure sweeps in behind the cold front bringing sunny skies and cooler temperatures in mid-60s. Overnight lows much cooler, in the upper-40s due to this change in air masses.

Friday – with a cold start, high temperatures will likely top out in the mid-60s again under sunny skies. Overnight lows warm up into the low-50s.

NYC Weekend Weather – Feb 7, 2020

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We start this weekend with a high wind warning as a strong low pressure center passing overhead. A much colder air mass will be on the heels of this passing storm. A brief calm Saturday spell punctuates an otherwise active pattern with another storm approaching to start next week. High temperatures during this time will generally be at or above normal (~40°F) with a big warmup by Monday.

Rest of today – high temperatures have already peaked in the mid-50s but the remainder of the day will see a continuing fall in temperatures through the 40s and 30s as strong cold air advection kicks in. This is due to a potent low pressure system (972 mb and strengthening) passing overhead. The tight pressure gradient around this low, in addition to a well-mixed layer forming with winds aloft at 50 knots mixing down will yield very strong winds. A high wind warning is in effect this afternoon when sustained winds could easily be in the 30-40 mph range with gusts exceeding 60 mph in places. Winds will abate overnight as the low exits northeast, temperatures will keep falling all the way into the upper-20s with cold air advection driven by winds from the northwest continuing.

  • Weather Prediction Center surface forecast for 1 PM today. Note the tight packing of isobars around the 972 mb low pressure center moving just north of the area.
  • NAM model’s forecast sounding for 1PM today. Very strong unidirectional wind profile is indicated, with winds just above the surface in excess of 50 knots. A well-mixed layer is evident as well up to about 850 mb where winds look to range between 55-65 knots. This should allow strong gusts and sustained winds to make it to the surface.

Saturday – high pressure builds in briefly, and should yield a mostly sunny day. With overnight lows in the upper-20s, high temperatures will be decidedly colder around 40°F. Overnight lows remain on the cold side around 30°F.

Sunday – clouds increase with high temperatures in low-40s as the next frontal system approaches. Winds will shift to the south. There is a chance for rain/snow mix then rain during the day. Overnight lows in the mid-30s.

Monday – prolonged southerly flow will help kick temperatures up to the low-50s as the frontal system slows in its approach. This will also bring prolonged chances for rain. Overnight lows in the upper-30s.

NYC Weekend Weather – Dec 15, 2016

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Apologies for the lack of updates recently. Winter weather has come in full force a few days ahead of the actual Winter Solstice. We’ll see possibly record-tying or record-breaking cold Friday in some parts of the area, our first measurable snowfall in the city this season, all while temperatures swing about 30ºF from now through Sunday. The medium term shows a continuance of average to below-average temperatures in the upper-30s and low-40s.

Rest of today – we had some passing snow showers this morning, and there will be another chance for snow showers this afternoon. The main story will be the wind, cold temperatures, and low wind chills. A wind advisory is in effect for today with a high wind warning in place for tonight. Sustained winds of 20-30mph are expected, with wind gusts between 40mph to as high as 60mph possible later. Combined with high temperatures only in the mid-20s, this will result in wind chills of between 0-10ºF in the city.

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Friday – slightly colder than today with highs in the mid-20s, with a very cold start to the morning as overnight lows drop into the teens. Winds will slowly abate through the course of the day as the high pressure center depicted above moves east over us, lessening the pressure gradient. Overnight Friday, a warm front approaches and brings the possibility for 1-2″ of snow.

Saturday – the snow will continue into the first half of Saturday with the possibility of 1-2″ additional inches of accumulation before temperatures warm and winds turn towards the southwest. There is some question as to whether some period of freezing rain will occur before a transition to all rain from south to north in the afternoon hours. High temperatures rebound nicely into the upper-40s in the wake of the warm front passing through.

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Sunday – a cold front will follow the passage of the warm front mentioned above, but that shouldn’t happen until late Sunday. Ahead of that cold front passing, temperatures will continue to warm into the low-mid 50s as rain continues to fall. That snow won’t stick around long!

NYC Weekend Weather – Nov 18, 2016

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An extended period of well above normal temperatures comes to an abrupt end this weekend as a strong cold front pushes through overnight Saturday into Sunday. On the back side of this frontal boundary, temperatures will average around 15ºF lower than we’ve seen this week. If you like it mild, go out and enjoy this weather before Saturday!

Rest of today – sunny and mild with high temperatures in the low-60s.

Saturday – another mild day on tap with lots of sun and a high around 60ºF. Chances for rain increase into the overnight hours, at this point peaking around midnight. Winds will pick up first from the southeast ahead of the cold front, then to the west. Sustained winds of 15-20mph with gusts over 30mph are possible.
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Sunday – rain chances taper off but winds remain in the 20-30mph with strong gusts up to 40mph. High temperatures will be significantly colder than we’ve gotten used to and below normal in the mid-40s. A tight pressure gradient sets up between the departing low and a high pressure center to the southwest, blasting us with cold Canadian air as a result.

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Monday – clouds diminishing gradually, winds still pretty breezy, and a high only in the low-40s.

 

NYC Weekend Weather – Oct 28, 2016

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This weekend we will see a brief warmup in temperatures. Saturday will have the best weather, with another round of rain likely for later in the day Sunday. Temperatures dip back below normal Monday to start off next week.

Rest of today – it’ll be a mostly sunny day. However, a tight pressure gradient around the low pressure and storm system that brought us moderate to heavy rain yesterday will result in stiff winds from the northwest. Temperatures will be below normal in the upper-50s.

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Saturday – a very pleasant day on tap with temperatures bouncing back nicely into the low-60s, not too much wind and mostly sunny skies.

Sunday – a cold front will be draped from west to east across the Northeast and push through late Sunday. Temperatures ahead of the frontal boundary will be quite mild in the low-70s with mostly cloudy skies. We get another chance at much needed rain with this frontal passage.

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Monday – temperatures fall back into the upper-50s as a result of the cold front passing through Sunday. Mostly sunny skies though.

 

NYC Weekend Weather – Dec 18, 2015

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We get a taste of cool weather this weekend, with high temperatures at or slightly below normal for Saturday and Sunday, before we rebound strongly into much above average and possibly record-breaking warmth once again by mid-week next week. Saturday in particular will be feel quite brisk, with a stiff wind from the west dropping wind chills into the 30s. There could even be a couple snow flurries north and west of the city!

Rest of today – mostly cloudy to partly sunny skies with high temperatures hovering in the mid-50s. Temperatures will fall rapidly to near freezing in the city overnight.

Saturday – the low pressure system that was responsible for the soaking rains Thursday will continue to intensify as it moves over the Canadian Maritimes Saturday. As a high pressure center builds to the south, a tightening pressure gradient will yield stiff winds in the 15-25mph range on Saturday. This, combined with a blast of cold air behind the cold front that passed yesterday, will result in high temperatures only in the low-40s, with wind chills making it feel like the 30s throughout the day. There could be enough instability in the atmosphere to spark a couple flurries over the interior!

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Sunday – high pressure will remain in control Sunday, so expect sunny skies, and with the high pressure center closer to us, the pressure gradient will diminish. Winds should likewise calm down, and it will feel considerably less raw with high temperatures in the mid-40s.

Monday – temperatures will jump into the low-mid 50s as the high pressure above moves to our east and return flow of warmer air from the south and southwest begins to take hold.

 

White Christmas? Not a chance.

Looking ahead at the week of Christmas coming up – not only will there be no chance of a white Christmas on the Eastern Seaboard, we could be looking at record-breaking warmth again with high temperatures in the low-mid 60s! The Climate Prediction Center’s 6-10 Day Temperature Outlook and 8-14 Day Temperature Outlook are both strongly confident (> 90% probability) that we will see warmer than average temperatures.

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NYC Weekend Weather – Nov 12, 2015

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Periods of rain this afternoon give way to drier weather over the weekend as a cold front passes through late today into the overnight hours. Drier weather prevails this weekend, though with the passage of this cold front, gusty northwest winds will enter the region, bringing in significantly cooler temperatures for Saturday. Temperatures rebound Sunday as we enter another period of slightly above normal temperatures.

Rest of today – showers have moved out of the area at this point, but a few scattered showers may still pop up later today. Otherwise, cloudy with high temperatures already peaking around 60.

Friday – mostly sunny with winds from the west in the 15-20mph range, gusts up to 30mph.

Saturday – winds again in the 15-20mph range with gusts up to 30-35mph. Sunny skies, but temperatures well below normal in the upper-40s, highs may not break 50 in the city. With the winds, it will feel like temperatures are in the upper-30s to low-40s.

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Sunday – winds finally start subsiding, and temperatures will rebound back to around normal in the mid-50s with sunny skies.

Monday – as the high pressure depicted above begins moving to our east, southwest flow on its backside will bring temperatures back into the low-60s.

 

NYC Weekend Weather – Jan 15, 2014

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We end this week off with a windy day Friday, followed by an intrusion of cold air on Saturday before a warmup Sunday that should be accompanied by some rain during the day, then possibly a mix of rain and snow Sunday night. Some chance of snow persists into early Monday.

Friday – a cold front dropping from Canada will tighten the pressure gradient ahead of it, bringing with it breezy west-northwest winds between 15-25mph during the day tomorrow. High temperatures will be about normal in the upper 30s, but with wind chill values only in the 20s.

Saturday – subsequent to the passage of that cold front, we get another shot of cold, arctic air, with temperatures on Saturday struggling to even reach 30 in the city, and only in the 20s elsewhere.

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Sunday – a low pressure system will be moving steadily northeast into Quebec by Sunday. This storm system will have a trailing cold front as well as a preceding warm front. We should enter the warm sector behind the warm front passing over us Sunday. This will allow for temperatures to rise into the mid-40s (possibly higher in a few spots). There will be a transfer of energy to a secondary low pressure center which is forecast to form off the Mid-Atlantic coast. This will result in the chance for us to get a few periods of moderate-heavy rain on Sunday, especially in the afternoon hours. As the coastal low moves off to the northeast, rain should taper down during the overnight hours into Monday, and temperatures will be cold enough to support a chance of rain/snow mix.gfs_namer_087_1000_850_thick

Monday – snow showers should end early Monday. High temperatures will be about average for this time of year, in the upper 30s.