Tag Archives: low pressure

NYC Weekend Weather – Mar 31, 2017

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March ends on rainy note. It’s been a cooler and wetter month than average, after a much warmer February. The snow and rain has made significant positive impacts on the drought in this region. We get one good day this weekend, before more rain moves in to start the first week of April.

Rest of today – overcast, periods of rain, heavy at times due to a slow moving low pressure center. The heavier rains look to come later this evening into the overnight hours. Easterly and northeasterly winds will make it feel cooler than the high of around 40ºF.

Saturday – due to the slow pace of this storm, rain is still likely to be falling early tomorrow. High temperatures will remain well below normal due to the continued onshore easterly winds and cloud cover, only reaching the mid-40s.

Sunday – with the low pressure center finally exiting east, we should see dramatically improved conditions with highs rebounding to normal levels in the mid-50s and lots of sunshine.

Monday – starts off similar to Sunday with mostly sunny skies and temperatures in the mid-50s. Conditions deteriorate later in the day as the next storm system starts moving in.

 

Average Temperatures, Above Average Precipitation to Start April

Due to the influence of several storm systems forecast to impact the area, we’re expecting normal temperatures and above average precipitation to start the month off.

NYC Blizzard Update – Mar 13, 2017

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Classic major nor’easter to bring blizzard conditions to a large swath of the Northeast Tuesday just days from the official start of spring. Areas in and around NYC likely to see snowfall accumulations of over 1 foot, locally higher. This may end up being one of the biggest snowstorms/blizzards in history for the month of March in NYC.

Rest of today – the proverbial calm before the storm. Mostly sunny, cold, with high temperatures in the low-30s.

Tuesday – a major late season nor’easter will bring heavy snow and blizzard conditions to the area. Blizzard warning in effect for the entirety of Tuesday. Snow starts falling overnight into Tuesday. Heaviest snows forecast to begin around the morning rush and continue through most of the day. Blizzard conditions expected on the coast with steady north to northeast winds 30-35mph and gusts over 45mph. Visibility near zero at times. High temperatures at or below freezing. Widespread accumulations over 1 foot and approaching or exceeding 18″ expected around the NYC metro area. Details on the storm at the end of this post.

Wednesday – lingering chance for snow showers early with wrap around moisture on the backside of the departing nor’easter. Mostly cloudy with a high near freezing.

Thursday – skies clearing, high temperatures in the low-mid 30s.

 

Major Blizzard to Impact the NYC Region

Winter Storm Stella, as the Weather Channel refers to it, is set to bring widespread heavy snow to the area beginning overnight Monday and continuing throughout the day Tuesday.

Impacts – Snow accumulations over 1 foot, in many cases approaching 18″. Locally higher amounts, with some areas possibly approaching 2 feet. Heavy snow and blowing snow during the day Tuesday. Snowfall rates 2-4″ per hour and possibly higher in the heaviest snow bands possible. Thundersnow may accompany the strongest snow bands. Blowing and drifting snow with steady northeast winds 30-35mph and gusts 45-50mph will contribute to blizzard conditions with near zero visibility at times. East and northeast facing shorelines may experience moderate coastal flooding during high tide cycles. Heavy, wet snow at the coast combined with high winds may lead to power outages. Hazardous travel conditions, severe disruptions to aviation likely. High confidence in storm total snowfall at this point, but there is still uncertainty about whether and where mixing could occur.

Timing – Snow begins early in the overnight hours Tuesday. Light accumulations of 2-4″ possible by daybreak. Heavy snow likely beginning during the morning rush hour and continuing through most of the work day, as well as into the evening rush hour. Winds quickly intensifying from the morning and staying steady through the evening hours. Heaviest snow tapers off in the early evening hours, but snow showers could continue overnight. Winds remain strong overnight into Wednesday. Conditions improve going into the morning Wednesday.

Discussion – an area of low pressure that had its origins in the Pacific has made its way across the northern US, impacting the Northern Plains and Upper Midwest with snow. This storm system will phase with a secondary, coastal low pressure system that is currently moving up the coast from the Southeast. As these storms merge, the coastal low will undergo rapid intensification and cyclogenesis, becoming a strong Nor’easter. This storm will be drawing on subtropical moisture, and will encounter an airmass that will be quite cold due to the presence of an Arctic high pressure system prior to the storm’s passage. These ingredients will set the stage for a classic major blizzard for the Northeast late in the winter season, only days from spring.

As always, uncertainty remains about the exact location of the heaviest snow bands with this storm. Areas that are impacted by these bands can easily rack up several more inches than surrounding areas that are spared. The storm is expected to track west of the 40°N/70°W benchmark. However, during the last model runs, the storm track has trended north and west, increasing the chances for the city itself to see the heaviest snow, in addition to areas north and west. If this track shifts west some more, warmer air off the ocean wrapping into the core of the storm from the south could induce mixed precipitation with rain cutting down on totals in the city and Long Island. If the track shifts east, heavier snow would fall over points east of the city.

NYC Weather Update – Feb 27, 2017

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The beginning of this week will somewhat echo the end of last week, with temperatures starting off on the cooler side, then ramping up before the passage of a cold front that could also bring some thunderstorms. After this cold front passes, temperatures take a dive closer to normal levels.

Rest of today – increasing clouds will cap temperatures in the low-50s.

Tuesday – warmer but with increasing chances for rain during the day. High temperatures in the upper-50s.

Wednesday – during the early morning hours, a warm front associated with a low pressure center moving across southern Ontario will push through. This will set the stage for possibly record-breaking warmth during the day. Southwest flow will allow temperatures to steadily climb into the upper-60s and possibly over 70°F. Later in the day, a trailing cold front will make its approach. This will serve as a trigger for showers and thunderstorms to develop late in the day and into the early overnight hours. Some of the storms could approach marginally severe criteria.

Thursday – following the cold front passing through, winds shift to the northwest. This will result in much cooler temperatures dropping through the day into the upper-40s.

 

Cooler Weather Ahead

Looking ahead to the mid-month period, it does appear we may see some cooler than normal temperatures prior to the formal onset of spring.

NYC Snowstorm Update – Feb 08, 2017

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We’re in for a wild ride over the course of the next 24 hours as our weather goes from possibly record-breaking warmth to what is expected to be the most significant winter storm so far this season. Significant snow accumulations over 6″ and possibly as much as a foot are expected across the region, resulting in a winter storm warning for all of the NYC metro region.

 

Timing

Judging by the amount of sun we’re getting, temperatures will likely hit record-breaking levels in the low-60s in the city today. They will drop steadily to around 50ºF by the evening commute as a cold front pushes through and Arctic air flows in from the north. Overnight, temperatures will continue falling rapidly to around freezing. Precipitation is expected to begin around 3-4AM Thursday here in the city and continue through the early afternoon. Unfortunately, the timing of the heaviest precipitation does look to bring significant impacts to the morning commute.

North American High Resolution simulated radar 1km resolution, tomorrow at 8AM.

 

Impacts

Rain/snow mix to start, but by the morning rush, expecting all snow through the region. Heavy snow at times possibly reaching 1-2″/hr. Some thundersnow could occur. Hazardous travel conditions during the morning rush as plows will have trouble keeping roads clear with traffic and the moderate to heavy snow. Gusty winds could produce near-blizzard conditions with low visibility.

 

Snowfall Totals

Here are some graphics for snowfall totals from our local National Weather Service Forecast office. The general forecast calls for 6″-12″ in the city. The exact extent of totals will depend, as is generally the case with this type of storm, on where the heaviest snow bands set up and for how long they sit over an any given area.

Probabilities for 4″+ and 6″+ of snow respectively

 

Discussion

An shortwave that’s made its way rapidly across the country from the Pacific will move along the cold front that is pushing through today. As it does so, it will spawn a secondary low off the Mid-Atlantic that will strengthen rapidly as it moves over open water. At the same time, plenty of cold air will wrap around the deepening coastal low with high pressure to the west. This will put in place all the ingredients for a classic coastal winter storm for this area. The only thing keeping this storm from being a major blizzard with snowfall totals exceeding 2 feet is the fairly quick pace that it’s expected to move at.

This coastal storm will drive the expected heavy snows tomorrow. Its track is expected to take it just outside the 40ºN 70ºW benchmark, a spot that from a climatological perspective has translated to heavy snow storms for this region.

 

NYC Weather Update – Feb 06, 2017

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The weather story of this week will be some wild temperature swings as we encounter two storm systems Wednesday and Thursday.

Rest of today – mostly sunny to clear skies with high temperatures topping out in the low-40s.

Tuesday – temperatures start to warm up with an approaching warm front. A low pressure system north of us will pull lots of warm, moist air ahead of it as it moves through the region. High temperatures are expected to hit the low-50s with periods of rain throughout the day.

Wednesday – overnight, temperatures will actually rise due to the influence of warm air flowing into the area following the passage of the aforementioned warm front. Rain should end by the morning commute, giving us a chance to break some record high temperatures in the area. High temperatures are expected to range in the upper-50s to the low-60s with any significant breaks of sun.

Thursday – the warmup does not last. As the low pressure system above continues to track northeast across Quebec, a secondary low pressure center will form along a trailing cold front attached to this first low. High temperatures will only be in the low-30s, almost 30ºF cooler than Wednesday. Overnight from Wednesday to Thursday, it should get cold enough for the secondary low pressure center to spark some accumulating snows in the city. Snowfall totals are expected to be light, 1-3″ max in the city.

 

NYC Weekend Weather – Jan 27, 2017

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The weekend period will see a gradual return to seasonably cold temperatures, a departure from the long stretch of above normal warmth we’ve seen the last week or so. A series of weak disturbances will move through the area, but these are not expected to bring much in the way of precipitation.

Rest of today – breezy with west winds of 20mph. Mostly cloudy with high temperatures in the low-40s. A weak disturbance brings a chance of snow flurries, but no accumulation is expected.

Saturday (Lunar New Year) – still above normal with high temperatures in the mid-40s and partly sunny. Not as windy as today, but with a strong low located over Labrador, westerly winds in the 15-20mph range will persist.

Sunday – high temperatures start to fall back to around 40°F. More clouds than sun.

Monday – colder, with high temperatures in the upper-30s and partly sunny skies.

Drought Update

The 1-2″ of rain we picked up during this past week’s Nor’easter, while beneficial, did little to change the drought picture as compared to last week.

NYC Weather Update – Jan 23, 2017

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Main weather headline to start the week will be a potent and slow-moving coastal storm bringing a variety of hazards to the region later today through tomorrow morning. This storm is the same one responsible for this weekend’s deadly tornado outbreak down south. Conditions improve dramatically towards mid-week.

Rest of today – a flood watch, coastal flood advisories, and high wind warning are in effect mostly through tomorrow morning. Cloudy with high temperatures steady around 40°F. Winds continue to increase throughout the day as a strengthening coastal low approaches and the pressure gradient between it and a high pressure center over Quebec tightens. A low-level jet will enhance winds. Sustained east and northeast winds of 30-40mph with gusts between 50-60mph will become commonplace late today and overnight. The strongest winds will occur closest to the coast.

Along with the strong winds, periods of heavy rain will bring the potential for 1-3″ of precipitation, which could lead to minor to moderate urban and small stream flooding. Timing of the onset of rain will be around 3pm this afternoon.

The persistent and strong northeast winds off the water will contribute to minor to moderate coastal flooding. This will be exacerbated during a couple of high tide cycles.

High resolution rapid refresh model simulated radar output for 3PM this afternoon
The storm approaching spans the better portion of the entire East Coast

Tuesday – rain and wind abate during the day, tapering off by the afternoon. High temperatures about the same as today in the low-40s.

Wednesday – as the coastal storm continues to pull away, temperatures rebound and mostly sunny skies return. High temperatures anticipated around 50ºF.

Thursday – another nice day with high temperatures in the upper-40s and mostly sunny skies.

 

NYC Weekend Weather – Jan 20, 2017

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We get a round of light rain late today and overnight. Temperatures warm up Saturday, then moderate Sunday as a storm system approaches from the southwest. Temperatures will remain above normal as this storm system looks set to bring soaking rains Sunday and Monday.

Rest of today – cloudy, with light rain arriving around 3PM and lasting till about midnight. Temperatures will drop from the mid-40s to low-40s overnight.

Saturday – warm, mostly cloudy, with high temperatures in the mid-50s.

Sunday – chances for rain increase in the afternoon. Mostly cloudy otherwise with a high in the upper-40s.

Monday – a low pressure system will be moving off the shore of North Carolina and Virginia. With this strengthening low and a high pressure center over Quebec, a tightening pressure gradient will build resulting in steady and increasing winds. Rain and wind will be constant on Monday with high temperatures in the mid-40s.

Drought Update

Recent storms have brought beneficial rains and snows to the region, but a drought continues, especially in the downstate area. This next storm should continue to help alleviate the drought here.

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.

screen-shot-2016-12-15-at-10-06-40-am

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 Weather Update – Nov 29, 2016

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It’s the tale of two very different weather regimes this week. Starting the week, we have mild, rainy conditions accompanying a couple storm systems. This rain is still desperately needed as a drought continues to grip the area. Later in the week, things dry out, but temperatures also move in a downward trend back below normal.

Rest of today – mild with a high temperature near 60°F, rainy, with rain moderate to heavy at times. Rain tapering off by about 7PM this evening.

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Wednesdaay – a complex set of of frontal boundaries move through the area tomorrow in association with a low pressure developing over the Great Lakes. In terms of sensible weather, expect a brief pause from the rain early Wednesday, but another round of overrunning rain that could then lead to a line of stronger storms with gusty winds late in the day as the cold front pictured below pushes through. Mostly cloudy with high temperatures again around 60°F.

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Thursday – becoming sunny with high temperatures still holding up in the upper-50s.

Friday – cooler with high temperatures dropping to around normal in the low-50s with sun and clouds.

Drought Still Not Abating

Despite plenty of rain recently, large deficits built up from earlier in the year are still hard to beat, with many areas still in a moderate to severe drought in the NYC region.

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